Performance Regrinds

[Can1991Ram]

I will be talking to a number of manufacturers soon regarding regrinding the 4G63 SOHC camshaft I have on the head I am rebuilding.

I'm unsure if the 4G64 SOHC cam will interchange (I know the 4G63 has lobes for fuel pump and jet valves)

I plan on going Turbo with mine eventually but I will be N/A to begin with.

As you need to make a tooling lobe, I hoping they will make it available to other members of the club.

My question to I'm looking for maximum lift and duration that can be reground from my cam as I am try to maximize power as my truck is a toy.

I will also get suggestions on springs that will be needed.

Anyone else interested in this project?

[geezer101]

Rules of thumb with Mitsubishi engines - you want duration, not lift. Big lift can kill power in 4G5X/4G6X engines. If you go turbo, more valve lift will become less relevant. I wonder if there are specs for RalliArt cams floating around somewhere...

[Can1991Ram]

Remember the very SMALL lift increase you will gain from a regrind. I agree the duration gain is certainly what I want, but certainly lift is a bonus on the base circle regrind.

I'm curious why this would be a rule a thumb? I have ported the head for better flow as well as it will have raised compression from the head being milled. I'm unsure why increased lift would hurt a modified version of this engine.

[dash]

waste of time concerning youself with duration and lift 'numbers'..... they don't mean anything
Your biggest challenge will be finding a cam that actually works..... Such an obscure motor lessen your chances alot more
U get a 'grind' from a master profile + questionable quality control + no R&D/feedback = a dice roll at best.
Most likely you'll order a cam, but get the 'shaft'. Seen it waayyyyy to often
As popular as DSMs are, Crower and Web failed to come up with an HKS(the benchmark) "equal"..... even copying didn't work
Years later... I believe someone got Competition Cams to deliver for the DSM
Deltacams also proven performer in DSMs as a lower cost HKS alternative. Forums have threads on the subject
Delta would be my USA choice to try a SOHC regrind
Schnieder most popular for 2.6 starquest. Mixed results, majority suffer same torque nosedive as stock cam dyno
One member actually had to twist Schnieders arm to redo his cam properly to match cam card specs
Extra effort paid off. Gained almost 100hp, same setup!! So its not like they 'can't'.... its a matter of what the end user will likely recieve in the mail
Rezone from austarion/facebook has lotsa starion experience - consult him for camshaft / spring/ performance feedback
Camtech most popular (HKS Ralliart copy). Wade, Crow and a few others seen in builds
Redzone ran a 2.4 head on his 2.0 staz

My question to I'm looking for maximum lift and duration that can be reground from my cam as I am try to maximize power

Then get straight to boostin. Our quickest 2.6 street starquest went 10.6 ~1999. Pump gas, mpi, T4, stock cam, nos. Still 11.2 no dope

[Can1991Ram]

I have heard that stock cams are not bad under boost.

I'm just so curious how my headwork would be N/A. I suppose I will through the stock cam in and measure the increase in performance between the ported 2.0 head and the stock 2.4 head. I know I will get increased performance from the smaller combustion chamber of the 2.0.

I really hate the part of the chamber for the jet valve. I would love to fill it but I could only image the increase of compression ratio that would bring.. maybe 10 to 1 with it filled?

[geezer101]

Close to it. The port work won't make power (you already know that) but it'll make it more efficient. You will be able wring extra torque and throttle response out of it by tuning it. Using the G63B head has pros and cons. Up the CR = good, smaller intake valve* = good for low down in the rpm range. Not great for upper rpm range. A little fettling off the back of the intake valve + port work will compensate for the smaller intake valve. Normally the cam profiles on lower displacement engines are more aggressive so the stock G63B cam might actually make a HP improvement. A cam is a PITA to swap, but luckily the SOHC belt engines are more forgiving to work on so it might be worth butt-dyno'ing both to compare.

*I'm not 100% on the intake being smaller on the G63B but it's an educated guess...

[Can1991Ram]

Its a 4G63 head