I am going to install an oil pressure gauge over the winter. What is the thread size for the sender unit (1/8 NPT or 10x1)?

Will these work with the 0-80psi VDO gauge?

1/8NPT sender

10x1 sender

I think the usual installation is to use the extension hose and mount the dual sender remotely. This is because the sender body is larger than the hole in the tin for the oil pressure sender. You could file out the hole but I'd rather not modify tin when the hose is relatively easy. That said, the hose is not metric thread while the case is. Someone will answer here that the threads are the same but I'd rather not mess up my case with non-metric threads. Also, when I installed the hose in my white 1.8 car, it leaked alot, so much that it messed up the windshield of the car behind me. Probably installation error but I removed it to work on later.

The case thread is 10mm x 1.00. I use Loctite 565 on the threads to help seal them and have never had any issues.

not to hijack, but what is the oil pressure supposed to be at in a 914? i too am going to install an oil pressure gauge, just want to know for future reference.

Yes the sender will work with a new VDO gauge, but not with an old one.
Mark

So the threads in the case are not tapered?

From the research I did here on the forum, a hose from either a greasegun or paintball gun is needed between the case and the dual sender. Those use 1/8" NPT fittings. Will a sender with 10mmx1 threads thread into the 1/8NPT female end of the extension hose and will a 1/8"NPT male end of the hose thread into the case?

Use the paintball gun hose, and yes, yes and yes.

You need to build a cool little mount for the sender. The body of the sender needs to be grounded. Mounted on the fna shroud works great and there are a few extra holes on top of the shroud to make a funky bracket.

Bracket fabrication is my specialty. My car is off the road for the winter. Gas tank is out and the motor is ready to be removed. Engine rebuild here I come.

The sender will not clear the dizzy to well, as well as having to cut the tins. I used the grease gun hose and a conduit clamp both from ACE hardware.

paint ball gun hose is stainless bling...

Rich

I,m not sure I have ever seen any factory recommendations for oil pressure for the 914.........But I know what works...10 psi for every 1000 rpm,s...( with the engine oil hot)... this is a good "rule of thumb".... some 911.s have such low pressure at idle it barely reads, but they have l o t s of volume of oil so it works fine.... a race engine with 70 PSI, even at 8200 rpm is also ok. Seems like 70 psi is the majack maximum pressure number.

IRRC the factory recommendation is one bar (14.5psi) per 1000 rpm.