3.2 Short stroke and 3.6 short stroke

[daloff]

I have a 3.2 short stroke race engine with 98mm pistons and rsr sprint cams. I also have a 3.4 race engine with a 3.2 crank 98mm pistons and elgin 100 cams. The 3.2 short stroke seems crisper while not as torquey as the 3.4 I like the 3.2 short it seems to run better.

My question is will I get a similar effect by using a 3.2 crank in a 3.6 case with 100mm pistons and similar type cams ? Also will there be a "significant difference in overall performance from the "3.6 short stroke" or is it not worth it at all ?

Cheers,
David

[camgrinder]

I am curious about the compression ratios used in both engines. What induction system are you running?
The RSR Sprint cams are similar in duration to the 100 cams, but the 100's have more valve lift and area under the curve.
With the short stroke 3.6 litre I might choose our 314/296 cam on 104 lobe centers. This camshaft gives similar top end HP, but a wider more usuable powerband.

[daloff]

Compression in each engine is 3.4 ~11.3:1 the 3.2 about 10.8:1. Using PMO 46mm Webers. Probably could go to 50mm.

David

[camgrinder]

Our cams would benefit from more compression and the PMO 50's.
I also like the wider lobe center 314/296 grind with the PMO carbs. 104 or 106 depending on the powerband you want. I would expect the driveablity to be much better.
How are the cylinder heads prepared?
John

[daloff]

John -
What information specifically on the heads are your interested in ? The valves are 49 intake and 42 exhaust. What else ?

Thanks
David

[camgrinder]

Just wondering if the heads had been modified more on one engine than the other.
Do you have two cars or have the engines been swapped in the same chassis?

[daloff]

Heads are basically the same on both engines. Have one car that I swap the engines.