Reverse Oil Pressure???
01-06-2004, 07:54 PM
#31
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01-06-2004, 08:33 PM
#32
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I removed the windage tray before the last rebuild. I turn up to and including 7,000 with no problems whatsoever in oil pressure.
FWIW, I'm running the stock pan with a Melling HV oil pump. I hold about 55-60 cold idle PSI and warm idle is around 35-40. I've got over 10k on mine in current trim.
-Shannon
FWIW, I'm running the stock pan with a Melling HV oil pump. I hold about 55-60 cold idle PSI and warm idle is around 35-40. I've got over 10k on mine in current trim.
-Shannon
01-06-2004, 09:19 PM
#34
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Join Date: Nov 2003
Posts: 102
Got windage
We had a similar problem in my freinds 383. Its not an LT-1 but it was the same problem. you could rev it in neutral all day and oil pressure would be fine, but get it out on the road and under hard acceleration and it would drop like a ****. the cure for us was to install a windage tray and the oil pump baffle. the oil pump baffle is the small plate that sandwhiches between the oil pump and the rear main. It keeps the oil in the pan and not flooding the rear main cap under acceleration. The problem you are facing is severe windage from the crank in conjuction with some blow by or just the wind created in the crankcase from the pistons moving up and down. All of this is blowing the oil away from the pickup and thus causing the pump to cavitate in the airiated oil.
Another good way to help cure/prevent this problem is to use an some sort of crank case vacuum setup. There are some that connect into the exhaust to create a vacuum and then there is the systems that use the an air pump.
the oil weight isn't a problem, you can stick with your 15w50 if you like, but get a good quality windage tray and pump baffle, check your pickup clearance to the bottom of the pan, and always weld or braze that oil pump pickup in place so it doesn't work its way out on you.
Another good way to help cure/prevent this problem is to use an some sort of crank case vacuum setup. There are some that connect into the exhaust to create a vacuum and then there is the systems that use the an air pump.
the oil weight isn't a problem, you can stick with your 15w50 if you like, but get a good quality windage tray and pump baffle, check your pickup clearance to the bottom of the pan, and always weld or braze that oil pump pickup in place so it doesn't work its way out on you.
01-07-2004, 12:45 AM
#35
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Hmmm well anyone know what the correct clearance from the top of the pan to the bottom of the pickup is supposed to be then?
Also would having the pickup a little too high be better than having it too low? Im just trying to see what each situation would cause...
Also would having the pickup a little too high be better than having it too low? Im just trying to see what each situation would cause...
01-07-2004, 01:17 AM
#36
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3/8 to 1/2 inch from the bottom. A little high is better than to low. What I do to get set it is to put the pump and pickup on the engine (put the pick up in just far enough that it swivels easily but not fall out and is also exagerated to the deep side to the point that it looks like it would physically be outside the pan). Then leave out the oil pan gasket and install the pan. This will allow you to force the pickup down to a poit which is one thickness of the pan gasket away from the bottom of the pan. You can then measure the position from the pan rail of the block to add the 1/4 to 3/8 of an inch (assuming that the pan gasket is 1/8 of an inch.
Good luck!
Good luck!
01-07-2004, 01:29 AM
#37
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Originally posted by 442olds
3/8 to 1/2 inch from the bottom. A little high is better than to low. What I do to get set it is to put the pump and pickup on the engine (put the pick up in just far enough that it swivels easily but not fall out and is also exagerated to the deep side to the point that it looks like it would physically be outside the pan). Then leave out the oil pan gasket and install the pan. This will allow you to force the pickup down to a poit which is one thickness of the pan gasket away from the bottom of the pan. You can then measure the position from the pan rail of the block to add the 1/4 to 3/8 of an inch (assuming that the pan gasket is 1/8 of an inch.
Good luck!
3/8 to 1/2 inch from the bottom. A little high is better than to low. What I do to get set it is to put the pump and pickup on the engine (put the pick up in just far enough that it swivels easily but not fall out and is also exagerated to the deep side to the point that it looks like it would physically be outside the pan). Then leave out the oil pan gasket and install the pan. This will allow you to force the pickup down to a poit which is one thickness of the pan gasket away from the bottom of the pan. You can then measure the position from the pan rail of the block to add the 1/4 to 3/8 of an inch (assuming that the pan gasket is 1/8 of an inch.
Good luck!
I will handle this as soon as my new pickup get's here friday.. Got my oil pump exchanged tonight but no one had our 3/4" pickup in stock
I will keep the topic posted...
Thanks guys
01-09-2004, 08:56 PM
#38
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Well for everyone that's been keeping up, I pulled the pan today and everything is still in tact... Going to pull the pump out and swap it and the pickup with a new one AGAIN 
One thing I am questioning is that I heard some kinda rattling in the pan when I took it out. I noticed that UNDER the little tray thats welded to the pan, (NOT the windage tray) but the actual windage tray thats ON the pan. Well there is a smaller tray under that, which looks like one side of it has made it's way loose.. Anyone know if this is what could be causing the problem??
