Pre-Oiling
Thread Starter
Instructor
Joined: Mar 2007
Posts: 103
Likes: 8
From: Cataumet MA
Pre-Oiling
I've read about all the pre-oiling tips, and special tools used to do it. I have even used the drill with the blade tip, but, what is really wrong with just cranking the engine with the starter,(ignition disconected of course)and let the oil pump do its thing. The pressure builds up to normal in just a few seconds. You have presumably used plenty of assembly lube when you put the engine together, so you won't have any metal to metal contact for the few seconds that the starter is doing its job.
Any thoughts out there?
I've read all the replies to date, and want to thank everyone for the response. I guess that I will stick to the drill procedure. Probably will rent one of those tools from Auto Zone.
Any thoughts out there?
I've read all the replies to date, and want to thank everyone for the response. I guess that I will stick to the drill procedure. Probably will rent one of those tools from Auto Zone.
Last edited by Kfmorgan; Mar 22, 2007 at 12:31 PM. Reason: Appreciate the response!
Melting Slicks
Joined: Dec 2000
Posts: 3,363
Likes: 303
From: Lansdale 19446 PA
2024 C3 of the Year Finalist- Unmodified
St. Jude Donor '10-'11, '15, '19
In my mind - it is not worth the risk! A couple minutes at 1K rpm per minute can cause a failure. I put together a 283 years ago and didn't pre-lube. I used plenty of assy lube (at least I thought I did!
) A couple months later I spun a rod bearing. I have pre-lubed using an old distributor i gutted. haven't had a problem since.
) A couple months later I spun a rod bearing. I have pre-lubed using an old distributor i gutted. haven't had a problem since.
Le Mans Master
Joined: Oct 2006
Posts: 7,123
Likes: 433
From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
Lots of empty oil passages to fill and then flush out any trash from the build. All the crank passages would be empty. All it takes is one turn with no lube to scar a bearing. IS it worth the risk?
Drifting
Joined: Jan 2006
Posts: 1,944
Likes: 22
From: Yooperville MI
If you crank it with the starter, all the rotating parts and cylinder walls will wipe themselves dry of your assembly lube before your oil pump even gets primed. By pre-oiling you rotate the pump which primes it and then the pump can distribute oil throughout the engine before you start it. You can also check for leaks. Not worth the risk.
Racer
Joined: May 2003
Posts: 378
Likes: 0
From: Phoenix Az
St. Jude Donor '09
I agree with everyone else about this too. With the time and Money you invest in a new engine, it would not be worth it to risk spinning a bearing.
Bad idea to try and just turn over the engine.
Bad idea to try and just turn over the engine.
Team Owner
Joined: Jul 2004
Posts: 40,338
Likes: 786
From: Redondo Beach, California
From what appears above, it looks like everyone is in favor of pre-oiling;removing the distributor, and using an electric drill and tool to spin over the oil pump.
After pre-oilling, it seems like it'd be a good idea, after re-installing the distributor, to then next remove the spark plugs and spin the engine over with the starter motor. With no compression, the engine turns fast, and in addition to oil pump operation, you also get crank oil splash on the cylinder walls. This also pumps oil through the crank journals with the crank spinning but with no cylinder firing loads on the crank journals. Does anyone do this as a normal new engine start up procedure? Is it worth the trouble?
After pre-oilling, it seems like it'd be a good idea, after re-installing the distributor, to then next remove the spark plugs and spin the engine over with the starter motor. With no compression, the engine turns fast, and in addition to oil pump operation, you also get crank oil splash on the cylinder walls. This also pumps oil through the crank journals with the crank spinning but with no cylinder firing loads on the crank journals. Does anyone do this as a normal new engine start up procedure? Is it worth the trouble?
