I'm not claiming to be an ex expert by any means. Just stateing that upgraded valve, springs and a cam that would make power that high up in rpm is definatly do able. It was a race car and probably had less than 5k miles put on it the 2 seasons I raced it. What needs to be done to a c30/32 to be able to rev and make power to 8500 rpm? I have seen more bottem end failures out of the c series than I have out of the j series. I'm sure there is more to it than just rev amount, but does the 90 degree vs 60 degree have any benefits when it comes to the strain on the pistons/rods/crank?
I think the C30/32 will do 8500 rpm now if the fuel shut off would allow it.
It's an engine configuration that is designed to rev high with acceptable stresses.
In Jon Martin's 3.8 liter engine the stroke was only 88 mm, so piston speed at 8000 was much less that a J35 or J37 with their longer strokes.
Jon said he felt the biggest challenge to overcome making power with the C30/32 was improving the ability to get more air/fuel in but rpm was not an issue.
No question improving an engine's ability to breath will increase power and much work has been done to make power in this area alone.
If we look back at all the work done to small block Chevy's over the years, the first things builders did was install more cam, large valve better flowing heads, and stronger valve springs, all designed to increase the engine's ability to pump more air/fuel mixture and rev higher without valve float. After those gains were made then work might be done to reduce reciprocating mass and beef up the bottom end. But if a built 5 liter (4"bore x 3"stroke) Chevy small block could be revved to 8000, piston speed was only 20 m/s- less than our C30/32.
Perhaps the reason more C30/32 engines fail is because builders are adding stress through forced induction or longer stroke causing the engine to run closer to its design limits.
I'm not aware of a large number of stock or near stock C30/32 engines failing unless they have had significant mods. but I'm not an authority on this for sure.
My understanding is a V6 engine can't be balanced because of the odd number of cylinders on each bank. I've read however that 60 degrees offers a better balance than 90 degrees. Our C30 90 degree has split crank journals to mimic a 60 degree firing order.
Your J35 at 7150 rpm has the same piston speed as the C30/32 at 8500 rpm.
I suspect the C30 has a lower reciprocating mass as well
If you could get your J35 to 8000 rpm through breathing and valve spring improvements you will have racing engine piston speeds. At the 8500 you say is possible with breathing you are at NASCAR piston speeds.
At 8000 rpm or more it would seem you would need to do what Honcho suggests and reduce reciprocating mass as much as possible because of those very high piston speeds and stresses inside the engine.
Probably better to go with a lower revving boosted J35/7 ,than trying to make a low rev engine design into a high revving engine
