I noticed the rebuild kits often show the 2 gears and some gaskets. I noticed my spring holding the valve relief ball is worn on the side. That may be limiting my pressure output. It isn't shown in the kits. How do I change it ? Where can I find one of the right spec ? Can I put a coin behind it to increase the tension and check its relief pressure ?
I was thinking that the spring or something (grit or wear) is not letting the valve close completely. That could bleed off pressure. You can try to increase spring pressure, but it may take several tries to get it right. I would just get a new or good spring. I would disassemble my later pump for the spring (64) and send it to you, but I am not sure it is the same as those on the earlier pump. Cheryl
Cheryl... thank you so much for the offer ! This is what my spring looks like (sorry not the best pictures).... Is yours anything remotely similar ?
RJBT, I took my 64 spring out of the pump and measured it this am. It has 10 coils, is 2.175" long, is 0.575 wide and the coil wire diameter is 0.055". PM me your address if you think it will work, and I will send it air mail. Cheryl
You can shim the original spring about 1/8" to raise oil pressure. There is a spring retainer in the pump where the pickup bolts on.... that is where you shim it. Be certain the shim has an inside diameter at least as large as the retainer.....you don't want to restrict flow with a smaller opening.
Thanks Cheryl ! I'm going to drop my oil pump this evening and measure the spring. wkillgs -> My oil pump is different. It has a separate bolt that holds the spring. I'll take a picture of it later.... i'll follow your 1/8" shim advice.
I pulled my pump out. I had not tightened it down very well (I could unscrew the bolts with my fingers!) since I did not have the torque values (how much ?) and was going to take it out again to double check things. So maybe there was some loss there. My spring has 10 coils, is 1.95" long, is 0.494 wide and the coil wire diameter is 0.051". So it seems slightly smaller than the 64. I'll try to slightly shim it (and make sure the ball is well seated). An experienced US car guy here in France told me I was wrong using 10W40 and on older engines like this one I should be using 20W50. Does that make sense ? Should I do that ? I have seen nowhere on boards people mention this.
RJBT, The oil pump repair section of the 1960 Buick manual starts in paragraph 2-24 here. I would question if you have the side of the idler gear with chamfered teeth inward and away from the cover, and if your gear to cover clearance is between .0005" and .005" after reading that section. It also covers the spring and check ball, but gives no torque specification for the screws. I always used 10w30 in my stock 63 Riv with a 401 and 20w50 in my 455 race engine with larger bearing clearances. I think you are OK with 10w40. Cheryl
Thanks, I have the manual and saw that... except I dont quite understand the " idler gear with chamfered teeth inward and away from the cover" .... I look at my idler gear and cant see a chamfered teeth side/vs non on the other side !!!! Maybe I'm not sure what I'm looking at Anybody want to help me here !
In your pics, I only see a chamfer on the tip of the idler gear....are both sides like that? My '66 manual states a torque of 8-12 ft lbs for oil cover bolts. Loctite on the threads will help keep them from loosening. Looking at the '60 pump, it appears you can use a washer to shim the pump spring. Place it in the retaining nut. As Cheryl said, a poor seal at the check ball could cause leakage as well. Replacing the spring is another option. Did you check gear end clearance? ...place them in housing, put a straight edge across, and measure the gap.....manual calls for 0.0005" to 0.005". Oil... 10w30 if you see temps near freezing 10w40 for warmer use 20w50 in hot weather only. Thick oil is difficult to pump.
Here are both sides of the idler gear...only difference is the chamfer on the inside hole (to ease putting it on the axis).... Edge of gears has same chamfer on both sides .... o No:
The things that will really affect oil pressure are,,,, rod and main bearing clearance, oil pump clearances, and loose,worn cam bearings....and also the pressure relief spring system....and the viscosity of the oil and engine temp....
I got my oil pump out and sanded the casing and plate surface to a mirror like finish with fine sand paper on plate glass. I checked clearance and it is in spec. I put a small washer behind the spring of the relief valve. Got everything back together and added a temp sensor and it runs at: +25 psi oil pressure warms up to 210 temp I just ran it inside a parking garage (have no bumper or lights) and oil pressure wont really move up much. Grrrrrrr ! Temp worries me too. I have a 180 thermostat. I will bring the radiator closer to the fan and see what happens. I took off my water pump and painted it. I noticed it had an different impeller than the ones you guys often post. The impeller looks more like the fans you have on generators or alternators. I have the original radiator (that i repainted) on the car. As the car heated up the oil pressure lowered When I accelerate it comes back up to 25psi. Is my car running too hot ? Should I still be concerned about the low oil pressure ? Should I use 20W50 instead of 10W40 ?
In short, yes and yes. Oil pressure too low and water temp too high. It will of course get higher than normal just sitting there idling, but that is too high for me. Mine would sit around 180 - 190 if left idling for 1/2 hour at normal idle speed (no choke). How are you measuring these temps/pressures ? With a mechanical gauge and/or IR thermometer ? Don't think the viscosity of the oil is going to make too much difference at this stage. As has been said, you should be getting 40 lb straight off when you start it from cold.
I put an Autometer electric oil pressure and water temperature gauge. I assume they are pretty accurate. I have taken the oil pump off several times and cant get the pressure any higher up. In the oil filter housing plate there was a little valve with a spring that did not seem very resilient. I assume that is not a pressure relief valve. I will try to bring the radiator closer to the fan (its kind of distant right now) and see if that brings temp down. For the oil pressure I am at a loss of ideas other than a full rebuild (which I cannot do at this time).
Have you done a leak down test on the engine ? Moving the radiator forward will help, as will a shroud, but it sounds like you have a restriction somewhere in the system - whether this is a faulty thermostat, or a blocked core, or faulty radiator cap, or .............
I never understood what a leak down test was... and what it tests. I'll look it up but I thought it was for checking piston valve or ring leakage ? I should test the thermostat too ...
The oil pump itself does not create pressure. It produces flow and the resistance to that flow produces pressure. Resistance is created by the orifices in the engine block through which the oil flows, and the amount of clearance between the bearings and crankshaft journals. As the bearings wear, clearances increase allowing increased flow which reduces pressure. A leak down test is a compression test in reverse. Instead of measuring the ability of the engine to create pressure, compressed air is introduced into the cylinder through the spark plug hole. One gauge on the tester measures the pressure of the air entering into the cylinder and the other measures the percentage of the air escapingor leaking from the cylinder. The loss percentage will indicate the condition of the cylinder and overall condition of the engine.
You are most probably losing the oil pressure due to well worn clearances between the crank/cam and bearings. See my and Tom Telesco`s posts back in Jan. on the original thread. Consider this a lesson learned the hard way :Smarty: :eek2: :ball: , drive the car lightly and enjoy it until you can do a proper rebuild of the motor. Good luck! Tom Mooney
Tom, I went back and looked at your post (and Tom Telesco's) and yes you both are totally right. But I have learned a lot through the process and gained much assurance in my dismantling/ rebuilding ability. When my situation allows it I will one day do a full rebuild. In the meantime I will drive it lightly (that's all I do in Paris anyway) and closely monitor the gauges I put in (feel much better having something to monitor). Thanks for all the advice Roland