HERE is what im talking about. As you can see it normally goes in there flush but I have one side pulled out so you can see what Im talking about... You can see that one side has made it's way loose..
One thing I am questioning is that I heard some kinda rattling in the pan when I took it out. I noticed that UNDER the little tray thats welded to the pan, (NOT the windage tray) but the actual windage tray thats ON the pan. Well there is a smaller tray under that, which looks like one side of it has made it's way loose.. Anyone know if this is what could be causing the problem??
HERE is what im talking about. As you can see it normally goes in there flush but I have one side pulled out so you can see what Im talking about... You can see that one side has made it's way loose..
01-10-2004, 12:37 AM
#39
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Well I got the new pump and pickup on. Took it out for a spin and I SWEAR it was like working fine for a couple times then it like started doing it again It doesn't seem to be as bad yet...
Im wondering if that stupid thing in my oil pan could be causing the problem? I just kinda tucked it back under there but its still not being held stationary, I was think that since I put the pan in and had it in place is why it was working fine for a minute, then maybe it came loose again...
Anyone know what THIS thing does? Or if it's causing my problem.
It doesn't seem to be as bad yet...Im wondering if that stupid thing in my oil pan could be causing the problem? I just kinda tucked it back under there but its still not being held stationary, I was think that since I put the pan in and had it in place is why it was working fine for a minute, then maybe it came loose again...
Anyone know what THIS thing does? Or if it's causing my problem.
01-10-2004, 09:32 AM
#40
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My car has the exact same problem, exactly, and I am ALL stock really.
I have heard this is a common problem in 93-early 95 lt1's. There was a guy in advance tech that solved his problem with a bigger pan(Canton I believe??) and the appropriate windage tray for it. Before that he replaced his pump, pickup, few different oils and filters, etc., none solved until he replaced his pan/tray.
GM supposedly came out and said it was ok, since bearing dont get hot enough to spin until you go past 7K and have less than 30 PSI of pressure.
They were too lazy to fix it
I have heard this is a common problem in 93-early 95 lt1's. There was a guy in advance tech that solved his problem with a bigger pan(Canton I believe??) and the appropriate windage tray for it. Before that he replaced his pump, pickup, few different oils and filters, etc., none solved until he replaced his pan/tray.
GM supposedly came out and said it was ok, since bearing dont get hot enough to spin until you go past 7K and have less than 30 PSI of pressure.
They were too lazy to fix it
01-10-2004, 12:15 PM
#41
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Location: Akron, OH.
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I have a stock pan with a MV55 pump on my rebuilt 355 with no windage tray. Same problems as these other guys, only under hard accerlation does the pressure go down, even at 5k steady it reads 65psi. Mine only drops to 35psi but when i up th eboost and add the intercooler the G's may make the problem worse. I am wondering if replaceing the windage tray will fix this or do I really need a bigger pan? Man this thing is a money bucket. The machine shop told me ARP does make a stud kit to retain the windage tray. Man is it fustrating to think that I will have the the motor inorder to fix a problem when I paid to have this motor assembled.
01-10-2004, 04:02 PM
#42
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Originally posted by Flip94ta
I have a stock pan with a MV55 pump on my rebuilt 355 with no windage tray. Same problems as these other guys, only under hard accerlation does the pressure go down, even at 5k steady it reads 65psi. Mine only drops to 35psi but when i up th eboost and add the intercooler the G's may make the problem worse. I am wondering if replaceing the windage tray will fix this or do I really need a bigger pan? Man this thing is a money bucket. The machine shop told me ARP does make a stud kit to retain the windage tray. Man is it fustrating to think that I will have the the motor inorder to fix a problem when I paid to have this motor assembled.
I have a stock pan with a MV55 pump on my rebuilt 355 with no windage tray. Same problems as these other guys, only under hard accerlation does the pressure go down, even at 5k steady it reads 65psi. Mine only drops to 35psi but when i up th eboost and add the intercooler the G's may make the problem worse. I am wondering if replaceing the windage tray will fix this or do I really need a bigger pan? Man this thing is a money bucket. The machine shop told me ARP does make a stud kit to retain the windage tray. Man is it fustrating to think that I will have the the motor inorder to fix a problem when I paid to have this motor assembled.
I mean I don't see how ALL 6 qts of oil can NOT BE getting to the pickup WTF??? I seriously dunno what to do next... It's either a canton pan, which will cost me another friggin $300 and I heard they suck a$$.. Or I get some kinda windage tray in there, which I don't see that being much fun with the size crank I have plus I just barely pulled the ARP studs out that I orginally bought when I first put my motor together cause I thought that I was gonna be able to use the STOCK windage tray, but then it didn't fit...I don't care I just wanna know WTF the deal is...
01-11-2004, 01:22 AM
#45
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Originally posted by 96ltz
Oh, if it did work i would consider it a quick fix at best and find out what I needed to put a windage tray in there
Oh, if it did work i would consider it a quick fix at best and find out what I needed to put a windage tray in there
I was also looking at either THIS TRAY
OR
THIS ONE
Also looking at installing THIS as well
Any comments? Suggestions?