[FHummel]

Can the oil pump pressure be changed by simply installing a 60 psi relief valve/spring in place of one in an 80 psi designated pump?

Any help would be appreciated. Thanks

Fhummel

[AG]

You need to change the spring and the spring housing that screws into the pump body to hold the spring. The 60 psi spring has a different one than the 80 psi spring.

[DOC]

Are you trying to lower your pressure? What weight oil are you running? Do you have any leaks due to high oil pressure?

[Tom Vaught]

Finding a 80 psi spring and "cup" assy is hard to do without buying a new oil pump.

You can swap a spring from Any used 60 psi oil pump and use the same spring 60 psi cover plug on your 80 psi deal. Just need to find a old 60 psi pump for parts. The used parts will work fine and will not wear out even after 200,000 miles typically.

Tom V.

[FHummel]

Thanks for the replies guys. I have the original oil pump with the 60 psi spring, etc.

If only that could be changed out without pulling the engine it would be a simple fix. Alas, can't be done. So this will be a wait-for-Spring project.
I also contacted Butler about this and was told they had never had a problem with this. What I haven't told you guys is that the new pump I installed earlier this year was in a box that was designated as a 60 psi pump. So I thought that it was correct, but it is definitely putting out more than 60 psi. The gauge is pegged at/above 60 psi during most of the driving range. Only when the car has been run for some time the gauge will drop down to less than 30 psi at idle. I use 10w-30 Castrol oil and always have, so no change there.

By the way, once the hood is off I can pull the engine in less than 3 hours by myself. It is an auto trans car and I have devised a method to pull the engine without pulling the trans with it, thus avoiding disconnecting the trans lines, etc. and subsequent loss of trans fluid and mess. Also do not have to pull the radiator or disconnect the starter wiring at the starter.

Again, thanks for the replies.

FHummel

[Tom Vaught]

With a proper Cherry Picker, QUALITY Jack Stands, and a Lift plate with tilt capability, it is very easy to just remove the engine on a auto trans vehicle. A 2x4 under the converter cover of the trans case and a Floor Jack keep it in a proper safe location while the engine is out.

WHEN YOU REMOVE THE OIL PUMP, THE DRIVE SHAFT FOR THE PUMP WILL FALL OUT ON THE FLOOR UNLESS YOU PAY ATTENTION.
DO NOT BUTTON UP THE OIL PAN WITHOUT KNOWING THAT THE DRIVE SHAFT FOR THE PUMP IS PROPERLY REINSTALLED.

Tom V.

[FHummel]

Originally Posted by Tom Vaught

With a proper Cherry Picker, QUALITY Jack Stands, and a Lift plate with tilt capability, it is very easy to just remove the engine on a auto trans vehicle. A 2x4 under the converter cover of the trans case and a Floor Jack keep it in a proper safe location while the engine is out.

WHEN YOU REMOVE THE OIL PUMP, THE DRIVE SHAFT FOR THE PUMP WILL FALL OUT ON THE FLOOR UNLESS YOU PAY ATTENTION.
DO NOT BUTTON UP THE OIL PAN WITHOUT KNOWING THAT THE DRIVE SHAFT FOR THE PUMP IS PROPERLY REINSTALLED.

Tom V.

,
Thanks Tom, but there is just a bit more to the removal, such as removing the tri-power carbs and alternator, setting the PS pump aside, disconnecting the exhaust pipes, removing the convertor cover to remove the torque convertor to flex plate bolts (3), removing the fan shroud and the fan assembly, disconnecting and setting aside the wiring to the alternator and temp sending unit, spark plug wires and distributor (just to be on the safe side), removing the bell housing bolts, ground straps, and maybe a couple more things that I may have forgotten. I have devised a strong-back setup to support the trans in position that allows the reinstall of the engine in the correct alignment angle. Also, since I have to move the car back out of the way temporarily to actually get the engine out and on to the engine stand, the exhaust pipes have to secured up off the floor, then the motor mount bolts have to be removed, water drained from the engine/radiator, and hoses removed. I also remove the battery for safety and to have some place to tie the PS reservoir out of the way. A strong-back I devised utilizes 2 inch square steel tubing that spans the engine compartment fender to fender, with some towels for cushioning, back by the firewall and two threaded hooks that are directly above the ears on the trans housing attached by correct length chains. I simply adjust the hooks upward to the point where the trans is up against the tunnel which is a perfect position to release the engine so that it will let the engine move slightly forward and upward allowing the starter to clear the PS box and raise the engine clear of the car. Whew!! That's how easy it is to remove the engine without removing the trans with it. I am also going to change the rear main seal while I have it out this time. Yep, I know about the oil pump drive rod. Oh, I drain the oil after I get the engine out of the car and on the engine stand.

