Crazy '88 Ram 50 build: Twincharged-Twinturbo SOHC 6G72

[speednsnake]

Well, I've finally gotten fed up with the 2.6l slushbox combo, and I'm ready to move on to bigger and better things.
I'm about to attempt the 6g72 SOHC swap in my second gen power-ram 50, and I'm bringing the montero's 5 speed/transfer case along for the ride. I've heard that this swap isn't too unusual, but my further plans for the motor probably are. I want to twin-turbo/twincharge the thing. I've already picked out turbo's and a supercharger (the turbos are from a vr4, and the supercharger is a Paxton SN89). Reliability is sure to be an issue here, but I'm not afraid of fabrication, and I'm not shooting for crazy hp. Whatever power the final build makes will be plenty, and my primary concerns will be cost (within reason) and reliability (also, within reason).

For the swap, I'm expecting the need to fabricate/replace:
-A one piece intake manifold
-Both exhaust tracks
-the intercooling system
-motor mounts
-tranny mounts
-any parts needed to prevent interference
-any parts needed to install both of the turbos and the supercharger
-both drive-shafts
-both axles
-most of, if not the entire, electrical system

Basically I was wondering what kind of issues that I might face, which parts will be prone to failure, and what I should also replace to maximize reliability.

I'm hoping to stick with the SOHC, and it needs to stay manual and 4wd. Any alternate turbo or supercharger suggestions would be appreciated, as I am new to forced induction (though I understand the concepts). Once again power production is not my primary concern here, a semi reliable 350hp truck would be better than a 1000hp self-destructing monster.

Here are a few pictures of the thing for reference:
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As the project gets off the ground I'd be happy to post pictures of the process for those who are interested. I'm also part way through swamping a dodge raider dash into it.

[Rahtid]

the sohc v6 engine has a lot of potential stock internals and big turbo.good luck with the project

https://www.youtube.com/watch?v=W6klErTRqHA

https://www.youtube.com/watch?v=C7-5IfDfLno

[BradMph]

Rahtd suggestion is great, V8 is great too. Parts are easy to come by either and especially on American made products which are cheaper as well. Every build is different in my experience of watching them being done here and to pin point exactly what to do and not to do is very hard to put down in a parts list. Decide what will make you want to build it and go for it. We can help and support you all the way through. Keep them build photos coming so we can watch too! :)

Nice truck!

[speednsnake]

Thanks guys!

Quick update. I'm omitting the supercharger for now as there simply isn't enough room under the hood of my truck for so many components, and sheer complexity of such a build would be a bit beyond me. I'm currently looking into water/methanol injection.

The good news is that I found my donor vehicle for only $1000; a V6 Gen 1 Montero 5 door with an automatic. The real kicker is that he's just going to throw in two 5 speed trannys w/ transfer cases, most of an overhaul kit for the 6g72, two bouncy seats, and (wait for it) THE TWIN-TURBOS AND INTERCOOLER OFF OF A VR4!! This guy is the real deal, he's been building raiders and other vehicles with the 6g72 for years and he was ready to move off some of his accumulated spare parts.

Here is a revised list of what I'm going to do to get this thing up and running:
-Fabricate engine and tranny mounts
-Swap out wiring harness for the montero's
-Fabricate both drive shafts
-Fabricate Turbo manifolds & run dual exhaust system*
-Make necessary modifications to the interior to facilitate a manual transmission
-Figure out how to mount the Raider dash**

Time gap (the vehicle should run and drive by this point)

-Swap out ECU for programmable ECU
-Run intercooler piping
-Make necessary modifications to the throttle body
-Swap both axles & drop gear ratio
-Set up boost controller (I'm shooting for 1 bar ~15psi)****
-Set up water/meth injection system***

*I'm planning on hooking up the turbos to the exhaust but not running the intake piping, thus leaving the engine NA for a few months of daily driving. I have it on good authority that this is safe to do. Advise would be greatly appreciated here.
**I'm in desperate need of a 2nd gen interior wiring harness diagram (I'm looking at you Brad). The Haynes manual didn't cut it.
***Still on the fence about this one.
****As far as I can tell, this truck should make between 270hp and 310hp at those boost levels

As I mentioned before, I'll keep you guys updated with pictures as progress occurs. Thanks for all of the support so far.:)

[speednsnake]

Figured I'd put up a few pictures of the dash install. The stock dash came out fairly easy, and if you've ever wondered what it looks like behind them, I'd go with dusty. We couldn't resist setting the raider dash in place, and from what I can tell the biggest hurdles are going to be with wiring, providing clearance for the parking brake, and unfortunately leaning in the top front corners of the dash about 1cm on each side. As it sits in the picture it's around 4 inches too close to the driver on top and according to the inclinometer (which is oddly handy in this situation) it's also leaned back by ten degrees.

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The raider dash looks well enough at home here, though that subtle color difference will probably grate on me.
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Any thoughts on how to wire up the darn thing? So far i'm torn between splicing together the two harnesses wire by wire, and just replacing the whole harness with the Montero one. As always any bits of advice/opinions are greatly appreciated.

[speednsnake]

HELP NEEDED!!! SEE BOTTOM OF POST IF YOU KNOW ANYTHING ABOUT THE V6 TRUCKS*

Ok It's been a long few weeks but the motor and trans are in the truck. Here are a few pictures.

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I've done a whole lot of research on this particular swap and every thread that I have found has either claimed that it's been covered many times elsewhere, or merely states that it is possible. Well that first one sure as heck ain't true so I'll just go ahead and immortalize it here.



The Swap:
Starting with: 1988 PowerRam 50 4X4 Ext. Cab W/ 2.6L G54B and factory Auto trans. (Meaning that if you have any 2nd gen mighty max or Ram 50 with 4X4 this is applicable to your truck.)

This swap pertains to replacing the 2.6 with a 3.0L V6 (6G72 SOHC) out of a 1990 Mitsubishi Montero, and replacing the auto trans. with a 5 speed out of a V6 Dodge Raider (V5MT1-1)

More simply:
2.6L I4 (G54B) ---> 3.0L V6 (6G72 SOHC)

Auto Trans. (KM-148) ---> 5 speed Manual (V5MT1-1)



Pros:
-The Sticks (shifting levers that is) line up perfectly with the existing hole in the cab, and in my case only required a few cuts to make room for the transmission stick (I had an automatic). The transfer-case stick was fine.

-The motor mounts lined up perfectly and can even be bolted in. No need to make new ones.

-The ECU harness is (somewhat) separate from the main wiring harness and the ECU is located in the same place in the Montero as the "Carburetor Control Unit" is in the Ram

-Gobs of clearance on everything besides the oil pan and the brake lines.

-147hp NA and can be twin turboed for ~250hp with relative ease using factory Mitsubishi TD04 9Bs. (I got my twin turbos with intercoolers for $200)

-Pretty easy to do if you are willing to do a full drive-train swap in the first place.

-If you want to do a dash swap from a raider too (Highly recommended, they look sweet) You can take the whole harness and enjoy all of its cool features like cruise control, intermittent whipers, electric locks, and headlight sprayers (if you're into that).

-Pretty much turn-key after everything is reconnected (Shouldn't have any ECU troubles).

-You can contact me if you hit a roadblock and I'll try to help.

