greatskiiiier

iTrader: (10)

whos done it? any gains?

i saw 16rwhp with 1.75 and PRs so i figure .05= 15hp

looked into pricing and 1.75 can be had for $170, 1.85s for nothing less than 450

whats everyones gains with higher ratio rockers?

DONT SAY JUST GET A CAM! its not in the budget yet so im just looking for some hp

Old SStroker

Do your math for 2.2 ratio arms. A quick 150 hp!

It really doesn't work like that.

Save the money you would spend on rocker arms and put it toward your future cam, springs, retainers and pushrods. The stock rockers are more than fine....they are probably better than the aftermarket 1.75's.

allforspeed

iTrader: (1)

i've wondered this too, i think i'm just going to put the AFR heads on by themselves soon since money just got real tight and do the cam later but i have a buddy who has some 1.8 roller rockers he'll give me cheap and was wondering what kind of gains just swapping rockers on a stock cam car would get.

anyone know if the aftermarket ones are heavier than stock ones too since they are stronger??

Old SStroker

Aftermarker aluminum rockers are rarely, if ever stronger or stiffer than stock LS steel rocker arms. Stock LS arms have less moment of inertia (MOI) than aftermarket roller arms which is the thing the engine "sees" in operation, especially high rpm operation. Stockers are also lighter than most aftermarket arms. Hard to believe, isn't it?

Some "ultralight" aluminum rockers have extra machining done to the basic aluminum extrusion which removes material in areas where it really isn't doing anythig useful. That extra machining costs money, so ULs generally cost you more. Compare pics of standard and ultralights from the same manufacturer.

The stocker is cast and has metal placed where it works and not where it doesn't. Those under $15/each stockers are some nice pieces inspite of (or because of ) being OEM parts. It costs about $16/each to have Harland Sharp replace the trunnion bearings on stockers. That's their weakest point. Not every 7800+ rpm LS engine which uses stock rockers has the bearings replaced. The stockers work fine, providing the rest of the valvetrain is correct. The same thing applies if you use aftermarket rockers, but becaue they are heavier, have more MOI and are less stiff, it's more difficult with aftermarket rockers. Read that as stronger, heavier springs, retainers and perhaps pushrods required with aftermarket rockers.

Some aftermarket heads don't have exactly the same geometry as stock LS heads, so you may be forced to use aftermarket arms. Pity.


Jon

allforspeed

iTrader: (1)

thanks jon, that answers every single question i had actually, i appreciate it, stock rockers it is! thats another thing that has me on the fence, i got some cheap AFR 205 heads from a buddy but i really would just like a motor i can put together and never really take apart again so i'm wondering if perhaps some cnc ported 243/ls6 heads may be a better choice for that due to the rocker geogmetry, since i don't really want to buy a set of 800$ aftermarket rockers that will probably require more maintenance anyway, i know the AFRs would probably make maybe 15rwhp more at least than the 243 but im strating to think that the hassle and the additional 1000$+ is probably not worth it.

thanks man

Old SStroker

No offense to AFR, but if you can score a pair of used 243s for a reasonable price, the corrcet valve job, a little milling and the right springs and retainers (and maybe valves, but often not necessary) you can see significant power improvement for a reasonale price, especially with the right cam. Stock rockers work just fine here. Call it a "Stage .5" head.

Jon

allforspeed

iTrader: (1)

yeah, i'm positive i can sell these AFR heads for more than i paid for them and i see stage 2 ported 243 heads on the classifieds brand new for 1000$ or less all the time and i paid nearly twice that for the AFR heads i have, that extra $1K could probably put to better work i think. the more research i do the more i think i will end up doing the ported ls6 heads. have till summer to finalize my decision but thanks for your help man, that is good stuff to know. save me from making expensive mistakes! haha
i'm going to have a custom cam made for me too btw. if i make 430rwhp with a smallish cam i'll be very very happy too.

total setup plans are now:

cnc ported ls6 heads or the AFR 205's (leaning to the ls6 heads now)
custom cam in the low 220's (have to pass CA smog)
MAC mid headers with better "Y" welded into the Y pipe
ASP pulley
FTRA
FTRA 90mm lid
85mm MAF
ls6 intake with ported 85mm TB or a FAST 90/90 if i find a decent deal before summer
flow matched injectors
cut out (and magnaflow catback)
aluminum flywheel/ls7 clutch
C5 z06 rims
stock 10 bolt for now

i think that about covers it

and all port matched/put together right/professionally tuned

plus i have a 100 shot on there too.

allforspeed

iTrader: (1)

reliability if FAR more important to me too than squeezing every single horse power out of the setup since its my only car and my only ride to work. i have a race car too so just looking for a fun street car rather than trying to set new records or anything.

Old SStroker

Do your research on who should port your 243s. It's easy to screw them up. I also wouldn't buy "ported" heads from someplace like ebay. "Pig in a poke" comes to mind. Used, unported 243s can sometimes be found for a reasonable price on ebay, however. Check with your head guy, when you find one, for a quote on what it will cost to do a set of used 243s.

Good luck with your car.


Jon

allforspeed

iTrader: (1)

thanks man, yeah, i'll just go with one of the proven sponsors on this board, probably texas speed. i'm not really trying to pinch pennies too much anyway. the funny thing about being cheap is that it usually costs you money in the long run.... haha....

Old SStroker

Ain't that the truth!