Low Deck 451 Oil Pressure

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vestracing

vestracing

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Quick question: bought a used 451" motor that is fully race prepped. I won't go into specifics but when started and cold it pegs out the oil pressure gauge at over 110PSI. Typically it is still running over 80 psi at the finish line. Is this normal and adequate. Even when I didn't turn the fan on for a run and the water temp crept up to 210° the oil pressure at the finish line was over 75PSI. This block is half filled also. Running Valvoline 20W-50 VR1.
 
I'd try an adjustable spring setup for the pump. I believe 440 source & milodon carry them. You can chop a coil off yours to try & get it down as well. Sounds like very tight clearances on the build. May consider a 10-30 or lighter sythetic too.
 
that is what I was thinking but they guy we bought it from said that was normal from when he had the motor built. I am going to give the engine builder a call this afternoon and get the scoop from him.
 
Long as it ain't blowin the filter off, it's good.
 
it has a system 1 reusable filter so it is not going to do that. I am really not that concerned about how fast it is as it is a bracket car. Just don't want to have to worry about drive gear and cam.
 
You definitely want to get it down. It's going to cause leaks down the road. Had similar issues with my smallblock. Kept having oil filter leaks & other gaskets until I lightened up on the oil.

Personally, I'd rather the motor a little looser so I could always run 20-50. Never had bearing problems with that oil.
 
We have always ran vr1 20w50 in all of the big blocks we have raced as well. Another question: with the indy head oiling lines coming out of the rear of the block where can I install an oil temp gauge? I am switching over to alcohol over the winter and want to be able to monitor oil temperature.
 
vestracing said:
Quick question: bought a used 451" motor that is fully race prepped. I won't go into specifics but when started and cold it pegs out the oil pressure gauge at over 110PSI. Typically it is still running over 80 psi at the finish line. Is this normal and adequate. Even when I didn't turn the fan on for a run and the water temp crept up to 210° the oil pressure at the finish line was over 75PSI. This block is half filled also. Running Valvoline 20W-50 VR1.
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Mine did the same. Dropped to 5w40 oil and oil pressure is about 80 on startup. 40psi at idle hot. and 65ish at cruise RPm hot. Still high but not nearly as bad.
 
that motor is a mopar that's a good psi:cheers:.that thing should last for ever (not a big fan of the split wt.oil though:violent1::violent1:.I like a strat 40or50wt.racing oil:cheers::cheers:.( and I hope you're running the big oil psi line:prayer::prayer: and not the little 1/8 inch one!!big no no.:violent1::violent1:.I would leave it alone and run it............Artie
 
IMO - I'd check the lower end clearance myself to see what the clearances are. It sounds like an HV oil pump and tighter clearances. When you add together the 1/2 fill and all that wasted pumping and bypassing - you get the higher temps. I'd be curious what the oil temperatures are...
If it has tight clearances that's fine. I prefer tighter. But - I don't run the HV pumps. I run a stock pump with a higher pressure relief and I prefer running 10/30. With clearances of .0015 -.002 on the mains and .002-.0025 on the rods and decent lifter bores this should max around 70psi and have around 20psi at idle hot.
 
vestracing said:
explain yourself on the line size. Pressure is pressure, shouldn't matter what size the line is.
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the bigger line will let you know exactly what your oil psi is doing right now.and it will move with your tic.touch the gas pedal and the oil psi will move with it.if you have a bad bearing or one going bad you will no it write away with the gage fluctuating buy 10psi.with the small line you shut the motor down and can usually watch the oil psi drop off slowly..or when you go thru the traps and the gage says you have say 80 psi.when you really don't have any tell its to late.look at all the the pro guys and see what they're running...I guess the little line is good for a temp.get it going thing but I think the 30.00 bucks is well worth it.and besides when that little line starts to leak or brake is one hell of a mess to clean from the carpet..hope this explains it ok good luck and i'm sure that 451 is bad ***........Artie
 
godfatherofchry said:
the bigger line will let you know exactly what your oil psi is doing right now.and it will move with your tic.touch the gas pedal and the oil psi will move with it.if you have a bad bearing or one going bad you will no it write away with the gage fluctuating buy 10psi.with the small line you shut the motor down and can usually watch the oil psi drop off slowly..or when you go thru the traps and the gage says you have say 80 psi.when you really don't have any tell its to late.look at all the the pro guys and see what they're running...I guess the little line is good for a temp.get it going thing but I think the 30.00 bucks is well worth it.and besides when that little line starts to leak or brake is one hell of a mess to clean from the carpet..hope this explains it ok good luck and i'm sure that 451 is bad ***........Artie
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I understand what you are saying BUT.....what good will a large line do when you are feeding thru a very small fitting? The fittings become the restriction....had this very discussion a while back with a trans shop about running larger cooler lines.....Not looking for a war, just to understand....
 
