Oil pressure drop at end of 1/4 mile pass

Is it generally accepted that the easy fix for this is an oil accumulator? I am looking at the 4.5"X10" Moroso unit with a sandwich adaptor in between the block and filter.

Oil pressure looks good the entire 1/4 mile pass, but after I go through the lights and brake, oil pressure drops to below 25 psi for 3-4 seconds then comes back up. I did two 1/4 mile passes this way, then decided to stop until I find a solution.

Note: 1/8th mile I don't have the problem at all.

Consider a sump baffle with a trap door.
Old school but it works.
Never messed with accumulators, but I know dudes that swear by them.
I am just a plain old (trick) baffle guy.
Keith

[quote="psfracer"]Is it generally accepted that the easy fix for this is an oil accumulator? I am looking at the 4.5"X10" Moroso unit with a sandwich adaptor in between the block and filter.

Oil pressure looks good the entire 1/4 mile pass, but after I go through the lights and brake, oil pressure drops to below 25 psi for 3-4 seconds then comes back up. I did two 1/4 mile passes this way, then decided to stop until I find a solution.

Note: 1/8th mile I don't have the problem at all.



I INSTALL THESE IN THE PORT BY THE BACK OF THE BLOCK, IF YOU INSTALL THEM AT THE FILTER THEY TEND TO FILL THE FILTER AND YOU LOOSE SOME OF THE EFFECT.


I HAVE 2 FOR SALE

psfracer wrote:Is it generally accepted that the easy fix for this is an oil accumulator? I am looking at the 4.5"X10" Moroso unit with a sandwich adaptor in between the block and filter.

Oil pressure looks good the entire 1/4 mile pass, but after I go through the lights and brake, oil pressure drops to below 25 psi for 3-4 seconds then comes back up. I did two 1/4 mile passes this way, then decided to stop until I find a solution.

Note: 1/8th mile I don't have the problem at all.

Pretty common problem to have the oil slosh away from a rear pick-up during DE-celeration. At least you looked and caught it.
Most Super Stock racers just turn OFF the engine and click it in neutral however, that doesn't FIX the problem; just gets around it.
A horizontal baffle over the forward half of the sump usually solves it but, sometimes a more involved baffle is necessary.

3 qt accusump plumbed into the port above the filter, electric switch on the accusump tied into the ign switch................never a dry start....never a pressure drop issue even on short shutdown tracks with the chute pulled and the brakes smokin hot.

Ran this setup on the previous build and the bearings looked so good I resued um. I wouldn't fiddle with the pan as I remeber you had a decent piece on it already. Get the 3qt acccusump deal and be done with it.

I like the port above the filter better myself as its a straighter shot to the bearings and the ports bigger.............I have used the port on the rear of the block with no issues its just a preference.

Also I dont use a switch to open the valve when the pressure gets low, its open the whole time the ign switch is on.

How did the car run?

Mine did the same thing then it just broke off this past weekend....I always wondered why my oil pressure would drop after a pass

Thanks for the feedback everyone.

richter69 wrote:How did the car run?

Ok for now. I only ran two passes because of this issue. First full 1/4 mile pass I did I let out as I still do not have my license, so I ran a 9.94. Second pass I blew the tires off, so I let it straighten itself out, then got back in it around 80 feet out, and ran 141 mph at Fontana where the DA was 3837 at the time. It will mph 145 and should turn 9.40s to 9.50s when I get this all sorted out. I am just a little frustrated right now as I am correcting a few "new car bugs".

On another note I weighed the car at the track and it was 3420 (with driver).

As been mentioned, click the tranny into "N". Another idea comes to mind! Of the issue, where to locate the line from the oiler to the block. Just my opinion, if your oil pressure line that feeds the oil pressure guage is located near the oil filter (block mounted), the oil pressure at the rear of the block could be less. As to mounting the oil pressure guage feed, I'd prefer the rear location, also inject the oil from the oiler at the rear, since the oil pressure may be lower at the rear of the engine than the front during starvation. What ya think?

I assume the stopping distance is greater with a 1/8 mile pass, reference to the oil pressure is non-existent as well the engine run time is less. Then again, her ass could be pumping like an oil well!... ...

Dave.

I have the oil pressure sending unit off of the rear of the block.