Oil Priming on L31 Vortec

[HotrodZ06]

I lube everything that moves with assembly lube, Soak and prefill the lifters. As long as everything is correct it makes no noise on initial startup.

 

[rebelyell]

I've used a cut-down old dist as a prime tool. But ya don't have to do that --- instead & with Any dist installed, ya can use a $10 cheapo pump-up garden sprayer and pressurize the system while rolling motor thru at least two complete revs

 

[rebelyell]

Sent the bare block to the machinist and reassembled everything myself but yeah this weekend hopefully I get the thing stabbed and started

Did you replace the small oil gallery plugs (Right & Left) at front face just behind top timing sprocket?
If so, did you replace with same type; OE L31 have a small hole in both R & L plugs ? It matters.

 

[Scooterwrench]

Did you replace the small oil gallery plugs (Right & Left) at front face just behind top timing sprocket?
If so, did you replace with same type; OE L31 have a small hole in both R & L plugs. It matters.

Chain oilers?

 

[Road Trip]

I'm rebuilding the L31out of my 96 GMC K2500 and am nearly to the point of putting the thing in. I know that it's best to prime the oil system before starting the truck, so I bought a proper tool that attaches to a drill. My engine has the oil filter housing that runs two lines to an oil cooler in the radiator, and when I spin the oil pump it comes right out of the holes for the lines on the oil filter housing. So my question is do I need to either somehow block the holes, or hook the lines up to both the rad and the filter housing and spin it then? Maybe possibly something entirely different I'm not thinking of but any help is greatly appreciated.

Hello katwood16,

I like your thought process with your newly rebuilt engine -- Trust but Verify.

Reading what you wrote, I have a question for you. How much do you trust what
is left inside your oil cooler? Did the previous engine go out in a blaze of glitter
(failing parts filling engine oil with debris?) or was this engine rebuild just a
common sense investment with an eye towards the future?

In English, is that engine oil cooler clean, or does it need to be flushed before
being put into service with your brand new motor? Are you going to work your
truck with towing and other HD use, or is this a fun toy? The reason I ask is
that if you are going to really work the vehicle then it makes sense to renew
the engine oil cooling system and take advantage of it.

If on the other hand you are just going to drive it for pleasure, you might consider
running without the oil cooler and all the attendant extra time/effort/money to ensure
that it's as clean/leak free/long lasting as the new engine.

And if you are worried about higher oil temps, you could choose to run a modern synthetic.
Whatever you do, make sure that anything involved with your new engine is clean clean clean.

Best of luck -- the first fire of a new engine is pretty close to hearing your newborn wail
for their first breaths. Some of the best stuff on the planet.

 

[Schurkey]

Chain oilers?

Everyone thinks that. In fact, oil gallery plugs are vented to purge air from the gallery at startup, (to reduce lifter ticking when the engine is first started) not to lube the timing chain. The chain gets plenty of lube from the oil coming out of the front of the front cam bearing, and the front of the front main bearing, plus whatever is drizzling down from the lifter valley.

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[Frank Enstein]

I like to leave the pre-luber in place when installing the engine so I can't damage the distributor cap. I run the pre-luber with the air drill while I spin the engine over slowly with the alternator nut 2 full revolutions and then put the distributor in after.

 

[rebelyell]

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^^^THIS^^^
per GM powertrain parts list for L31, that hole measures 0.025"
that cup plug is PN 10110897

 

[0xDEADBEEF]

I mostly mess with LS motors and you can't prime them without some kind of external contraption so I don't bother. Anyways, that's what assembly lube is for and it works.