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Too Much oil pressure?

3K views 4 replies 3 participants last post by  rifraf 
#1 ·
Hello all. I recently had a 454 rebuilt and dropped into my 1971 Nova. Well Thursday Night was the first time we had ever crunk the freshly rebuilt motor. The motor was rebuilt with a very healthy to the point where it should make around 475 horsepower at the flywheel.

My questions is, is there a such thing as too much oil pressure? The bottom end was totally rebuilt with all new bearings, the block was vatted, baked and honed, the rods were all reconditioned and fitted for ARP bolts,and a Melling Hi volume (Melling HV-77) oil pump was used.

Well anyway, upon the motors first ever start up the motor was carrying around 95-100 pounds of oil pressure. There were no leaks or anything like that. Eventually the pressure fell off and stayed to about 85 pounds. My father also has a 454 in his 69 'Vette, but his tends to only carry around 65 pounds of pressure. Do I have any reason for concern? Or is that much oil pressure a good thing? Any info is appreiated and thanks in advance.

Rob
 
#2 ·
Well yes,there could be some problems with that,how big of pan do you have,and what sort of oil do you have in it,also,is this a roller cam motor? Its pretty tight yet,how much pressure do you have at an idle and at what temp,and are the pressures you gave at a rev? It doesn't necessarily sound like a bad thing.
 
#3 ·
249-CL11-250-3
Xtreme Energy XE284H Hydraulic Flat Tappet Camshaft
Lift: .574''/.578''
Duration: 284°/296°
RPM Range: 2300-6500

Thats the Cam that was used in the motor. As for the oil pan, its a 5 quart.. and the only oil pan I could find that wouldn't hit on the steering. The oil that we used was Valvoline 10-w30. When first started at a higher idle (maybe 1200 rpms) the oil pressure was 95-100. As the motor was heating it, it wasing being sped up and slowed down and the pressure kept fluctuating between 85-95 poiunds.

Thanks for your response.

Rob
 
#4 ·
During cam break in you should of had the RPMs in the 2000-2400 RPM range.

Before you worry about too much pressure I would change the oil and the filter (should be done right after cam break in). Right now you have assembly lube (if you used it) and other things floating around in your oil.

The main thing that would cause your oil pressure to be so hign is you bearing clearances. Do you remember what they were set at? Sounds to me like they are on the tight side, with that and a high volume pump your oil pressure will be high.

Tthe only problem are the possibilty of having busted oil filters, pushing the O ring out, and heating up the oil.

After you do an oil and filter change and run the engine for a while, see how the pressure acts. If the pressure doesn't settle down I would probably pull the pan and change the oil pump/spring. You really only need about 10psi per 1,000RPM (meaning at 6,000RPM you need 60psi of oil pressure).

ROyce
 
#5 · (Edited)
A couple things,my one concern was you thrashing your dist and cam gear,but I would guess you didn't use a bronze one because there was no need with that cam so your good there,also,you run the risk of sucking the oil out of the pan at high rpms and hurting the bearings"cant drain down fast enough",it could all end up on top,also,if you feel the need,you could put a lighter spring in the pump,some come with one,high pressure and high volume are two different issues,I am getting ready to put the same cam in a 454,how does it sound? do you like it? I would stay with a lighter oil for awhile.

Also like camaroman7d says about the filter blowing,that would fall into the"bad thing"category,they have filters with high burst pressure ratings you might want to think about.
 
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