Let's talk 318/349/390 strokers.

MoparDemon said

Great thread, ive been thinking about the 390 as well, ive read that because the 318 bore is so small any intake valve over 1.88 will give it a shrouding affect being so close to the cylinder wall therefore losing power or just not making what you expect with the big valve heads..so my question to you is when making the 390 does this rule still apply??

Click to expand...

The bore size is exactly the same whether its stroked or not so, yes, there is some shrouding with a 2.02 intake BUT all this really means is that the heads will not flow what the flowbench says. However, on a 390 or even a really stout 318 the 2.02 still has its advantages. I'm using 2.02 intake RHS heads on a 390 (.030" over for a 3.94" bore) and notched the top of the bores for more clearance. I chose to match the bore tops to the combustion chamber shape reasoning that eliminating the step would be a good approach in the absence of being able to test different ideas back to back.

All I need to do now is find a head gasket with exactly the same shape...:-k