Cylinder head rebuild, do these figures exist for Type IV heads Options

[Mueller]

I found this 911 engine rebuild manual online, too bad no luck for Type IV motor found yet.

I have new SS 2.0 valves to install in my 1.8 heads which means I need bigger seats. Depending on how much the local shop quotes me tomorrow I attempt this myself. ( I do have a few extra heads to practice on)

I'm mostly interested in the valve seat info.

https://www.porscherepair.us/porsche-911-19...nder-heads.html

[Dave_Darling]

Which manuals have you checked, Mike?

The factory workshop manual only mentions the width of the seat contact area with the valve; the intake on a 2.0 should be 1.8 - 2.2 mm; the exhaust should be 2.0 - 2.5 mm. They also talk about the angles that the seats should be ground. (15 deg, 45 deg, 75 deg.)

The Tech Specs book merely says that if the seat is so worn that the 15 degree cut would be larger than the OD of the seat, the head should be replaced.

So it seems like they were regarded as disposable back in the day. You'll have to use your own judgement (or that of someone who knows aircooled engines very well!) to work out the info you need....

--DD