340 or 408?
Ok, so I and others (probably after too many beers) have toyed with the idea of building a high rpm, high HP small block to compete in FAST. The idea being it softens the launch and really comes alive down track, (and might allow for some high end converter magic) but the foundation for a build like that is having the maximum amount of head flow the LA architecture can support. Also with equally capable intake and exhaust components. Which I THINK isn’t possible starting with the stock castings and through x head. I just kept coming back to, I have to create the largest “depression” I can at the back of the intake valve. I can do that by longer stroke or more rpm, but at some point velocity gets too fast and things go sideways. It has always been interesting, but I think the box I’m forced into makes it not worth it. If I can create the same level of depression at the back of the valve with more stroke at a lower rpm, what’s the downside?
I’ve explained it already.
Comparing what the OP wants to a FAST car is a bad example.
The OP has already said he likes his 4.56 gears.
What many are doing is trying to convince the OP he doesn’t know what he wants and that what he wants in not doable.
It is doable and it’s not hard.
Maybe, just maybe he’s a guy that likes rpm. He must because he’s running a gear most wouldn’t even consider.
There are a number of reasons to not build a 4 inch stoke engine IF you are induction limited.
Let’s think it through.
Using a 4 inch stroke with ANY head with non offset rockers makes the engine induction limited.
You can use a tunnel ram but that’s worse than using 4.56 gears to most people. And that STILL doesn’t fix it. It helps a bit.
Let’s see what engines use a 4 inch crank with PRODUCTION HEADS.
400 Chevy 3.75
396 Chevy 3.76
427 Chevy 3.76
454 Chevy 4.00
470 Chrysler 3.91
What do we see? One 4 inch crank. The OE’s aren’t stupid. They are FAR more concerned about drivability than power.
And, a 375 horse 396 had square port heads on it. It’s only 375 horsepower and it needed all that port area.
I forget the 427 numbers but I know a 450 horse 454 had square port heads too.
And none of the above was an rpm screamer.
Look at the G3 Hemi. How much stroke does it have?