Best heads for a 306 that will be receiving a supercharger?

[ZoaFan08]

Right now I have a 302 stroked to a 306, 10:1 compression, CompCam XE266HR-12 and wanted to do a head swap in anticipation for the supercharger the car will be receiving this winter. Right now I am torn between the Trickflow and the AFR. Which one would be better and what model would be best for my setup? Thanks!

[bobcowan]

I'd recommend Dart Pro-1 heads. They "only" flow 190cc, but they are capable of making a lot of power. They also come with quality hardware. Change the springs if you have a radical cam, otherwise just clean them up and bolt them on. They were recommended to me by Mike Forte, and they're making close to 600hp NA.

[blykins]

Hard to beat the AFR head. I use them as much as I can, they tend to flow as advertised and are assembled with quality parts.

Trick Flow makes some good stuff too, but be careful about which ones you pick. Their TW heads will require different pistons.

The AFR 185 would be perfect for your application...

[Z-linkCobra]

For starters how did you only manage to stroke a 302 to 306...something aint right. AFR's are a pretty good. I would say you need to look into what kind of boost you want to try and make. Then take a SOLID look at how much boost your rotating assembly and block can handle. The rods and main caps being the major weak link. Unless your sporting some nice parts I wouldnt build much more than about 8psi of boost.

With all that being said I would talk to the supercharger guys and see what they think would be a good fit.

You could forgo the supercharger and all the headaches that come with them and buy this set of Yates heads I have. If your running stock block and rotating assembly these heads will make more than enough H.P. to break those parts without any boost. 49cc chambers,all Jesel valve train, titanimum valves (2.125/1.580),keepers,retainers, ported,polished and ready to go. $4500.00 for the pair complete. I'll even throw in a set of exhaust flanges so you can build some new headers.

Just a thought....lol.

[ZoaFan08]

Originally Posted by Z-linkCobra

For starters how did you only manage to stroke a 302 to 306...something aint right. AFR's are a pretty good. I would say you need to look into what kind of boost you want to try and make. Then take a SOLID look at how much boost your rotating assembly and block can handle. The rods and main caps being the major weak link. Unless your sporting some nice parts I wouldnt build much more than about 8psi of boost.

With all that being said I would talk to the supercharger guys and see what they think would be a good fit.

You could forgo the supercharger and all the headaches that come with them and buy this set of Yates heads I have. If your running stock block and rotating assembly these heads will make more than enough H.P. to break those parts without any boost. 49cc chambers,all Jesel valve train, titanimum valves (2.125/1.580),keepers,retainers, ported,polished and ready to go. $4500.00 for the pair complete. I'll even throw in a set of exhaust flanges so you can build some new headers.

Just a thought....lol.

Not interested in getting max horsepower, just more interested in putting the awesome looking Kenne Bell blower on top of the engine . 6-8psi would be more than enough to get me to my 350hp I'm looking for.

[Z-linkCobra]

Nothing like a blower. Gonna run carburated or injected?. Back in the day we ran a v-671 Dyers blower on a 302 in a 69 fastback mustang. When it was on the track we ran 12-18psi of boost. On the street however we would drop it down to about 8psi max. You couldnt hook it up even then on the street. We ran 2 4412 Holley 2 bbls. They had some work done to them to flow a little more but the biggest problem we had was keeping it from loading up sitting a stop light. The problem with a blower is the massive vaccum on top of the blower and boost underneath keeps the power valves from opening up to richen the motor at higher rpms. If you richen up the mixture then it wants to load up all the time. The ol man tapped in below the blower and brought a line up to supply positive pressure to the powervalve chamber to open them once you were off the idle circuits. Sounds confusing I know...lol. If you need help let me know.

[Z-linkCobra]

Nevermind....went and looked at the site...your running injected..lol.

[Dwight]

My 302 EFI made about 380 hp at the flywheel. I think the best was 308 rwhp.

You need 60 or 64 cc heads. If you boost a 10:1 motor, your compression will be in the 14 to 1 ratio range.

if you bore a 302 to .030" over you have 306. Boring a motor will increase the compression.

You need to start with a 9:1 setup and when you add the blower you will have a motor that you can run on 91 or 93 octane on the street.

I would talk to Keith Craft about the heads.
Wayne Presley could tell you about the supercharger and all the parts you need to make it work.


Dwight

[blykins]

Zoa,

If you do some research and decide to go through with your plan, let me know as I'm a dealer for AFR heads and can get the others too. As an engine builder, I can help you decide on the chamber size and port size that would be best for you.

[cobrashoch]

Whatever you settle on, I would for sure get the biggest combusion chamber heads that I could get; ie - that are practical to find. Set up your ignition to run verible retard and yes, unless you have engineered the whole car for a supercharged application you
WILLno doubt break parts. You would also be very smart to pay close attention to your safety equipment selection. In other words, consult a few pro's about this and think very hard about this. Good luck,,,,,,,
cobrashoch

[Racer_X]

Z-linkCobra: A 302 at .030 oversize pistons is a 306c.i.

ZoaFan08 - I'll also echo using the AFR 185 heads with 65 c.c. combustion chambers.
You don't want a lot of compression with blown or turbo engines, especially small block fords, as they have a tendency to lift the heads with anything over 7-8 psi. Run ARP studs, Cometic gaskets (o-ring preferred) and a flat top forged piston or even a dished. Drop that compression down to a more blower friendly 8.0 to 1 or lower.

Folks have been known to get plenty of HP with the stock H.O. cam. Remember, it's all about effeciency of getting the fuel/air charge into and out of the combustion chamber. ARP Rod bolts are a MUST as the factory rod bolts are a major weak link on a factory 5.0 engine. I'd suggest H-beam rods with ARP hardware, ARP main studs, and a windage tray. If you're looking at 500HP, you're going to split that factory block down the middle of the crank and cam bore. They can't take 500HP and live a long time.

[Z-linkCobra]

Racer X: If you read his first post it says "I have a 302 STROKED to a 306" not bored. I was just giving him a rash....lol