Not all OEM blocks have the same amount of material between the bores. So there is no clear “limit”. Many have made more than 1000WHP on factory blocks. I’m not saying you can’t. I’m saying it is the weakest link assuming your running a beefed up rotating assy. Makes no sense to hog out the cylinders more if you don’t have to. Engine will have more potential with added block strength.

I believe Kurt Urban said around 1200whp the factory crank flexes pretty good. I’d think tons of other factors would come into play, but would want to steer clear of that area personally.

That same 370 block pictured above ran OEM crank and aftermarket pistons/rods. It had crank run out issues and beat up the bearings. The rods and pistons checked out good. Was Zbrowns engine I’m sure you could ask him about it. He would be able to tell you more about it than I could.

 

I thought this was Zbrowns LS3 block?

 

Was a .030 over 6.0 iron block.

 

on 1000+ whp what about 1/2 block fill on good (i.e sonic tested) 6.0 (with required oil cooling) for reliability?

Also, make sense to run motor plates vs mounts to minimize cylinder distortion?

Lastly, pin the sleeves/water jackets to eliminate the 10 a clock top sleeve failure?

Not trying to hijack just some mind rambling on stock block reliability. Don't know if Skinnies, Stock48 or others been down this road.

 

Marketing probably plays a part in the stroker market. Stroker kits are cheap and every where. A good stock stroke crank or short stroke is expensive and hard to find(long wait). Some where in China a village is making 4" stroke ls cranks by the Ox cart full.

 

top fuel dragsters are boosted. why does Nhra need to limit displacement to 500ci and why in the world don't they run smaller engines if it makes no difference or all the power is in the boost?

because boost is not a replacement for displacement when all else is held equal. you guys saying certain blocks or bore and stroke combos hold boost better even if it's less ci are not holding all else equal, which clearly removes you from the scientific world and makes your comments null.

you cannot accurately compare a variable unless you hold all other variables equal. more cubic inches moves more air per rpm no matter what else you do to the engine. this is one of the simplest things to understand. if you want to talk about "not needing" the displacement to hit a certain power level, that's fine, you don't need mammoth motors these days to hit numbers like 1000 or even 1500.....but that doesn't cancel out the rule that a bigger motor is going to make more power.

the only argument you can make is the physical limitation of larger heavier internals being rpm limited and saying rpms are a replacement for displacement once you hit the physical rotational limits of heavier parts.

there is no replacement for displacement is a theoretical argument that you have not and can not disprove. all you are making is a practical argument, that I don't disagree with, that you don't necessarily need the displacement to hit your power goal.

 

So anytime the "power" discussion is had between a FI 370 or 408 comes up..... when the 370 guys realize they've lost the arguement, it quickly turns into a "durability" discussion.

What where we discussing here? I forgot. lol

 

If your on a budget build a 370! If your not build a 408.

 

What thread are you reading?

 

If I could do it all over again, I'd go 370 ci all day long for my TT build.
I have an iron 408.

Mostly because of the 2618 piston material that needs much more clearance as well as the side skirt issues. The torque is nice, but like everything, a well thought out setup will make that 370 do nasty things. And, you "Could" potentially get more reliability out of that engine.

 

I have a 370 and twin 6262s.. setup will be on its 3rd season, certainly is reliable and makes damn good power.

 

How much HP is the 370 with the 6262's making?

 

Mark's notchback had a 403 And went 7s for a while after going 8s with a smaller turbo for a long time so I wouldn't say a stroker is unreliable.

 

Made 803 on a dynojet on 12psi and 848 on a Mustang Dyno at 17 so your guess is as good as mine. I currently have a 225/225 cam in it, bigger cam and bigger injector this year, so hoping for more.

 

A 2700lb mustang not blowing up after a few great runs doesn't count as "reliable" in my book. The blocks not going to live long at those power levels reliably IMO. The point is with a factory bore/stroke the same power (or more) could have been made with less worry of damaging the block.

 

Definitely respectable numbers from your 370 but, just think about a 427 with all the proper guts such as one from ERL or other reputable builder, a couple billet 7575's on the same amount of boost. Your "damn good power" just shot up another 30-40%...

 

Im not looking to make 1500 rwhp nor spend another 20 grand lol.... my long block cost me $4500.