Oil Pressure Dips with Heavy Braking

[BUDFIVE]

During the second go cart drive of my Roadster yesterday I bedded the brakes, cooled them, then hit them pretty hard to test front to rear proportioning. This car stops really fast. Out of the corner of my eye I watched the oil pressure gauge and sure enough, during heavy braking, the oil pressure dips. It didn’t drop to zero and returned to 60+psi quickly so I don’t think I did any damage. But, Clearly my baffle and a 4 quart pan (5 system) is not enough. The pan is a Dorman 264-022 factory Mustang replacement with dual sump. I am using a Melling M-68 standard pump and rear sump pickup with a welded-in baffle forward of the sump. Perhaps not enough oil is under the baffle when I slam on the brakes?
IMG_4241.jpegIMG_4242.jpeg
I’m looking at oil pans for the Ford 302/347 with a higher capacity—-I’ve found:
Kevko F901 rear sump-7qt pan
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Has anyone used this pan? Comments?

Are there other pans I should consider?

I’m trying to stay away from 2 drain plugs.

BTW I welded in the baffle and I was watching the oil pressure since Jeff at Texas Engine Machine had warned me and a few of you had questioned my pan choice. I was listening. Now I’ll suck it up and spend some money.

[egchewy79]

I have this pan. Good quality for the price.

[CraigS]

That looks good to me. Check w/ Levy Racing as they sell that or similar pans. Be sure to get a matching oil pump pickup tube. Also look at Canton pans.

[burchfieldb]

I have one from Kevco for my Cleveland, it is a nice piece. They also had the pickup I needed. Although I have only run it on my engine stand at this point. Their customer service was also really good.

[tonywy]

SBF - 289/302, original 289 Cobra 7-1/2" front sump Road Race pan. Includes custom pickup, 4 door trap assembly, slosh/windage tray w/ welded in lip scraper. Maximum oil control with maximum ground clearance. Includes custom pickup.

Length: 15" Depth: 7 1/2" Width: 12" Quarts: 8
Price: $574.60

SKU: 155-55355

Check out Aviaid

[GoDadGo]

I'm sure adding the baffle will help control the oil sloshing a bit better, but upgrading your pan will too.

.....................Good Luck, Merry Christmas & Happy Hanukkah!

[BUDFIVE]

Thanks all.
GOdadgo—fyi, the welded in baffle was already in place so it’ll have to be a new pan.

[GoDadGo]

Thanks all.
GOdadgo—fyi, the welded in baffle was already in place so it’ll have to be a new pan.

I bet you solved your problem, at least for now.
The link below is what I'm running on my Dark Side MK-4:
. https://www.summitracing.com/parts/mil-31503

[BEAR-AvHistory]

You should be looking for a trap door pan. More money but keeps the pickup submerged.

[rich grsc]

100% agree with Kevin. Get a pan from Kevco with trap doors and you won't have any issues. They also have the best bang for the buck.

[AC Bill]

Does it always normally idle at 60psi, or is this when you're back on the throttle again after stopping?
It wouldn't be totally abnormal to see the psi drop when you lift off the throttle pedal and are stepping on the brake, as the rpm's also drop. I believe at rpm idle my engines oil pressure is only 20-30 psi, but 50+ when driving, so I would expect a to see a drop when I lift.

You could test to see if the pick-up is actyally starved of oil, by popping the car into neutral, and left foot braking, while keeping the rpm's up with your right foot. See if the psi holds, or drops.

[Ford & Jeep Fan]

My Cleveland is getting a 20530 Moroso pan that has been modified quite a bit by yours truly. It was a originally a 9 inch deep (drag racing) 8 quart pan. and it is for a fox chassis having 2 drain plugs. what I have now is a pan 7.5 inches deep in the back and a narrower 6inch sump in the front (one continuous sump, like a pan for a boat). the original part of the pan that was supposed to be above the rack and crossmemeber is now a short windage tray. The center is now a "Windage tray / psassage " for front oil to get from the front sump to the back sumps AND it has Many holes in the "top" to let oil in the passage.

