Hydraulic roller lifter leakdown

[PeteyDaMan]

Hi Guys,
I have a Comp Cams hydraulic roller cam in my 512. I built it 3 years ago but have yet to get it into my Charger (ended up doing a full resto). I have it on a run in stand and fire it up every couple months. After the last run I decided to check the valve lash so I let it cool down for about 30 mins so I could take the valve covers off without burning my fingers.
When I as adjusting to a half turn of preload, some of the lifters had very little pressure. The springs in the lifters were working but I could push the pushrods into the lifters with the rocker arm although they did spring back.
Is this just a symptom of not running the engine enough or are the lifters garbage?

Worst case scenario, I go for a solid roller cam.

 

[lewtot184]

doubt "half turn" of preload is near enough. that's about .020". probably not easy to measure plunger travel now to get a good idea of where to put the preload.

 

[PeteyDaMan]

yea, the lifter preload isn't the issue. I could have put 3 turns in it and I still would have been able to compress the lifter more by hand.

 

[PRHeads]

Hydraulic lifters bleed down against spring pressure after shut down.

IMO, It’s not really desirable........ but it is normal.

Down near the bottom of the page.......
https://www.gatermanproducts.com/faqs.html

 

[Challenger340]

Was it just a 'few' of the HR Lifters or 'most' of the HR Lifters ?

HR Lifters need to "pump up" and fill with Oil and they do this by Oil Pressure fed through the Lifter Bore.... they then 'leak' that pump up Oil normally in operation when compressed against the increased V/Spring pressures required for HR Cam Profiles.
During normal operation and constant Oil Pressure feed to pump up and V/Spring pressure bleeding off.... they do indeed leak down somewhat and it's not uncommon to have one or two Lifters after shutdown that are basically empty/soft.

Where a 'problem' can exist specific to BB Mopars(with very short Lifter Bores that were never intended to utilize/seal against the higher V/Spring pressures required for HR cams).... is the Lifter Bores in the 440 Block itself can be excessively worn at the bottom just below the intersecting Oil Pressure gallery = insufficient Oil Pressure is maintained around the HR Lifter(Oil Pressure leakage out/around instead of "IN") to maintain adequate 'pump up' against the higher HR V/Spring pressures and lots if not all of the HR Lifters are soft ?

I will invite anyone here with a dis-assembled 440 Block to take a flashlight and go inspect the part of the Lifter Bores below the intersecting Oil Gallery and look for the "Half Moon" wear pattern sometimes even intersecting the Oil gallery itself on some higher mileage 440 Blocks to "SEE" the problem with Lifter Oil Pressure ?
Let be against the HIGHER V/Spring pressures required for HR cams ?

 

[Challenger340]

If the problem persists ?
Get a "Street" Mechanical Roller profile = waaay more power/rpm stability than a HR could ever provide, and once lash stabilized you'll never know it's there.

 

[PeteyDaMan]

I was only a few of the lifters. The block was a low mileage RV block and machined/inspected by LRB Performance in Franklin NJ so the lifter bores should be ok.
Like PRHeads was saying, it's probably just the stiff valve springs on the Eddy RPM heads putting a lot of pressure on the lifter when shutdown.

The solid roller option is sounding pretty good about now. Just not thrilled with spending another grand.

 

[IQ52]

doubt "half turn" of preload is near enough. that's about .020". probably not easy to measure plunger travel now to get a good idea of where to put the preload.

The installation instructions for the Comp Cams 8921-16 hydraulic roller lifter is interesting reading. Especially the pre-load adjustment.

https://gafiero.akroncdnr.com/docs/ValveAdjust.pdf

 

[BSB67]

The installation instructions for the Comp Cams 8921-16 hydraulic roller lifter is interesting reading. Especially the pre-load adjustment.

https://gafiero.akroncdnr.com/docs/ValveAdjust.pdf

Hmmmmm. Been doing like that for HFT for over 40 years. Usually keep it to myself as nobody wants to hear it or believe it.

It is also my opinion that if the hydraulic lifter are junk to begin with (i.e. they bleed down), adjust all you want, it really won't matter.

 

[khryslerkid]

doubt "half turn" of preload is near enough. that's about .020". probably not easy to measure plunger travel now to get a good idea of where to put the preload.

The installation instructions for the Comp Cams 8921-16 hydraulic roller lifter is interesting reading. Especially the pre-load adjustment.

https://gafiero.akroncdnr.com/docs/ValveAdjust.pdf

That's the way I've always done it also. My 440 I have now, flat tappet, I set at .020 preload. I checked the height of the lifter piston and compared to a 1/2 turn adjustment and .020 is what it is. They have been quite and I haven't had any problems at all.

Do they bleed down after sitting? Yep. You can hear this in one of the videos I did on cold start up. Once the engine fires you can shut it off, crank it over with the coil wire removed and all cylinders have compression. You don't hear the bled down lifter anymore.

 

[PRHeads]

If you think you have it bad with your HR lifters...... this is usually a good reminder of how bad it can be........



There was a thread on some forum that went along with the video.
Believe it or not...... the motor got run on the dyno with it making all that racket!!!
And then installed in the car!!

A couple years ago I had a customer who called telling me he put a HR set up in a 505. After it was all warmed up he said it wasn’t all that bad, but on start up it was really loud(according to him).
So, I had him watch this video........ he said the one he had there was almost that bad.
Then he made some calls...... put a different brand of lifters in it.
Then it was pretty quiet on start up, but got pretty loud when at full operating temps.

He ended up putting a SFT cam in it....... said it was way quieter.

 

[PeteyDaMan]

Wow!!! Mine isn't near that noisy on startup. Makes me feel a little better although I'm still leaning towards a solid roller like the COMP Cams CL23-741-9 (current is the Comp Cams 23-712-9)

Thanks!!

 

[lewtot184]

If you think you have it bad with your HR lifters...... this is usually a good reminder of how bad it can be........



There was a thread on some forum that went along with the video.
Believe it or not...... the motor got run on the dyno with it making all that racket!!!
And then installed in the car!!

A couple years ago I had a customer who called telling me he put a HR set up in a 505. After it was all warmed up he said it wasn’t all that bad, but on start up it was really loud(according to him).
So, I had him watch this video........ he said the one he had there was almost that bad.
Then he made some calls...... put a different brand of lifters in it.
Then it was pretty quiet on start up, but got pretty loud when at full operating temps.

He ended up putting a SFT cam in it....... said it was way quieter.

good grief!!!!!! why do people buy this stuff?