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to get the most out of the 2.6 you need duration, not lift, as the heads are lift limited due to the design. There are a lot of people who have tried Schneider cams with wildly varying success. Others have used Oregon Cam grinders. The starquest crowd love the Tim C line of cams, but I don't know if they are still made - screaming banshee, Monster banshee, ultimate banshee, etc
What's your alls thoughts on polishing the chambers? Some people say it's worth it some say it's not. The chambers in my new head are machines out and are already smooth I know it's already helping against carbon buildup. So would touching it up with polish be worth the extra few hours?
If I remember right pennyman you mentioned to another fella about the manual section having a mopar performance specs guide. Not sure if that's relevant to camshaft spec or not yet but I'm still gonna download it.
My thoughts - on older heads anything that reduces surface area where carbon can anchor to it, definitely (the quality is usually not great - porous castings etc). But there's a bit more to it. You got lots of sharp edges in there around the valve reliefs and the spark plugs and those edges can potentially do the same thing. Just radiusing them off will also aid in reducing turbulence of gas going in and out and can help with fuel ignition propagation (the fuel charge can pass through the spark plug relief instead of sort of bouncing around it). By looking at the chambers you can imagine how the gases swirl into and out of the valves so you want to speed up that process.
Better cylinder charge fill and improved burnt gas scavenging = more efficiency. :woo:
as is the case with most any production headQuote:
to get the most out of the 2.6 you need duration, not lift, as the heads are lift limited due to the design
Banshee cams popular because they were born in the SQ community..... more miss than hit tho, especially the rollers where u had to source other crap to run em, for little to no gainQuote:
a lot of people who have tried Schneider cams with wildly varying success. Others have used Oregon Cam grinders. The starquest crowd love the Tim C line of cams, but I don't know if they are still made - screaming banshee, Monster banshee, ultimate banshee, etc
One dude had to pester schnieder to grind his cam properly to the specs on the schnieder supplied card. Reward was an amazing 100hp gain!
The red 800+hp 9sec starquest I posted way back, torque curve shaped like no other 2.6 I've seen. No characteristic tq nosedive
So schnieder can provide a proper cam. Most of the faster 2.6s ran em back in the day. Some ran TEP cams also
I believe consistent quality control is lacking, compounded by 9 out of 10 folks do not bother to degree their cam
One 2.6 guru (5spd 10sec street starquest), says he's even seen oem gears incorrectly marked
Correct valvespring pressure is essential, and another topic
This is sort of my point with setting up optimal ignition timing, there's a ton of variables and you can't even be guaranteed you've found TDC from factory.Quote:
Originally Posted by dash
With a long duration cam would I have to go with dishes pistons and if so how much compression would I lose? Any recommendations for a brand of pistons or where to order them?
It will not change the clearance enough to require dished pistons. A trick that the starquest guys use is to replace the rocker arms with rockers from a 3.0 l v6 Mitsubishi motor - this changes the rocker arm ratio from 1.5 to 1.6, and some of them even has a roller tip as well for less friction. I found new rockers on eBay for about $10.00 each: https://www.ebay.com/itm/CHRYSLER-DO...53.m1438.l2649. Here is the roller tip ones: https://www.ebay.com/itm/Engine-Rock...ta1qpu&vxp=mtr
Attachment 20356Attachment 20357Attachment 20358Attachment 20359 This just a few pics of what i got done so far. Im basically rounding down any sharp corners, trying to make the alu around the steel seat meet the runner walls as flush as possible(kinda hard to explain what i mean with that) getting rid of all the rought casting lines and high marks. 80 grit in intake 120 in exhaust tring to focus a some on the short radious spot and tried to keep a spiral effect in the intake as well. went ahead and started polishing the chamber as well. Why not?
Nice work :thumbup: Get yer finger in there and probe around for high spots and undulations - you'll feel them before you see them. Not easy working the valve bowls is it? I made a tool to lap the walls in the galleries from a broken screwdriver shaft. I cut off the tip, chipped off the remaining bit of the broken handle and then cut a slot into the cut off end. I wedged some folded up sandpaper in there and locked it up in my power drill chuck. I managed to get a very nice uniformed finish out of it.
