Oil pressure drop when warm

[prj7103]

I have a 1963 88", original engine and Solex carb. I recently had my carb rebuilt by someone I trust with a kit from Ike and it ran great for a month. It was like a new truck. Out of nowhere, once the engine warms up to its normal operating temp, at idle the oil pressure drops pretty dramatically. I've never had oil pressure issues in the past. At a cold start, the idle is great and oil pressure is strong and steady. Once warm it drops and I have to rev to keep it from dying off. I mention the carb rebuild not because I'm certain it was a factor but mainly because it was the last thing done to the truck which has never let me down. Before I start poking around I thought I would throw this out there to see if others my have some guidance. Thanks in advance and I'll also mention I am away from my phone and computers for long stretches so any questions my take a while to get answered.

[erik88lr]

I have a 1963 88", original engine and Solex carb. .... Once warm it drops and I have to rev to keep it from dying off. ...

Is the oil pressure low because the idle is low as it tries to stall out? Maybe fixing the idle problem will fix the oil pressure problem at idle.

Only other thing I can think to check that's related to the carb / fuel system is fuel in the oil thinning it out and lowering the OP.

[jimrr]

my dozer did this after running on a steep hill where it wouldn't pick up oil. I added a couple gallons of lucas oil stabilizer and after it's hot it'll still maintain 15psi, you might try a additive like that. It saved this cat engine and the idea of rebuilding that is nearly prohibitive !!

[prj7103]

In the limited time I've had to trouble shoot I do believe the idle on the carb is the leading candidate. I tend to focus too much on mixture adjustment, and not think of the idle adjustment. Thanks for the help.

[jimrr]

if it's a electric guage plumb in a mechanical guage and compare results.