Priming Hydraulic Lifters?
Thread Starter
Drifting
Joined: Oct 2003
Posts: 1,426
Likes: 1
From: VetteMOD
St. Jude Donor '05-'07
Priming Hydraulic Lifters?
I am assembling my engine and was planning on priming the lifters but the method described in the manual does not seem to work. First method is to pump oil into the side hole, that hole is partially shielded and you would be lucky to eventually fill the lifter with oil. Second method is to put the lifter in a container of oil and work the plunger back and forth with a push rod. Maybe it's just me but I am unable to push the plunger back by hand with a pushrod. Perhaps there is a tool to do this.
I intend to prime the engine with a drill on the oil pump before starting. Seems like this would be a better method of priming the lifters. Am I missing something?
I intend to prime the engine with a drill on the oil pump before starting. Seems like this would be a better method of priming the lifters. Am I missing something?
Safety Car
Joined: Oct 2004
Posts: 3,926
Likes: 739
From: Youngstown Ohio
Originally Posted by torqvette
I don't know if flat tappet lifters are different from hydraulic lifters in terms of priming, but I just soaked mine in oil then primed the engine while turning it before initial start up.
Same here.
Melting Slicks
Joined: Dec 2004
Posts: 2,161
Likes: 0
From: pr, frederick md.
the tried and true method is to soak in oil overnight. i always do the plunger method. it just makes me feel better about the whole process. lifter shoul be reletively easy to push. will only move 1/4" + or -. do this in conjuction with the drill prime method.
Pro
Joined: Nov 2004
Posts: 607
Likes: 0
From: North Alabama
Just food for thought...I just went through this installing new hydraulic lifters in my engine and wondered the same...everythign i read said DO NOT pump up the new lifters...on the soaking them in oil thing...I called crane and asked about this...they said, not required...so I went with their install instructions and took them out of the box, coated them with assembly lube and put moly grease on the bottom of them and dropped them in the engine. No problems...I would do the same again. I did pre-oil the engine before firing. 
Le Mans Master
Joined: Aug 2003
Posts: 7,720
Likes: 12
From: Chattanooga TN
Originally Posted by vettepilot68
...so I went with their install instructions and took them out of the box, coated them with assembly lube and put moly grease on the bottom of them and dropped them in the engine. No problems...I would do the same again. I did pre-oil the engine before firing.
Drifting
Joined: May 2001
Posts: 1,651
Likes: 13
From: Holly MI
You can soak the lifter for days if you want, but it won't pump it up. When a heavy load is applied to a full lifter, a very small amount of oil is pushed out of the lower reservoir. Oil is not compressible, but the oil is pushed out the small gap between the outer housing and the inner piston. When the load is taken off the lifter, an internal spring tries to push the piston back to its natural position. This creates a lower pressure in the reservoir than in the top of the lifter. The result is that oil flows into the bottom reservoir. There is a spring loaded ball or plate that controls the pressure this occurs at. Letting the lifter soak in oil will not create a pressure differential. The spring loaded ball/plate will stay closed, and no oil will get into the reservoir. If you can't push the lifter down by hand, it's full.
If you can cycle the lifter up and down a little, that will help. It can take a long time to fill up a lifter, even in a running engine. It depends on many factors: oil pressure, oil temp, oil viscosity, valve adjustment, etc. Put the lifter in oil and pump it a few times. Then install it in the engine. If you prime your lifters, but then wait more than a few hours to start the engine, the valve spring is going to collapse them anyway.
Ken
If you can cycle the lifter up and down a little, that will help. It can take a long time to fill up a lifter, even in a running engine. It depends on many factors: oil pressure, oil temp, oil viscosity, valve adjustment, etc. Put the lifter in oil and pump it a few times. Then install it in the engine. If you prime your lifters, but then wait more than a few hours to start the engine, the valve spring is going to collapse them anyway.
