Oil pressure drop during hard right turns

[Glory Bound]

I have a 460 CJ crate engine in my MKIII with a Canton baffled oil pan (15-764) and windage tray. When I take hard right turns at speed my oil pressure drops from 70 to 20. It rebounds when I take a left turn or go straight. Anybody else see this happen in their cars or other's cars?

[Rscocca]

the oil pump HV? If so you starving it on corners, also, how far from the pan is the pick up. I usually put some tape over the pick up then some playdo to measure how far away it is. Should be less then 1/2 in.

[Glory Bound]

I ran it with almost 2 quarts overfilled last weekend at an SCCA AX and oil pressure stayed constant. I plan to continue to do that unless i find another root cause. Probably losing some HP but still have plenty to spare with my newb skills.

[Tad]

Probably losing some HP but still have plenty to spare with my newb skills.

That'll be a very small price to pay considering the alternative is losing ALL your HP from starvation. I would definitely run the extra oil. I understand high volume pumps and slow oil drainage back to the pan from running high revs often causes this.

I just recently did a track day and used all the tricks I could to prevent this same problem with my 4.6 dohc mod motor. I installed a Champ pan, Accusump, AN12 lines, Setrab 19 row oil cooler, and a huge Wix Racing oil filter set-up. Several guys with mod motors have posted about oil starvation issues and destroyed engines so I was a bit paranoid. But no issues while on the track - I watched the oil pressure gauge like a hawk for the 1st couple of sessions. Like you, I also over filled by about a quart or two.

[Bob Cowan]

Overfilling the oil pan is a bad thing. Not quite as bad as out-right starvation, but pretty close. Yes, you will keep the pick up covered, and that prevents the pressure gauge from dropping. Bad things will still happen.

One of the goals of a deeper pan is to get the oil resevoir further away from the crank shaft. You definatly do not want the crank throws to be hitting the oil. Somebody do the math here - a 4" crank throw moves how fast at 6,000 rpm's? I don't know, except that it's really fast. Take a stick, and hit the surface of a pond as hard as you can. Feel the shock wave? No imagine that shock wave apmplified to the speed of the crank throw. And then do that 100 time per second. That's a lot of trauma to be imparting on your rotating and reciprocating assembly.

Now, do this. Get a quart of motor oil in a bowl, and whip it up with a blender at high speed. The oil foams up due to the air introduced into semi-solution. Do it long enough and hard enough, you'll end up with 2-3 qts of oil foam. If you feed that to your bearings, they won't last long.

The real answer is a high quality standard volume/standard pressure pump, a good oil pan, with a matching pick up that's been properly installed and adjusted. If you need more help, then use an accumulater like an Accusump. Anything else will make you feel good when you "...watched the oil pressure gauge like a hawk...". But it will make you feel bad when the engine blows up.

[Tad]

Overfilling the oil pan is a bad thing. Not quite as bad as out-right starvation, but pretty close. Yes, you will keep the pick up covered, and that prevents the pressure gauge from dropping. Bad things will still happen.

One of the goals of a deeper pan is to get the oil resevoir further away from the crank shaft. You definatly do not want the crank throws to be hitting the oil. Somebody do the math here - a 4" crank throw moves how fast at 6,000 rpm's? I don't know, except that it's really fast. Take a stick, and hit the surface of a pond as hard as you can. Feel the shock wave? No imagine that shock wave apmplified to the speed of the crank throw. And then do that 100 time per second. That's a lot of trauma to be imparting on your rotating and reciprocating assembly.

Now, do this. Get a quart of motor oil in a bowl, and whip it up with a blender at high speed. The oil foams up due to the air introduced into semi-solution. Do it long enough and hard enough, you'll end up with 2-3 qts of oil foam. If you feed that to your bearings, they won't last long.

The real answer is a high quality standard volume/standard pressure pump, a good oil pan, with a matching pick up that's been properly installed and adjusted. If you need more help, then use an accumulater like an Accusump. Anything else will make you feel good when you "...watched the oil pressure gauge like a hawk...". But it will make you feel bad when the engine blows up.

I gotta agree with you Bob - everything definitely needs to be "properly installed and adjusted" and you don't want to whip it into a froth due to overfilling. However, with a DOHC modular engine as in my car it is my understanding (gleaned from the experienced folks that run these engines) that when run at high revs, oil drainback is very slow and a lot is retained within the heads - even with the stock pump that I have. Thus the extra quart at static to maintain proper pan level at higher revs. That logic may not apply to anything else but a DOHC modular. I am definitely paranoid about the modular engine oiling system. Especially after all the horror stories I've heard & read about with these engines but I HOPE I've learned and have it covered based on the experiences and recommendations from others. If you've got some knowledge there, please pass it along.

[Someday I Suppose]

The only question I have is are you sure you are now over-filling the pan? Are you judging based on a line on the dipstick, or based on the number of quarts you put in the pan and the pans capacity?

_Scott

[AJ Roadster NJ]

Were the baffles in the Canton pan working correctly (i.e., not binding) when you installed it? They should flap open really easily against the spring. I have one too, virtually the same pan except sized slightly differently to fit a Roadster's frame rails (Quality Roadsters pan by Canton). I set my pickup to be about .250 off the floor of the pan, and it is difficult to envision it starving.

Another possibility is that something is clogging a portion of the pickup screen. Has the pan been off since its original installation?

AJ