Thread: Whats The Total Camshaft Lift You Can Run?'s

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OK since I'm asking questions I'd figure I'd ask one thats been buggin me for awhile. Is there a downloadable list out there for chevy that tells you whats the Maximum amount of lift you can have on your camshaft while running a stock head (with stock 1.5.1 rockers for SB and 1.7.1 for BB). I know this will probably be different with different years and sizes of motors thus the wondering of a Magic list. Thanks for anyone that can point me in the right direction. I don't wanna smash a valve with a piston but I want to get as close as possible safely.



Mike....

only way to know for certain is by measuring the clearance. Theres more to the problem than just lift, duration & overall valve timing are as much a factor. you could have 2 cams with same lift, but differant valve timing, 1 would work & the other may not. & of course it has to do with what pistons are in it, what head gasket, have the decks been milled, or the heads shaved..all these are an issue.

Yes all those would be an issue and would either raise or lower the valve. But is there a list if you were to install a cam into a tottaly stock engine where all numbers should be identical and not changes since they should al come the same from the maker?

no...like I said2 cams with the same lift...but differant duration & valve timing will have differant piston to valve clearance.

generally speaking, for a stock chevy street head with the 1.95 intake and 1.5 exhaust valves .500 lift is the max you can go, because of stock port and valve restictions combined with the low to midrange engine revs required for street driving. Sure you can go to higher lifts but the ports just wont flow the air and you will wear out the valvetrain faster with those high lifts.

Is that .500 lift also taking into consideration the rockerarm lift or 1.5.1 which would be 1.5.1 X .500 making .750 total lift.... is your .500 the total lift or the cam lift alone? thanks guys this site rocks...


Mike

Also how much lift is needed to get your engine to lope at idle, (well a very good noticeable lope) gotta love that lopeing sound (Romp, Romp, Romp).



Mike...

Originally posted by Gyva
Is that .500 lift also taking into consideration the rockerarm lift or 1.5.1 which would be 1.5.1 X .500 making .750 total lift.... is your .500 the total lift or the cam lift alone? thanks guys this site rocks...


Mike

generally when we talk lift, we talk total lift at the valve, so i'm refering to .500 total valve lift for the street. Incidentally, while talking about lift, you see camshaft manufacturers bandying lifts of .480 and .493 and .497 and so on, a difference of a few thous either way of these figures is broadly speaking not going to affedt performance all that much anyway. Now having said that, lifts up to .025 lift difference either way will make a difference in performance and wear characteristics.

Now i'm going to ask you a question, what type of moter is it ? you know BBC or SBC and is it intended for the street as fast transportation, as your sole means of transport or is it a recreational dual purposec vehicle. (fun car to drive )

GYVA, lift doesnt have much effect on idle quality..duration & valve timing have a much larger effect on idle.

Just a normal chevy 350 thats going to be a half and half, its going to be for transportation but also going to be a FUN car to drive... I'm thinkin about bolting on the Edelbrock pro ram II tunnel ram to it too that I just bought.... I just wanted to pick a gutsy cam and I don't care at all about gas mileage. I'll probably put either holly 450's for edelbrock 500cfm carbs on it. now I do love that lopeing sound so if its possible I'd love to pick a cam to settle that desire as well... .



Mike...

Okay any idea what the compressio0n ratio is ?

Stock compresson I'd assume, flat top pistons. now stock is 6 to 1 or is it 7 to 1 in a 70's t0 80's chevy 350.


pull a plug wire huh???? don't tell someon who drives a rice rocket that he'll believe ya....... lol....

now I'm assuming that compression ratio.... not stating as fact as I dont know lol....

OK IM done

okay here are 2 of cranes older grinds that may work with your combination, It will pay you to check with their help desk. So have year of car weight final gear ratio auto or manual torque converter stall speed tyre daimeter compression ratio and induction plus headers and type of exhaust system.

part no 11382 Blazer 300h

part no 114561 CCH_304-2-NC