Oil pressure sensor adapter?

[Pescatore]

I would like to measure the oil pressure on my small block V65.
I'm not trying to make a full time monitor, just checking how it varies.
The stock pressure sensor looks like this, with a long stem:


The pressure sensors I find online look like this, shorter:


Does anyone know what might happen if I use the shorter sensor?  Will it measure wrong, or will oil get into bad places?
Some time ago I saw an adapter, just the stem portion, and I can't find it anymore.
I also will add the 1/8 thread to M12 adapter and a 90 elbow to keep it under the air box.

Thanks,
P

[Frenchfrog]

The pin part of the original part is crucial...earlier smallblocs used a two piece sender set up but god knows where you would get that from.I think the pin bit has something to do with camshaft bearing location.

[Frenchfrog]

I think this would be the part here : https://guzziepiushop.de/oeldruckschalteradapter-breva-v7-5.html

[Chuck in Indiana]

Does anyone know what might happen if I use the shorter sensor?  Will it measure wrong, or will oil get into bad places?

Neither one. What *will* happen is the cam bearing will rotate, and you will "be in a heap of trouble, boy.." 

[guzzisteve]

$25  from MG cycle to do it right w/light.

[Kiwi_Roy]

Just hook up a 0-100 psi gauge then, it will run at ~60 psi
You can hook it to the pressure switch or either of the lines supplying the valve gear, they are at full system pressure, there is a flow restrictor in the head.

[John A]

Do the modern small block oil pressure switches still have the locating pin for the cam bearing?
Edit: I reread . They do.  I must have been feeling good…..

[Pescatore]

Thanks for the info about the bearing.  I'm glad I didn't turn the engine while I had the switch out.
Is it the half bearing #23, or a bearing in the engine casing?  Just trying to visualize the purpose of the stem.

[Frenchfrog]

That's the one !

[Pescatore]

 Thanks