Cons:
-You will likely need a whole donor vehicle for the V6 to get all the appropriate parts. (try to get a 5 door Montero LS from '87-'90. They have all of the bells and whistles)

-The oil pan out of the Montero/Raider is completely incompatible with our trucks. The lowest part of the pan hits the front axle and differential within 4" of the motor mounts. You must buy or fabricate one for your truck.

-Not necessarily the most powerful swap when naturally aspirated (much better than the 2.6 though)

-Want to upgrade the ECU or anything at all in the motor? I hope you can tune your own ECU and fabricate precision parts because that's all you can do (besides pay a bunch of money to have a shop do it for you)...

-The transmission crossmember has to be modified (not extensively though).

-The shifter from the Raider is at an uncomfortable distance from the seat if you like to lean back. Try to find a factory one for the Ram/mighty max.

-You need to make new driveshafts

-If you want to turbo it you can't just buy turbo headers or down pipes. You must make them.

-The V6 radiator hits the factory power steering lines so they must be (slightly) rerouted.

-The brake lines from the booster are uncomfortably close to the driver side manifold and should probably be rerouted. See for yourself:
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-The battery in the Montero is in the opposite corner as the one in the ram, so modification to the wiring harness is needed (to extend it to the front drivers corner that is. You can't just move the battery to the same place as the Montero's as the location is too shallow for it.).

-Fuel lines need to be rerouted in the engine bay, and the stock fuel pump is inadequate for the V6.

-Obtaining the clutch pedal and linkage is all but impossible unless your junkyard has a miraculously un-crushed manual 2nd gen.


*Regrading the Oil pan.
I just ordered this oil pan from Orielly's:
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Does it look anything like the V6 Ram 50 Pan? More specifically, Does that pan look like it will fit around the front axle/pumpkin?
I could really use the help. Thanks in advance.

[idahoram50]

I am thinking about doing this to my ram 50. Mine has the 5 speed manual now. Do i still need to swap the transmission?
Thank you

[speednsnake]

I am thinking about doing this to my ram 50. Mine has the 5 speed manual now. Do i still need to swap the transmission?
Thank you

I'm knee deep in the swap now, so I'll be happy to help. Unfortunately, I'm going to have to hit you with a slew of questions, as I am only familiar with what I'VE done. First of all, I'm going to have to assume that you have a first gen 4wd as you specified it as an '84 power ram. That implies that your trans is a KM 145. If you hope to keep it you will inevitably run into reliability issues, as a little research will show. Let me know what your trans code is (it should be on a metal plate under the hood on the firewall, as well as on the trans itself.) and we can move from there. I don't know anything about the 1st gens but in my case the motor dropped straight in on the mounts no problem. There is a reason that they switched the trans for the v6 rams, and I'd highly suggest that you replace it. More directly, the bellhousings look mighty different to me.

For reference, here is a picture of the V5MT1-1 bellhousing, a picture of (I think) a KM 145 bellhousing, and a picture of that id plate on a 1990 power ram 50 with the 5-speed. The wiki states incorrectly that the V6 Dodges had a V5MT2, but the plate states otherwise.
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The silver lining here is that If you DO choose to get a V5MT1 (out of a 1st gen V6 Mitsubishi montero, a V6 dodge raider, or best of all a V6 ram or mighty max) The sticks will line right up with your existing hole and you should be able to use at least the front driveshaft, maybe the rear as well. Let me know if you have a hydraulic clutch as well.

Feel free to contact me if you need to know anything about the swap and remember that pictures help.

If you can drive to southwest Oregon with the means to haul a trans, I happen to have a good spare V5MT1 that we could negotiate on... Can't ship it though.

Also, check out this link http://www.car-part.com/ if you need ANY parts. (You will almost certainly need a parts car and if they list something mundane like a dash or door panel for one of the previously mentioned possible donor vehicles, they probably have a whole truck sitting there waiting to be scavenged)

[speednsnake]

Quick update. The motor is getting dolled up and the oil pan pictured above most definitely will NOT fit. Had to get a used one from a junkyard (by god was that junked ram 50 a goldmine! Got everything that I thought I had to fabricate right off a factory truck). On that note, don't order an uncommon oil pan from O'riellys, because they are a pain in the ass to return. Just find a junker to strip.

Oh, and here are a few pictures for those who like pictures. First is the motor as it was yestrday with the CORRECT oil pan in the background (note the dramatic indent for the front pumpkin), and the second is my attempt at making the ugly intake manifold more attractive. I'm going to block sand the raised "V6 3000" back to raw aluminum when the enamel cures.
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While I've got the engine out I'd be happy to take a picture of any component on it or the truck upon request. If you need pictures or measurements for anything you have maybe two weeks to ask me to get them for you.

[speednsnake]

Ok so I am pleased to announce that IT LIVES! But is far from done... As per the usual here is a wall of text.
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If you are thinking of attempting this build I will once again outline what I needed to do so, just to do it.
This rig needed two donor vehicles, one if you get a running V6 ram/mighty max to tear apart (why would you do that though?)
In my case I had a running Montero 5 door donor(fully loaded), and a junkyard V6 Ram 50 at my disposal.

Engine:
A 6g72 from a first gen Montero/Raider will drop right in with no modification. Take the radiator while you're at it, as it is slightly larger, but in order to make it fit you will need the power steering lines from a V6 2nd gen. The engine bay fuel lines could be done custom, but it's easier to take some from the aforementioned 2nd gen (and then done custom back to the tank, fuel injection's a bitch). The exhaust I have now is temporary in my case, but to get it running I was forced to use the y-pipe from the junkyard ram, which is frighteningly close to one of my brake lines (which are different in the V6 models) my line has showed no sign of failure or fatigue, but I would have preferred to get some more breathing room. If you felt so inclined you could take the whole booster and line system from a V6 model to make the clearances more relaxed. I'll update with a picture of the engine bay tomorrow morning. The MAF is clunky and awkward to fit, but given my new harness I was able to move the radiator overflow and washer fluid reservoir elsewhere to make room. When the turbos go on I will be converting to a MAP and megasquirt III ECU.

Transmission:
I used a V5MT1-1 from a raider, but was forced to use the cross-member from my donor Ram. I fit right into place after that without any fab work, even put the sticks right where they aught to be. I had to expand the hole in my tunnel to fit the gear shift lever, but that is only relevant if you had an auto in the first place

Wiring:
I used the ENTIRE harness from the Montero. This had pros and cons.
pros: It allowed me to use all of the cool gizmos from the Montero (cruise, intermittent wipers, headlight cleaners, power everything, and a whole bunch of extra circuits), and made the dash swap possible.
cons: Using this harness required a complete reroute of the harness to fit the truck, extending the hot lead to the battery, made some tom foolery with the taillights, and forced the dash swap, but if you use a 2nd gen V6 mightyram harness you will be fine. Ground everything that was grounded and label your wires well and it will work just fine. Certain components needed special attention, but I'll cover that in a minute.

Fuel:
You will need a high pressure pump, and the stock tank won't allow you to put one in it. If you get the tank from a fuel injected 2nd gen this is a non issue. In my case I simple put the pump above the frame next to the tank and ran all of the lines needed. This allows you to upgrade it later if needed as a plus. Unfortunately, the damn thing is quite loud, and will need to be more isolated from the frame in the future.

Driveshafts:
These were a bit of a pain, but in the end I was able to use both of them from the donor Ram, and for the rear I had to take the flange from the Montero's 9.5 (which I will be salvaging at a later date). The rear is a two piece w/ carrier bearing (your truck has the brackets for it even if it has a one piece), and I will be swapping to a custom one piece driveshaft when I swap to the 9.5.

