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No Oil Pressure

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Ray Smith

Jedi Hopeful
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Have a big problem that requires your input, please.

Did all of the necessary things to start the BJ7 after a complete mechanical rebuild. Filled the oil filter, used a pressureized pre lube kit (oil from the kit was being ejected from the rocker shaft, so assume that the oil galleys are clear, block was hot vated during rebuild,) Removed plugs and rotated the engine for approx a minute, oil pressure did not build. Started engine momentarilly (15-20 seconds), sill no pressure. Removed oil pressure union from block and rotated engine, no oil appeared. Dropped pan and removed oil pump, the original one. Put pump in a pan of oil and spun with a drill. Pump appears to pump oil. Check clearance between pump gears and pump case. Specs indicte one thousands tollerance. My readings approx 4-5 thousands. Would this amount of wear cause the pump to be unable to pump oil throughout the engine? What are some other areas that I should address? I am really stumped. Can anyone tell me the path oil takes when it is injected into the oil pressure gauge union. How can I ascertain that the oil passages are clear?

Need your expert suggestions. Was sooooo disappointed that the oil pressure did not register after waiting so long to finally start the engine.

Cheers,

Ray
)
 
Hello Ray, I'm not an expert on Healey engines, But I have read that if an original oil filter/canister does not have it's internal parts, things like the flat plate,etc assembled in the correct order/positions, that the filter might either block oil flow or bypass the filter showing signs of reduced pressure. Even thought it is recommended to use new oil pumps, I have used old ones without checking much on them because the engine had good pressure before the rebuild. Your clearance seems alot to me but I would not think that it could not put out any pressure. With the same pump that you have before and assuming that you have tighter clearances than before the rebuild you should have at least as much pressure as before. Make sure what ever filter you have is not blocked. Also make sure the clearance in the pan around the pump pick-up is as it is suppose to be. Is the pick-up set where it is suppose to be. Just some ideas. Good luck.
Dave
 
I gather you are using an original oil filter setup. I know from experience that if you use an adapter and a standard canister filter that the wrong filter size will leave you without oil pressure.

Scott
 
Can you check oil gauge? Spray soapy water around the block and fittings looking for leaks if you don't see oil seeping out? Run engine with the oil gauge union removed a few seconds to see if oil comes out there?
 
Ray, If I may relate my experience with my 100 engine, perhaps it may help. I do not have the shop manual for the 6 cylinder engine so please, if it is different forgive me. If you look at the diagram of the oil passages for the oil filter you will see that one line comes from the pump to the filter and one line goes from the filter to the rest of the oil system. When I cranked my engine after rebuild I had the same result as you. I had pumped oil into the outflow line from the filter to the rest of the engine. Great, I knew I had oil going to all the bearings, and the pressure gage. Cranked without spark plugs for a few seconds and no pressure on gage. I then recalled what someone had told me to do when I installed the oil pump (which I knew was turning). It was suggested that I pack the pump with grease so as to eliminate any possibility of the pump not having a prime (charge of fluid)when first cranked. (The pump gearset appears to sit slightly above the normal oil level). I had not done this because all of my experience with aircraft engines (I have a lot of that) said, "nah, don't need to do that". I had thought that the lubricant I had used on the cam and crank during build-up would be thick enough to allow the oil pump to suck oil. So rather than drop the pan and pack the pump with grease, I simply injected some oil into the other line for the oil filter. I didn't even do this with much pressure. I took a big syringe with a small tube and fed it as far as I could into that line, and put about 100 CC of oil into the pump that way. I have a spin-on filter so this was a quick way to try and get oil directly into the pump. Cranked the engine and sure enough had oil pressure very quickly. Just because you have oil going to all the places it goes from the filter does not mean your pump is pulling it out of the sump. Hope this helps.
 
Dave, what do you mean insure that the pick up is in the correct location? I thought that the pickup was located in the screen filter on the bottom of the pump.

The filter is a new filter adopter with a fram filter 3600. How can I ascertain that oil is going through the filter?

Where can I find a diagram of the flow of oil through the engine?

Please keep the suggestions coming.

Ray
 
When installing an oil pump, you need to prime the pump with oil. By having oil at the pick-up screen and having pressurized oil forced on the pump exit, you have trapped air in the cavity of the pump body. Prime the pump and you should develop pressure.
 
