i posted this in tech/general engine but i watned some racers suggestions or opioions on this as well. any info or suggestions would be greatly appreciated. i hope this doesnt get deleted i want some more answers. i will jsut post the link to the other post thanks guys.
https://www.thirdgen.org/techbb2/sho...hreadid=344281

 

Heads are what makes power. You can do intake, carb, exhaust, cam and get moderate increases but the biggest increase you can get is with some good heads.

The Canfield aluminum heads on my BBC are out of the box. Nothing done to them. If I ported them out I could get even more performance out of them but they're good enough for me right now.

The amount of power potential from heads has to do with air flow. Theoretically the most HP you'll get out of a set of heads on a NA engine can be calculated based on the air flow.

HP = .2575 x CFM (@ 28" of water) x number of cylinders

Of course the rest of the engine must have the capability of drawing in that much air, mixing it with fuel and igniting the mixture without any problems. Technically the most air/fuel that can be drawn into a cylinder on a NA engine will be the volume of the cylinder. Since that number is impossible to obtain because of cam profiles etc, the more you can bring in, the more air/fuel can be burnt. More to burn means more power.

According to the factory flow sheets for my heads, they can flow up to 355 cfm at .800 lift. Using the above formula, my heads have a potential of producing 730 hp however DD2000 calculates my new engine should make about 830 hp. If I put the engine on a dyno, it's possible I could see that but I'll never see that much performance on the track. With the old 469 engine, my best corrected hp was only 585 but then I was also having main bearing problems.

Buy whatever heads you want or can afford. Differences between different brands on similar heads isn't very much.

 

so in your opioion i shuold just do the work to my heads. i did a recalculate on the desk top dyno and i got 483 h.p. and 487 tq. talk about a sad moment. the times that i have done dont refelct what i was told the motor should run but that was with a slipping trans, tires spinning on the rims, and still carbs problems i was working out. the biggest thing is that i really want to run 10's on motor. so really i am just in the dark here.

 

480's seems about right. That's still a lot for a SBC especially when you figure most good engines can do 1 hp per CID. Pushing 2 hp per CID NA is a lot for a motor.

If you're running 11.827 @ 115 mph with an estimated 485 hp, you're going to need at least 600 hp to break into the 10's. That's over the point where a SBC is anywhere near streetable. It will be easier if you make the car a lot lighter. It takes less hp to make a car go fast if there's less weight to move.

 

well my car is basically becoming a track car. i dont drive it on the street and i trailer it pretty much everywhere casue it runs on cam 2. my car now weights 3300 with me in it and i weight about 200. it still has a full custom interior. i show the car as well so looks are still important to me. i do want to get the plastic seats for the front and have them covered in my interior. i am not sure of what else to take out of the car. its pretty much already stripped. i still have to do the tube k member and a arms but that is in the plans for this spring, along with the coil overs.

 

instead of the plastic seats swap to 4th gen seats and save 16 pounds per seat on my home scale. that's 32 pounds and i can't imagine the plastic ones saving anymore weight after the metal sliders and brackets are added in, but they're definately not comfortable for me.

 

heads are the good thing to start with, i bought a set of R/R Protoplines in iron then worked then built my engine around them, now is a 440" sbc, N/A , heads flow 357 int. @ .800, motor made 844 hp @ 7700rpm, thats the best of everything though, so to date car has gone 9.23 @ 149 w/180ft. wheel stand, at 3325lbs.w/ driver, full exaust.

 

holy crap dude that is bad ***!!!!!!!!! i jsut want to run consitent 10's on sbc n/a. so whats your opioion just port the hell out of the ones i have or start with something that is better to begin with?

 

One thing to keep in mind when your talking about porting your heads, a DIY job is potential for focking up a previously good set of heads. I'm all for guys tweaking what they have when they have more time than money, but there does come a point you need to know when to say when and let the people know what they're doing touch them so you dont actually hurt flow characterisics of the head and get everything sooo oout of whack you have to spend a bunch of coin to get back to square one again.

Anyways, when you start wanting to go fast-fast, your edelbrock heads are a good improvement over stock and make some decent hp as they sit and even worked over a little bit. But your still limited by how much they can flow and when you want to start making bigger hp your now in the delima: Do i spend $1000K to have these Edelbrocks gone through professionally and still be limited by max cfm they'll be able to flow due to design, or do I sell these edelbrock heads and step upto the next bigger heads for a smaller investment but easier potential to make power. It almost turns into a catch 22, since you can go either way with it, but if you want max hp you need a bigger head that will flow large volumes of air and IMO if your at the point of dropping a ton of cash to have guys maximize your edelbrocks, off them and get a bigger head.

 

what you guys think of the afr 227 heads?

 

Their Huge.

Not to be rude, but I think your getting ahead of yourself. If the 11.8@115 was run on motor with that many problems, I would think there is a 10.90 in that motor.

Rebuilt Trans, maybe a higher/better stall, and have the tires pulled off the rims, rims cleaned and tires remounted or, screw the slicks on. The car is beautiful and the motor seems to be working pretty good esp for having problems. Get it on a Dyno, Tubular front suspension with some Drag Coilovers would also be a good idea. There is always the NOS.


BTW what kind fab was involved with smoothing the firewall like that? any construction pics?.

 

i just ordered the tube front end and the coil overs this past week and should be here this tues. i just had the trans rebuilt so that is good to go. if i change i want to chagne the heads and cam and converter. i am problay going to go with the afr 210, but just wanted to know what everyone thought of the 227's. i have the rims drilled for the screws now i just need the tubes so i dont have to keep pumping up the damn tires.
For the firewall i just took a sawsall and cut in all flush. then i made up some bardboard peices then tranfered them to a sheet of metal and weled it in. at first i thought boy what have i got my self into but it turned out ok, i am happy with it. i really did it for the distribitor purposes but then i just decided to cut it all off. i ahve some pics i will have to scan them and amd send them to you.

 

Righton man, sounds like your on the right track. With The Slicks/Trans/Carb problems all fixed, I bet she will just scream. The Tubular frontend will shed a few pounds but make it alot nicer to work under there. The Drag Coilovers with a 14inch spring light spring will really help plant the rear and get the 60-ft down. AFR210's would be a good choice for a 355 if you decide to upgrade later. Im going to see if I can run a 10.90 with my little 355 and AFR195 heads if I ever get around to building the damn thing.

Yea, the firewall looks sweet man, I know several ppl who seen it in camaro performers and were like "holy **** does a thirdgen ever look good with a smooth firewall."

 

cool man well hopefully we both can hit that majic 10 sec number. i also took off my front bumper that was a 24 pound loss, so with that and the front suspenison all done that shuold be in the neighborhood of 75 puonds. i am going to weight everything before i put it on and after i take it out to see how much exaclty i saved. i have a huge scale at work so should be no problem. right now the car weights in at 3300 with me in it. i am also trying to lose that weight but i think taking it off the car is easier. so after that is all done i would think maybe around 3200 pds.
thanks for compliments on the firewall.