Dash:
This one is only for those who really like it, as it was a nightmare to make work. The Montero/Raider dash is set such that it needs quite a bit of trimming to even fit, and once it does you have to fabricate a brace for the steering column as the stock pipe support is simply in the way (the wheel needs to be moved to the left anyway if you want it to look right). To get it to fit you have to flatten out the beveled section on the windshield side such that the dash goes straight forward from the defrost vents (you will know what I mean when you have one in front of you). Once that is done you will need to trim that section back to where the ark of the windshield is met and it juuuust barely touches the indented section where the defrost vents are. At the corners of the dash bordering the front take a cut straight down 90 degrees to the ground. It wont be very long. There are two brackets on the side that need to be removed from the cab carefully, and the dash will need some small nips on the sides to make room for a few needed brackets, such as the bracket for the steering column. These are all hidden. The Dash has two kicker braces in the middle by the heater core that need to be reattached to the top of the dash by whatever means you find. The top mounts (there are three) will need to be made from scratch, as will the side mounts. The center console needed to have the bottom most cubbie trimmed off, but fits perfectly without it, so there are no uncomfortable gaps. to make it's support fit simple undo the bottom bolts and flip the bottom bracket over. The vents need extensive work to fit, and I have yet to make them work. All in good time. The steering column is straight out of the Montero, and as such need the floor mount from the ram. It's a prick to swap given the grommet, but a little oil and patience will see it off. The parking brake needed a hole cut for it to clear the face of the dash. Don't ask how I got it out in the first place...

After all of that I gained a sweet new dash, the only one to ever be put in a Ram or Mighty Max, as well as an appropriate speedo, tach, oil pressure gauge, volt meter, that goofy "inclinometer", plus a bunch of real estate for the aftermarket gauges that I will be running (boost, fuel-air, water/meth level, Intake air temp, and maybe EGT and that AEM meth failsafe gauge).

Special Fixes:
The vent blower, wiper motor, fuel pump, and rear end harness needed some extra TLC to get working. To get the wipers working I needed the whole motor out of the Montero. The stock wiper motor will plug into the harness, but it will go constantly at low speed, regardless of wiper setting. Putting the Montero's motor needed only a new mounting plate and it works fine. On the bottom of your blower unit you will see two components screwed into the housing. One is the actual motor which has a triangular plate, and the other is a small rectangular component that the harness plugs into. Take the rectangular component from the dash's home vehicle blower and swap it into the project car. Viola the blower will work. The fuel pump needed a hot wire that is activated in the 'on' position. I used a wire which I now believe is the rear defrost circuit lol. This wire is NOT hot when the starter is running so cold starts may be a bit pesky, usually needing a crank or two in my experiance so far. At least it gives me a light on the switch to indicate that it is on (not that the constant whirring wasn't enough)... Lastly, the rear end harness from the Montero is incompatible. In my case the junkyard ram would have given me no advantage, so I reverse engineered the wiring harnesses and spliced them right under the passenger seat. Once you have that done properly, swap the brake pedal button for the Montero's (it has four wires as opposed to two), and remove the blinker wires from it, replacing at least one for a new wire which is routed to the green wire on the ram's rear end harness. If you don't do that your amber lights will turn on with the brakes and the red brake lights will always stay dark. This is because the Montero had all-red taillights which simply used both blinker circuits simultaneously as 'brake' lights. Our trucks, of course, have dedicated blinkers and brake lights.

The road forward:
As of now I have a completely rebuilt N/A motor with a tad over 300 miles on it, and a complaining 5 speed (I'm going to try out a few fluid recommendations before I attempt a swap or rebuild).

Endgame I am looking at:
-Swapping the ECU to a Megasquirt III (which I have read is super easy with these motors), and converting to MAP.
-Swapping out the rear end for a limited slip Mitsu 9.5" with plans to toss in the 2nd gen Montero's Air locker, and swapping out my front for the 8" in the donor Ram, moving my limited slip guts over from my current rear end.
-Fabricating the turbo headers, re-clocking my TD04 turbos, and running full 3" dual pipes from the turbo outputs clear to the back end, with an X-pipe in the Y-pipe's old spot so I can bung in a wideband O2
-Replacing the Injectors with 3SX injectors of in-determinant size.
-Porting the heads as wide as they will go, and upgrading the rockers and spring according to this guide: http://www.3si.org/forum/f36/sohc-above-beyond-mod-bible-476200/.
-Replacing the pistons with VR4 pistons, to handle the boost and heat. (I've been told that the stock crank can handle about 500hp, not that I will be seeing those numbers... Oh, and our trucks weigh less than the 3000gts. Go figure)
-Plumbing an intercooler in place of the AC condenser and running an inline oil pump and dual oil coolers for the turbos.
-Getting the water for the turbos from... somewhere, not sure yet, but there are two ports in the block already. Not sure if they are sufficient yet.
-Adding a water/methanol reservoir in the spot currently occupied by the MAF, and adding the necessary parts to allow it to function.
Here are the turbos btw. Sorry for the crappy picture, just took it a second ago.
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-Upgrading to a ceramic clutch ($500, ouch... Not that the stock replacement is much better at $300)

The supercharger dream isn't dead just yet, and I have a few ideas kicking around...
To make one work, I figured I would need a fairly large one to make it work less hard and thus produce less heat (that's the idea at least). As such I am looking at an Eaton M112 from a wrecked 03 Mustang Cobra, which run about $800 used. To put it on I will need to do the following:
-Obtain a custom air/water intercooler core to fit between the stock fuel rail, and making a new manifold to fit it that replaces both stock intake manifolds and allows the mounting of the Eaton and all of the needed fluid lines
-Moving the water/meth injectors to said manifold to avoid putting water/meth through the blower, and moving the MAP and boost sensor to get accurate readings.
-Praying that I don't generate a disgusting amount of intake air heat.
-Reworking the intake before the blower such that compressed air flows from the turbo's intercooler, past a large blow off valve, through the throttle-body, and into the blower (yes, I know that that will "double compress" the air, but the alternative would be a nightmare to make work properly)
-Tuning everything to only ever allow 20lbs of boost (this setup will absolutely generate more than that), including wimpifying the turbos and over-driving the blower.
-Praying that the trans will handle it.
-Driving the blower with the alternator's serpentine
-Possibly cutting a hood scoop for blower clearance
-Adding yet another heat exchanger to the front of the vehicle for the supercharger's liquid intercooler (at this point I would have a radiator, two oil coolers, a large standard intercooler, and the aforementioned liquid intercooler).
-Praying that the whole frame doesn't just bend at the bed to cab seam.
-Praying for strength.
-Relocating a few components for clearance, such as the coil.
-Upgrading the injectors and fuel pump yet again.

...and If it worked I would be looking at close to 500hp with a super unique power curve and wicked sound (quintessential mustang blower whine, followed by turbo spool and a heavy blow off at closed throttle, all with a lovely unrestricted V6 growl to round it out).


Anyhow just thought that I would update the thread with my progress and future plans. Don't be discouraged if you are looking to swap, it was worth it. Any advise and constructive criticism is welcome, I'm still learning the ropes.

C'mon people, I feel like I'm talking to an empty room here, a few replies would be nice, even if you think it sucks or want help with a personal swap. Either way I'll keep this thread updated as progress is made.

