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Dec 25, 2003 | 11:48 AM

GrapeApe

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From: Brew City

cam question

lookinhg to up my cam a lil --I have a custome grind that is working real well
i want to keep the specs close to what it is now but i need some more Lift
the cam is a lunatti 226/234/558/575@112 now i want to go 226/234/575/592@112 when will i run into clearace problems -and could i get the same effect out of a diff raitio rocker?

Dec 25, 2003 | 12:20 PM

jrp

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From: Valencia, Ca

if they make 1.75 rockers that'll put you at the lift you want :shug:. why do you want more lift and what are your other mods?

Last edited by jrp; Dec 25, 2003 at 12:50 PM.

Dec 25, 2003 | 12:42 PM

CAT3

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From: Sierra Vista, AZ

ditto, upgrade your rockers. You will benefit two-fold, better rockers, and more lift.

Dec 25, 2003 | 03:47 PM

GrapeApe

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From: Brew City

Quote:

Originally Posted by jrp

if they make 1.75 rockers that'll put you at the lift you want :shug:. why do you want more lift and what are your other mods?

well i got a weind intake ported heads hooker longtubes 3500 stall
i recently swapped my 2:73's the best i did on them was 11.97@114 N/A i went to 3:73 gear and went 11.80@114 so i'm thinking i would benifit .my car is heavy but the numbers should of dropped .4 with just the gear swap
So it seemed like i was runnin out of cam or fuel on the top - and i could squeek more out of 3rd rather than going into overdrive --i put some 4:10s because i lost my tranny and rear at the same time the night it did 11.80-i only got 4 runs in before it went--i was happy with it before because i could say i'm in the 11's on a 2:73 N/A with stock weight -now since i upped my gear the problems it created suck azz- so I'm trying to find that happy medium again -what would 1.8 rocker put it at? whats the formula ya use to come up with the overall lift-Its been a shhiiitty time -i bought a yank tranny and 3/4 do not work so i'm just a lil peeved at the car right now

Dec 25, 2003 | 09:26 PM

jrp

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From: Valencia, Ca

Quote:

Originally Posted by GrapeApe

what kind of lobes does your lunati grind have? higher ratio rockers are usually only recommended for slow ramp and low lift cams. with 1.8 rockers your looking at .591/.609 which means you'll need new springs. the forumula you use is taking your lift (.558) and divide it by 1.7 (stock ratio). take that number you get and then multiply it by what ever size ratio you want. honestly if you have xe-r type lopes then your better off getting a new cam ground to your new specs as opposed to getting new rockers and springs. it'll be cheaper anyway. cam: 400-425$ vs rockers/springs: 500+

Dec 25, 2003 | 10:42 PM

99 Black Bird T/A

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Quote:

Originally Posted by GrapeApe

the cam is a lunatti
226/234/558/575@112

now i want to go

226/234/575/592@112

FWIW

What type of heads do you have? If they are stock I don't think adding more lift with basically the same will get you much of a gain. If the heads are ported you get a little more but the real key is the valve timing and the duration to making power with a cam not lift. Lift is just a by product of X amount of duration with a specific cam lobe.

226/234 XE-R ~.585 lift/~.600+ with very fast ramps should get some area under the curve.

Also a

226 XE intake lobe would get you more lift ~.568 or so with a faster ramp rate

If your going to do another cam...call Futral or one of the other sponsors and have them make a custom cam for your application.

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