No oil pressure on new build
 

I have a friend that is working on a 37 21 stud that was Rebuilt 30 years ago. When starting, it has no oil pressure. Removed the sending unit from the rear of the engine and there is no oil coming out when cranking it over.
The fuel pump is working.
What could be some of the issues on a new build and no oil pressure?
What else can be checked?

Re: No oil pressure on new build
 

It's possible the front or rear oil gallery plug was left out , it's happened before.

Re: No oil pressure on new build
 

oil plugs left out, oil pump needs priming--pour oil down the sending unit hole until full, even if the plugs where left out pump still would move some oil. picture of a plug left out 20 plus years ago. this engine did push oil out the sending unit hole but just a dribble

Re: No oil pressure on new build
 

Remove the spark plugs and crank the engine. It may take a while, but he should show some pressure. Crank about 30 seconds, then try again.

Re: No oil pressure on new build
 

Was the oil pump primed? Packing the oil pump with Vaseline Petroleum Jelly is a good way to do this...

"Don't ever just install a new oil pump right out of the box. There are two easy methods of insuring the oil pump will create the seal needed to pull oil in on initial start up. The first method is to pack the oil pump full of Vaseline. Vaseline will create the seal needed for vacuum to draw in oil. The Vaseline will then be quickly dissolved into the oil. The second method is to use engine assembly lube and lube all the moving parts. The goal here is to sufficiently coat all moving parts so when the pump spins for the first time vacuum is created to draw the oil into the pump and then push it through the system."....

Re: No oil pressure on new build
 

Pull the sending unit and prime the pump from the top and that seem to solve it.
He actually had the car running and it still didn’t pull prime
Seems to be OK now

Re: No oil pressure on new build
 

I had an issue on an 8ba where the idler gear in the back of the block that drives the oil pump was installed backwards, causing it to not mesh and not spin the oil pump.

Re: No oil pressure on new build
 

had to do the prime trick with a 60 hp motor that had sat for 10 years after running fine before that. also used some STP in the past, Lucas make a real good alternative to that stuff

Re: No oil pressure on new build
 

If I had an engine that was rebuilt 30 years ago I'd probably tear it down and reassemble it just for peace of mind. All that lube that was put on back then is probably dried up and gummy now.

The chances are it can all go back together with a few new gaskets. I'd also prime the pump with some vaseline.

Re: No oil pressure on new build
 

Pre oil with a garden sprayer. Works well for what you want to attempt.


https://ls1tech.com/forums/generatio...l-priming.html scroll down to see the set up.


R