[DroppedMitsu]

Awesome thread and build man, can't wait to see you go forced induction with it. Keep the updates coming.

[speednsnake]

Here are the shots of the engine as promised. Changing my motor from a G54b to the 6G72 in my bio was immensely satisfying by the way :grin:. I only wish that I could select the G54b as the 'former' engine, if only as an homage to that gutless wonder.
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It isn't quite routed how I would like just yet, particularly on the passenger side. Also note the unmounted MAF, washer fluid reservoir, and coolant overflow. Had to get it on the road in a bit of a hurry. The cruise control isn't mounted yet but after I fab up a bracket it will be going between the battery and brake booster. The hole in the firewall is the windshield wiper motor's spot, which still needs work on the mounting plate. All of these things are going to happen periodically over the next few months as side projects until I have some time to put the turbos on.

Thanks DroppedMitsu, and believe me I can't wait for the forced induction either. I'll keep the updates coming as they happen. There is precious little info on our trucks and I intend to add my own experiences to our knowledge pool for future owners. I'll tentatively say that It should be twin-turbod by this time next year.

[Chargerx3]

Excited to see the turbo's get installed. Fun build.

[Tsiturbomightymax]

Why not just swap a dohc 3000gt engine or better yet the vr4 engine! Great work by the way, kinda digging the dash.

[geezer101]

Why not just swap a dohc 3000gt engine or better yet the vr4 engine! Great work by the way, kinda digging the dash.

The VR4 engine will be impossible to install in a RWD configuration. The amount of ancillary components hanging off the 'back' of the block will prevent it from fitting in. You would need to buy a complete front cut engine and rat it for the turbo manifolds and other parts. This is a tough but very rewarding build. Once it is completed it will definitely be worth it. I like the full dash swap too - very cool and different :grin:

[speednsnake]

Thanks for getting that for me man, but yes Tsiturbomightymax, the DOHC is super impractical for our trucks. Doesn't mean that they aren't out there (never seen a complete one but I have seen two or three terminally in-progress builds), but they sure as hell aren't easy. The stock turbo manifolds are actually a detriment of the engine, because they toss the suckers at odd angles for a longitudinal mount and they sit right where the motor mounts belong, necessitating custom fabbed headers and re-clocking anyway.

Thanks for all of the compliments on the dash guys, everyone I show it to tells me they couldn't tell it wasn't stock, which is pretty much what I was going for. It's still nice to hear that folks who know what is supposed to be there like it too :).

Sorry to say guys, but the dash is about the only thing that hasn't broken so far. Lost the tranny in september after I clicked second gear at about 5500 rpms, leading to a gnarly synchro-grind and the stick locked in the 2nd gear position with no power to the rear wheels. Ouch. Swapped out to my spare V5MT1-1 as soon as I could and it's still doing alright, but 3rd is starting to sound funny and I'm chocking it up to 20-30 years if use. The carrier bearing shredded itself due to a slight difference in the mounting from the 1990 long bed frame to mine (the bracket is too close to the end of the transfer case. Not so much that it doesn't bolt up, but enough to cause excess wear.), and I'm waiting until I can swap to a single-shaft driveline like it used to have. The cherry on the cake here is the motor seemingly spinning a bearing at 1560 miles.

Took it out to the sticks last weekend and let a friend do doughnuts in a mud pit after a shooting trip and he basically had it pinned at the rev limiter in 1st the whole time apparently. This was, at most, a 1 minute long doughnut, but evidently that was one minute too long. The motor rattles constantly when warmed up, growing in volume with rpm, and under load above 2000 rpms it develops a deeper knock that sounds an awful lot like a rod bearing going out.

The motor had its first oil change at 600 miles with noticeable sparkles in the oil, and here at about 1560 it has sparkles in the oil again and a rod knock. It has always ran cold, maybe a third way up on the gauge, and it was running just as good when it started knocking as it did before, that is, no loss of oil pressure, no increase in running temp, and no loss of power. This last change I ran 20w-50 non synthetic, a quart of Lucas oil stabilizer and a fresh filter. The "new" trans is running a bottle of pennzoil synchro-mesh and GL-4, with pure GL-4 in the transfer case. Those are the fluids that I've had recommended to me by folks who know this drivetrain, so I don't see that being the issue.

I'm starting to get pretty unconfident in this drivetrain. The (admittedly old and used) V5MT1-1 5 speeds I've ran have proven to be sloppy and weak, while the NA 6g72 is blowing itself up at 1500 miles at the first sign of hard use. Do I have gremlins or something?

So I know that there are a lot of powerful SOHC 6G72s out there, and they seem to do fine, but I've never heard of how well the 5 speeds handle power... Does anyone here know the torque rating on those trannys? Do people with high output 6g72s baby them everywhere? I just want to know from folks with experience with these drivetrains if I'm building a grenade that I'll have to always drive like it's already breaking down.

I'm not canceling the build, though I will obviously have to remedy the engine first, but I'd like the questions above answered before I dump more money into this already money pit of a truck.

As for the dash I'm loving it. It's everything that I'd hope it would be :).

[Rymar Garage]

Sick build! love that dash swap, looks like a factory job from pics. excited to see the boost!

[Chargerx3]

The VR4 engine will be impossible to install in a RWD configuration. The amount of ancillary components hanging off the 'back' of the block will prevent it from fitting in. You would need to buy a complete front cut engine and rat it for the turbo manifolds and other parts. This is a tough but very rewarding build. Once it is completed it will definitely be worth it. I like the full dash swap too - very cool and different :grin:

Not so. As long as you have a donor RWD 6g7# motor to take the upper intake and the proper coolant crossover pipes it will fit just fine. The hardest part will be the exhaust manifolds as they will likely not fit. What is nice about this though is that you have a much larger engine bay in the trucks to facilitate a custom setup. I will be tackling this next spring.


Thanks for getting that for me man, but yes Tsiturbomightymax, the DOHC is super impractical for our trucks. Doesn't mean that they aren't out there (never seen a complete one but I have seen two or three terminally in-progress builds), but they sure as hell aren't easy. The stock turbo manifolds are actually a detriment of the engine, because they toss the suckers at odd angles for a longitudinal mount and they sit right where the motor mounts belong, necessitating custom fabbed headers and re-clocking anyway.

Thanks for all of the compliments on the dash guys, everyone I show it to tells me they couldn't tell it wasn't stock, which is pretty much what I was going for. It's still nice to hear that folks who know what is supposed to be there like it too :).

Sorry to say guys, but the dash is about the only thing that hasn't broken so far. Lost the tranny in september after I clicked second gear at about 5500 rpms, leading to a gnarly synchro-grind and the stick locked in the 2nd gear position with no power to the rear wheels. Ouch. Swapped out to my spare V5MT1-1 as soon as I could and it's still doing alright, but 3rd is starting to sound funny and I'm chocking it up to 20-30 years if use. The carrier bearing shredded itself due to a slight difference in the mounting from the 1990 long bed frame to mine (the bracket is too close to the end of the transfer case. Not so much that it doesn't bolt up, but enough to cause excess wear.), and I'm waiting until I can swap to a single-shaft driveline like it used to have. The cherry on the cake here is the motor seemingly spinning a bearing at 1560 miles.

