1952 A7 oil to rocker box

[bsa-bill]

Loosening the banjo nuts indicates oil reaching the end of the rocker spindles.

Do you have an old type oil can with thumb lever, if you do could you try squirting oil into the end of the rocker shafts, - a bit of a long shot but would eliminate the shafts - leaving the banjo bolts

[anjimehra]

Opened the prv & it was completely dry. Poked a wire as far as it would go in both the gallery from pump & one to the camshaft. Timing chest had oil in it when I took off the outer cover . Totally foxed !?
Anji

[chaterlea25]

Hi Anji
I would remove the oil pump and see if oil is flowing through from the oil tank
Carefully strip the pump and check its condition, They can seize up when left idle and then shear the gears or drive when the engine is run 
No oil at the PRV means no oil was going to the crank

John

[muskrat]

G'day Anji.
I agree with John. When the oi; pump is off, use an oil can to pump oil in the feed hole and see if any gets to the prv. It might have spun bronze bush inside the steel case main bearing blocking the holes.
Cheers

[anjimehra]

Loosening the banjo nuts indicates oil reaching the end of the rocker spindles.

Do you have an old type oil can with thumb lever, if you do could you try squirting oil into the end of the rocker shafts, - a bit of a long shot but would eliminate the shafts - leaving the banjo bolts

Hi Bill
Thanks. Stripped the rocker box again & checked oil galleries. All clear, so problem elsewhere. will strip the pump & see.
Anji

[anjimehra]

Hi Anji
I would remove the oil pump and see if oil is flowing through from the oil tank
Carefully strip the pump and check its condition, They can seize up when left idle and then shear the gears or drive when the engine is run 
No oil at the PRV means no oil was going to the crank

John

Hi John
Will strip the oil pump today. However, if its a pump problem, how is the timing cover full of oil everytime I remove it , & oil is returning to the tank? I have also squeezed petrol into the horizontal gallery in the PRV housing & it comes out into the inner timing cover. oil pump nuts are tight.Anji

[anjimehra]

G'day Anji.
I agree with John. When the oi; pump is off, use an oil can to pump oil in the feed hole and see if any gets to the prv. It might have spun bronze bush inside the steel case main bearing blocking the holes.
Cheers

Hi Muskrat
Good point will check today. Thanks
Anji

[chaterlea25]

Hi Anji,
Only a strip and examination of all the parts will reveal the problem

I have also squeezed petrol into the horizontal gallery in the PRV housing & it comes out into the inner timing cover. oil pump nuts are tight.Anji

That does not sound good ?????

While you are at it arrange something to rest a screw driver on and under the crank nut
Try and lever the crank upwards, if theres movement then the main bush is in trouble 

John

[anjimehra]

Just clearing my own thinking on the general subject of lubrication. As far as I understand, oil from the pressure side of the pump travels via the PRV to the mains & big ends. From there it drips into the sump to be returned to the tank. When the oil pressure exceeds 50 psi the PRV lifts & allows oil to the cam shaft & timing chest. Sop, if the pRV is dry, presuure side of pump not delivering ?? Is this possible as the pump is working & oil returning to the tank, albeit in spurts & not a continuous flow.
Could someone please sort this out for me
Thanks
Anji

[muskrat]

G'day Anji.
The oil is fed to the bush, from there it's fed to the big ends. It also branches off to the oprv. If the pressure builds to 50 Lb excess is then diverted to the cam & timing gears.
From what I read the bush has spun depriving all but the sump, oil. What oil is getting to the sump is picked up by the scavenge side of the pump and returned to the tank.
I hope I'm wrong, but if anyone can come up with a better explanation, a total strip is in order.
Cheers

[anjimehra]

G'day Anji.
The oil is fed to the bush, from there it's fed to the big ends. It also branches off to the oprv. If the pressure builds to 50 Lb excess is then diverted to the cam & timing gears.
From what I read the bush has spun depriving all but the sump, oil. What oil is getting to the sump is picked up by the scavenge side of the pump and returned to the tank.
I hope I'm wrong, but if anyone can come up with a better explanation, a total strip is in order.
Cheers

Thanks Muskrat. Not looking forward to this.
Another thought. If oil branches off to the prv on the way to the mains, then why is the prv dry ? If the pump is delivering, then irrespective of whether the bush has rotated, oil should reach the prv. Have stripped the pump & all seems in order. As a precaution have lapped the pump end covers. Tried blowing compressed air from the prv housing end, but not exiting from the pump end port. Am sure all galleries were cleared before assembly.
Anji

[duTch]

 

... Tried blowing compressed air from the prv housing end, but not exiting from the pump end port...

 Isn't the anti syphon valve in there, which would stop the air?
 Maybe blow the other way?

[anjimehra]

... Tried blowing compressed air from the prv housing end, but not exiting from the pump end port...

 Isn't the anti siphon valve in there, which would stop the air?
 Maybe blow the other way?

Hi Dutch
Tried blowing from both ends ie. from the prv side as well as from the delivery port on the case.
Anji

[muskrat]

If the bronze bush inside the steel casing has spun the holes will not line up preventing oil to go anywhere but seep out the pump or around the outside of the bush. Solid bronze bush's are safer than the 2 piece variety.
Cheers

[trevinoz]

But oil will flow around the outside of the bush into the prv port.