[PontiacHO]

Recently completed my cam and lifter change for my 1968 Firebird 350. Used an Elgin “066” cam and Hy-lift Johnson lifters. Also replaced valve springs, rocker arms, pushrods, and valves. Engine runs quiet and smooth. I have several lifters that clatter for maybe a second when first started cold. After that it’s totally quiet. Is that a known characteristic of Hy-lift Johnson lifters?

[PAUL K]

That's the sign of a lifter with sloppy internal clearance.

[PontiacHO]

Originally Posted by PAUL K

That's the sign of a lifter with sloppy internal clearance.

That’s the risk I assumed with flat tappets vs roller I reckon….

[grivera]

HR lifters are not immune from sloppy internal clearances

[Cliff R]

Excessive plunger to body clearances and fast leak down rates have plagued lifters since the beginning of time. It's worse these days, and why I prefer to "tight lash" hydraulic lifters vs just taking up all the slack (zero lash) and tightening them another 1/4 to 1/2 turn or so as many do and recommend.

Instead I either bottom out the plungers on the base circle of the cam and back up the lock-nuts 1/4 turn or so or just bottom them out with a feeler gauge between the rocker and valve tip. Pick your poison there, but if you want quiet operation and not much "clacking" after the vehicles sits a few days er on the tight side vs looser. .010 to about .020" works well and the engine will also be quieter in operation as well especially when it get really heat soaked and the oil thins out some......

[Formulas]

I have found internal lifter bores that are tapered, ... IE if you push a plunger all the way down they can get stuck at the bottom of travel due to interferance fit there

[PontiacHO]

Originally Posted by Cliff R

Excessive plunger to body clearances and fast leak down rates have plagued lifters since the beginning of time. It's worse these days, and why I prefer to "tight lash" hydraulic lifters vs just taking up all the slack (zero lash) and tightening them another 1/4 to 1/2 turn or so as many do and recommend.

Instead I either bottom out the plungers on the base circle of the cam and back up the lock-nuts 1/4 turn or so or just bottom them out with a feeler gauge between the rocker and valve tip. Pick your poison there, but if you want quiet operation and not much "clacking" after the vehicles sits a few days er on the tight side vs looser. .010 to about .020" works well and the engine will also be quieter in operation as well especially when it get really heat soaked and the oil thins out some......

I guess warm weather operation will bear that out. I’m a true novice but in my past life as a dealership tech (1976-1983) engines ran smoother with no more than 1/2 past zero lash. If this gets worse I’ll try your method. It runs quiet otherwise but it is still winter….

[PAUL K]

Originally Posted by PontiacHO

That’s the risk I assumed with flat tappets vs roller I reckon….

Similar, both roller and flat tappet can have the same concern. The results are usually different once the sloppy lifter causes an issue.

If you can isolate the problem lifters I would replace them.

[JSchmitz]

I would try adjusting them a little tighter and see what happens. My Comp hydraulic rollers were a little noisy at 1/4 turn. They were quiet at 1/2. Oil weight could be a factor as well. Whatcha runnin?

[PontiacHO]

Valvoline VR1 mixed equal amounts 20W50 & 10W30. Resembles a 15W40.

[srmmmm]

Originally Posted by Formulas

I have found internal lifter bores that are tapered, ... IE if you push a plunger all the way down they can get stuck at the bottom of travel due to interferance fit there

Encountered this exact condition with a set of Comp roller lifters. Took three of them apart to verify and gave up on the set. Went with Johnsons as the solution.

[Kenth]

Originally Posted by PontiacHO

Valvoline VR1 mixed equal amounts 20W50 & 10W30. Resembles a 15W40.

Use 10w30 viscosity.
The lifters needs oil as fast as possible or they´ll tick due to lack of oil.

FWIW

[PontiacHO]

Originally Posted by Kenth

Use 10w30 viscosity.
The lifters needs oil as fast as possible or they´ll tick due to lack of oil.

FWIW

That’s the plan. Thanks