Took it out to the sticks last weekend and let a friend do doughnuts in a mud pit after a shooting trip and he basically had it pinned at the rev limiter in 1st the whole time apparently. This was, at most, a 1 minute long doughnut, but evidently that was one minute too long. The motor rattles constantly when warmed up, growing in volume with rpm, and under load above 2000 rpms it develops a deeper knock that sounds an awful lot like a rod bearing going out.

The motor had its first oil change at 600 miles with noticeable sparkles in the oil, and here at about 1560 it has sparkles in the oil again and a rod knock. It has always ran cold, maybe a third way up on the gauge, and it was running just as good when it started knocking as it did before, that is, no loss of oil pressure, no increase in running temp, and no loss of power. This last change I ran 20w-50 non synthetic, a quart of Lucas oil stabilizer and a fresh filter. The "new" trans is running a bottle of pennzoil synchro-mesh and GL-4, with pure GL-4 in the transfer case. Those are the fluids that I've had recommended to me by folks who know this drivetrain, so I don't see that being the issue.

I'm starting to get pretty unconfident in this drivetrain. The (admittedly old and used) V5MT1-1 5 speeds I've ran have proven to be sloppy and weak, while the NA 6g72 is blowing itself up at 1500 miles at the first sign of hard use. Do I have gremlins or something?

So I know that there are a lot of powerful SOHC 6G72s out there, and they seem to do fine, but I've never heard of how well the 5 speeds handle power... Does anyone here know the torque rating on those trannys? Do people with high output 6g72s baby them everywhere? I just want to know from folks with experience with these drivetrains if I'm building a grenade that I'll have to always drive like it's already breaking down.

I'm not canceling the build, though I will obviously have to remedy the engine first, but I'd like the questions above answered before I dump more money into this already money pit of a truck.

As for the dash I'm loving it. It's everything that I'd hope it would be :).

Sorry to hear about the motor and the trans going. Like you I have a similar build going on. I too have the V5MT1-1 trans. I believe they made the -2 starting the 91 model year. Look like most of the upgrades were small, but the 2nd gear syncro did get a different angle cut to likely fix its being prone to failure. Another route is auto. They made a couple Mopar A-500's (which is a 904) capable of handling over 500 hp. They might be hard to get your hand on though.

The 6g72 motors are pretty strong when taken care of. I dont know much about the SOHC versions, but the TT ones can take a fair beating.

I would like your honest opinion though. What condition was your motor and drive-train in and how bad did you beat on it? I will be dropping in a 6g75 into my 1990 4x4 and want it to last.

[speednsnake]

If you have concerns about the V5MT1-1 I'd jump right over the -2 and look at the -3. They had trouble with 1 and 2 synchros and were weaker for it. If you already have your -1 I'd look at the fill (or maybe drain?) plug on the trans for a white paint mark. That mark signifies that it was put through the recall and fixed. As for the auto suggestion, that may work for some people but to me, switching to an auto is an unacceptable solution. If you read some of my tomes above you will see how much work I had to do to get rid of mine (which I do believe was the 904). Believe it or not the V6 part of this swap was initially a means to an end of getting a manual in it. The KM145 was said to be weak, so I found the V5MT1 and by extension the 6G72.

The bottom end of the SOHC is the same as the 2 bolt main DOHC motors, so in theory they should take just as much abuse. The extent of what it means to "take care of" a 6G72 is my question here. Obviously keeping fluids fresh and full is a must for any motor, but would I have to run it like an economy car on top of that? This build is meant to be fun, and if I can't actually have fun with it without it immediately exploding, what is the point?

As for my block, the crank and rods were inspected and found to be fine, the block had 185k on it and only needed a hone to get back in ideal shape. Everything was put together torqued to spec, well lubed, and with fresh bearings, gaskets, and good clean seals. I drive the truck in a more sporty fashion than most, but I don't abuse it. I may shift at 4k, but I wouldn't redline it, or bangshift, or ever allow it to run with bad or low fluids. Basically I drive it like I drove my non-rebuilt 280k '89 2.0 truck that never failed on me. Both of the trannys were dropped in with fresh fluid but untouched beyond that. The first one went in part because I used GL-5 in it by mistake, but this second trans has the fluid that it is supposed to take. The stock clutch was swapped for a centerforce dual-friction clutch during the tranny swap.

[Chargerx3]

What year was the -3? Ill check my fill plug to see if the recall was done, if not is the recall still active?

Not too keen on the lower end of your SOHC but at least the rods, pistons and I think the oil pump are different. Im betting you ran into some oil starvation. This may have been caused by spinning doughnuts in the parking lot and all your oil not reaching the oil pickup. 6g7# motors are very finicy when it comes to getting proper oil pressure and volume. I think even our capacity is more iirc.

[dash]

I'm thinkin oil starvation too. Death to any motor. Is the oil pan adequately baffled ?
The turbo junkyard $90 build early in the thread made a believer out of me, as I've always wondered what a stock SOHC V6 could do if boosted. Very impressive. Wouldn't want or need the vider VR4


I personally would love a boosted stock caravan 3L, mated to a 4spd auto, to power a daily driven, lowered 2wd mighty max
Should be smooth running torquey FUN - ala buick grand national style

Read on sigma galant, that the bellhousing was the 5spd weak link. So much so that they sold boxes without em ?


Anyway MOST OF ALL.... Great build & detail!! Thank u

[speednsnake]

What year was the -3? Ill check my fill plug to see if the recall was done, if not is the recall still active?

Not too keen on the lower end of your SOHC but at least the rods, pistons and I think the oil pump are different. Im betting you ran into some oil starvation. This may have been caused by spinning doughnuts in the parking lot and all your oil not reaching the oil pickup. 6g7# motors are very finicy when it comes to getting proper oil pressure and volume. I think even our capacity is more iirc.

The -3 SHOULD be the newest one with an actual stick for the transfer-case. As for the year I couldn't tell you, but that should be a start at least. In my research I have found a whopping two threads on that trans, and they detail mostly on fluid setups and synchro issues. There is a service manual available in PDF that will give you a good bit of info on them (excluding their respective torque max's unfortunately). Just google V5MT1 and you should find it in the first page. As for the recall still being active I couldn't say. I'm not an expert in them, but I've picked up a fair bit of info in my searches and personal experiences.

There is conflicting info on our pistons, but this (http://www.3si.org/forum/f36/sohc-above-beyond-mod-bible-476200/) thread claims that we were blessed with the best oem cast pistons for boost... go figure. The rods are for sure the same (at least for the early 2 bolt main DOHC motors), The first gen cranks seem to be the same, and you are correct in saying we have different oil pumps (rendering ours un-upgradable). The montero guy I got my donor truck from claimed that he slapped a 24v SOHC crank in a project of his to get higher compression (10:1 vs 8:1) and a stronger bottom end. I can't confirm it, but it is definitely interesting.

Admittedly I hadn't considered oil starvage, but the design of the pan makes it... unlikely. Go out and look at yours to see what I mean. The part that the sump sits in is the only low point and it is at least twice as low as the rest of the pan. Another thing to consider is that my motor came from a Montero, not one of our 2nd gens, and had an external oil cooler to feed. It takes 6 quarts when dry, and it was about 1/2 quart low (I knew I should have replaced those damn valve seals) when I checked it immediately after noticing the sound.



