3.2/3.5 advice

[Jnikic]

Purchased a track toy recently with a rebuilt motor and it turns out that what I thought was a 3.2 is actually displacing 3.5 liters thanks to 100mm cylinders and JE pistons. During the build, Pauter rods were installed, the case was boat tailed and 46mm webers were added. But the stock cam was left in, as a full race build was planned for a later date. For a car that will take on more of weekend driver role, what kind of cam (if at all) would you run? Any other mods I should consider at the same time? Not that I want to spend the money, of course, but ...

[lindy 911]

More info please: if it's got stock 3.2 cams with carbs and JE pistons (CR?) seems like something with some more lift and overlap (GE60) would really wake that motor up. Make sure the springs and retainers are up to the task but the sky's the limit with cam choice.

Give some more detail and you'll get better answers:
1. Compression ratio
2. Head type
3. Ignition system
4. Exhaust
This info will help others help you.

Lindy

[Jnikic]

Lindy - Thanks!

I'm afraid I have more to learn - both about the motor itself, and about motors in general - than I have answers to lend. Most of what I know about the motor is from a conversation with the shop that built it a few years ago. What I can answer for though:

1. 9.5 or 9.8 (This from the shop that built the motor, he doesn't recall specifically. Is there a way to check without opening the motor?)
2. Need to check
3. Need to check
4. SSI

I'm going to see if my mechanic can confirm the rest easily; he's currently rebuilding my carbs. The good news is that he also checked into leakdown/compression, and both were very good (5% / 225 respectively).

[KTL]

Agreed the original 3.2 cams are not doing that engine any favors. One of the great benefits of the Weber's 6 individual throttles is being able to run a more aggressive (overlap) camshaft. However if you want it to remain pleasant for street use, you don't want to get crazy with th cam.

Guys here can provide a lot of very helpful advice when they know what your current setup is and what changes you plan to make. Lindy asked for the right information. Take a closer look at the engine and see how many spark plugs it has. With the Webers, odds are the ignition system is not original. Do you still have the mechanical ignition distributor installed?

The general consensus is going to be that your exhaust is a bit of a bottleneck too. Typically the SSI headers are good up to 3.0L or 3.2L. Beyond that displacement, the SSI is a slight compromise- good low end torque but you begin to lose top end due to the relatively small primary pipe size. Point being is a larger set of headers will benefit your cam change.

[Jnikic]

Was hoping to bring this back to life. Thinking more seriously on a cam recommendation with winter not so far away ...

Details: 3.5 L / 100mm cylinders and pistons / 9.5:1 compression / single plug / crankfire-type ignition / SSI's with a Monty exhaust

[otto in norway]

Check with dougherty racing cams. Send him the information on the forms you'll find on his website. He'll give you a straight answer. And he can grind your stock cams to your desired profile too...

[lvporschepilot]

+1 with checking with Dougherty. I'm thinking DC20 though. Not really enough compression to go much higher.