Full disclosure: I did not cut up a new $450 dollar oil pan. I bought one that had a bit of damage/and a few holes on ebay cheap.

it looked this when new

[BUDFIVE]

The baffle has been in all along since before first start so the baffle did not prevent the problem.

The oil pressure dropped in gear or out and to levels below my idle pressure. Pressure returned quickly (~1-2 seconds) when I let off the brakes, even without rpm increase.

It makes me curious if Mustangs with this pan had brief drops in oil pressure during braking or do our cars have that much higher g-forces when stopping? If I’m totally objective, I have to ask if my baffle somehow made it worse? (Damn, can’t get the engineer out of me) Interesting but moot question—I won’t accept the drop in OP so I’m getting a new higher capacity pan with a gate/trap door.

[rich grsc]

Baffles are not trap doors, They should help if properly installed. A trap door system will let oil into the pump pick up area, but not out

[Ford & Jeep Fan]

.......
It makes me curious if Mustangs with this pan had brief drops in oil pressure during braking or do our cars have that much higher g-forces when stopping? If I’m totally objective, I have to ask if my baffle somehow made it worse? (Damn, can’t get the engineer out of me) Interesting but moot question—I won’t accept the drop in OP so I’m getting a new higher capacity pan with a gate/trap door.

Yes The G forces are that much higher. THe weight of the your car is about 2/3rds of a (1988) mustang and Tires are are MUCH bigger giving more grip.

[Mike.Bray]

SBF - 289/302, original 289 Cobra 7-1/2" front sump Road Race pan. Includes custom pickup, 4 door trap assembly, slosh/windage tray w/ welded in lip scraper. Maximum oil control with maximum ground clearance. Includes custom pickup.

Length: 15" Depth: 7 1/2" Width: 12" Quarts: 8
Price: $574.60

SKU: 155-55355

Check out Aviaid

I'll second Aviaid, very very nice product. You can also check out 155-55362 as it gives a little more ground clearance. I have the same one except for my 351W.

https://aviaid.com/shopsite_sc/store...s_sbf-ss2.html

[Avalanche325]

I agree that a trap door pan is the way to go. Make sure you check the pickup to pan clearance.

[CraigS]

One other thing that affects this is FFR gauges. What you are seeing in your FFR is as near as can be to a live OP reading. What you see in nearly any daily driver car that happens to have an OP gauge is a heavily damped, or modified, or processed gauge reading. They don't want to listen to complaints.

[BUDFIVE]

Craig, I agree-even my c6 vette OP seems less real time and more of an average.

[BUDFIVE]

Update-hey y’all I ended up installing the Kevko F901 pan (7+1 rear sump with trap door). I detailed the install in my build thread if you’re interested.

https://thefactoryfiveforum.com/show...-Upgrade/page3


Bottom line is the engine is back up and running with good oil pressure (stationary) and I’ll retest performance during braking at the next gocart.
I’ll close this thread out then unless I still have a problem. Thanks all.

[kevin j sullivan]

My oil psi drops from 60 to 20-30 at a stop light after it's warmed up. Recently rebuilt my motor - (stroked out windsor - 610 HP) Car still does the same thing. Oil is always full, no leaks. Builder and all the "experts' say the same thing. No worries, oil is moving around, it's normal. I have a melling manual pump and a 2 stage pan. So long as it doesn't drop too low and stay there, I think your'e O.K. Have mine for 8 years now.

[BUDFIVE]

Kevin, it’s completely normal for the idle OP to drop to something like you said (20-30psi) once the engine and oil are warmed up. I consider (among other factors) where the hot idle OP is in choosing oil viscosity once an engine is broken in. Sometimes this makes me choose 10w-40 over 10w-30 if the 10w-30 hot idle OP is too low for my liking.

Anyway, this is totally different than the original point of this thread where oil pressure dropped, independent of temperature, during heavy braking.