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oil pressure 91 454cid

S

slauder

Regular Contributor
What causes the oil pressure to move up from the 45 psi at idle to 60 psi at higher rpm and load.

Also how can I measure the oil pressure directly on the running engine?
 
Scott; movement of pressure up from idle is pretty normal, especially when warmed up. My experience is that 40 is the upper pressure setting at the stock pump. You might try a mechanical, local gauge with maybe even a clear tube adapter so you can get the guage in a better position to read it. Even if the 60 psi is real, I would not consider pulling an engine to reduce it to 40; too much effort, unless the engine was already out. High pressure will load the oil drive system a bit, especially at cold start with straight weight oil, but 60 should not be a big deal.
 
Like DD said, get a mechanical gauge. If you use an extender hose, make sure it is rated for the operating pressure it will see.

When we rebuilt, the higher pressure spring was installed in the oil pump. With 15W-50 on a cold morning, the initial OP at startup will easily show 80+ PSI for the first few minutes. Once warm, oil pressure at idle will range 30-40 and cruise will show 40-60. last time I checked the senders are the root of the fluctuations.

I've read many horror stories of high pressure/high volume oil pumps destroying big blocks. Based on my limited samples, this isn't an issue.
 
The common spot is to pull the 'warning horn' switch or the sending unit and connect the gauge there. There's a pipe fitting in the block above the oil filter adapter. Many installs have a T fitting there for the switch & sender which usually are 1/8" NPT. Best way is to use a pressure rated hose to connect the gauge to the port. If you need a hose, a grease gun flex hose is usually readily available at the auto parts stores. The 3' ones are the min length I'd suggest.
 
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