964 valves into a 930 cylinder head

[reclino]

Are there any problems with putting 964 intake valves into 930 cylinder head? The stems are hollow, sodium filled and weight is about 6 grams less than the 930 valve. This is supposed to result in 200 rpm higher redline. I am not building a monster motor, but i figured if its a small improvement with no downside I will do it now that i have the chance. Just need to find a couple more intake valves. Bought a lot of 10 964 valves here and only 4 or them are actually 964 valves, the others are the heavy 930 valves.
thanks
David

[bpu699]

Originally Posted by reclino

Are there any problems with putting 964 intake valves into 930 cylinder head? The stems are hollow, sodium filled and weight is about 6 grams less than the 930 valve. This is supposed to result in 200 rpm higher redline. I am not building a monster motor, but i figured if its a small improvement with no downside I will do it now that i have the chance. Just need to find a couple more intake valves. Bought a lot of 10 964 valves here and only 4 or them are actually 964 valves, the others are the heavy 930 valves.
thanks
David

Lots of people spend lots of money to make sure they take out the sodium filled valves and never use them as they crack and destroy motors... at least with Ferrari’s...

[KTL]

For all years of 930, take a look in the PET catalog and it calls out the 930 intake valve as part number 964.105.409.08. Look up the intake valve in the 964 PET and it's the same 964.105.409.08

The exhaust valves are different part numbers between the naturally aspirated 911s and the turbos but they too can be interchanged because they have the same dimensions.

I thought that it's the exhaust valves that are typically sodium filled and the "hot ticket" (pun intended) to have because the sodium aids in the heat transfer? I recall that was something Chevy lovers highly touted on the special edition '96 Corvette LT4 engine (last year of the C4 chassis). That would be the last Gen II LT1-variant engine. I'm not talking about the "legendary" LT5 engine of the ZR-1.

I guess years later we're finding those sodium filled valves ain't so great? I also recall one of the added features to the '87-'89 Club Sport 911 models were the special sodium filled intake valves 930.105.409.14 but they come up No Longer Available/discontinued on a Porsche dealer network part number search. I used to have a factory Porsche document that was a club sport spec sheet sort of publication. I think I got it off of eBay in the early 2000s. It listed all the differing features of the club sport. I foolishly gave it to the guy who bought my '87 Carrera..........

[RedCoupe]

I don't like the idea of reusing old exhaust valves, particularly if I don't know the history of the engine they were in. My dad had his aircraft A&P ticket, and whenever we overhauled air cooled engines we replaced the exhaust valves. When I just did the heads on my 150k mile 964 engine, it got new exhaust valves.

[reclino]

I have bought new exhaust valves.

[Mixed76]

Seems like a good idea. Lighter weight is generally a good thing, and sodium filled valves do lower exhaust valve temps.

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