slp97camaro

just as the title says, im trying to figure out which cam would go the best w/ the afr 227 heads, i was looking at the comp cam 300br-6, but i dotn know much about this stuff. any help would be appriciated!

96capricemgr

How can you expect an answer when you don't evn offer displacement and if the answer to that is stock then DO NOT USE THESE HEADS unless you want to spend a lot and end up slower than the guy who just ported his stock heads.

Honda Hunter

When should/could someone get these heads? Unless his sig is outdated Im thinking a 350.

Kevin Blown 95 TA

Straight from the AFR catalog -

"350-434 cid engines in drag cars, sprint cars, and late model oval trackers operating from 4500 rpm and up."

Does that sound like how you are going to drive your car?

rskrause

To make use of those heads you will need high static CR and a big cam as well as a good intake. The fewer cubes you have, the more rpm you will need to turn to make hp. This will influence cam choice, as others have suggested. I suggest you get your parts from someone like Bret Bauer who will then be able to advise you on component selection.

The combionation needed to achieve your goals is what you need to concentrate on.

Rich

LT193

Im really unclear on how heads determine RPM range, i just cant see how this would really be that big of a factor. Isnt the cams Duration all about what RPM to use? I did not think the heads had anything to do with that. Maybe someone can help elaborate on this, im lost lol.

Kevin Blown 95 TA

The port size makes a difference in the velocity of the air going through the heads. Smaller port, more velocity. You want velocity, swirl, and good combustion on a street car - that makes more power. If you can get smaller ports that flow good, this is what you want for the street. Otherwise, when you're just driving around town, or cruising around at low rpm's the velocity through the heads will be slow and the car will seem lazy and unresponsive, mileage and torque will suck. If you are at 8000 rpm with 227cc RACE heads, then you want all the flow you can get, and this means bigger ports, big valves, and a longer duration cam, and a fancy and expensive valve train. Smaller ports and smaller cams are for lower rpms and better for the street and a lot more fun to drive - just look at all the low end torque the TPI cars had. Heads & cam, Intake & Exhaust all work together as a system. It's a big mistake not to match the parts to eachother and to the intended use of the car.

Honda Hunter

So what would be the better street AFR head?

LT193

How about this combination then, AFR 220 CC heads, and a 222 230 cam with about .600 lift. Even know the AFR heads flow exceptionally well at like .300 i guess there ports are to big for this? I mean if the cam has a small duration then it will technically idle well, so to me its hard to see why a head will make bad low end torque if the flow numbers for the head are the same at low lifts. Especially if the cam is low duration meaning it will respond well to lower rpms because the air wont escape through the exaust valve. When overlap is low and LSA is around 114 or even 112. To me in my head its kinda like why not have the bigger flowing CC heads with a smaller cam for daily driving. If u could clairify again that be great, thanks for the reply.

Kevin Blown 95 TA

You're mixing up volume with speed. Flow is a volume over time (cf/m), velocity is just how fast it's moving (f/m). In the old days, if a guy had a 650 double pumper, a dual plane manifold, stock heads, 1 1/2" headers and a smallish cam, he would have a torky fun car, but if he put a dual 6oo tunnel ram, lopy roller cam, 1 7/8" headers and p&p heads, that thing was a dog for 98% of his driving. Also, in your case, if you have an automatic, you will need more stall and a gear to run a setup like that. You have to be honest about how the car will be used, then set it up to work in the rpm range it's geared for. Having a broad torque band is what you want. That makes a lot of average power.

rskrause

This may help: http://www.highperformancepontiac.co...hpp_part2flow/

Rich

96capricemgr

For stock displacement stay with ported stock castings, even LT4s are overkill there and would require too high an RPM to make them really work, AFR offers nothing I would recommend on a stock displacement motor. Even on a stroker for all but a wild one the stock heads can be reworked to be great, LT4s being the next step, wouldn't recommend an AFR for most driven strokers either. Once you get into all out race car then maybe look at their stuff and having it competently reworked NOT their CNC porting.

slp97camaro

ok so what setup would u guys go w/? what heads and what cam? im looking for around 450-500 hp if i could get that? i dont wanna do a whole stroker kit, cuz i plan i doing the head and cam while the engines in the compartment. like i said, i dont know much about combinations w/ heads/cams so thanks for the help

96capricemgr

There are several shops that frequent this forum who can get you in that range FLYWHEEL on a stock bottomend with a set of 95 or earlier heads. Your heads flow more stock but are less desirable for porting.