Priming the pump

[motogman]

I am reading up on various engine assembly threads and need some more discussion on the issue of getting oil pumping after a rebuild.

If I understand correctly - and this is more of a question than a statement - with a rebuild, if the oil pump has only light lubrication then air will compress and leak and the pump will not draw sufficient vacuum to pull in oil and get the system primed and working properly.  So is this correct?

I have read where some have used Vaseline and others while lithium grease to load the pump and this will provide sufficient sealing and thus allow the pump to start working and pull in oil, thus priming the system and getting correct oil pressure.

One sage (perhaps Roper) posted something like putting air pressure into the sump via one of the oil lines and thus pushing oil up into the pump to prime the system.

I am probably a week or two (likely longer based on my typical rate of progress) away from putting the pump and other bits back together but I am trying to plan for success.  I also expect the motor to sit for months before I am ready to fire it up.

So what do y'all recommend?

Thanks

[oldbike54]

 Never heard of using air to pressurize the sump , not sure how that would work . Probably just oil up the pump , and spin the engine with the spark plugs out until the pump pressures up .

  Dusty

[cruzziguzzi]

Power spin the oil pump before hooking up the timing chain?

I have tool-rods cut to do this to several different American V-8s with the drive shaft removed.

Dunno about Guzzis in particular.


Todd.

[motogman]

Never heard of using air to pressurize the sump , not sure how that would work . Probably just oil up the pump , and spin the engine with the spark plugs out until the pump pressures up .

  Dusty

Dusty...

I found that advice here.  It wasn't Roper but Wayne Orwig - I think another of the sage gurus...

http://wildguzzi.com/forum/index.php?topic=23132.0

[oldbike54]

Dusty...

I found that advice here.  It wasn't Roper but Wayne Orwig - I think another of the sage gurus...

http://wildguzzi.com/forum/index.php?topic=23132.0

 OK , can see where that would work .

  Dusty

[Wayne Orwig]

Dusty...

I found that advice here.  It wasn't Roper but Wayne Orwig - I think another of the sage gurus...

http://wildguzzi.com/forum/index.php?topic=23132.0

That can't work.

[Chuck in Indiana]

White lithium grease is what VW recommends for that. I just used assembly lube on the Aero engine, IIRC. I know I pulled the plugs and cranked it, and the oil pressure light went off almost immediately. I'll look back through the thread and see if I remind myself. 
Edit:
Looked back in the thread.. I used a roughly 50/50 mix of 15/50 syn and STP. Worked fine.

[oldbike54]

That can't work.

 So... blue or red shop rag Wayne ?

  Dusty

[pat80flh]

Packing the pump gears with vaseline has worked for me on several different engines, it was SOP for some GM engines(Buick 231) to prime. Cranking the engine with spark plugs disabled until oil pressure builds should also be acceptable.

[Aaron D.]

Just make sure to pull the plugs and spin the engine-I do like Chuck's primer though.

[Vasco DG]

Pressurising the case will achieve nothing. The pressure will be the same on the pick up and delivery sides so the net gain would be zero.

On the few I've had with recalcitrant pumps that don't want to prime I've simply dropped the sump and pumped a bit of oil up the pick-up gallery with a drum pump while spinning the motor on the starter. Probably more difficult with a loop due to the pick-up design.

Pete

[Wayne Orwig]

If you pull the center banjo bolt on the oil feed lines. Pressurize the case. Then see oil coming out of the case . Wouldn't that have passed through the pump.

[Vasco DG]

Yup, but you'd have to block the rocker feed lines to pressurise the case.

Pete

[Wayne Orwig]

Yup, but you'd have to block the rocker feed lines to pressurise the case.

Yep, the lines were 'oozing' oil too. But having just had the worn pump and gear go out on the V10, I wanted to verify that everything was 'wet' with oil before I turned it over.

[Kiwi_Roy]

My Eldorado (130,000 miles) primed within a few spins of the starter, I think I may have used assembly lube.

The oil light came on a few days later out on the road, I loosened one of the rocker banjos and the oil pissed out when cranked over. Another switch bites the dust.

I made a second banjo for the RH rocker feed with a longer drilled bolt and added a 100 psi gauge to the RH crash bar so I can verify the pressure, 60 psi is normal, drops down to 20 at idle.

[garbln]

I just used a liberal amount of assembly lube in the pump.  Just before I started the engine with no gas in in the carbs, and the plugs pulled, I cranked the thing till I had oil pressure.  I let it sit over night and did it again, I figured that would get any bubbles out.  Put the plugs back in, turned on the gas and it started in about the first revolution.  Been running great since!