I know I've seen posts on this but when I search I get way too many hits.

I have a '70 1.7. My 1976 vintage Haynes manual says .15mm(.006") for intake and exhaust.

I also have a vintage 1972 Carbooks manual which PO gave me with the car covering only '70-72 914's and it says .10mm (.004") for both.

I just checked # 1 and they are both at .004. Should I go to .006? Was the spec. changed for early cars at some point?

.006

OK, .006 it is. But, does anyone know if the spec. was changed by Porsche (VW) at some point or is my old manual in error?

Far as I know its always been .006 only the sodium filled exhaust valve equiped cars (2.0L) had the .008. .004? sure you weren't looking at a type 1 spec.

Thanks Geoff. Using a book (which I like better than Haynes for some things) "Porsche 914/4 1970-72" by E.S. Schechter published 1972 by Carbooks, Inc.. Brooklyn, NY. Calls for .004" in text describing the process and in the spec. table.
Looked at my owner's manual but can't find spec or process there as in 356 manuals. Just says do it every 6000 miles.

I think it is an error that was in one manual and that data has been incorrectly included in many subsequent manuals much like rear brake venting clearance.

the consensus from the experts here: .006"

Jim