oil pressure problem

need some advice, this problem just started after letting out from the burn out the oil pressure drops from 130# to 30# then will only come up to around 60# when staging the car the pressure is going from 60 to 80 when leaving the lights it is over 130# all the mains look good all the rods look good..this is on a kb hemi.......HELP!!! thanks Dave

 

is it a wet sump or dry sump.? is the presure drop during breaking ?

 

sounds like it is running out of oil
you do the burn out it all gets put up top
by the time you stage it is getting back to the pan
but only if it is a wet sump

you dont have them 3/4 groove mains in it do you

 

Pressure Issues

Dry Sump or Wet Sump?
How many qts. in the system?
Tank? what size?
Is it baffled or Not.
Answer these and I'll try to help.

 

(FWRC) wet sump, 13 qt, trap door pan...this is a 526 kb- brad deal. this problem just started knocked off the pan between rounds and checked all the bearings they looked new (BRUCE) It seems to start after the burn out (john) yes after the burn out..but I have never had this problem before
Thanks guys for helping

 

Did you change heads?

Have you done a good leak down check, it sound like a bad case of high crankcase pressure.

How many laps on the ring sets?

 

Oil Pressure Issues

If its in fact a Wet Sump with no external tank then it has to be a Cavitational Issue.
Seems that your pick-is losing Oil feed and sucking Air.
Typicaly Oil Pumps will not recover from cavitation to full flow in short order.
As to why this Gremlin has just arrived?
Make sure the Pick up hasn't moved.
Make sure all oil lines are tight and secure.
I know this sounds dumb, but confirm oil capacity in the Pan.
13 qts is a huge oil mass moving around in that Pan from rear to front in a second.

 

when i ran a wet sump it was normal to loose oil pressure during breaking, both after burnout and while slowing in the shut down area. even with 13 qts. in the pan at start up. if you are running any type of rocker oilers you can fill the valve covers real easy. FWRC brought up a good point about cavatation. just because it didn't happen before doesn't mean the punp could have worn to the point that is cavatating now. i never hurt a bearing when it would lose pressure during slowdowns. if you can swing it during the off season, look into a dry sump. acceleration and deceleration won't affect the pressure anymore.

 

I have the car sitting in the shop right now with two rod hanging out the side of the block and it was from the same thing you discribe. I would have fluctuating oil press after the burn out and then we would see it decline over the coarse of the run on the racepac. I believe what we had happen to us was the pickup sucked itself to the bottom of the pan. It didnt cover all the pickup screen area but it does decrease the screen area about half. with the added resistance in the pickup it would cause the pump to cavitate, a pump does not need to draw air to cavitate all it needs is a restriction on the inlet side if a pump is trying to push more than it can suck it will cavitate....
P.S. My bearings always looked good too. I was working on the problem when all hell broke loose. The last change we made was to get rid of the HP6 filter and go back to a system one thinking this was the restriction......well that was the last straw as soon as we relived the restriction on the pressure side it amplified the cavitation issue and the old girl hung her legs out. Im not saying this is your trouble but it will give you one more thing to check.
I hope you find it before it bites you.
Best wishes
Gary

 

Oiling Issues

Afueldigger
Sorry about your loss.
I concur with your comments on Cavitation and I agree with the HP6 filter.
One should never use a paper filter.
It decreases flow,clogs easily and unless you open it up after every pass you don't have a clue whats happening in your Engine.
The alternative is a good 60 micron S/S screen filter either in line or designed into the Pump itself.
As for Systems themselves I would always recomend a "dry" Sump over a Wet sump.
The reasons are elementary, Windage,Oil control by scavenging from the Pan,Valley and Valve covers.
When you consider the cost for Bearings, Rods and early trips home they are worth the investment.
Just ask Will Hanna or Jeff Wilson.

 

Thanks guys for all the different thing to check..all of you had great answers.
I might add when this problem started it was getting a lot colder than when we didnt have the problem, could this be an issue. also I was told that most ta/d with a wet sump use around 16 quarts.. (so lets hear it)..Thanks Dave lowe