Looking at building either a 604 or 572, 4.5 vs 4.75 stroke. I have an Indy block and maxed out -1 Indy heads. Which should I go with and y. How much better would the 604 run or would it not really because the heads r to small?

I know what a lot of guys will say that the 604 over the 572 is a waste of money using -1 heads, but it really depends on your combination.

Me, I like the more cubes idea, and the way we run leaving at only 1900 and shifting at 6400 and running 9.81 on pump gas with just a 512 says anything, I am going to go with more cubes...If you prefer not to rev it as much.

I went to the 605, why not go as big as you can. Mine is head limited but still makes 853hp@5782rpm and 818ftlbs@4818rpm. It's a monster down low to the shift point.513hp and 764ftlbs@3500 rpm. It hold 800+ftlbs from 4100 to 5500rpm. It runs on 89.5 octane and never needs to see more than 6500rpm.Dave

An engine is an air pump. The bigger the pump, the more air it moves............IF the heads will flow the air into the pump. So, building a pump larger than your heads are capable of feeding is a waste of time. Stroke adds more swept volume to the cylinder, but bore size HELPS the head, by unshrouding the valves and helping it move more air.

So.........what should you build??.........The answer is,how good are your heads??

Monte

What do you heads flow?

What is the application and expected rpm? Is there bigger heads in your future? The general consensus is maxed out they will flow around 385 at .800".


IMHO They are both bad choices for -1's. The biggest I would go would be a 4.5" bore 557.


I ran a 572 with maxed out -1's for a few years making 940+ BUT. Your going to need to keep rpm's below 7k, most likely a SM intake, and a custom cam that makes the engine think the heads flow more. Jetting is fun due to the air speed.

They flow low 380's if I remember without looking at the sheet. I all ready have them so I'm gonna use them. I would like to run -13's or b1's some day but for now all I need to finish the motor is a crank and pistons. Also gonna have bullet grind a cam for it.

Would fully ported B1MC heads support a 604?

My 440-1 528 cube motor , single Terminator on alky has gone 8.77 at 153 carrying 3000 lbs, and did it with a roller of 280/288/110 duration, at about1600 Da. Max shift point is7100. You can build it as big as you want but it might be a good idea to keep piston speed in mind. I would think anywhere from 528 to 557 ought to work very well and be a decent split between piston speed and valve train speed. Either can cost you.