Porting heads

[Fritter]

I am planning to build an 81x66 with Solex cams and JE S type pistons with stock '68 normal heads.

Would slight or "street" porting of my heads add a lot of power potential?

I would like 2.0 S type power out of this little "mouse" motor.

Thanks for any thoughts.

[304065]

With nailhead valves? 39 Intake 35 exhaust?

If originality isn't necessary why not use 2,2 heads? They are a lot better and the valves are a fifth the price (actually, SWB valves are probably NLA by now- I used some NOS ATE and SI valves for the exhausts-solid stainless, not sodium-filled)

[Fritter]

Yes, nailheads. I'd like to use as many parts as possible from the 2.0, it's my first 911 engine build. I figure a nice pocket porting/smoothing job would help flow on the 2.0 heads.

[911quest]

A set of core 2.2 heads can be had for little money usually the "T" heads run about 150.00 a set andthe "E" & "S" go up from there.

[911pcars]

Enlarging the smallish early heads may be costly. In addition, the heads would still have the original small valves. It's better to begin with a later head, the 2.2 heads that John suggested would be a better base and require fewer modifications. We'll assume new guides and valve job for both; maybe new springs, retainers as well.

Sherwood

[Fritter]

Thanks for the input everyone. Are the 2.2 heads usable with 2.0 cylinders? I know the seal changed on the 2.2? Decisions decisions.

[911pcars]

Thanks for the input everyone. Are the 2.2 heads usable with 2.0 cylinders? I know the seal changed on the 2.2? Decisions decisions.

Hmm. That could be problematic. How about 2.2 cylinders as well? Let's see what others come up with. Are later cylinders (e.g. RS P/C) out of the question/budget?

Sherwood

[Neunelfer]

I agree with the 2.2 heads.

Porting them isn't really rocket science. The factory did a fairly good job at picking ports for cams. I'm building a 3.0 MFI motor with 36mm intake ports (yes, 36mm) and S-Cams. Look over all of the engine codes and the cams used and see where they maxed out the intake ports. Find someone with a vertical mill and have at it.

I'm currently driving a 2.5 with 41's on the street right now and all I can tell you is, you don't really wanna go there. Sure is fun (past 4k) but, no bottom end torque.

[Fritter]

You're saying just run a mill down the port to open it up and that's it? Seems kinda crude, but then, what do I know?

[Fritter]

Hmm. That could be problematic. How about 2.2 cylinders as well? Let's see what others come up with. Are later cylinders (e.g. RS P/C) out of the question/budget?

Sherwood

You guys have me thinking to sell my 2.0 heads and also the Biral normal piston/cylinders. Then I could buy some 2.2 heads and maybe some 84mm jugs and have JE S spec 85mm pistons fitted. All of this would slip right into my '68 shortblock.

Question: Are cast iron or Biral 2.2 cylinders best? (I felt like Dwight Schrute asking that for some reason)