Hi,

My name is Patrick and I'm new to the forum. I did a search for threads that might help me but, didn't see much. I'm sure it's out there but, I'm having difficulty.

Just rebuilt a '77 LT 350 out of a 'Vette and put it in a Ford Rat Rod. Engine runs well with good oil pressure and everything when you first crank it up but, once it warms up oil pressure drops from around the 30PSI mark to all but zero. the engine is a fresh rebuild so, bearing clearances should still be good and I just replaced the oil pump today with a brand new high volume pump. Still has the same issue. The gauge I'm using is a Sun Pro mechanical model and the engine never makes a strange noise like it is starving for oil. I'm now outside my expertise and afraid to lock up this brand new build.

This is my first Chevrolet build and I haven't built much of anything in the last 15 years or so. Just thought I would talk to some guys with a little more experience.

 

if the oil pressure is good enough when you start it but they drop when it warms up ,i would look at bearing clearances especially the main's and cam bearings . check the crankshaft journal sizes also

 

Thanks, Old Dog. I was hoping to not have to pull the engine again but, I guess I'll just have to bite the bullet.

 

I'm not that old school - but...

Are you sure the gauge is correct?

What happens when you give it gas? Does it go from 0 to xx ??? Or does it stay at 0?

Are you squirting oil up top?

Did you do or need to do an engine break in?

What weight oil are you running?

okay this is really ignorant question since I don't know and not about to google up years of engine building - is this a roller or flat tappet setup?

 

I wasn't sure the gauge was correct. When you hit the juice the pressure would climb slightly and then drop again. I didn't pull a valve cover yet but, I did hook up the oil pressure tester. It shows 18-22 PSI at idle even after warm. No break in yet. I just dropped it in a couple of weeks again the truck still isn't ready to drive. Castrol 10/40 in a flat setup.

 

Is that oil flat tappet compatible?


List of Flat-Tappet Oils - Corvette Forum

What does your engine builder say, or did you build it yourself?