Heads for 306

[94stroker]

Im about to begin to build up a 306 for 95 cobra and having a hard time trying to figure out what heads to use. I was originally going to use victor JRs but then i was reading up on the AFR 205 and the trick flow R's or high port's. I think im gonna end up using an Anderson cam one of there high rev cams i think the nv-91? Let me know what you guys think would be a good combo.

Thanks Jim

 

[Yobi1Kanobi]

I think all 3 of those are to big for a NA 306.

 

[blksn955.o]

I would say no more than AFR185's or some TFS heads at most...like those new ported ones you can get.

205's are a head for a 393-410 or boosted 347+.

 

[95Vert]

I'm no expert in this area and I will say that I read a long thread on this very topic, and the conclusion was that those aren't too big. A bigger head allows room to grow and allows the cam designer to work 'freely' when designing the cam which translates to more power.

There was a long discussion on this same topic by VERY knowledgeable people on another site and that was the consensus. I would post up the link but it's censored on this site.

 

[5spd GT]

What kind of RPM range are you looking at running?

That is a KEY factor.

 

[Pokageek]

Yep, its a street vs track question.. Like do you want no power from idle-3000+ RPM and all upper? or do you want some low end TQ?

 

[final5-0]

By what I read in Jim's original post .........................

I see by his consideration of cam choice ..............................

He is talking about a race or high rpm type of application .................
rather than typical lower rpm street application

You gotta have bigger ports if you wanna flow at high rpm's

His application is different ... so ... His parts are gonna have to be different

Grady

 

[Grn92LX]

None are too big for a 306.

If youre going to use an anderson cam, call up their tech line and discuss your goals and stuff and let them help you. Gear the car properly, 3.73's wont work here This thing is gonna FLY! Whats the race weight?

 

[5spd GT]

Make sure you get a good balance, stronger rod bolts, and a lightweight valvetrain that the AFR heads come with

It all depends on what kind of RPM range he is working with.

If he is looking at 6k shift points, the AFR 205cc heads are to big.

If he is looking at 8k shift points, the AFR 205cc heads are not to big.

Piston speed increases as RPM increases.

Have fun.

 

[Pokageek]

8k RPM is pretty high..I bet that is expensive but if $$ is no object, I wonder how much top end HP you could get out of one! I bet it would be a pretty cool ride. I'd prolly put a set of 4.30's in er too! Almost be like a DOHC motor!

I think it was hot rod that got [EDIT] 530 WHP out of a 331 IIRC? But that revved to 7k I think. 8k would be pretty awesome.

 

[94stroker]

The car is going to be driving on the street but not daily haha 4:30's and a spool arnt to much fun on the street. I'm looking to be making power around 7500ish range but im not sure if im gonna stay with fuel injection or go carb.