Awesome man thanks! Lol na not even remotely easy but it's ok. I'm just hoping all the effort is gonna pay off the way I'm expecting. I think I have an old tire plugging tool somewhere I might try that seems to be the same basic idea
Don't expect real gains in torque or HP without other mods to back it up, but it should run nice and smooth on and off idle and have good throttle response (you gotta do your intake manifold yet!) You'll probably go back over it one or maybe 2 more times before you deem it 'finished'. I put about 40 hours into my head and all the mods on my intake (including preparing it for repairs as the coolant plenum rotted out from underneath which was a common thing to happen to G63B manifolds) and even now I could rework a few minor places I'm not 100% happy with. OCD much? :rolleyes:
Here is what happens when you are bored, in your garage getting rained in at night and don't know when enough is enough -
Attachment 20368
finished the ports and started on the combustion chambers at this point
Oh yea I know it's not gonna be crazy if I put it on now. I mean once I can get everything together I'm looking into cam specs now and trying to get some prices may see about sending the new cam out if possible. I did get some high temp jb weld to work on the manifold that's what I'm gonna work on next. One of the things I want a do is see about modifying the mount for the weber. I'm not a fan of the multiple bracket assembly.
And also wow that's what get when you get bored...I'm a lil scared to see what it's like when you planning on putting the time in loljk but seriously tho those are crisp man
Thanks. That head was garbage from factory and I had already put money into it for reco and machining, so I tried to make the most out of it. I'm not a fan of the big adapter plate either and a Weber install is in the pipeline for me as well - but I had to go and get some obscure weird Weber didn't I... I've been following up on where this thing is meant have come from and it's either from a Monte Carlo or a Maserati (34/34DATA) The bolt spacings are close to the Mikuni so I ovalled out the mounting holes on the carb (blasphemous to hack a carb like this), installed the Mikuni throttle linkage onto it, added a return spring and mount, and managed to get it converted to an electric choke. The real trick now is getting the correct rebuild kit for it as none of the kits have the matching numbers for it. It actually looks very close to what an OEM installed carb would've looked like (gotta dig up my little pocket digital camera and do updates on what little progress I've made)
p.s. my intake ports don't look like they're halls of mirrors anymore as I've lapped them with my home made drill attachment, but I found polishing them first exposed areas that looked distorted and could do with tidying up. They still look shiny but have lots of nice, uniformed ribs in them.
Holy crap! That's nuts man I wouldn't mind seeing some pics of that whenever you get the posted. I hope you can find that kit tho. I got the manifold alternator and ac and bracket off and dissasembled. Gonna clean and modify the bracket to just go over the front cover and hold the alternator. I'm deleting the ac as the compressor is bad and I wouldn't mind more room in the bay the manifold is gonna take a bath in mineral spirit tonight until I get back from work to clean it up.
Just as a little update I have the manifold cleaned up and got the sharp edges and all the rough casting down. Cut the center out where the carb mount was and cut that steel ring out. I plugged all 4 egr ports even where the carb mounts with jb weld and it's now baking. And gonna start painting the head, valve cover, manifold and probably exhaust shield as I'm finished with the porting. Polished the chambers more as well.
I do have a cam question I think I'm understanding that a performance can would effect low end. I'm wondering if anyone would know roughly how much and would a header like from d.g. or even a longer exhaust compensate for that lost low end. What about the flip side...like a stepped down cam would increase low end but what could one do to compensate?? Oversized valves and beehive springs? I'm just trying to get the whole picture of what changes with different profiles of cams and how to make the best of both changes.
There's no free lunches with engine building - everything you do affects the engine characteristics in some way. Depending on the cam and how you've timed it in, it might not have great response below 1500 rpm but will really come to life after that. Headers will help in compensating with low down torque. I've wrapped mine in an attempt to keep engine bay temps down and try to aid cylinder charge efficiency (hot gases move faster - faster exhaust gas exit, less effort to fill the cylinder = improved power) It might change fuel efficiency but allows a slightly more aggressive engine tune, I'll have to wait and see on that one. You're doing all the necessary mods to make the most of the carb, it's gonna be a completely different animal when you fire it up :)
T.E.P. , Scheider, or Oregon that's the question that has me stumped...and is there a difference in cam design for roller and glider type rockers
iirc TimC from starquestclub had contacts that raced NON-turbo 2.6 trucks. Racers r a good source for 'proven' grinds
Schneider came from crower cams. That may have something to do with their inconsistent quality control. Crower sux
Personal experience with Isky cams made a believer out of me
Deltacams.com regrinds dyno'd impressive in DSMs. Crower, Web cams, etc.. for years failed to provide an HKS equal for the DSMs