AFR BBF Head

Gary Blair wrote:

Lem Evans wrote:



AFR deal with custom dome.

Nice looking piston work.

Rebco?

Is that 14.4-1 with the 75 CC chamber?

HorsinAround wrote:What push rods do you recommend? AFR recommends 3/8" thick wall, and my cam will be an .819 lift, so I want to get the best set possible to limit side deflection and good tips.

Lem Evans wrote:

HorsinAround wrote:What push rods do you recommend? AFR recommends 3/8" thick wall, and my cam will be an .819 lift, so I want to get the best set possible to limit side deflection and good tips.

Depends on the cam and valve springs used.
.135" wall x 3/8" are used in many applications.

HorsinAround wrote:

Lem Evans wrote:

HorsinAround wrote:What push rods do you recommend? AFR recommends 3/8" thick wall, and my cam will be an .819 lift, so I want to get the best set possible to limit side deflection and good tips.

Depends on the cam and valve springs used.
.135" wall x 3/8" are used in many applications.

Gotcha. As I mentioned the max cam lift is .819 (I'll have to look at the cam card when I get home to get all the specs) and I am using the PAC Racing #1224 1.625" OD Solid Roller Dual Valve Spring 275 lbs. on seat, .850" maximum lift.  

I have always used Comp push tubes, but did have trouble with a tip collapsing usually once or twice a season on the pulling truck and the lift wasn't quite as big. Also this is a 533 drag motor build, so it won't see the rpm that the puller saw...

BOSS 429 wrote:

BBFTorino wrote:So let me try to get this right....and correct me if Im wrong.
The AFR heads are a quality product, and they are better 'out of the box' than a P-51 or SCJ head, yes?
But with some porting, the P-51 and SCJ's would make more power than the AFR's, yes?
But with further porting on the AFR's, they would out perform the P-51 and SCJ's, yes?

Has anyone done any custom porting on a set of AFR's yet??....I mean like somewhat beyond the out of the box CNC job that they already have??
If so, it would be interesting to see the comparison of the CNC version against a hand ported version.

As I understand it, a set of P-51 or SCJ heads still needs the intake to be ported/matched to the heads (if one wants to optimize their combo), but the AFR intake matches the AFR heads a lot better right out of the box, yes?

YES, HAD A SET OF THESE HEADS in my hand today, I hope I get to work on a set.keep in mined THEY come ported from AFR.

Gary Blair wrote:Mike Stark built an 1100 HP 598 with AFR heads. He did some hand porting on the heads. He also did some plenum modifications. It has 14-1 compression and used Q-16 gas.

Look at Oakley's build. Pretty much out of the box heads and manifold. Impressive. AFR says there are some upgrades on the way as well.

dfree383 wrote:

Gary Blair wrote:Mike Stark built an 1100 HP 598 with AFR heads. He did some hand porting on the heads. He also did some plenum modifications. It has 14-1 compression and used Q-16 gas.

Look at Oakley's build. Pretty much out of the box heads and manifold. Impressive. AFR says there are some upgrades on the way as well.

Yeah they have some catching up to do…….