Hey guys, need your advice. I have a 63 215, recently rebuild except I put standard main and rod bearings back in it. Also put a Melling HV pump kit in it. Starts with the Oil pressure at 60, drops to 20 when it warms up. Engine runs very smooth and quite. My wife and I like to drive to the N. GA mountains and cruise at 40-45 mph. Is 20-25 psi enough until I get the energy to pull the engine out again and see what is not happening?
thank you for your advice. Should I use 20-50W oil?

 

Your oil pressure is fine.

 

I agree, that is not worryingly low.

I would use 20W50 if I were you - won't hurt, might help.

What is the pressure with the engine warmed up, at idle?

- Eric

 

When it reads "0" you need to worry!

Mike

 

when it it's warmed up, I'm getting 20 lbs at 2K rpm,(my cruising speed) at idle it's 12-15 lbs. with a HV pump is it getting enough volume to compensate for the lower pressure? Before the rebuild it was steady at 30 lbs. Only rebuilt it because there was alot of blow by from the pistons. Turned out that the rings were in really bad (stuck) condition. Cylinders were fine we just had them honed.

 

I wouldn't do the 20-50, I'd use 10-40, or 20-40.

 

Just curious, why not the 10-40?

 

I think Eric means he would not use the 20-50, but he recommends either 10-40 or 20-40

 

Why not 20W50, especially in a car with slightly low oil pressure?

I've used it for years in older American engines.

The only disadvantage I can imagine is a slight decrease in gas mileage.

- Eric

 

Sorry, I edited in the "I'd use" part.

The 20-50 in winter, is just too thick IMO.

 

In a fresh, tight engine, I'd agree, but he's got 12-15psi at idle, which, while not harmful, is a bit low for a normal-clearance street motor with a HV oil pump.

I'd also agree about not using 20W50 in the winter, but he's in Georgia, where there is no winter, and most folks these days do not drive their older cars in the winter anyway (I remember a trip I took one winter in my '68 88, where it was -20°F and I had to keep scraping ice off the INSIDE of the windshield - pretty much nobody would drive one of these cars under those conditions nowadays).

I understand your point, but I think in not-cold conditions, with a slightly low pressure, he'll benefit from the slightly thicker oil.
I also think that it's not likely to hurt anything to just keep using 10W40, so I don't want to make a big deal out of it, just throwing in my 2¢.

- Eric

 

I'm in N Texas and we have about 1 month of winter, just not all at once. It can range in temp from 17 deg to 80, either in a single day, or in a weeks period. I believe Georgia is the same.

The other thing I've found oil pressure will fluctuate depending on oil filter, Wix for instance will register higher than say a Purolator.

 

Okay, that's one hell of a winter!

- Eric

 

When I had my motor rebuilt I felt my oil pressure was a tad low. I was using a Joe Gibbs BR30 which I later found to be the problem. Instead of dumping all the oil (at $9 a quart) and replacing with a higher weight I added 2 bottles of STP oil treatment which did raise the pressure about 3-5 psi. Maybe you could try that.

 

thanks for all the input. I'm not a master mechanic, just a poor country boy trying to make a living in the big city of Atlanta. I drove the car last night and as long as the operating temp didn't go over 175 the oil pressure stayed at about 25 lbs. So if the engine getting too hot makes the oil thin, why not get a lower temp thermostat, say 165 and keep the engine cool. The strangest thing, put the Melling HV pump and attached a new Thrust plate to the housing. The instructions (I followed them exactly) said to torque the pump housing screws to 10lbs. When I did this the gears wouldn't even turn! So the screws are only maybe 5lbs. Now that the engine has run for an hour or so, should I try to tighten up the screws to 10 lbs.? It's not leaking, but can there be too much clearance and I'm embarrased to ask, how do you measure the clearance on the pump gears? I agree about the temp in Atlanta, the car is my baby and stays in the garage always where it's warm enough to work on it if I wear a sweat shirt.

 

thanks, I'll try a Wix oil filter. Are there others that are less restrictive? Will changing the relief valve spring from 40 lbs to 60 lbs do anything to the running oil pressure?

 

I think the higher engine temp actually raises the clearances when everything expands so the pressure drops
I would try a bottle of Lucas at the next oil change

 

The fram racing filters are less restrictive

 

The relief valve spring is the major control of oil pressure. Heavy spring, more pressure. I shimmed one once, blew off the oil filter.

 

You might want to avoid NAPA gold filters. I put one in my 1980 Cutlass and it would stumble everytime I hit the gas.

Put in an AC Delco and all is well.