I'm thinkin oil starvation too. Death to any motor. Is the oil pan adequately baffled ?
The turbo junkyard $90 build early in the thread made a believer out of me, as I've always wondered what a stock SOHC V6 could do if boosted. Very impressive. Wouldn't want or need the vider VR4


I personally would love a boosted stock caravan 3L, mated to a 4spd auto, to power a daily driven, lowered 2wd mighty max
Should be smooth running torquey FUN - ala buick grand national style

Read on sigma galant, that the bellhousing was the 5spd weak link. So much so that they sold boxes without em ?


Anyway MOST OF ALL.... Great build & detail!! Thank u

The 4x4 V6 pans had the sump in a well baffled low point that took up maybe 1/3 of the total pan area and was twice as low as the rest of it. Does that rule out oil starvage? No, not necessarily, but it seems a little unlikely to me. At the end of the day however something had to have failed. Oil starvage is an easy scapegoat for that, so I will do my best to investigate.

If you have to use a caravan motor for your build watch out for the dipstick/oil pump orientation. Van motors have that stuff on the wrong side from our trucks, which may cause fitment issues. You do get lighter cam pulleys and a bigger throttle body though for your trouble :).

I'm not done with it yet, I'll continue to add what I know here and give y'all progress info and pics of course. I've been incapable of finding torque limits on our parts, but it's looking like I will be breaking more stuff in the future so that you won't have to ;).

[thillskier]

Wow, Great project and build!
I had many of these trucks startng with my first new vehicle, a 84 diesel 2wd ram 50. 450,000 miles and wrecked, then another 160 or so before trading it in on a v6 4wd.
Got 450,000 with a 5th wheel hitch towing a 4wd 580K case backhoe on a triaxle gooseneck, once from Miami, at 55mph in 3rd gear at 4000 rpms all the way back. I did break the bearings after 120,000 miles, (running Amsoil), so cant complain really.
No oil use etc as new when sold! GREAT engine, IMHO. Oil was changed at 10,000 miles (Amsoil) and oil tested "as new" then. Trans and diff oil at 100,000 miles.

I'd put some "Energy Release" in your trans fluid IF its not worn out. This product makes oil seek heat. I have it in my backhoe and have not replaced a spider gear that was a biannual repair (undersized bearings) before I added it to the Amsoil in my transaxle. I still change it every 500 hours though, but much less "shavings" shiny things in the oil when changed. Its a GREAT drilling fluid if using it on tool or hardened steels, as well! Order off net...
I used and tested the stuff in airplanes and in all kinds of (my) equipment w/o oil starvation failure (yet:). However, running an engine with oil starvation (centrifugal forces from doughnuts moving oil up side of oil pan and block away from pickup is ALWAYS bad...)

[Chargerx3]

Checked my trans for the marking. No dice. Still going to stick by the oil starvation for now unless your rebuild wasn't performed properly. Bouncing the motor off the Rev limiter while spinning in a circle would surely airate your oil and leave your crank unprotected. Another thing to check is the condition of your oil pan. For us 3s guys people tend to jack up the car by the oil pan denting it and compressing it against the pickup. This causes oil starvation and spun bearings. Make sure yours looks good.

[speednsnake]

Wow, Great project and build!
I had many of these trucks startng with my first new vehicle, a 84 diesel 2wd ram 50. 450,000 miles and wrecked, then another 160 or so before trading it in on a v6 4wd.
Got 450,000 with a 5th wheel hitch towing a 4wd 580K case backhoe on a triaxle gooseneck, once from Miami, at 55mph in 3rd gear at 4000 rpms all the way back. I did break the bearings after 120,000 miles, (running Amsoil), so cant complain really.
No oil use etc as new when sold! GREAT engine, IMHO. Oil was changed at 10,000 miles (Amsoil) and oil tested "as new" then. Trans and diff oil at 100,000 miles.

I'd put some "Energy Release" in your trans fluid IF its not worn out. This product makes oil seek heat. I have it in my backhoe and have not replaced a spider gear that was a biannual repair (undersized bearings) before I added it to the Amsoil in my transaxle. I still change it every 500 hours though, but much less "shavings" shiny things in the oil when changed. Its a GREAT drilling fluid if using it on tool or hardened steels, as well! Order off net...
I used and tested the stuff in airplanes and in all kinds of (my) equipment w/o oil starvation failure (yet:). However, running an engine with oil starvation (centrifugal forces from doughnuts moving oil up side of oil pan and block away from pickup is ALWAYS bad...)

I wouldn't be here if I didn't love these trucks like the rest of you lol, and It's a nice change of pace to hear folks talk about how these trucks held up straight from the lot. Thanks for that account of your V6 rig, it's pretty reassuring to hear how long it lasted even with that caliber of use. So far my only insight into this drivetrain was the occasional blurb here and the testimony of the guy who sold me the donor truck (he said pretty much what you did).

I'll definitely give that "Energy Release" a try when she goes back together. Is there any specific type that you would specifically recommend (they appear to sell several oil related products)? I still find oil starvage to be a bit of a stretch, but so far it does seem to fit the profile, and it's be the first thing I look for once I have it back apart...



Checked my trans for the marking. No dice. Still going to stick by the oil starvation for now unless your rebuild wasn't performed properly. Bouncing the motor off the Rev limiter while spinning in a circle would surely airate your oil and leave your crank unprotected. Another thing to check is the condition of your oil pan. For us 3s guys people tend to jack up the car by the oil pan denting it and compressing it against the pickup. This causes oil starvation and spun bearings. Make sure yours looks good.

Well I've found that the 1-2 shift on the V5MT1s to be the best judge of imminent failure, so if that's good I wouldn't lose any sleep over the recall. Would you mind telling me your tranny's serial number? Of my two, the newer (and currently working) tranny had gone through the recall, while the older one had not.

My oil pan looks undamaged from my initial inspection, but as you know, the portion above the axle is a bit difficult to inspect, so I'll make sure to check that. I have found an immediate issue however that could very well have damaged it, torn motor mounts.

When I replaced the trans, I ended up having to have a mechanic lift it back in due to a lack of tools. When I picked it back up I found that they had bolted it to the motor and left off any other support. Essentially, it was being held up by the motor mounts and the y-pipe... Since then, on a peppy take-off, the engine and trans will twist about 15 degrees such that the stick will look like it's in 5th when it's really in 1st... I'd assumed that it was excess friction from the blown carrier bearing until I went to unbolt the mounts last week and found them at odd angles.

How much damage does it take to the pan to cause the situation you described?

[Chargerx3]

Ill have to take a look at it tonight.

Sorry to hear about the crappy install. All it takes is as little as 1/8" dent to cause it to starve. Any dent is a restriction, especially when taking in account your maxing out the revs on our motor.

[speednsnake]

Got a video of the noise a minute ago. My phone's mic is too cheap to record it from the engine bay without it being drowned out by other noises, so I had to record it from the cab. At least this way you get to see rpms and oil pressure. The trans was in neutral, clutch out, and the truck was started for the first time that morning about 30s before I started recording. I also checked thoroughly for any oil pan dents and found it unscathed. After researching why​ dents cause issues it became apparent that the issue is when the low part gets rammed up into the pickup screen causing it to collapse and restrict. Mine is fine, and I should add that in order for that to happen you'd have to annihilate your steering in the process, as it runs right below the pickup's location.


https://www.youtube.com/watch?v=10GDosKdEZg

Note the subtler knock on acceleration as well as the rattley clicking that is somewhat constant above 1700 rpms (extra obvious on decel).

