what heads do I have?

[ayrerperformanc]

Hey all. I'm working on some heads for a guy. He got them from a U-Pull-It, has no info on them. I don't know much about Porsches. The casting numbers are 022-101-372 and 021-101-371 Q. I figured out they're 1.7s. I need to get parts for them. The valves are measuring weird.

Intakes: 1.608 head diameter = 41 mm correct? (fits 1.8?)

Exhausts: 1.294 head diameter = 33 mm

Did guys commonly put 1.8 valves into the 1.7 heads back in the day?

[Dave at Pelican Parts]

The 1.8 valves should fit 1.7 heads (except for the valve head diameter) and flow better, so I can see why someone would do that. Sounds like the intakes only were changed, as the 1.8 heads would have had 34mm exhaust valves, not 33 like the 1.7s did.

The register where the cylinder fits into the head is smaller on the 1.7 heads; 100mm diameter versus the 104mm (105mm?) of the 1.8 and 2.0 heads.

--DD

[ayrerperformanc]

Originally Posted by Dave at Pelican Parts

The 1.8 valves should fit 1.7 heads (except for the valve head diameter) and flow better, so I can see why someone would do that. Sounds like the intakes only were changed, as the 1.8 heads would have had 34mm exhaust valves, not 33 like the 1.7s did.

The register where the cylinder fits into the head is smaller on the 1.7 heads; 100mm diameter versus the 104mm (105mm?) of the 1.8 and 2.0 heads.

--DD

I'm measuring 4.135" roughly 105mm. Which still doesn't make sense because of the smaller exhaust valves. Unless at some point someone bored the register out. Is that another common mod?

Btw thanks for the response.

[Dave at Pelican Parts]

Not super common, but it is done. You can fit the 1.8 cylinders (93mm) or go up to 96mm without the cylinders getting thin.

--DD