Ken
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Drifting
Joined: May 2001
Posts: 1,651
Likes: 13
From: Holly MI
Jim,
There are two reservoirs in a hydraulic lifter, the low pressure one on in the top half of the lifter, and the high pressure reservoir in the lower half of the lifter. The bubbles you see are of the low pressure reservoir filling up. It will help a lifter pump up, because the low pressure reservoir is where the high pressure reservoir gets oil. However, the high pressure reservoir is NOT filling up by letting the lifter soak. Using a primer in the engine will fill the upper reservoir.
Ken
There are two reservoirs in a hydraulic lifter, the low pressure one on in the top half of the lifter, and the high pressure reservoir in the lower half of the lifter. The bubbles you see are of the low pressure reservoir filling up. It will help a lifter pump up, because the low pressure reservoir is where the high pressure reservoir gets oil. However, the high pressure reservoir is NOT filling up by letting the lifter soak. Using a primer in the engine will fill the upper reservoir.
Ken
Drifting
Joined: May 2001
Posts: 1,651
Likes: 13
From: Holly MI
Originally Posted by joe73vette
If you prime the oil pump with a distributor like tool until oil comes out all the pushrods, the lifters are full and the motor is ready to run. Joe
Joe,
The lifters are NOT full. Priming the engine will only fill the top half of the lifter. If the high pressure reservoir is not full, you can prime the engine all day, and it will not fill up. The only way to pump up the lifters is to run the engine. Priming the oil system does put oil into the upper, low pressure reservoir, which makes oil available to the high pressure reservoir sooner. This will help the lifter pump up faster, but it will not fill the high pressure side.
Ken
Safety Car
Joined: Oct 1999
Posts: 4,101
Likes: 10
From: NorCal
Pretty basic...
Lubing the lifters with the proper lube is probably the most important. I just stick 'em in, prime the engine, adjust 'em and fire it up. Takes a second to quiet down (up to a few minutes), but then alls well.
Hans
Hans
Melting Slicks
Joined: May 2002
Posts: 2,431
Likes: 52
From: Florida
Originally Posted by bb69
Jim,
There are two reservoirs in a hydraulic lifter, the low pressure one on in the top half of the lifter, and the high pressure reservoir in the lower half of the lifter. The bubbles you see are of the low pressure reservoir filling up. It will help a lifter pump up, because the low pressure reservoir is where the high pressure reservoir gets oil. However, the high pressure reservoir is NOT filling up by letting the lifter soak. Using a primer in the engine will fill the upper reservoir.
Ken
There are two reservoirs in a hydraulic lifter, the low pressure one on in the top half of the lifter, and the high pressure reservoir in the lower half of the lifter. The bubbles you see are of the low pressure reservoir filling up. It will help a lifter pump up, because the low pressure reservoir is where the high pressure reservoir gets oil. However, the high pressure reservoir is NOT filling up by letting the lifter soak. Using a primer in the engine will fill the upper reservoir.
Ken
I didn't know that.
Monkey see, monkey do in this case. I learned that from a friend of mine. You can see how worthless info keeps getting spread around. 
Thanks again
Drifting
Joined: May 2001
Posts: 1,651
Likes: 13
From: Holly MI
Originally Posted by jimvette999
Thanks Ken
I didn't know that. Monkey see, monkey do in this case. I learned that from a friend of mine. You can see how worthless info keeps getting spread around.
Thanks again
I didn't know that.
Monkey see, monkey do in this case. I learned that from a friend of mine. You can see how worthless info keeps getting spread around. Thanks again
No problem. I'm just trying to help out as I have been helped many times. The reality is that it can take a long time to pump up a lifter. The OEM's today have very strict tests that the lifters/valvetrain must pass. In one, they let the engine soak at -40 degrees for 24 hours and then start the engine. The lifters have to fully pump up (they actually measure vibration which is caused by excess lash) within 2 minutes I believe. It's been over 3 years, so I don't remember the exact time, but it's not long. I witnessed this test, and it was unbelievable. No engine wants to start at -40. The best thing you can do it lube the lifter and cam and then prime the engine as close to starting it as possible.
Ken