[geezer101]

Your valvetrain noise 'should' back off after running it for a while (needs to get some blood pumping through it by warming it up). The knock sounds like a second order noise from somewhere else - your gearbox mounts and cross member are good? You might need a friend to jump in the cab and rev the engine while you get under there and investigate. Unfortunately these kinds of noises are hard to hunt down unless it is something glaringly obvious. :shrug:

[speednsnake]

Yeah that's pretty much where we're at :shakehead:. The valvetrain (for lack of a definitive source) noise is persistent and gets worse as it warms up to the point that it is present straight off the idle (about 500-750 rpms). It does have your typical lifter click for maybe a second and a half after a cold start, but that will cease and give way to the noise in the video from then on. You can barely see in the vid that my oil gauge was reading about 40psi, and it does indeed work correctly

That deeper noise has (seemingly) migrated to to the driver's side bank (err, by that I mean the right one, usdm and all) in the week since the truck started last. I will replace the motor mounts before I tear it down to see if I'm getting a slight oil pan contact with the front axle, although as the video shows it is present even when the truck is stopped. My next step from there is the old screwdriver test for bad rod bearings and/or wrist pins.

As for the tranny mount, it's solid and was inspected after the noise occurred. The rubber isolator is quite flexible, but clearly not ripped. Even so I will try your suggestion when I have a second person available for it. I'll also unbolt the crossmember with the trans supported to ensure that the mount is good.

There is an exhaust leak from the right bank manifold to the y-pipe (old gasket), and it makes an audible noise that will also be remedied before the teardown.

Thank you for all of you time and thoughts on this, this forum is one of the best vehicle specific websites that I've encountered, and folks like you and the others who chime in are what make it so :).

[camoit]

I herd lifters and an exhaust clunking around I think.

[speednsnake]

Ok, I've done some more diagnosis on the engine and found the source for both noises within a good margin of confidence. The light tapping/clicking noise is due to a crack which has re-formed in the driver-side exhaust manifold. It had previously been brazed over as a temporary fix before the turbo manifolds were fabbed and installed. So that's the good news I suppose. Here are a few pictures of other potential sources of exhaust leakage, with the first two and last being known sources of leaks: driver's side manifold, the driver's side joint to the Y pipe (makes a dull muffled pulse, but not one that is easily ignored even from in the cab), and the joint from the y-pipe to the rest of the exhaust (lets out some of the motor's growl).
15958159591596115960

The exhaust is not a strong point for this build ATM. It is a known temporary component and has not received much attention due to the redundancy of perfecting it. Don't worry, it's all going in favor of dual 2 1/2" stainless piping all the way back (with an x-pipe for the O2 sensor just below the passenger foot-well).

The other noise is more than likely a spun rod bearing on the #4 rod. This was determined by removing the spark wires systematically until the noise ceased. When I got to #4, the knocking under load went away, but the clicking persisted (makes sense). The test for the clicking was to unbolt the valve cover for the driver's side bank to see if the noise grew in volume when it was slightly lifted, while performing that test, I noticed the crack. The noise did not grow while the cover was lifted. Due to the shape of the intake I was unable to remove the valve cover entirely for inspection without a much more in-depth disassembly.

As for the cause of these problems, I still need to wait until I have the funds and time to actually fix the motor entirely to pull it apart for a more thorough investigation. Thanks as always guys for all the help on this project. It isn't dead, just on the back burner. More will come in the future, but I'll need to fix it first.

[speednsnake]

OK, I'm going to be cracking into the engine within the next two or three days, depending on weather. My suspicion is either a loose oil pickup that let air into the system (unlikely given my fairly good oil pressure, but it is a possibility) or a crank bearing that was installed backwards. Since #4 went rather than #6 (the most common source of failure based on my research), I'm betting (and hoping) that I simply made a mistake on the rebuild. The oil is already out, and despite it being the engine's 2nd batch of oil and only ~700 miles old, it has a lot of fine, powder sized, shavings which to me seems very excessive even for a newly rebuilt motor. Whatever I find will be reported here for future owners to avoid and or be cautious with.

Once again, with the motor coming out I will be happy to provide any hard to access measurements or potential hazards that anyone wishes to know. I can already tell you that the rubber brake line that goes from the master the the frame is dangerously close to the driver's side manifold. Once my motor mounts sheared, the small (~1/2") change in proximity caused the line to melt and burst on the trip to the shop. I'm going to try to retrofit the '90 MM brake lines into mine to fix the leak and avoid any future issues.

With regard to the turbos, the manifolds will still need to be welded up, and I will need to get it running off of an aftermarket ECU before they can be installed. The stock VR4 turbos need to be reclocked to be properly installed up high where they will fit, and I'm going to be running the stock V5MT1 until it fails. Wherever that point is will be recorded here as a stress test for future builders. Hopefully there will be nothing to report...

Does anyone here know what a good stock N/A fuel and timing table might look like for these motors? I've read about a few who have already switched theirs over to a megasquirt II, but so far I have been unable to find any tables for a base safe tune.

[BradMph]

Do you have a flopping piston on a wrist pin in that engine? Like maybe a wrist pin fractured possibly. I had an engine sound just like that and it was worse when the compression wasn't putting pressure on the piston and it allowed it to literally flop around in the cylinder from the worn out pin.
If your going turbo, your going to put a major stress on engine parts. If you don't go through the engine and replace/rebuild things, you may find out rather quickly which parts were the weakest, lol.

Great build also...keep it going. :)

[speednsnake]

Do you have a flopping piston on a wrist pin in that engine? Like maybe a wrist pin fractured possibly. I had an engine sound just like that and it was worse when the compression wasn't putting pressure on the piston and it allowed it to literally flop around in the cylinder from the worn out pin.
If your going turbo, your going to put a major stress on engine parts. If you don't go through the engine and replace/rebuild things, you may find out rather quickly which parts were the weakest, lol.

Great build also...keep it going. :)

Not sure how much of the thread you've read, but the entire engine was rebuilt before being put in the truck, just 1500 miles ago. So far it seems like I'm already finding out what the weak parts are in these motors (and transmissions...) lol. It was late in the day when I pulled the pistons out, so I didn't check each one to see if the wrist pins were holding up, but I'd be willing to bet that they aren't in too hot of shape due to metal shavings in the oil... I'll check 'em first thing tomorrow morning.

Anyway that brings me to the findings... Spun rod bearings on #2, #4, and #5. The lower oiler retainer ring on #1 folded over, gouged out the cylinder wall, cracked in several places, and smashed the oil ring land on the piston. Even the rods that still had good bearings seemed scored, and all of the unspun bearings were elliptical rather than hemicircular when removed... As far as I can see the block is shot until it can be bored out, and the crank and rods are probably in need of repair and/or replacement.

Here is a picture of the ring damage on the #1 piston. Apologies for the quality, I had to use my phone.
16439

And here is a spun bearing, with maybe 30 miles on it. All of the spun bearing rods, plus the rod for #1, were more difficult to remove. To me that suggests that they may have become slightly egged out, thus moving the main studs closer together and binding up the rod cap.
16440

The oil I drained out of it was free of large debris, but the crankcase had lots of big coppery colored shavings throughout. The pickup tube was completely undamaged, but did have some shavings stuck in the screen. It's gasquet looked fine too. Many of the machined surfaces felt gritty to the touch. Looks like the bearings took it out on the rest of the motor after they spun.

