375 Hp Oil Pick-up Tube Seal Tech - ZR-1 Net Registry Forums

A26B · 08-05-2008

ADVISORY, Pertaining only to 90~92 375 Hp LT5 engines:

Background: A couple of years ago, I tore down several 375 Hp engines which were part of the lot of 29 used 375 Hp engines I acquired that originally came out of GM storage about 2004. During inspection of rod bearings, some bearing wear matched the "cavitation" pattern. Due to the proven reliability of the LT5, I noted the findings but could never understand the wear pattern until now.

During "reverse engineering of gaskets & seals utilizing GM engine drawings & actual engine parts, I found that the OEM o-ring #10106189 used for the oil pump suction tube in the 375Hp engine did not meet the industry design spec calling for 25~30% compression when the oil pan was installed with the OEM pan gasket, only compressing the o-ring about 3%.

Recalling the design problems of the LT5 pertaining to crankcase windage & pressure, coupled with the oil suction tube o-ring findings, the bearing cavitation wear pattern began to make some sense. I believe crankcase vapor (air) was getting into the suction of the oil pump.

Now, I'm not being "chicken-little" and advocating the sky is falling. I do however advocate that a different o-ring than OEM #10106189 be used when the oil pan is removed. I also recommend that if a pan gasket other than OEM is used, that one should thoroughly investigate whether it meets the same standard of compressed thickness of the OEM gasket when installed. I know for a fact that there are aftermarket pan gaskets presently offered for sale that do NOT meet that criteria. If the gasket is too thick when installed, it will make the cavitation problem worse when used in conjunction with the OEM oil pump suction tube o-ring #10106189.

The pan gasket I sell, compresses to the same thickness of the OEM gasket and is made from very high quality material. The oil pump suction tube seal (o-ring) that I sell under PN 10106189, has a larger cross section diameter than the OEM part. I know that it will compress to o-ring design spec with the OEM or my pan gasket.

If you are removing the oil pan, please use the correct gasket and corresponding oil pump suction tube seal (o-ring) to insure proper sealing. Obviously the OEM parts work very well, but there have been main/rod bearing failures. I am not recommending that anyone remove the pan to install a different gasket or o-ring. However, if you do have the pan off, consider my findings in you decision for the replacement gasket & seal.

Jerry

DaveK · 08-05-2008

I'm planning on replacing the pan gasket on mine in the near future, so I should replace the o-ring for the pickup tube at the same time?

I have an OEM gasket but if yours is superior to the original, I may as well put the best in if I'm doing the job anyway.

A26B · 08-05-2008

Quote:

Originally Posted by DaveK

I'm planning on replacing the pan gasket on mine in the near future, so I should replace the o-ring for the pickup tube at the same time?

I have an OEM gasket but if yours is superior to the original, I may as well put the best in if I'm doing the job anyway.

Yes you should replace the o-ring. I won't tell you that my pan gasket is superior to the OEM. My pan gasket does not have the silicone seal on it. (I actually prefer the plain gasket) If I had an OEM pan gasket, I would use it before buying another.

Kevin · 08-05-2008

Thanks for the post Jerry, i don't know where we would be without you

A26B · 08-05-2008

Quote:

Originally Posted by Kevin

Thanks for the post Jerry, i don't know where we would be without you

LOL! Maybe better off Kevin! Miss seeing you at BG. When are you coming back?

Kevin · 08-05-2008

Quote:

Originally Posted by A26B

LOL! Maybe better off Kevin! Miss seeing you at BG. When are you coming back?

I miss being in BG and seeing all the guys. I'm going to pm you here in a second explaining why i've been mia at carlisle and bg.

FU · 08-05-2008

Quote:

Originally Posted by A26B

LOL! Maybe better off Kevin!

Easy on yourself Jerry. We love you big guy !!

Quote:

Originally Posted by A26B

Miss seeing you at BG. When are you coming back?

Yea Kevin....what he said !!

Kevin · 08-05-2008

Quote:

Originally Posted by FU2

Easy on yourself Jerry. We love you big guy !!

Yea Kevin....what he said !!

pming you too frank

08-05-2008	#2
DaveK Join Date: Jul 2004 Location: Sudbury, Ontario. Canada Posts: 1,540	Re: 375 Hp Oil Pick-up Tube Seal Tech I'm planning on replacing the pan gasket on mine in the near future, so I should replace the o-ring for the pickup tube at the same time? I have an OEM gasket but if yours is superior to the original, I may as well put the best in if I'm doing the job anyway. __________________ 1991 #1516 Black/Black davidmkelly.com Author of fast-paced, sci-fi thrillers.

08-05-2008	#4
Kevin Join Date: Jun 2005 Location: pittsburgh Posts: 4,632	Re: 375 Hp Oil Pick-up Tube Seal Tech Thanks for the post Jerry, i don't know where we would be without you __________________ It's not the car, it's the people - Doug Johnson 90 r/r "KEYS ON" nick named "T.L.B"

08-05-2008	#1
A26B Join Date: Dec 2003 Location: Arcadia,OK Posts: 3,396	375 Hp Oil Pick-up Tube Seal Tech ADVISORY, Pertaining only to 90~92 375 Hp LT5 engines: Background: A couple of years ago, I tore down several 375 Hp engines which were part of the lot of 29 used 375 Hp engines I acquired that originally came out of GM storage about 2004. During inspection of rod bearings, some bearing wear matched the "cavitation" pattern. Due to the proven reliability of the LT5, I noted the findings but could never understand the wear pattern until now. During "reverse engineering of gaskets & seals utilizing GM engine drawings & actual engine parts, I found that the OEM o-ring #10106189 used for the oil pump suction tube in the 375Hp engine did not meet the industry design spec calling for 25~30% compression when the oil pan was installed with the OEM pan gasket, only compressing the o-ring about 3%. Recalling the design problems of the LT5 pertaining to crankcase windage & pressure, coupled with the oil suction tube o-ring findings, the bearing cavitation wear pattern began to make some sense. I believe crankcase vapor (air) was getting into the suction of the oil pump. Now, I'm not being "chicken-little" and advocating the sky is falling. I do however advocate that a different o-ring than OEM #10106189 be used when the oil pan is removed. I also recommend that if a pan gasket other than OEM is used, that one should thoroughly investigate whether it meets the same standard of compressed thickness of the OEM gasket when installed. I know for a fact that there are aftermarket pan gaskets presently offered for sale that do NOT meet that criteria. If the gasket is too thick when installed, it will make the cavitation problem worse when used in conjunction with the OEM oil pump suction tube o-ring #10106189. The pan gasket I sell, compresses to the same thickness of the OEM gasket and is made from very high quality material. The oil pump suction tube seal (o-ring) that I sell under PN 10106189, has a larger cross section diameter than the OEM part. I know that it will compress to o-ring design spec with the OEM or my pan gasket. If you are removing the oil pan, please use the correct gasket and corresponding oil pump suction tube seal (o-ring) to insure proper sealing. Obviously the OEM parts work very well, but there have been main/rod bearing failures. I am not recommending that anyone remove the pan to install a different gasket or o-ring. However, if you do have the pan off, consider my findings in you decision for the replacement gasket & seal. Jerry __________________ Jerry Downey JERRYS LT5 GASKETS & PARTS http://www.jerrysgaskets.com 1994 *ZR-1*, Black/Black, Lingenfelter Aerobody, 416cu in, 3.91 gears, coil-over susp, Brembo brakes, etc. 2016 Black-Red, 3LT-Z51 Auto 8-speed.