AMR oil pump cure

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seattle##gs

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Oct 28, 2014
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I am dealing with a 750 motor with an AMR mod and no oil pressure. The fat o-ring should have some squeeze to it when the timing cover goes on...correct?
There is none. The timing cover snaps on snug all the way around instead of the usual gap at the oil pump with the standard faucet washer style seal. The standard gap is around .050 and the timing cover screws provide the pressure to make the junction oil tight. I'm correct in this?? With the AMR fat o-ring there should be about the same amount of squeeze as stock? Right now I'm getting ZERO oil pressure. NOTHING is traveling up the rocker feed line. The fitting at the head is BONE DRY.
How to achieve the squeeze at the fat o-ring? I have some of the shim washers for the oil pump but I think it's going to take several to obtain a .050 squeeze. It's possible that a thinner timing cover gasket is necessary if I could find one. I dimly remember something about an Atlas vs Commando timing cover gasket. The big question is: How much squeeze on the AMR fat o-ring and how to achieve it.
 
Have you checked all the other possibilities? Crank seal, oil pressure relief valve, oil pump gasket on the correct way, oil getting to the pump, oil in the tank, oil lines not reversed? I know you know what you're doing but anyone can make a mistake.
 
seattle##gs said:
The standard gap is around .050 and the timing cover screws provide the pressure to make the junction oil tight. I'm correct in this??
.
.
How to achieve the squeeze at the fat o-ring? I have some of the shim washers for the oil pump but I think it's going to take several to obtain a .050 squeeze.
Click to expand...


Where are you getting .050" from?
According to Norton Service Release N.20 it's .010".

seattle##gs said:
It's possible that a thinner timing cover gasket is necessary if I could find one. I dimly remember something about an Atlas vs Commando timing cover gasket.
Click to expand...

The Atlas gasket doesn't have the loop surrounding the return drilling between the cover and crankcase which shouldn't matter if the OPRV has been modified to vent into the timing chest and the crankcase return is blanked off.
The Atlas gasket also has no loop surrounding the points housing gallery drilling.
 
What you haven't said is if this has ever worked successfully, or the problem has existed since the first installation of the AMR cover?

If it has never worked, I would look seriously at oil way alignments. When I originally built my current motor, just to be 100% sure, I poked lock wire through each hole and out the other side to confirm the required pathways with gaskets in place. You may think things are aligning, but it is difficult to see.

If it is a re-installation, I would go with the swapped feed/return or oil pump gasket orientation issues.
 
Aren't shims available for behind the oil seal?

Shim oil pump feed

Hi All. When you must shim the oil pump feed? 1971 shows two shim, 1972 no more. I have found on my 1971 two shim but the oil pump seal was very compressed. Thanks. Ciao Piero
www.accessnorton.com www.accessnorton.com
 
You don't mention if this is a new installation. Break the joint on the cases where the oil line junction block attaches. Loosen it enough to let oil flow out, then tighten it up. Sometimes there is an air bubble that prevents oil priming the pump. Good luck!
 
Call AMR great people. There is a set screw that needs to be installed after their mods. You will not get oil pressure if it is not installed.
 
I did remove the oil junction block met the cases and oil did drip out of the oil lines.
The set screw is in place.
This motor came to me already built so I have no knowledge of what it was like before. All I know is that I don't have oil pressure so I have to solve this before I start it up again. I really don't want to disturb the oil Pump but nothing else is making itself known. Since there is no oil in the rocker lines I blew into one end and it is clear.
I arrived at the .050 number...the gap between case and timing cover at the oil pump area when the timing cover is lightly pressed into position is just an observation, no measurement taken. Yesterday I placed the cover on to the motor with just hand pressure and I could see that the gasket at that area could move just a little so it shows there is some squeeze going on.
 
And the reason is a blocked oilway in the timing cover, or a blocked oil pipe? Root cause analysis should be a chore. Try blowing compressed air in the opposite direction of oil flow.

- Knut
 
Or could it be that though pump moves oil, unable to make pressure, either from something not sealing at pump or perhaps pressure relief not sealing oil?
 
No it isn't. I can put it back together start it up and give it a minute to build up oil pressure but I don't like that idea.
 
seattle##gs said:
the issue is that no oil is flowing to the rockers therefore the gauge reads no oil pressure.
Click to expand...
seattle##gs said:
No it isn't. I can put it back together start it up and give it a minute to build up oil pressure but I don't like that idea.
Click to expand...

Do I take that to mean you haven't actually started the engine? It shouldn't take anywhere near a minute to show oil pressure.

Unless the crankshaft and timing gallery have been primed immediately beforehand, I wouldn't expect there to be any measurable oil pressure or for oil to begin reaching the rockers from turning the engine over using the kickstart if that's what you are doing.

With the engine running, oil should begin to reach the rockers in a few seconds after which the oil pressure should begin to rise to the normal level.
 
Yes that is correct, no oil pressure shows on a pressure gauge fed off rocker while just kicking engine over. Upon fire up, I see full pressure on my gauge within a second or two.
 
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