HELP!! Double Roller Chain/Oil Pump/Cover Clearence Issue
Thread Starter
Melting Slicks
Joined: Apr 2006
Posts: 2,509
Likes: 9
From: Norman OK
HELP!! Double Roller Chain/Oil Pump/Cover Clearence Issue
I am doing some major mods on my 2005 LS2. Ran into a problem on the install tonight. The engine front cover/timing cover will not fit back on the engine. 
I installed a double roller timing chain as well as a melling oil pump. The double roller requires the oil pump to be shimmed out with supplied spacers. Well the melling seems to be "thicker" then the stock oil pump. Add all of this up and the oil seal cup on the back side of the cover hits the oil pump and leaves 1/8" or so of a gap around the cover to the engine block!!!
My first thought was that the cap screws with the safety wire were touching the cover. I replaced them with the stock GM pump bolts and gained a little clearece bolt wise, but the cover still did not move back any closer to the block. I then placed some tape on the inside of the cover and gently tapped it. This is when I figured out I was actually hitting the seal cup area against the pump.
I think my only option is to go back to a standard timing chain.
Any experience/ideas with this situation???
I installed a double roller timing chain as well as a melling oil pump. The double roller requires the oil pump to be shimmed out with supplied spacers. Well the melling seems to be "thicker" then the stock oil pump. Add all of this up and the oil seal cup on the back side of the cover hits the oil pump and leaves 1/8" or so of a gap around the cover to the engine block!!!
My first thought was that the cap screws with the safety wire were touching the cover. I replaced them with the stock GM pump bolts and gained a little clearece bolt wise, but the cover still did not move back any closer to the block. I then placed some tape on the inside of the cover and gently tapped it. This is when I figured out I was actually hitting the seal cup area against the pump.
I think my only option is to go back to a standard timing chain.
Any experience/ideas with this situation???
Safety Car
Joined: Sep 2007
Posts: 4,359
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From: Los Alamitos California
St. Jude Donor '09
Pro
Joined: Oct 2005
Posts: 641
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From: Tampa Fl/Afghanistan
I encountered the same situation.
I did some very careful Dremel grinding on the Mellings and very minor clearancing on the front cover - be careful as I wasted one front cover by grinding too much. I also found one of the oil pump bolts was hitting from behind and was able to fix by using a round cap screw with an allen wrench head.
Once that was resolved, I then simply doubled up the front cover gasket to get me the add'l clearance. With these being metal w/rubber seals, there is no worry about oil leakage. This was just enough to give me the clearance I needed.
Everything else fit back on fine.
I did some very careful Dremel grinding on the Mellings and very minor clearancing on the front cover - be careful as I wasted one front cover by grinding too much. I also found one of the oil pump bolts was hitting from behind and was able to fix by using a round cap screw with an allen wrench head.
Once that was resolved, I then simply doubled up the front cover gasket to get me the add'l clearance. With these being metal w/rubber seals, there is no worry about oil leakage. This was just enough to give me the clearance I needed.
Everything else fit back on fine.
Tech Contributor
Joined: Jul 2002
Posts: 14,950
Likes: 266
From: St. Louis, MO
St. Jude Donor '08
My friend had a bad experience with a double roller - after his double chain broke the port mortem told the story that the chain was rubbing on the oil pump and eventually rubbed the rivets on the chain down until it failed. Took a couple of years to do it but it happened. Just one more clearance to pay attention to if you go double roller.
