boldguy

The Car: 1992 Chevrolet Camaro 5.7L Speed Density, manual 5 speed. 3.42 gears. air intake headers exhaust, "bigger than factory injectors", 91 Corvette Aluminum Heads. 1.6:1 Roller Rockers. the works*
i have been shopping for THE CAM for some time now and i have narrowed it down to these. I have looked at all the companies and these two really seem to know their stuff especiallly TPIS. Even their name says it all. anyways here they are let me know your thoughts and If you know of a better suggestion dont be afraid to share!

So Here is choice #1 by Lunati

Part Number: 54779LUN
Duration @ .050 In/Exh: 215* / 224*
Valve lift w/1.5:1 Ratio: .489 / .489
LSA: 112*



and here is choice #2 by TPiS

Part Number: ZZ9
Duration @ .050 In/Exh: 212* / 226*
Gross Lift: .483 / .520 (What is Gross lift as opposed to valve lift?
LSA: 112*

Does anyone know off hand if the TPIS specs are for factory rocker ratio?


Thanks to anyone who Shares
Boldguy

Kevin91Z

iTrader: (1)

Is the Lunati a roller cam? Either one of those will require custom chip tuning to optimize the combo, dont forget. You can also go with the Comp XFI268HR-113. Both of the ones you listed are for the stock 1.5 ratio rocker arms. But the Comp is rated with 1.6 rockers.

What springs do you have on those heads? If they're still stock, you're going to want something better. Let me suggest Manley 22410-16 springs and 23652-16 retainers. They'll let you run cams up to .550" lift and bolt right onto those heads.

Grim Reaper

Sorry, but TPIS is overrate and overly expensive. TPIS is very helpful and knowledgeable until they get your money.

I forget the part number but Comp Cams have a 218/224 with a 112* LSA Roller Cam that will perform better than either of those cams and availabe at a much cheaper price from any of the major parts dealer (like Summit Racing...though I am not suggesting them). But if you are interested in the Comp Cams 218/224 112 LSA Hyd Roller Cam, I'll dig up the part number for you. Or you can just call up Summit Racing and they'll give you the P/N and price.

BTW, you don't mention your intake, but regardless of ANY cam, you really need to do something with the intake or you'll hit a "brick wall" at 5,000 rpm and your power will die off faster than ...

PS: Kevin is correct on both the springs and eprom - regardless of cam selection.

boldguy

DONE! i am a click away from ordering the 268XFI HR13, however the lift on this one is .570 / .565 !!!
this shouldnt be a problem right? now with the springs, the springs are new, but they are stock replacement style. I think i am going to go with the 26918-16 beehive style springs/retainers. What is the point of these besides "Better Harmonics", is there that much of a diffference?
sorry for all the noob questions, but once i find this stuff out i can help out the next noob
Thanks once again guys,
Boldguy

formula_novice

iTrader: (1)

The 268XFI is rated using 1.6 ratio rockers. If you are using "factory replacement" springs, they will not handle the lift.

Best of luck!

boldguy

Yeah im sold on that cam. im gonna get the new springs and these 26918-16 beehive springs/retainers were the ones they suggested. should i get these or something better. i do like the manley ones you suggested Kevin91Z. but i think i want either dual springs or behive...
thanks for the help all.

boldguy

I have decided to get these products from CompCams:

08-466-8: 268XFI Cam
28619-16: Beehive Springs/retainers


the lift on this thing is .570/.565
that better work. everyone ive called says yes that should be no problem...
but its not their money/time/engine .
Thanks again ALL
-Boldguy

jamon8

iTrader: (3)

are those corvette heads cut to handle that much lift?

guide bosses and pushrod hole!!!!

boldguy

thats MY question! lol

Both lunati and compcams said it shouldn't be a problem...

jamon8

iTrader: (3)

have a machine shop measure

Kevin91Z

iTrader: (1)

Definitely measure your retainer to valve seal clearance. You might want to get +.050" locks to give you some more room. The biggest cam I have run with ZZ4/L98 heads is .541" lift.

Not to scare you away or talk bad about the Comp beehive springs, but Allen (1989GTATransAm) just replaced his Comp's with Manley 221428's, and after less than 3000 miles, his Comps went from 130 lbs seat pressure to 100 lbs seat pressure.

boldguy

ouch. i knew they were too good to be true.
i have some questions for you Kevin. ill pm them to you later on in the day.
thanks again.
Boldguy