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View Full Version : SR20det valvetrain: hydraulic lifters bleed themselves @ 120psi?


Kingtal0n
09-06-2012, 08:45 AM
I was talking to a machine shop that builds sr20det engines. We are discussing the oem lifters for the sr20det engine.

According to him, the correct procedure for setting the valve clearance on the sr20det engine, is to

1. completely remove all of the oil from the lifters first
2. Install the dry lifter into the engine to check the "preload" and adjust the valve clearance
3. Pressure the oil system at 120psi of oil pressure to fill the oilpump, bearings, lifters, etc... when finished


I was under the impression that OEM sr20 lifters cannot bleed properly when installed, once there is air in them.
I quoted the FSM, which the engine builder said was a "standard procedure and does not apply in this case"

TheWolf
09-06-2012, 09:33 AM
There is to much voodoo in the above statement. Tell them to quit reading engine builder magazine.

It's a HLA not a rocket ship.

Soak in oil. Stick in. Install cams. The only reason they'd need to check "preload" is if they cut the seats to deep in the head and had one bottom out a lifter. There's no other reason. Nissan didn't when they put them together on the assembly line.

Kingtal0n
09-06-2012, 03:03 PM
The engine builder thinks that the dry empty (full of air) lifters are going to take up the proper amount of oil when he applies 120psi of oil pressure to the block.

My question is as follows:

Will they?

Or will they stay full of air?

Kingtal0n
09-07-2012, 03:12 PM
this is a good question, because Ive never heard of anybody doing this. Yet apparently this is a standard procedure- he mentioned that Honda engines receive similar treatment.


According to the FSM, running the engine will not remove the air.

But 120psi will?

Kingtal0n
09-08-2012, 06:01 PM
So heres a new one.

If the rocker arm cannot be pressed down, that is, if there is no play in the lifters plunger when the rocker is pressed with a finger; then that means that the lifter is full of oil, amirite ?

The FSM seems to specify that this is so "the rocker should not move 1mm or more", but my question is, what if the lifter is approx 80% full of oil, that seems to indicate that the rocker will move 20% of it's lifter's plunger's cavity filled with air, which may not be "1mm or more". So at that point, would I take all the lifters out (assuming they all deflect 20% or so, < 1mm) and re-bleed then reinstall and re-check?