FHummel

[Tom Vaught]

Nice post with all of the assumed "other items that need to be removed" listed.

A good reference post.

It would really save having to replace a ground strap (which I have missed in the past on a engine removal).

Tom V.

[FHummel]

Originally Posted by Tom Vaught

Nice post with all of the assumed "other items that need to be removed" listed.

A good reference post.

It would really save having to replace a ground strap (which I have missed in the past on a engine removal).

Tom V.

I did forget one item - the gas line to the fuel pump (and plugging the line). I do sometimes also remove the fuel pump as well to give just that little bit more wiggle room removing the engine. Oh, and my GTO has the 3 ground straps.

I also modified the wiring to the starter so that it can be disconnected just above the tube that routes the wiring down to the starter. This was accomplished by installing some 'bullet' type connectors. These are not visible because of the original-type plastic tape wrapping as used by GM. The positive battery cable stays with the engine as well. I just hated having to lay under the car to remove the wiring from the starter.

[ANDYA]

In your previous post you said that you believe that you installed a 60 psi pump but your gauge shows much higher pressure. I have the same problem with two cars using factory oil pressure gauges. One is a 70 GTO with a rebuilt 400 and a 60 psi Melling pump. The factory gauge will show 80 psi while cruising and 40 psi hot at idle. At the time of the rebuild, which is 30yrs ago, I installed a new sending unit. I have put lots of miles on this car over the years with no problems. The second car is a 67 Firebird with a 326 HO. This car is all original with 26,000 miles. The engine has never been apart. Unless some one at the factory made a mistake there is no way it should have an 80 psi pump. The factory gauge in this car acts like the factory gauge in my GTO, it is almost pinned at 80 psi. On the other hand, I have a 69 Firebird with a 428. I'm running a 60 psi Melling select pump and a Stewart Warner mechanical pressure gauge that shows exactly 60 psi at cruising rpm and 40 psi hot at idle.

[giles]

Before you rip into this you might want to verify pressure with a mechanical gauge. Old clusters, wiring and grounding issues could conspire to mislead you. You should be able to verify pressure with a mechanical oil pressure gauge in an hour.

[FHummel]

Thanks guys. I appreciate all of responses.

My GTO is a 73K mile documented total numbers matching original. Although the engine has now been refurbished (too much to explain) and now has what is supposed to be a 60 psi pump (according to the Melling box it came in) I am getting a higher pressure on the gauge as I have already explained. The wiring is in excellent condition. The original pump put out the correct psi according to my gauge. I have the original pump and when I pull the engine I will change out the spring/valve setup to the new pump which is less than a year old and less than 500 miles of use. My main purpose is to replace the rear main seal. I'll let you all know what the outcome is, but it will be sometime this coming Spring before that happens.

Happy Holidays and a very Merry Christmas to all you Pontiac buffs.

I also drive a 2009 G8 GT and a 2009 Solstice GXP roadster.

FHummel

[Bill Hanlon]

I used one of these

when I was concerned about the accuracy of the after market oil pressure gauge that came in my '52 GMC. It was $16 at Northern Tool. Accuracy was +-2%. Drove it with this gauge T'd into the oil pressure port where the dash gauge connected to the engine for about a week to get used to what actual pressure was, especially at a hot idle after a long highway run in the summer with the A/C on. Once I got used to the real reading I removed the big gauge.

[tom s]

Are you running a castiron cam and factory dist gear?If so I would just run it.If you were running a billet cam with a bronze or poly gear I might change it.Also are you running the same oil filter you always used?I changed filter style awhile back and it showed more pressure.Went back to my old one and it went back down.Tom

[FHummel]

Originally Posted by tom s

Are you running a castiron cam and factory dist gear?If so I would just run it.If you were running a billet cam with a bronze or poly gear I might change it.Also are you running the same oil filter you always used?I changed filter style awhile back and it showed more pressure.Went back to my old one and it went back down.Tom

Yes, yes and yes.

FHummel