I believe he's saying the small line accompanied with the thick oil makes it slow to bleed back to the motor as the pressure decreases. Whereas the large line will allow the oil to drain back quicker giving you a more "real time" pressure based on throttle, etc.
 
inkjunkie said:
I understand what you are saying BUT.....what good will a large line do when you are feeding thru a very small fitting? The fittings become the restriction....had this very discussion a while back with a trans shop about running larger cooler lines.....Not looking for a war, just to understand....
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well if you get the fittings to go with the big line you will see what I mean.if you call summit they sell the big line in a kit I think the whole kit is like 60.00 bucks but if you get just a line (can't remember the size 4 I think)here better yet (sum-G2960 3ft.line kit 24.95)there I even looked it up for ya and is cheaper than I thought.try it I think you will be impressed.and it will last you a life time If taken care of.............Artie
 
80fbody said:
I believe he's saying the small line accompanied with the thick oil makes it slow to bleed back to the motor as the pressure decreases. Whereas the large line will allow the oil to drain back quicker giving you a more "real time" pressure based on throttle, etc.
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and it doesn't matter if its thick oil or thin it will still reaked the same.........Artie sum-G2960 $ 24.95 oil or gas same kit:cheers:...thank me..lol Artie
 
Maybe I learned under different mindsets, but I was led to believe a blueprinted standard volume oil pump with the correct oil viscosity was the way to go...reduced oil temps and reduced likelihood of popping the filter canister or end cap and bypassing the filter element, also less parasitic losses.

Are those not correct?
 
txstang84 said:
Maybe I learned under different mindsets, but I was led to believe a blueprinted standard volume oil pump with the correct oil viscosity was the way to go...reduced oil temps and reduced likelihood of popping the filter canister or end cap and bypassing the filter element, also less parasitic losses.

Are those not correct?
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I have no idea how to answer this never was too technical.about things like this didn't think I had to when it comes oil psi. on a mopar.I know on the old FE fords you had to do a lot oil oil mods to race them but the mopars were race ready off the showroom floor.:cheers:and with the HV pump I have twisted all my big blocks to 7 or 8ooo.with no trouble.but you better have at least a 7qt.oil pan to do it...im sure this is not answering your Question but its the only one I have:wack:eek:oooo well ..........Artie
 
Yeah, not really...I'm sure there are different schools of thought on this subject, but utilizing too high a pressure will certainly heat up the oil, and of course, heat kills oil and diminishes it's protective properties. Also, too high a pressure can pop the filter cap or the element itself and cause a bypass condition where the oil is no longer being filtered...just recirculated.
 
As long as the cooling system keeps the engine heat down, the engine oil will be fine. Pressure has nothing to do with the load on the intermediate shaft, either. It's the volume that causes the drag. Once you have an HV oil pump, you have an HV oil pump. As long as you have the hardened intermediate shaft, you are fine. Stress on the shaft does not go up with pressure. If you have an HV pump, you have all the stress you're ever gonna have on the shaft right there. Stress does not increase with pressure, only volume. So, a standard volume pump has one level of stress and an HV pump another. Simple as that. I have always said that as long as the engine is not blowing oil filters off or apart, leave it alone. I think you are looking for trouble where there may be none.
 
So you blow an oil filter apart at the track an oil down your tires at the big end? Should he wait till then?
 
vestracing said:
Quick question: bought a used 451" motor that is fully race prepped. I won't go into specifics but when started and cold it pegs out the oil pressure gauge at over 110PSI. Typically it is still running over 80 psi at the finish line. Is this normal and adequate. Even when I didn't turn the fan on for a run and the water temp crept up to 210° the oil pressure at the finish line was over 75PSI. This block is half filled also. Running Valvoline 20W-50 VR1.
Click to expand...

More than adequate by far IMO.
And I don't see any reason to run 20w50 in a combination like that.

RustyRatRod said:
As long as the cooling system keeps the engine heat down, the engine oil will be fine. Pressure has nothing to do with the load on the intermediate shaft, either. It's the volume that causes the drag. Once you have an HV oil pump, you have an HV oil pump. As long as you have the hardened intermediate shaft, you are fine. Stress on the shaft does not go up with pressure. If you have an HV pump, you have all the stress you're ever gonna have on the shaft right there. Stress does not increase with pressure, only volume. So, a standard volume pump has one level of stress and an HV pump another. Simple as that. I have always said that as long as the engine is not blowing oil filters off or apart, leave it alone. I think you are looking for trouble where there may be none.
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RRR, please take some time to study how your hydraulic brakes work and think about what you just stated as fact.
 
CPMotorworks said:
More than adequate by far IMO.
And I don't see any reason to run 20w50 in a combination like that.
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X2

Like I said before try some 5w oil and you'll most liekly end up with something that is more resonable but still high.

Crazy high oil pressure robs power and beats the crap out of the oil.
 
CPMotorworks said:
More than adequate by far IMO.
And I don't see any reason to run 20w50 in a combination like that.



RRR, please take some time to study how your hydraulic brakes work and think about what you just stated as fact.
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Piston operated brakes are an entirely different application than a gerotor style pump. But for the sake of a 12 page argument, you're right. I'm wrong.
 
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