My lt1 was doing this on hard acceleration and one person on here called it (javier? ithink) my stock short block was dropping oil pressure by the oil climbing the back of the pan and getting aerated by getting whipped up in the crank. the oil fills with bubbles which get sucked into the pickup and dont provide very good lubrication.
My fix was removing the stock pan and windage tray and installing the milodon 7 qt pan and moroso rear pan baffle. The most important part was this baffle that went inbetween the oil pump and rear cap. After that I run 5.5qts in the 7qt system three years now no more pressure drops AND HAPPY BEARINGS. Do not drive the car with the pressure dropping until your sure the guage is faulty. Everyone said my guage was bad but it wasnt, the air was compressing in the oil pump.

 

I should add my milodon pan looks similar to your canton (screen windage). did you use the rear pan baffle?

 

No rear pan baffle, but I don't see how the oil can climb up the back of the pan in 3rd gear with a suspension setup that doesn't squat or lift the front end up. When there is 6 quarts in the system the oil level is only up about 1/8" off the bottom of the dipstick, if I run any less I'de have no way of measuring how much oil is in it.

 

Mine does the same thing, what spring is in the oil pump? I think mine may relieving itself under wot. It has never hurt anything but I am not on a roadcourse. Mine gets whipped on 10.5 seconds at a time.....


I have the same pan and a Melling select pump. I run a K&N long filter and 5 quarts in the pan. Barely touches the stick. On long cruises I put in an extra quart.

WHat I have noticed is mine only does it when the oil is hot, when the oil is cold it will almost peg the gauge on startup. I have never run the car hard when its cold though. I have never had the ***** to WATCH the gauge, just glance at it.

WHat oil is in the car?

First thing I would do is put a good gauge in the car.

 

I can fill a 5gallon pail and spin in a circle and watch it climb.

 

You have the proper pickup for that pan? the pickup should be mounted 1/2" away from the pan floor. That being said, you have 7(?)qts of oil above that point, unless your valcovers,oil filter and crank are holding all of that oil after running for awhile (clean your return passages!) Im not following why you need more oil in the system.
It could be a faulty pump as fastfatboy said, bad guage or your getting oil in the rotating assembly. Gauge first if that doesnt fix it pull the pan an put the baffle in it.
I tried everything first because I had to pull my pan without a lift, it stinks.

 

The point I was trying to make is a 3rd gear pull doesn't pull anywhere near as hard as a sub 1.6 second 60' so I don't see the oil climbing high enough up the back of the pan to be an issue.

 

I figured I'de throw another quart in to see if it helped since it only takes 30 seconds to do and I'm changing the oil this week anyway. My heads/intake manifold have been off plenty of time and there is no sludge or anything blocking the return passages. I'm pulling my intake manifold so I'm going to put in a new oil pressure sending unit while its off and I'm going to give canton a call tomarrow to see what they say. The pickup is ~3/8" off the bottom of the pan, and if that was the issue I would think it would do it all the time, not just at WOT.

 

yes, but it may empty the oil alreasy in the pick up while you are accelerating and uncover the screen (too much clearance from the bottom?) making you lose oil pressure. I believe the baffle on the back of the pan is needed on the canton pan as well as the stocker.

 

It's called windage for a reason. Once the agitation starts it doesn't take much for it to keep going. I'm sure you know, but just want to clarify, the crank doesn't have to contact the oil for the agitation to start or continue.

 

Your pickup clearance is good. It should be 1/4-3/8"

1/2" is pretty far off

 

I had a similar issue recently when I replaced my sending unit and my pressure was reading half of what it should. Took it off and tossed the new on in the garbage and got a different brand. Pressure is back to normal now.

 

Video update.

http://www.youtube.com/watch?v=1LOkKxY-n4o

 

You move fast with the install. Sorry to see it wasn't something simple.

 

It didn't hurt that the gauge was pretty much pre-wired.

 

I run the same Canton oil pan, and I've never had any WOT oiling problems. I run 6 quarts of oil, factory-volume oil pump with GM "white" high pressure release spring. Got rid of the stock oil cooler. I'm using everything the canton came with, though I had to notch the crank scraper.

Skimming over the thread, I don't believe this was mentioned, but you might check your dummy distributor shaft at the rear of the lifter valley. It has a plastic retainer holding it to the block. The gear on the end of the shaft is turned by a gear on the rear of the camshaft, and this in turn drives your oil pump. If that dummy shaft is lifting off of the camshaft at high RPM, that will *definitely* cause a loss of oil pressure until the dummy shaft comes back down into contact with the camshaft gear.



For this reason, I welded up a metal retainer for the dummy distributor shaft. A company used to make something like this years ago, but they've since gone out of business.

 

Herron Performance now has billet oil pump drives available. Not a cheap option, but looks like a nice piece.




Alex94TAGT- Any pics of the modifications you did with yours?

 

Yeah, that is a nice piece. Billet is going to be expensive, but I guess it's cheap piece-of-mind compared to losing oil pressure at WOT and potentially trashing the rotating assembly, etc. I know people have had the plastic arm break off completely = zero oil pressure.

I don't have pictures, but mine wasn't anything fancy -- it was just a brace, using what I had laying around. Think I used 1/8" or 3/16" flat metal stock (cut into the shape of the top of the shaft), and then welded on a round bushing that fit the I.D. of the dummy distributor shaft -- as well as using a longer stainless bolt w/ lock-washer and red threadlock. Probably cost me all of $3.00.

 

My car does this with a stock oil pan. It behaves exactly like the youtube video posted above.

 

I built a reinforcement for the oil pump drive and put a new on in with the pan so I'm pretty sure that's not it.