3.2 intake valve VS 930 intake valve
 

I am rebuild my 87 930 engine, my tech man told me I need to replace the intake valve.

What is the different between 3.2 intake valve and 930 intake valve? Can I use 3.2 intake valve?

Need you guys input.
Many thanks!

I'm no expert on porsche valves and I doubt you will get an answer from the experts, seems I never do with these questions .

My guess is the price difference between the 3.2 valve and the turbo (964-) valve is the turbo is sodium filled. I imagine this is the only difference.
Sodium vs non-sodium valves seems to be divided into two camps, one says they dissipate heat better and are lighter, the other say they are prone to breaking and heat isn't an issue if you run close guide tolerances.

Only the exhaust valves are sodium filled in the turbo.

I imagine the turbo intake valve might be a smaller diameter than a 3.2 because the ports are so small on the turbos.....but check the part numbers on Pelican to see if they are the same.

That would be a good indication they are interchangable.

Good luck.

The part numbers are not the same, even though the head diameter and stem diameter are the same. The turbo intake valve is made from mimonic steel alloy, which is why it is more expensive. Mimonic is more temperature resistant.

"IF" there ever was a Helll, Valves live there...

Squirrel is correct. Valve size is the same for turbo or non turbo.

Except that I meant to type Nimonic, not Mimonic.

All the dimensions are the same for 78-89 911 and 75-89 turbo so it must be the material is made of that's different?

According to Wiki...

"Nimonic alloys typically consist of more than 50% nickel and 20% chromium with additives such as titanium and aluminium. The main use is in gas turbine components and extremely high performance reciprocating internal combustion engines. The Nimonic family of alloys was first developed in the 1940s by research teams at the Wiggin Works in Hereford, England, in support of the development of the Whittle jet engine."

That's funny because I had read sometime ago now, that prior to the second war, the British knew that Germany was developing the first jet engine. Apparently Hitler wanted to impress the British (Churchill) and invited him to see some to some of their new ideas including prototypes of the jet engine. One of Churchill scientist supposedly wore shoes with especially gummy soles so that they could get a sample of some of the shavings that might be on the machine shop floor.

Anyway, the above is foggy in my memory and might be completely wrong, but I was just trying to make a connection that Nimonic is probably based off of the jet engines of WW2 Germany. From Germany to England and back to Germany...maybe.