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Oil Pump Priming.....

3875 Views 8 Replies 4 Participants Last post by  **DONOTDELETE**
G I know about the need to prime the oil distribution system before I fire up my rebuilt V8/304....incidentally I haven't fabricated the oil pump priming tool that CJDave waxes lyrical about in earlier oil pump priming posts (try saying those last 4 words quickly)...BUT my question is why does the Haynes manual talk about priming the oil pump by packing it with Vaseline/petroluem Jelly? Is there some purpose for this or is it just some perverted ritual that Haynes thought up for a laugh? AND what happens to the vaseline afterwards....presumably it doesn't damage the engine parts???
Cheers //Jules

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These are "para-quotes" from others that have tried to pre-lub the rebuilt motor without using the vasiline technique......or rather the responses that they got.
"If you don't do it'll spin the pump til you're blue in the face and never draw a drop of oil out of the pan."

It apparently provides a "gell seal" that will stay in place until the pump is primed.
I don't imagine the bad effects of the stuff outweight the bad effects of not using it (like not being able to use the motor).


Figures don't lie ....... but liars sure do figure.
The oil pump instructions says to soak it in oil to fill it, the motor remanfacturer suggest using a priming tool within two hours of starting it up the manual says to pack it with vasoline, since I was putting it together on an engine stand soaking it made no sence as it would just run out when I turned it upside down,I could not be sure of two hour window to start it so I packed it with vasoline, it does take a few minutes for it to get pushed up through the pushrods but at least I knew it was there and not seeped out.

Learn to let go of what does not serve you ,but forces you to serve it
/wwwthreads_images/icons/smile.gif Jules....I didn't know that anyone paid any attention to the ravings of a radical, right-wing old engine builder, but I guess you did! In the AMC v8, just ONE of the zillion shortcomings of the oiling system is the extra-long suction line that connects the oil pump to the strainer. Because the oil pump depends on the oil that it is pumping for lubrication of the very close clearances, running dry on startup would age the pump 60,000 miles before you even drove out the door. Vaseline does two things: provides a "seal" between the hard parts of the pump and encourages pumping action when there would have been none if it were bone dry; and TWO, it lubes the pump parts till the oil gets there. TECHNICALLY, the oil pump cannot "Suck" oil out of the pan, but draws it by displacing that oil which is in the pump body, causing a low pressure area on the inlet side. DRAT! Now is when you need an old distributor drive with the teeth ground off. Never enough junk laying around is there./wwwthreads_images/icons/crazy.gif/wwwthreads_images/icons/wink.gif Oh....yes, my chief moonguy-of-repair just reminded me to tell you to be sure that this engine has the cam/distributor gear oiling enhancement./wwwthreads_images/icons/smile.gif

I never believe any statistics unless my moonguys /wwwthreads_images/icons/crazy.gif/wwwthreads_images/icons/wink.gif made 'em up themselves.
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Excellent stuff gents! Now all is clear...I will of course lube up with vaseline at the appropriate time (as the Bishop said to the Actress)!!....for CJDave...just finished making my priming tool by grinding the ends flat on a an 8" bolt. An old distrib shaft would have been ideal but beggers have to be fabricators... Thanks again all! //Jules

Oil pump priming tool, a great use for those old points type and Prestolite distributors...
I always pack the oil pump on every build with engine assembly lube. It protects better than vaseline, it mixes better with the engine oil, and I always have it on hand.

Remember that you will have more metal come out of the engine in the first hour it runs than in the rest of it's life if it's built correctly. So run it about an hour, and change oil and filter. Change it again at about 150 miles, again at 500 miles and then wait the normal 3,000 to 5,000 miles.

Break in with 20/50 wt. if it's warm where you are, or if you are going to break the cam in in a garage. I personally prefer Valvoline 20/50 racing oil for break ins.
You have to run the engine at 1,500 to 2,500 hundred right after you start it for about 20 minutes, or the lifters won't pattern correctly on the cam lobes. See your cam information for specifics.

Have everything hooked up, all water, fuel, transmission, and especially gauges.
Have a couple of buddies that know what they are doing when you start it. One on transmission and radiator, one on timing and carb settings, one on the gauges! The one on the gauges must be trustworthy. If he lets it overheat, or the oil pressure drop with out shutting the engine off, your engine will be damaged in a hurry.

It's always better to pay someone to do this part, so if something goes wrong, you have someone to blame... (that's why we don't let customers in the dyno room while we are breaking a new build in...)

Hope this helps.. Aaron.

When a fool and a wise man argue, Onlookers can't tell the difference...
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Another Question

I just had my engine on a stand and havn't started it yet. I didn't concern myself with priming the oil pump since the engine has about 40K on it. I didn't think it would need to be primed again. i did turn the engine upside down. Do I need to reprime?
Re: Another Question

/wwwthreads_images/icons/wink.gif If the engine has had the pan off, and the oil pickup screen, and the oil pump, it is a candidate for a prime-up job. Don't forget to add the cam/distributor gear oil enhancement./wwwthreads_images/icons/crazy.gif

I never believe any statistics unless my moonguys /wwwthreads_images/icons/crazy.gif/wwwthreads_images/icons/wink.gif made 'em up themselves.
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Re: Thanks, and I sent a private

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