Hi Ray,
Roscoe & big6 both have good suggestions. A pump with that much wear could maybe work ok once it is primed, but be very hard to prime. As long as you have a new engine, spend the bucks to get a good oil pump. Above all else, don't start the engine "momentarily" again, until you are sure that there will be oil pressure. If you scuff the bearings while fooling around with the oiling system, you will be in worse trouble.
D
 
Ray, you do not need to do all those things. Big6 has put you on to the problem you must prime the pump if its going to pump oil after a rebuild and complete draining---Keoke
 
I agree about priming the pump.
Once you've got oil being pumped through, the next problem I had when I rebuilt the Frogeye engine, was that the gauge didn't register, because that needed bleeding. The feed pipe was full of air, and it needed to be full of oil, so I disconnected the pipe from the gauge and turned the engine over until oil came out, then reconnected it, then the gauge worked OK.
 
I have purchased a new oil pump and will install prior to next engine rotation.

Dave, how can I insure that I have oil pressure prior to starting the engine? Will the starter rotate the engine fast enough to build pressure on the gauge prior to starting? I used a pressurized prelube kit that I got from Eastwood prior to initial cranking. I will prelube the engine again prior to rotating the engine. Hopefully, this will preclude any damage to the bearing surfaces.

What is the best method of priming the pump? Will pouring oil down the outflow pipe of the pump prior to installing do the job?

Ray
 
How ever fast you spin the pump, it's possible that it will never start pumping.
It's designed to pump oil, not air, so when it tries pumping air, it doesn't get enough 'suck' to get the oil moving - air will leak through 1 thou clearance, whereas oil won't.
Fill the pump with something thick - STP or oil; someone else suggested grease - and this will provide enough suction to get it going.
 
I used a mixture of engine assembly lube and oil as primer for the pump.
 
Ray, i agree the pump should be primed as best as possible.
By positioning the pick-up I mean that (remember I don't know Healey engine internals) If the pick-up tube is not seated into the block or its mounting enough, the screen pick-up area can be too close to the bottom of the pan. This restricts oil into the screen. I happened to me once on a chevy 327. I also use a spin on oil filter adapter with a Fram 3600 filter. Used it all last summer. Run about 50 to 60 psi. When you put the spin on adapter on the the block make sure you didn't block the oil holes with gasket sealant. I used RTV silicone and it is easy to get too much in there. Having said that. Make sure you have the adapter and gasket on right. The adapter is off center to the original mounting location of the old filter assembly. The new spin on oil filter adapter has a "up" marked on the top.
Have to run. Good luck.
Dave.
 
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Hi Ray, You might just check out What John J below just posted that can happen---Keoke
 
Hi Ray,
Good move on the new pump.

On the Healeys, the pump is usually submerged in the sump oil enough to self prime. It maybe wouldn't if the pump was really worn. To be sure, pack the spaces in the pump with grease or Vaseline. If you just pour oil in, it will run back out through the pump intake before you get the pan filled & get it turning over.

If the pump weren't self priming, you would have to pack or prime the pump everytime you did an oil change. The oil in the pump runs out through it's intake when you drain the sump.

Crank it over on the starter until oil pressure shows on the gage. Shouldn't take more than 30 seconds. By this time, you should have a little flow to the rocker arms. If in doubt, crack the gage connection at the block & check there for oil flow. Good Luck,
D
john j,
I don't think that the oil pressure gage cares whether it is reading oil pressure or the equivalent air pressure. Pressure is pressure. It's likely that the gage would have started to read as soon as oil pressure was developed.
D
 
HI Dave, Intreresting thing, initially when using the external oil pressurizer on the engine no mention of oil pressure was made,only that oil was observed at the rockers. Further when the pump was tested independantly off the engine it pumped---Keoke---PS I agree I would never rebuild an engine without replacing the oil pump with new.
 
Putting a pump in a pan of oil & spinning it really doesn't tell much about the pump condition. Just that it works a bit. Four to five thousandths clearance is a whole lot in an oil pump. We may all feel kind of silly if the gage turns out to be defective. Stranger things have happened.
D
 
Dave, That has been in the back of my mind all through this discussion. /ubbthreads/images/graemlins/laugh.gif--Keoke
 
[ QUOTE ]
I agree about priming the pump.
Once you've got oil being pumped through, the next problem I had when I rebuilt the Frogeye engine, was that the gauge didn't register, because that needed bleeding. The feed pipe was full of air, and it needed to be full of oil, so I disconnected the pipe from the gauge and turned the engine over until oil came out, then reconnected it, then the gauge worked OK.

[/ QUOTE ]


Air in the gauge pipe shouldn't make a jot of difference. 50psi of air will read just the same as 50 psi of oil !

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