Oil Pump Spring?

[dn010]

I should specify that I'm talking about the Volvo B280F pump springs that were broken.

Unfortunately I have not found anywhere to get replacements so I have a few pumps laying around. These pumps or components cannot be used on the DeLorean engine because the gears are longer, the pressure relief valve is different along with the spring.

I'd guess you won't need to worry about this but if you do find that the spring is bad, I'd start by seeing if anyone here has a pump laying around due to having to part out their block rotten engine. You could also try getting a B28F pump somewhere to see if it is the same.

Get a set of oil galley brushes (engine brush kit on Eastwood) to clean up your oil passages and make sure nothing is plugged.

[David T]

If you do a complete teardown of the block, as part of the process you have the block "boiled". That should get all of the crud loose and out but as dn010 says, you wash and brush out the oil galleries and all the small passages with long brushes anyway. ANY engine builder will not trust anybody else to make sure EVERYTHING is clean. It is a real "rookie" mistake to lose an engine because of some dirt. Not too long ago someone had their valve covers blasted and powder coated (not a Delorean). Because of the baffles inside one cover some of the blasting media was not removed completely. You can guess what happened and it doesn't take long. A good engine builder will also number match everything as he disassembles, and measure everything himself as he assembles to make sure the machine shop didn't mess up. Building an engine is a very fussy and meticulous process. Any small mistake and it is all over. Take your time and if you have to, make up a checklist. I have found if you get interrupted while you do a build you can forget exactly where you were and miss something. If something is not fitting right, STOP and figure out what is happening, do NOT think you can force it and it will be OK. Keep track of your bolts and make sure you are using the correct fastener in the right place. Take pictures or make sketches. Sometimes you don't reassemble things right away and you forget. Check and double check your valve timing and distributor. When I build an engine I use mineral oil, not synthetic, and a quart of Marvel Mystery Oil for my break-in oil and change it after 1,000 miles. In a car that doesn't get a lot of mileage, 500 miles or 1 year. On initial start-up use a mechanical oil pressure gauge and make sure you got plenty of pressure or shut it off right away. Minimum 30 psi at idle plus 10 psi for every additional 1,000 RPM's.

[Parzival]

I did find a broken oring in the oil pick up. Not sure if it was effecting anything or not, but thats one thing that will be fixed.

[DMC-81]

I did find a broken oring in the oil pick up. Not sure if it was effecting anything or not, but thats one thing that will be fixed.

Definitely, that will help.

On reassembly tips: One thing my engine builder did is mark each bolt head with a dot using a paint marker to indicate that it was torqued. I thought that’s a great practice. I used assembly lube and always primed the oil pump before firing the engine. There are different ways depending on the type of engine to do this. On my recent Magnum build, the engine builder recommended STP Oil Treatment (15 oz) along with the normal spec engine oil. Change at 1,000 miles.

[Giamanut]

Definitely, that will help.

On reassembly tips: One thing my engine builder did is mark each bolt head with a dot using a paint marker to indicate that it was torqued. I thought that’s a great practice. I used assembly lube and always primed the oil pump before firing the engine. There are different ways depending on the type of engine to do this. On my recent Magnum build, the engine builder recommended STP Oil Treatment (15 oz) along with the normal spec engine oil. Change at 1,000 miles.

Alright I am no D expert But I have worked on a gazillion Oil pumps and that springs sole function in life is to maintain oil pressure at a given PSI if you use a stronger spring you will have higher Oil pressure. It just opens at a certain PSI and lets oil bypass most times back to the pump! Fuel pressure regulators work Identical adding washers tightens the spring creates more fuel pressure! Surprised anyone found a broken spring on an engine with normal oil pressure, I would suspect a broken spring would jam the poppet valve closed and create high oil pressure that really moved with RPM, or it would allow the poppet valve to stay open and lose a lot if not all oil pressure.
If you remove the spring you will find a little Poppet Valve at the end of it! And just inside of the cotter pin should be a washer or maybe 2.
Torque strip your bolts and you can even get different colors.