A junkyard kinda sorta near me has a good shortblock for $100. I will probably just buy that rather than try to fix mine. I'll probably post again tomorrow with any other findings...

[BradMph]

Oh wow, it looks like you have a lot going on in there.
When I had my engine rebuilt the shop must of left some debris in an oiler or installed too tight of rod bearings and clogged up. It took out the first bearing to not receive oil, #1. Bearing lost its coating onto the crank. Good thing I had a doner engine with a perfect crank. I did the measuring for the repair and replaced with racing rod bearings with a closer matched set so it got a better lubrication. If you want it done right, you got to do it yourself. I questioned their work because the bearing locked onto the crank at 25mph, so it definitely was something left in an oiler or missed measuring specifications and clogged. It's ran perfect ever since I fixed their work, lol.

[speednsnake]

Well I have the junkyard short block it currently at the machine shop being bored. I had taken the heads off of it to put on the original motor when I first built it, and the southern Oregon weather had not been kind to the cylinder walls... Still, it was in need of less boring than the original block, and hadn't endured the grit blasting from three spun bearings, so it made more sense to use than the original.

I will be rebuilding it and dropping it in over the next few weeks.

I figured I'd give you guys the final prognoses on the other block.

When piston #1 was being installed on the rebuild, the lowest oiler ring must have slipped past the ring compressor and folded in the bore. Over the course of its 1500 mile journey, the cylinder wall was being turned into grit by the dragging ring, which then cycled throughout the motor. That grit (which was visible in the oil and pan as a grey sludge) ate the bearings, pump, and every other bearing surface until the tolerances were so bad that they finally spun. The motor had simply reached its limit while out in the woods. The straw that broke the camel's back if you will.

Thankfully it appears as if the motor had a good reason to fail. We'll see how this next one holds up, but by every account that I've read they are very reliable. Hopefully it will survive the turbos.

[geezer101]

Not good news. Sorry to see all that work destroyed in such a short period of time. Hopefully the bargain $100 shortblock will be solid.

[Brady93]

Are you still pursuing this?


Thanks for putting up you're knowledge and experiences guys.


I've recently started buying parts to make a similar setup, when i did some research i found this thread.


My goal is 260 - 300 hp, on the 6G72 with twin turbo's, but i'm getting mixed opinions off the internet as to what these engines can handle, and what gives in etc... And local knowledge is all but non existent...


Does anyone know how similar the bottom end is to the twin turbo version? If they are pretty much the same, then we shouldn't have any trouble pushing decent numbers....


With that in mind, i am about to do a complete proper rebuild on a spare 6G i have here, and would like to know if i should be considering forged pistons or conrods, and are there any other upgrades or tricks i should be aware of while i have it all apart?


I'm in the process of stripping the engine down now. I'm hoping my 4D56T currently in my Triton lasts long enough to get this engine built. :D

[speednsnake]

Are you still pursuing this?


Thanks for putting up you're knowledge and experiences guys.


I've recently started buying parts to make a similar setup, when i did some research i found this thread.


My goal is 260 - 300 hp, on the 6G72 with twin turbo's, but i'm getting mixed opinions off the internet as to what these engines can handle, and what gives in etc... And local knowledge is all but non existent...


Does anyone know how similar the bottom end is to the twin turbo version? If they are pretty much the same, then we shouldn't have any trouble pushing decent numbers....


With that in mind, i am about to do a complete proper rebuild on a spare 6G i have here, and would like to know if i should be considering forged pistons or conrods, and are there any other upgrades or tricks i should be aware of while i have it all apart?


I'm in the process of stripping the engine down now. I'm hoping my 4D56T currently in my Triton lasts long enough to get this engine built. :D

Yeah, It's still going together, but a few months ago I got a job as an actual mechanic, so getting motivation to work on my own engine over the weekend is proving to be more difficult. I've got it long blocked now with the intake in place, and I'm going over to install the ridiculous $300 OEM oil pump today.

As for your power question, the SOHC 6G will hold that no problem, but the manual trans is probably approaching it's limits at those power levels. Unfortunately, no one has been able to provide any info on what the stock V5MT1 trannys can hold, so I'm probably going to be the guinea pig on that particular test (up to around 500hp that is). The auto trans is supposed to be quite strong however, so if already have one or you're willing to swap, you might find more reliability there. I know a guy who claims to have built a twin turbo SOHC up to about 310hp, with stock everything (in a Dodge Raider), and apparently he got 60,000 miles out of it without any issues. That was with stock wastegate actuators and the V5MT1 manual 4X4 trans too.

The bottom end is supposed to be the same for the SOHC and early DOHC 6G72s, and the rods are the same for the whole run of 6Gs. Truck pistons are among the most desirable for boost as far as OEM pistons go, so you should be fine there. The later DOHC 6G72s had a 4 bolt main and forged crank, but unfortunately there is no way to use that block or crank with our SOHC motors.

I hope that covers everything.
Feel free to ask if you run into any other issues along the way :).

[Brady93]

Thanks Speednsnake!

I'm unsure what i should do about an ECU, i have no ECU at the moment. With plans for boost, it would make sense to buy a standalone and fit that from the get go. Did i read you are going to use megasquirt?

Cheers
Brady

[Brady93]

Has anyone tried running a 6G72TT ECU on these engines or know if it would work? Both engines seem very similar.... Minus turbo's..

[rida4christ]

great work, I love the dash man! and I feel ya on the working as a mechanic deal its hard to get on my own projects as well.

[speednsnake]

Has anyone tried running a 6G72TT ECU on these engines or know if it would work? Both engines seem very similar.... Minus turbo's..

Unfortunately my experience with the DOHC motors is near nonexistent, so the nuances of it's ignition and fuel control systems is beyond what I can tell you. A few things immediately jump out at me though. First, the odds of it being able to be plugged right in is... pretty slim. Furthermore, making it try to figure out the distributor would be a pretty big hurdle, as the DOHC motors use coil packs.

If you passed that hurdle, you would still find yourself having to re-tune it anyway, as our heads breathe differently, and our stock O2 setup is incompatible with what it will expect, meaning that it would throw a whole mess of codes if you got it to run at all. Not necessarily impossible, but probably more trouble than it's worth.

You did read correctly that I will be using a Megasquirt, and since it uses it's own harness that will deal with whatever you give it, I found that to be the simplest solution (then again, I haven't gotten that far yet.). As a bonus, I've read that it works quite well with our distributor's single rpm output. The only issue with the Megasquirt is that I will need to find or make a stable ignition and fuel table to get the engine past it's first startup after moving over to it. Once I have those tables (and subsequent power tunes of those tables), I would be happy to provide them here for any future builders.



great work, I love the dash man! and I feel ya on the working as a mechanic deal its hard to get on my own projects as well.
Thank you :). I hope that I adequately explained the process of how to retrofit it into our trucks should you or anyone else try it for themselves in the future. As it stands, I believe that I am the only one to ever do it, but I welcome others to try it for themselves.

Yeah working on other cars sure gets you burned out on working on your own. I hope to drop my recently completed (N/A rebuilt) motor back in this weekend, but you know how it is. Between moving, doing the brakes on my parents' suburban, and actually enjoying my weekend, it's sounding less and less appealing lol.

[bouttreefity]

First, I will say nice build. I have the same truck well mitsu. I know I'm off topic a little from everyone but I was wondering, have you installed the bouncy seats? If so how have they worked out and how hard was the install? Thanks