Oil pump shim thickness.
12-20-2004, 10:02 AM
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Oil pump shim thickness. I just recently did a h/c upgrade and installed a Katech p&p oil pump. I installed a new o-ring and all appears fine. At idle I get 40psi cold and 29-30psi hot. At cruise above 1200 rpm I get around 38-42psi. At 4500 and above I get around 60psi. This may all seem ok but I was getting around 5psi more across the board with my old LS1 oil pump. I would like to shim the bypass spring to get that extra 5psi back. I am going back in there shortly and will have the opportunity to shim it, but I'm not sure how much to shim it, or where to get the shims. Does anyone have an answer? Thanks.
12-21-2004, 04:57 PM
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im having the exact same problem and simtoms with my ported pump from texas speed
it is a new motor and i baught a new pickup tube and o-ring and the pump
the pressure shoots up like it should but when hot its around 30
they told me that they shim the spring when i called and asked but im thinking maybe they did not on my pump
it is a new motor and i baught a new pickup tube and o-ring and the pump
the pressure shoots up like it should but when hot its around 30
they told me that they shim the spring when i called and asked but im thinking maybe they did not on my pump
12-23-2004, 12:46 PM
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Same issue with my Katech P&P pump in my LS6. Super careful on install, used new blue o ring, elongated the pickup tube mounting hole where it bolts to the main cap to insure proper alignment for a Rollmaster Dual Timing chain with shims.
On cold start up, 40 psi, at hot idle 220 F , oil psi goes down to 18psi. I have an accusump so, I'm not worried about going to zero, but...
WTF? I had more psi with my stocker.
On cold start up, 40 psi, at hot idle 220 F , oil psi goes down to 18psi. I have an accusump so, I'm not worried about going to zero, but...
WTF? I had more psi with my stocker.
12-23-2004, 07:29 PM
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I'm using Redline 1OW30. What type of oil and viscosity are you using?
Strangely enough, I checked the specs and 7psi per 1000 rpm are all that's required.
I thought the additional capacity of the oil cooler, AN 10 lines and Accusump could possibly diminish the oil pressure (oil capacity is now almost 12 qts) but my oil psi was fine with the oil cooler and stock pump. As an experiment, we disconnected the Accusump with the new Katech oil pump in place and the oil psi was the same as described above.
Maybe the P&P pumps flow so well the pressure drops due to less internal resistance. Synthetic oil supposingly has superior lubricity and flow characteristics, so "killer oil" psi theorectically results in more friction and less efficiency.
I can only wonder what similar ASA LS type dry sump power plants push their synthetic oil at?
Tech experts - Your thoughts?
Strangely enough, I checked the specs and 7psi per 1000 rpm are all that's required.
I thought the additional capacity of the oil cooler, AN 10 lines and Accusump could possibly diminish the oil pressure (oil capacity is now almost 12 qts) but my oil psi was fine with the oil cooler and stock pump. As an experiment, we disconnected the Accusump with the new Katech oil pump in place and the oil psi was the same as described above.
Maybe the P&P pumps flow so well the pressure drops due to less internal resistance. Synthetic oil supposingly has superior lubricity and flow characteristics, so "killer oil" psi theorectically results in more friction and less efficiency.
I can only wonder what similar ASA LS type dry sump power plants push their synthetic oil at?
Tech experts - Your thoughts?
Last edited by Z06er; 12-23-2004 at 07:34 PM. Reason: oops
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12-23-2004, 09:19 PM
#8
All the vendors selling the ported and polished pumps say you will see an INCREASE in oil pressure..
Having it drop is BS in my opinion. Slippery oil will not drop pressure that much, if at all..
I also read the 7 lbs per 1000 rpm...Will bet the ranch a motor will **** the bed idling with 5psi @ 700 rpm..
JMHO
Having it drop is BS in my opinion. Slippery oil will not drop pressure that much, if at all..
I also read the 7 lbs per 1000 rpm...Will bet the ranch a motor will **** the bed idling with 5psi @ 700 rpm..
JMHO
12-23-2004, 10:06 PM
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I'm using Redline 5W-30W, the same as before with my stock oil pump. I also elongated the hole in the pickup tube mount when I went in there to change my rod bolts. I did the rod bolts about 2 mos. before the pump change and the oil pressure stayed the same. I put a new o-ring in then too. I may pull the stock oil pump apart and inspect the bypass spring. Maybe there is a shim in there. If so I'll put it in the new one. If not I may have my local machine shop make me a shim using the old oil pump as a template. The only thing is I would like to have some reference as to how much shim causes how much oil pressure increase if I can. Just throwing a shim in there could be costly if I go too thick and crank the pressure. If I go too thin, I won't get any improvement. On a side note, I saw in the Pace catalog an oil pump dynomometer. It is supposed to run your pump and you can get a good idea of how much pressure it will develop. Not sure if this is snake oil or not and it isn't for an LS1, but I wonder if there is a way to predict how much oil pressure your pump will make given the known oil pressure and bypass spring pressure. I know it's all dependant on oil flow through the engine, but if I know I had 35psi at 750 rpm with brand x oil and 6lbs. of bypass spring pressure, what would I get with 8lbs of bypass spring pressure? This is assuming a correct installation. Just thinking out loud.