[Ron]

Alright I am no D expert But I have worked on a gazillion Oil pumps and that springs sole function in life is to maintain oil pressure at a given PSI if you use a stronger spring you will have higher Oil pressure. It just opens at a certain PSI and lets oil bypass most times back to the pump! Fuel pressure regulators work Identical adding washers tightens the spring creates more fuel pressure! Surprised anyone found a broken spring on an engine with normal oil pressure, I would suspect a broken spring would jam the poppet valve closed and create high oil pressure that really moved with RPM, or it would allow the poppet valve to stay open and lose a lot if not all oil pressure.
If you remove the spring you will find a little Poppet Valve at the end of it! And just inside of the cotter pin should be a washer or maybe 2.
Torque strip your bolts and you can even get different colors.

Actually, its purpose is not to maintain a certain pressure -- It is to limit pressure. The oil pressure will vary with RPM, etc. while the pressure is within the limit. If the limit is exceeded the valve will open and the excess goes to the crankcase, not back to the pump. Adding washers will not raise the oil pressure -- It will allow the pressure to exceed the limit (and probably damage the oil filter and/or blow out an oil galley plug).

[Giamanut]

Actually, its purpose is not to maintain a certain pressure -- It is to limit pressure. The oil pressure will vary with RPM, etc. while the pressure is within the limit. If the limit is exceeded the valve will open and the excess goes to the crankcase, not back to the pump. Adding washers will not raise the oil pressure -- It will allow the pressure to exceed the limit (and probably damage the oil filter and/or blow out an oil galley plug).

Weather it goes back to the crankcase or pump does not matter it relieves the pressure at a point at which oil pressure overcome the spring thus controlling Max oil pressure. And yes the purpose of controlling Max oil pressure is as you stated and adding stiffer springs or washers is done routinely to raise Max Oil pressure. In fact the total difference between a High pressure OP and a stock OP is the spring . Oil only rises with RPM until the Poppet Valve that is held in by the spring is pushed back.
Absolutely adding a washer will raise Oil because it will take more Oil pressure to Push open it to bypass Functionally Identical to the Fuel Pressure regulator in the FD. Functionally we are stating the same thing for the most part.

[dn010]

Like Ron stated, the valve does not regulate pressure. It only opens at a certain PSI to bleed high pressure. This argument doesn’t really matter since regardless, there are no springs available for our application.

[Giamanut]

Like Ron stated, the valve does not regulate pressure. It only opens at a certain PSI to bleed high pressure. This argument doesn’t really matter since regardless, there are no springs available for our application.

Exactly! To Bleed off or limit is to regulate! It is the same thing it does not come into play at low pressure Only Regulates/Limits/bleeds off high pressure. Or if you like bleeds off excessive pressure. Thereby regulating/limiting/bleeding off it to a spec max oil pressure. https://www.melling.com/aftermarket-...u-k/technical/

[Ron]

Weather it goes back to the crankcase or pump does not matter it relieves the pressure at a point at which oil pressure overcome the spring thus controlling Max oil pressure. And yes the purpose of controlling Max oil pressure is as you stated and adding stiffer springs or washers is done routinely to raise Max Oil pressure. In fact the total difference between a High pressure OP and a stock OP is the spring . Oil only rises with RPM until the Poppet Valve that is held in by the spring is pushed back.
Absolutely adding a washer will raise Oil because it will take more Oil pressure to Push open it to bypass Functionally Identical to the Fuel Pressure regulator in the FD. Functionally we are stating the same thing for the most part.

Exactly! To Bleed off or limit is to regulate! It is the same thing it does not come into play at low pressure Only Regulates/Limits/bleeds off high pressure. Or if you like bleeds off excessive pressure. Thereby regulating/limiting/bleeding off it to a spec max oil pressure. https://www.melling.com/aftermarket-...u-k/technical/

First, I'm not trying to step on your toes but simply clarify/correct the stated operation for the benefit of others...

Weather the excess goes back to the crankcase or pump matters when explaining/understanding the system.

There is more to it than semantics-
"Maintaining a given PSI" is not the same thing as "regulating/limiting/bleeding off it to a spec max oil pressure." The former yields a constant pressure. (The pressure regulator in the FD (PPR) is a good example.) The latter yields varying pressure, up to the spec. (Which is how the oil pumps actually work.) The PPR maintains -- The OP relief valve limits.