Thread: 572/620 hp How high can it rev

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I have a 572/620 h.p gm crate engine. I put a 1000 hp Holley on it. Using it mostly for drag racing. Does anyone have any experience with this engine as far as what it can safely rev to. GM says 6000 rpm. It has a hydraulic roller cam
Thanks,Terry

In its OEM trim I would not run it past 6000 rpm. The manual probably lists predicted valve float speed just above that (maybe 6200 rpm?) but in any case the torque curve has a negative slope up there so power gains are minimal ...............

Kitz

Piston speed is what limits long stroke motors. It takes super exotic materials and coatings to rev much higher.

That is about the same piston speed as a 350 chevy turning 7700 rpm.

Yeah, just because they can wind out a NASCAR engine to 12,000 and a F1 engine to 18,000 rpm I wouldn't recommended on just any crate engine, especially one put together GM's PPD. 6000 - 6500 would be about it, anything more and it might be headed south.

i tell you a McCarthy Performance 572crate engine can go way past 6500i keep telling the customer to look at the valve springs every now and then. a hyd roller cams do not like going past 6000 .they can be if set up right there some new rollers that can take more spring or use a rev kit to hold the lifters down .but they are not set up for more then that rpm in the GM crate engines there is on need to take it there if it not making any power your just beatting up on parts

Originally Posted by Flipper_1938

Piston speed is what limits long stroke motors. It takes super exotic materials and coatings to rev much higher.

That is about the same piston speed as a 350 chevy turning 7700 rpm.

no it is not as bad as you would think .but i get a kick from the sbc guys that say a bbc can not rev i have had some 468. 548. and a 632 rap like a chain saw .parts have to be good. but not exotic materials. you just have to know how to put them together

Higher RPM may not be the key to power on your crate engine..... Best bet would be to dyno the engine and see where the peak torque and horsepower is.... and as Pat mentioned, the hydraulic rollers are pretty much done making power before 6,000 anyway.....

Oh yeah........Can rev and should rev are two different things.

your 572/620 would have to be recam with a solid cam to find more rpm .but GM put the crat engines together with some parts that i would not use for hi rpm and i would take the engine apart and check all size things need to be dead on were they may not be so /so .i used alot of rods your engine has .the crank block will take hi rpm. things do not need to be coated that only slows things from welding .together.. if things are not right it is not going to help much from what i seen i used coatings on some parts my feelings on some of this stuff is mixed .i can show you cranks and bearings out of 8000 rpm500+cid engines on spray that look very good . like use them again good.. .oil is the big deal were it is going .and how good the oil is .the valve train will stop you from going were you want in rpm s the hyd lifters are very heavy so big springs can help .there is now a howards pro max hyd roller lifters that can go past 7000 rpm and will take the seat lbs 225and 575 open max some have used rev kits to help keep the lifters on the hyd cam .so a custom hyd roller and you could push past 6000.but i would look over your valve train well . i build a far amount of bbc .THE LINE OF COULD AND SHOULD that line seam s to be very thin .street hyd rollers are fine . if you are keeping the rpms low the hyd roller can do a good job .for guys that tell me if its still going to pull i am going to take it there.. well they get solid rollers.. you need to keep up on the valve train . i use hyd rollers for the street. for mud and drag cars and rev heads solid cam engines .alot of were things go south fast is the upper end