Melting Slicks
Joined: Feb 2006
Posts: 3,428
Likes: 5
From: Japan
All the aforementioned logic offered in response to your initial question here is valid AND totally consistent with practically every "How to Rebuild Your Small- [Big-]Block Chevy" (or Ford, for that matter) book ever printed. The main purpose of prelubing your engine is to prime all of the oil passages so that as soon as you begin cranking on initial start-up oil is circulating-priming the system by running it for a minute or two eliminates any air pockets and the possibility of a bearing hitting a dry spot. Also, smallblock Chevys in particular have a penchant for wiping cam lobes.....this is most likely to occurr during initial start-up and break-in and properly prelubing the system immediately before starting ensures an uninterrupted flow of oil during this period. Cranking the engine slowly on the starter (even with the plugs out) to prime the system is not a good idea as it takes a few seconds to build pressure and with cold, thick oil you'll likely wipe most of the assembly lube off before it can do any good. I'm no guru but I have built about ten engines and prelubed every one in this fashion and never had any cam or bearing problems during break-in or any other time.
Last edited by birdsmith; Mar 21, 2007 at 08:11 PM.
8th Gear
Joined: Mar 2007
Posts: 8
Likes: 0
All the aforementioned logic offered in response to your initial question here is valid AND totally consistent with practically every "How to Rebuild Your Small- [Big-]Block Chevy" (or Ford, for that matter) book ever printed. The main purpose of prelubing your engine is to prime all of the oil passages so that as soon as you begin cranking on initial start-up oil is circulating-priming the system by running it for a minute or two eliminates any air pockets and the possibility of a bearing hitting a dry spot. Also, smallblock Chevys in particular have a penchant for wiping cam lobes.....this is most likely to occurr during initial start-up and break-in and properly prelubing the system immediately before starting ensures an uninterrupted flow of oil during this period. Cranking the engine slowly on the starter (even with the plugs out) to prime the system is not a good idea as it takes a few seconds to build pressure and with cold, thick oil you'll likely wipe most of the assembly lube off before it can do any good. I'm no guru but I have built about ten engines and prelubed every one in this fashion and never had any cam or bearing problems during break-in or any other time.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
Le Mans Master
Joined: Oct 2004
Posts: 5,269
Likes: 54
From: Orlando Florida
St. Jude Donor '05
Pre-oiling is done without the crank or the cam spinning. Basically all of the above posts are correct 
Without the bushing around the priming tool (that chunk of aluminum that 'copies' the distributor housing) you'll get oil only to one side. I primed for a few minutes with the cheaper tool which is only a pump shaft extension and had no oil on the passenger side. After one minute with the correct tool I had oil at all rockers.
Cheap and easy insurance and piece of mind. not worth skipping this step. The tool is free at AutoZone (loaner).
Without the bushing around the priming tool (that chunk of aluminum that 'copies' the distributor housing) you'll get oil only to one side. I primed for a few minutes with the cheaper tool which is only a pump shaft extension and had no oil on the passenger side. After one minute with the correct tool I had oil at all rockers.
Cheap and easy insurance and piece of mind. not worth skipping this step. The tool is free at AutoZone (loaner).
Race Director
Joined: Nov 2002
Posts: 12,142
Likes: 54
From: Taylor Michigan
I use a air pressurized pre engine oiler. Dump 5-6 quarts of oil in the tank, connect to the oil pressure guage hole and turn the valve open and in a few minutes the engine is ready to fire after being topped off.
Le Mans Master
Joined: Jan 2006
Posts: 6,504
Likes: 139
From: Butler Pa
You concluded correctly. Without the tool or a distributor installed, the oil passage to one side is left open so the oil just drains back into the pan.
Le Mans Master
Joined: Jan 2006
Posts: 6,504
Likes: 139
From: Butler Pa
Le Mans Master
Joined: Oct 2006
Posts: 7,123
Likes: 433
From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
Le Mans Master
Joined: Oct 2004
Posts: 5,269
Likes: 54
From: Orlando Florida
St. Jude Donor '05
You'll be surprised how many tools you can "rent" at the 'Zone' or AdvancedAuto. Basically you're paying full retail price and then you get the money back when you return it.
I do not like all these extra charges on my credit card so I'll start using cash for their loaner tools - they charge your card and then it takes a few days to see the refund, just like when you return something....
I do not like all these extra charges on my credit card so I'll start using cash for their loaner tools - they charge your card and then it takes a few days to see the refund, just like when you return something....
