Question on 3.5 N/A build-up.

[drummer323]

Looking at taking the turbo 3.3 case, oil pump, crank and building a larger displacement going n/a. I know in the book it states to use 100mm pistons but can you safely go 102mm? I plan on using all aftermarket studs, perfect bore cylinders, je pistons, carrillo rods, probably s cams unless a better suggestion on cams , its heavy street driven (street raced) twin plug 3.2 heads and pmo carbs, headers with no heat, no smog requirements here. Any advice? Thanks, John.

[Steve@Rennsport]

Hi:

Make sure you have twin-ignition to run those big-bore motors on pump gas and use the Webcam 120/104 instead of the "S" cams.

[Porschekid962]

Just went 3.3 already thinking 3.5

Just built a 3.3 motor with 100mm bore. Going larger on an older case leaves either very little material left on the case spigots or you end up with a very thin cylinder skirt. I think that Andial did something like this with their 3.7litre engine.

[cnavarro]

I have made a 102/106.5 3.7 cylinder and have sold quite a few sets through various dealers (it's not in the Pelican catalog since they are custom order - I don't stock them, but just call Pelican and ask for them).

The original andial 3.7's use a 107 case register, our most recent 3.7's use a 106.5 case register, since our alloy is very ductile and strong (I have done thinner cylinders without incident). Knowing our cylinders hold up even with as thin as a 1mm thick skirt, I decided to leave extra material in the case.

What I would not do is run a turbo on the 3.7s since there is no room to flame ring and I would highly suggest twin plugging as a must.

I have done some single plug sets, but the highest compression I have done in that case was 9.3:1.

[Facey]

i am running a n/a 3.5L using a 3.3L turbo case and oil pump as the base.

100mm mahle P&C's, enlarged 3.2L heads, twin plugged, crank fire ignition, 1 3/4" headers, 46mm webers, carrilo rods, raceware bolts etc, etc....

i am using an S cam, however i would suggust something with a little more top end. The torque is VERY strong from early on, however i would be willing to loose a little to gain some at the top...not that it peaks too soon...but rather i wouldn't mind a surge 5000+.

great engine, allows me to keep up with alot of car that used to be in a different league.

[drummer323]

Thanks for all the replies. I've been doing some study of various engine combo's and I like this set up the best. What type of exhaust are you using? Using a G50 or 915 or 930 4spd tranny? I'm considering the 930 short bell-housing tranny and a good clutch package.

[Facey]

i'm using a recently rebuild 915 (5 speed, stock gearing....lots of fun with new power!!). I am using ....someone's stage 3 clutch, with .....i wanna say a powerhaus (2) flywheel.... could be out of left feild there...neither are stock, been a while... anyways, flywheel is light and lets the engine sing to redline, and the clutch grabs hard and never slips...kinda hard to do hill starts....


right now i am running 1 3/4" S.S. B&B's with heater boxes, the long collector version.

they are VERY nice, and are for sale....mostly because in my mid-year these headers don't allow for a proper muffler...not an issue with later cars.
-looking foward to following your build