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Author Topic:   oil presure
holeshot
Dirt Full Roller

Total posts: 53
posted March 25, 2002 01:24 PM UIN: 3728
last night at the races the guy that I help had problems with oil presure dropping started cold at 75 psi went out and did 6 laps and came in at 25 to 30 psi at idle.let sit and it was back up to 75. changed oil to 60 weight same problem,also when cold and at 75 psi if we brought the rpm to 3000 oil presure would start to fall off let it idle again and it would go back up to 75psi any ideas thanks

EVANSRACING24E
Dirt Forum Racer

Total posts: 80
posted March 25, 2002 10:40 PM
do you have a high volume high pressure pump if so you could be sucking all the oil of the bottom and putting it up on top of the motor.

[This message has been edited by EVANSRACING24E (edited March 25, 2002).]

Slam_Shifter
Dirt Full Roller

Total posts: 53
posted March 25, 2002 11:13 PM
MY high pressure stock volume pump did the same. Cold 80 @ idle and warm 30 @ idle and 80 under RPM. I wouldn't worry about it too much. the dropping off at higher rpm sounds like the previous post said.That you are pumping all your oil up top.Do you run restrictors in your block?I may be wrong but after looking futher into the topic I think a high pressure pump is a waste of time and HP. Accordind to the local engine builders here a properly built engine can survive with as little as 3psi @ idle and the less oil pressure you carry and can still keep the motor alive the more hP you will make and the less strain you will put on the distributor and cam.The latter part of this is just my personal opinion.I have ran motors both ways and both survived.

holeshot
Dirt Full Roller

Total posts: 53
posted March 26, 2002 10:19 AM UIN: 3728
8 qt oil pan hv pump and restrictors motor is from last year but different block last year motor had a sleve leaking but good oil presure.

dirtbuster
Dirt Freak

Total posts: 353
posted March 26, 2002 11:48 AM
A few years ago we had a new motor do the same thing. We broke it in fine and it would idle about 70-80# cold and 30-40 hot. Everthing was fine until it hit the track and after a few laps oil pressure dropped and it started spitting oil out of the valve covers. Bring it in to pit restart and idle about 60#. After a week or two of fighting it we found out the problem was a crack in the block and 1 set of rings never seated so when running it hard, blowby in that cylinder was building pressure in the crankcase and oil would not drain back.

Hope this helps, I know it was aggravating for us.

#28
Dirt Maniac

Total posts: 154
posted March 26, 2002 12:24 PM
You may want to check the oil filter also, I have had some brands (Fram) suck the element in and cause the pressure to drop.

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