oil pressure question
Thread Starter
Melting Slicks
Joined: Apr 2002
Posts: 2,546
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From: Orlando FL
oil pressure question
Hey guys,
I recently finished a rebuild on my 84 vette.. Since the rebuild I have about 390 miles on the clock. All the miles have been babied under 3k rpms.. Oil pressure from the beginning has been around 50+ at idle.. and over 60 while crusing.. Today i took the car for a spin (approx. 100 miles trip) just to break in the motor a lil faster.. Im cruising down the interstate about 30 miles from my house, and my oil pressure starts to slowly drop.. It dropped slowly.. about 1psi every mile or so.. By the time I made it home, the idle PSI was at 30.. I let the car sit a little bit, and then fired it up, idle PSI is under 20? what the heck is going on? Bad oil pump? I bought a brand new mellings high volume pump..
I did notice a lil oil somewhere on the front side of block (probably timing chain cover).. Could a leak cause the drop in pressure?
I recently finished a rebuild on my 84 vette.. Since the rebuild I have about 390 miles on the clock. All the miles have been babied under 3k rpms.. Oil pressure from the beginning has been around 50+ at idle.. and over 60 while crusing.. Today i took the car for a spin (approx. 100 miles trip) just to break in the motor a lil faster.. Im cruising down the interstate about 30 miles from my house, and my oil pressure starts to slowly drop.. It dropped slowly.. about 1psi every mile or so.. By the time I made it home, the idle PSI was at 30.. I let the car sit a little bit, and then fired it up, idle PSI is under 20? what the heck is going on? Bad oil pump? I bought a brand new mellings high volume pump..
I did notice a lil oil somewhere on the front side of block (probably timing chain cover).. Could a leak cause the drop in pressure?
Race Director
Joined: Feb 2004
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Hook up a mechanical psi guage and take a reading. If it is still low, you have serious problems. If there is a fram filter on the car, Get It Off!. They have collapsed on us (internally) while running on the dyno.
Race Director
Joined: Sep 2000
Posts: 17,298
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From: The Top of Utah
Not a little leak. It sounds like you have finally warmed it up good, for the first time. What is your oil change history on this new engine? I don't think you have a problem, but it may be time for a change.
RACE ON!!!
RACE ON!!!
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
It isn't "x-fire" specific. After all it's just another sbc, with a funny intake manifold. If your old engine idled at 50# oil pressure, hot, something was not right. However, the problem was more likely to be the gauge then the engine. The oil thins as it heats and the pressure should be expected to drop when it warms up. Also, at 400 miles, I would be nearing my 4th oil change. If you warm it up thoroughly before you change it this time, you may be surprised how thin and watery it is, as it drains. If so, this is a great contributor to the hot, lower oil pressure. There is nothing at all wrong with 20# of oil pressure at idle, hot. I'd worry more about 50# at idle, hot. As worn out as my engine is, I sometimes see less that 10# at a hot idle, and THAT isn't even a big problem.
RACE ON!!!
RACE ON!!!
Thread Starter
Melting Slicks
Joined: Apr 2002
Posts: 2,546
Likes: 0
From: Orlando FL
To be honest.. I was more scared about the pressure dropping I wasnt even paying attention to how it felt.. It gets an oil change in the morning, and I will than take it for a spin.. I'll keep everyone posted. Thanx for the info guys! I was sweating bullets....
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From: Good health is merely the slowest possible rate at which one can die
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Originally Posted by CFI-EFI
Not a little leak. It sounds like you have finally warmed it up good, for the first time. What is your oil change history on this new engine? I don't think you have a problem, but it may be time for a change.
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If you truly had 50 psi of oil pressure at idle, at best you'd be wasting HP creating more oil pressure than your engine needs. Definitely keep an eye on it and if you observe any irratic behavior, put the mechanical gauge on it and find out what's going on for sure. If it falls into a consistent pattern of say 20 psi at idle and a maximimum of 60-70, you're fine. Remember, oil takes about twice as long (or even longer in cold weather) to get to normal operating temps as does your coolant temp.
Thread Starter
Melting Slicks
Joined: Apr 2002
Posts: 2,546
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From: Orlando FL
Oil smells and look ok. The level has been very constant. Just for assurance, i drained and measured the oil today.. almost 5 quarts.. So there is nothing going in there..
I was reviewing notes and pictures of the rebuild. Here is something I havent been able to find in my book. The threaded piece that the oil filter screws unto is held into the engine block with two screws. My question here is - Is there a paper seal that is suppose to go between the engine block and oil filter attachment?
The engine gasket kit i received had a paper gasket that said "oil filter gasket".. It was obvious it did not fit on the filter it self, but fit in the hole on the block perfectly... Has anyone ever installed a gasket there?
I was reviewing notes and pictures of the rebuild. Here is something I havent been able to find in my book. The threaded piece that the oil filter screws unto is held into the engine block with two screws. My question here is - Is there a paper seal that is suppose to go between the engine block and oil filter attachment?
The engine gasket kit i received had a paper gasket that said "oil filter gasket".. It was obvious it did not fit on the filter it self, but fit in the hole on the block perfectly... Has anyone ever installed a gasket there?
Race Director
Joined: Sep 2000
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From: The Top of Utah
I haven't.
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After Thought: If oil leaks between the oil filter adapter and the block, where is the oil going to go? What would be the point?
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After Thought: If oil leaks between the oil filter adapter and the block, where is the oil going to go? What would be the point?
Last edited by CFI-EFI; Sep 28, 2005 at 08:52 PM. Reason: After Thought.
Thread Starter
Melting Slicks
Joined: Apr 2002
Posts: 2,546
Likes: 0
From: Orlando FL
I dont really know what the point would be either.. I have never installed one in the two other SBC's i've build, or the toyota motors i've done... I was kinda surprised to see it. I however can not remember if there are any holes this seal would have blocked.. I am pretty sure there wasnt.
On top of that.. This oil change was the cleanest filter change I have ever done. Virtually no oil ran over the filter and down onto my hands.. This is something im not use to..
On top of that.. This oil change was the cleanest filter change I have ever done. Virtually no oil ran over the filter and down onto my hands.. This is something im not use to..