Oil Pressure Gauge Equivalent to pressure…

[AllGoNoShow]

Does anyone know what actual oil pressure equates to the different spots of the stock oil pressure gauge in our trucks? I have a 68 and just swapped in a new to truck, but older rebuilt SBC that I put a new HV/HP oil pump in while “freshening it up” and the gauge was pegged past the markings on start-up. Just trying to figure out what oil pressure that equates to.

Also noticed my rear mail seal is still leaking (I took a lot of care in replacing it with a fel-pro) and curious if the high pressure can maybe cause that.

Nick
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[chev-obsession]

There are 2 oil pressure gauges, 60 & 80 PSI. 60 is the most common, which is most likely what you have and they peg out really easily. If you want to read what the actual oil pressure is, I’d recommend getting an auto meter gauge of your taste.

If you take the gauge out of the cluster it will say 60 or 80.

[sick472]

Some engine's rear seal leaks can be reduced or eliminated with a new/better PCV system. Oil pressure should have nothing to do with a rear main leak, but crankcase pressures can. I have heard of people on my Pontiac forum getting very good results with the adjustable Wagner PCV valve...

http://mewagner.com/?p=444

The old Pontiac motors tended to have high crankcase pressures, to begin with, and when they are souped up...it just gets worse. These valves are said to work very well when it comes to high crankcase pressures under WOT blowing the dipstick out and rear main leaks. Pontiac motors had a "stroked" design from the factory and stroked motors tend to build more case pressure. I have not tried them, but they have a high success rate from what I have seen.

Before you click on the Wagner link...be prepared, they are not $5.oo!

[too much stuff]

The marks on the gauge would be 15# increments on a 60lb gauge (which most are)
20#marks on an 80lb gauge

[Rich72C10]

Just to pop in on oil leaks, after my engine rebuild I fought random oil leaks. Some were actually due to various cover bolts that were missed being tighten up properly (darn brother). But it took me months to figure out I was building up engine pressure. On the passenger side the fire arrestor was more or less completely plugged up. After sorting that out my oil leaks are virtual gone.

I have also noticed since now that my engine is properly breathing, my Oil Pressure gauge seems to travel better between L and H. Though I guess that could also be because the engine has broken in too. At the beginning my gauge would reach/touch into H when cold or high RPM.

Anyways be on the out look on what could be causing pressure build up ... can't believe all kinds of people missed the fire arrestor being plugged up - doh!

[AllGoNoShow]

Thanks for the insight here gentleman. I think before I make a decision relative to trying to redo the main seal with the engine in the car, I’ll address the PVC situation (that’s a pretty cool adjustable one), then maybe try some of the snake oil Bars rear main seal fixer additive and see where I’m at. Or I can just accept the fact that it’s a SBC and the rear main seal leaks on seemingly all of them.
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[AllGoNoShow]

Quick, somewhat related question. Can you drop and remove the oil pans on these trucks (SBC) without unbolting the motor mounts and lifting the engine?
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[tdangle]

Originally Posted by AllGoNoShow

Quick, somewhat related question. Can you drop and remove the oil pans on these trucks (SBC) without unbolting the motor mounts and lifting the engine?
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Yes, but you do need to unbolt the motor mounts and put a 2x between the mount tower and the engine. this will raise the motor enough to remove the oil pan. Pain in the butt, but it can be done, I've done it. I recommend the one piece gasket by felpro