Why Delete AFM ..... stock cam
12-29-2010, 09:43 AM
#41
When I started my L92 build last year I did a pile of research on VVT and DOD engines and found then that in order to maintain oil pressure when the lifters collapsed the DOD engines used a higher volume/pressure pump. IIRC it was MAST that told me this I cant really recall exactly who or where I heard this now but it was buzzing around at that time. But I did find a few threads over at LS1tech where guys had swapped out the DOD lifters and all of a sudden had extremely high oil pressure ( Around 90 psi IIRC ) One was a dune buggy and the guy had all sorts of problems running the pan dry. He even blew his engine and everyone was wondering why and the oil pump was the issue. If you search out the PN's they should come up different between DOD and non DOD engines and again Im pretty sure there was a thread I was posting in somewheres that had this info. I'll post up a link if I can find it
12-29-2010, 09:44 AM
#42
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I did a couple quick searches and it appears that some AFM ( DOD ) engines use a high volume pump and some do not for whatever reason? So check the PN on your pump and google it and if it comes up as 2001 pump ( the current upgrade year ) then you should be good to go BUT if you have the white wring you might have to change it. Anyways heres a thread with some insight on the pump issues. Theres more out there search it out if your curious
https://ls1tech.com/forums/conversio...inate-dod.html
https://ls1tech.com/forums/conversio...inate-dod.html
12-29-2010, 09:52 AM
#44
Yes curious about that too .I read that on here before that it is a different pump but my understanding is its the same PN ??
Good info .......always more details when you dig into things .......my motor is the LC9 ....... I did not personally check the PN just asked a parts guy curious to know if the 2010 LC 9 uses the above pn oil pump now
Good info .......always more details when you dig into things .......my motor is the LC9 ....... I did not personally check the PN just asked a parts guy curious to know if the 2010 LC 9 uses the above pn oil pump now
12-29-2010, 10:08 AM
#45
After going back and checking the part numbers with the VIN filter turned off I am getting a second part #12612289. I will do some snooping around and see if I can find any more info.
12-29-2010, 10:13 AM
#46
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All I can tell you for certain is this; Theres a PILE of differences from one of these engines to another. Not to completely sidetrack here but heres one that baffled me for a while. Last year we were all having fits trying to figure out why one VVT cam'd engine worked great and one ran like a backhouse. Even COMP was confused. Turns out theres two different phasers that have different advance/retard capabilities and require different cams/limiters to function etc. I wish I could have found that buggy builders thread it had a lot of good insight into the oil pump problems.
Anyways Im so off topic now its not funny. I dont have all the answers to those wondering about these AFM engines but hopefully there is enough info going on in this thread to get some of you guys pointed in the right direction.
All said and done? Get yourself a 6.2L and enjoy
Anyways Im so off topic now its not funny. I dont have all the answers to those wondering about these AFM engines but hopefully there is enough info going on in this thread to get some of you guys pointed in the right direction.
All said and done? Get yourself a 6.2L and enjoy
12-29-2010, 10:35 AM
#47
Ok so here is another informative thread. Based on what I read here it would be in your best interest to take cams advise and swap oil pumps. Aparently my iron block is the reason for the standard oil pump, why it makes a difference I don't know.
https://ls1tech.com/forums/generatio...formation.html
This means I have given bad info in my previous post about the pump and I apologize.(ya I'm eating crow)
https://ls1tech.com/forums/generatio...formation.html
This means I have given bad info in my previous post about the pump and I apologize.(ya I'm eating crow)
12-29-2010, 10:42 AM
#48
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Ok so here is another informative thread. Based on what I read here it would be in your best interest to take cams advise and swap oil pumps. Aparently my iron block is the reason for the standard oil pump, why it makes a difference I don't know.
https://ls1tech.com/forums/generatio...formation.html
This means I have given bad info in my previous post about the pump and I apologize.(ya I'm eating crow)
https://ls1tech.com/forums/generatio...formation.html
This means I have given bad info in my previous post about the pump and I apologize.(ya I'm eating crow)
BTW that thread was a great find!
12-29-2010, 10:56 AM
#49
Thanks for the kind words. Still sucks to be wrong lol 
After reading the thread I posted a link to it looks like some guys are still running that part number without issues but its not worth the risk IMO. The pump you mentioned earlier may have been the first design with the 52psi relief valve though and that may have contributed to the issue.
After reading the thread I posted a link to it looks like some guys are still running that part number without issues but its not worth the risk IMO. The pump you mentioned earlier may have been the first design with the 52psi relief valve though and that may have contributed to the issue.
12-29-2010, 11:06 AM
#50
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The relief saves oil starvation but its also looking like the main problem with the piston rings failing on these engines. No one knows for sure but Ive read posts from GM techs who said the have rebuilt a few 5.3's on Warranty and the pistons above the relief were completely oil cooked right into the piston. FWIW the buggy thread problems had a pan swap and no relief. He only made it a few hours of running before BOOM