Just wrote this up, hopefully, it answers some questions. http://www.v8buick.com/index.php?threads/oil-pump-clearances-and-oil-pressure.326597/
Update..... new TA timing cover with pump assembly installed. Here are the results..... Started up timed to about 20 degrees at 1500 rpm, oil pressure immediately went up to 75 psi. I know too high but as it warmed up over the course of 15 minutes if dropped to 25 psi at 1500 rpm with a constant 190 degrees. Finished cam break in and shut it down. Will check fluids again tomorrow. I think I might be ok now as idled for just a few seconds at the end and pressure was about 12 psi... probably a little low but is this pressure acceptable? The TA pump assembly came with the adjustable regulator. As I remember this only adjusts high pressure. Should i change the color spring or adjust the regulator and which way do i adjust the regulator (clockwise or counter ckockwise) to decrease high pressure down to 50 or 60 Psi? Thanks
75psi is fine leave it alone especially cold You may still have low oil psi after you drive it , if so you have other things to address I've driven them with 10 psi at hot idle many times , but it sure does feel better when you see 20+lbs hot driven idle. Long as you stay above 8psi I wouldn't loose any sleep jmo
When I had the stock engine I hooked up a Mech oil pressure gauge and it had maybe 5lbs at idle and maybe went up to 25-30 or so. I worried about it but the car ran fine, so I would not worry about low oil pressure at idle. I ran the crap out of it and nothing happened for years, a lot of years before finally the crank cracked in half on me at the track due to the carb flooding out, and that crap Royal Purple synthetic oil I put in just before that, the oil pressure was lower with this oil. I was running 20-50 Valvoline Racing oil all the time and had decent oil pressure but not real good. It took 10 years to kill it. I was even using that Fram oil filter the whole time but I was using their Racing Filter instead and it was a longer filter than the stock one. They had them at Summit Racing. I never knew that Fram oil filters were crappy until I read it here, and I ran them for over 15 years. But I do not know if their Racing filters are better made or not. I use the Wix filter now get it at NAPA.
75 psi when cold is not too high. Leave the adjustment alone. You will need to drive the car at highway speeds for at least 15-20 minutes to get the oil as hot as it will get. Then see what your idle pressure is in gear. As long as you have enough pressure at higher RPM, you'll be OK. For the 455, 11-12 psi/1000 RPM, for the 350, 10 psi/1000 RPM.
People need to get over this incorrect practice of putting thick oil in to raise the pressure reading. This does NOT help your engine. Try this to help understand . Take a mouth full of water, then put a straw between your lips and blow the water out. Easy right? Now, take a mouthful of molasses and try to blow it out thru the same straw. Lots harder isn't it? Well that's exactly what you're doing to your engine. If you want outstanding oil pressure to show on the gauge, screw a pipe plug into the oil outlet hole in the timing cover. Your pressure gauge will read very high and you can sleep better at night. Of course the bearings will starve for oil and seize but boy you will have great oil pressure. Has my sarcastic point been made?
I think you'll find the oil pressure will be even lower when your actually driving the car. given the quality of the oil pump rebuild i would pull the motor and and start at square one.
I don't run a booster plate, never have. Bought one but don't see the need for it. Setup pump correctly and bearing clearances, all will be good. I have cover at .0015 or as close as I could measure after torquing cover down and not rubbing gears. Does the T/A cover come with the steel booster plate? I run a oil mix like Fox does, 3 qts 20/50, 2 qts 5/30. Castrol GTX, A/C filter, and hot hot idle (just off e-way) is 15lbs. @ 800 rpm. I run a 60 lb. spring.
Unless you have a nice oil pump cover the thrust plate is mandatory imo, it also acts as means to maintain a more consistent end clearance vs the aluminum which grows and will open up
I've ran 20/50 vr1 for years and thousands of thousands of miles, Rotella 15/40 the same, Royal Purple 10/30 the same, castroil, Pennzoil, 10/40 with a bottle of STP blue bottle low rpm use like yours will see just some Pennz or Whatever with a bottle of either Lucas zinc or STP would be all I do
You can run some thicker oil, but I wouldn't do that right away. See what your final pressures are. If you do end up running thicker oil, just be careful when the engine is cold. Let the oil warm up before you romp on it.
X2 From 1976 @ 46K miles to 110k, daily driver, stock eng. before 1st rebuild, I ran 20/40 Pennzoil. Changed @ 3k intervals. On teardown, crank mains & rod journals were perfect!
I wasn't promoting running thicker oil this is what I did back in the 80's This site and none of this info was available back then. Obviously, it was ran without much problems as others have used it here with out much fanfare. Heck, I used to run the 20-50 Valvoline racing oil then put one of those cans of that STP thick oil they used to sell. Did this for a bunch of years back in the day, ran that stock engine past 140,000 miles. and what did it in? putting in that 10-30 Royal Purple synthetic oil had 5 lbs less pressure across the board. so go figure. Anyone ever think since the oil pump is 6 miles away it takes that thick oil to make it work, I know, it makes no sense. One thing is for sure, no one is here saying there motor blew up running thicker oil. I wouldn't do it on a rebuilt motor. and most 350's are worn out now. Here on my motor I am really against the grain, I run the large gears in my oil pump and nothing ever wore out at the distributor or the cam. But, I have every oil hole in the engine bigger and I had TA set up the Timing cover and oil pump to accommodate the larger gear set up. I also have a big 455 square style pickup in the pan with a 7 qt pan. I run 2 qts 15-50 Mobile One and 4 qts of Mobile One 10-30 all Synthetic, and this nets me 50-55 lbs of oil pressure at 3000 rpm, 70 lbs at 6 grand and have 15-20 at idle in gear after a highway trip. I have an adjustable oil pressure relief on the oil pump. I have been doing it this way for the 20+ years I have had this motor running. Oil is not molasses at 190*
As far as oil goes, run whatever you want to try. My 1987 Mercruiser (350 chebby) manual states to run STRAIGHT 40w. If straight 40w isn't available, run straight 30w. I bought this boat new in 87, have ran straight 40w since, changed every 70 hrs. They say boats run at higher RPM's, but I troll at 1.5 to 2.7 mph (800 rpm), for 4 or more hrs at a time, and running out and back from fishing, run at about 3k. Top speed is 41 @ 4,500 rpm, with a clean bottom. So I never see 6 grand ever! And all that is with a 142 degree thermostat, go figure!
