Lifter priming?
Thread Starter
Burning Brakes
Joined: Aug 2001
Posts: 1,160
Likes: 3
From: Greensboro NC
Lifter priming?
I'm changing out my lifters trying to find an ellusive tick and have been told by 1 rebuilder that I need to prime my hydraulic lifters and by another that I don't and that they are self priming. Which is it? And if I don't prime them how do I set lash with squishy lifters? Also how does one prime a hydraulic lifter?
Drifting
Joined: Jan 2002
Posts: 1,484
Likes: 0
From: Northampton Ma
I'm not sure if what I did was called "priming" (it was a couple years ago), but the directions that came with my new cam said to completely submerge the lifters in new motor oil for 24 hours before installing. Hope this helps 
Le Mans Master
Joined: Mar 2004
Posts: 7,424
Likes: 1,458
From: Little Rock AR
I have never primed a lifter. 
"Squishy" lifters...
If you are setting the lash for the first time on a cold engine that is not running, you need to have the lash set at some point inside of the "squishy" area. It is not critical where you are within the "squishy" area but you do not want it to be too loose or too tight. You want to tighten the nut just enough so that the pushrod can no longer go up and down freely. If you are tight enough to be inside the "squishy" portion, you are fine. You should be able to push the lifter plunger down a small amount by pressing down hard with your hand on the rocker arm. You will feel the spring pressure from inside the lifter.
Do not tighten past the "squishy" portion of the plunger travel to where the pushrod is now tight as that is too far and the valves will be off thier seats.
Squishy is a pretty good way to describe it.
Do this one time to all the rockers, rotate the crank 360 degrees and re-tighten any of the rocker arms that are now loose where the lifter is not currently adjusted inside the "squishy" portion of the adjustment. Some of the arms will be very tight now but leave them alone.
If you have done the procedure sucessfuly, the exposed threads above the adjusting nuts will all be about eyeball equal length. That will get you started. You can do a hot and running zero lash later once the engine is fired up if you desire.
I like to prime a fresh engine with a pre-oiler made from an old distributor core. The lifters get plenty of oil at that time.
-Mark.
"Squishy" lifters...
If you are setting the lash for the first time on a cold engine that is not running, you need to have the lash set at some point inside of the "squishy" area. It is not critical where you are within the "squishy" area but you do not want it to be too loose or too tight. You want to tighten the nut just enough so that the pushrod can no longer go up and down freely. If you are tight enough to be inside the "squishy" portion, you are fine. You should be able to push the lifter plunger down a small amount by pressing down hard with your hand on the rocker arm. You will feel the spring pressure from inside the lifter.
Do not tighten past the "squishy" portion of the plunger travel to where the pushrod is now tight as that is too far and the valves will be off thier seats.
Squishy is a pretty good way to describe it.
Do this one time to all the rockers, rotate the crank 360 degrees and re-tighten any of the rocker arms that are now loose where the lifter is not currently adjusted inside the "squishy" portion of the adjustment. Some of the arms will be very tight now but leave them alone.
If you have done the procedure sucessfuly, the exposed threads above the adjusting nuts will all be about eyeball equal length. That will get you started. You can do a hot and running zero lash later once the engine is fired up if you desire.
I like to prime a fresh engine with a pre-oiler made from an old distributor core. The lifters get plenty of oil at that time.
-Mark.
