Hey All,

Mods feel free to move if this is in the wrong section.

I'm having oil pressure issues with a refreshed L33 swap into my 1985 supra. The engine is using a canton 240sx swap pan with a oem GTO pick-up. I initially swapped the engine and only changed the cam(oem LS1), crank pulley, and intake to fit it in the car. The engine was purchased as a running swap from a reputable parts yard so I'm guessing the changes I've made are causing the issue. After having pressure issues (which I'm having again), I decided to pull the engine and refresh it so here's the current set-up:

-2007 85k mile L33 5.3 refreshed with new rings and main/rod bearings but stock cam bearings and stock oil dog bone( I know )
-LPE GT2-3 Cam
-new lifters and hardened pushrods
-melling high pressure oil pump with new oil o-ring
-Z06 valve springs
-gto pick-up
-canton 240sx pan PN 15-276
-new cam retainer plate, oil pan gaskets, etc
-autometer electronic oil pressure gauge confirmed with a mechanical gauge

When I start the car, it has around 50psi of pressure at idle and revving the engine builds pressure to around 65-70psi at ~4000rpm. After driving and getting the oil/water up to temp, the pressure slowly drops to around 15psi at an oil/water temp of 200degrees. Once it gets to this point, revving the engine has no effect on pressure. The pressure remains at ~15psi regardless of rpm. I'm fairly certain the oil pump o-ring wasn't damaged and all gaskets and seals concerning oil pressure were changed. The first go around with this engine I changed the o-ring in the car with the correct one to match the pick up and my issues weren't resolved. Upon tear down, the o-ring looked prefect. During the refresh, I plastigauged all the bearings and all clearances were perfect. Before I hear it, I have a hard time believing cam bearings would cause my issue. Oil pressure should still build with rpm. Any ideas?

 

Is your pickup tube 3/8" from the pan? Since that's an aftermarket pan and a stock pickup tube, there's a very small window for where it needs to be in order to work (even with the stock pan). As the oil thins out, you could be sucking in some air if the pickup is too far away from the pan.

 

I also thought of that. However, canton designed this pan for the gto pick-up and searching found no one who used this pan having issues.

 

Might be good to clay it and make sure.

However, 50 PSI cold idle seems low. I'm around 85 PSI with a 10W30 oil.

 

I know my LS1 used to be at about 45 cold idle, 25-29 hot, 45 cruising, 60 WOT. That was on 10w-30 if I'm not mistaken.

 

Checked my pick-up tube to pan clearance with clay today(o-ring is perfect btw). There is less than 1/16in gap between the pick-up and the pan. I'm guessing I found my issue...

I'll keep everyone posted.

 

Updating for future people searching.

I cut my pick-up down to leave around 3/8in from the tube to the pan. Re-installed everything and started the car. I now have 55psi cold idle, ~45psi hot idle, and 70+psi above 3500rpm.

 

Good job. Pan to pickup clearance is so important yet so few actually check. For future reference, you can usually just bend the tube to get the clearance, instead of cutting anything.

 

This is fairly common. Unfortunately, Canton's quality control is not as good as it should be. Wrong pick up alignment, leaky welds, and poor fit are common.

The pick up for my pan had almost an inch of clearance, and was not parallel to the floor of the pan. I heated the tube and bent it until I had the right clearance.

 

Not to defend Canton or anything, but I've seen the same with Moroso and even stock pans. I think there are too many variables to get the pickup to pan clearance dead nuts right out of the assembly line.

 

Excellent. Glad to see it was something relatively simple.