grinder11

iTrader: (1)

Here is something I have never heard of, and I hope you guys can lend some insight: Yesterday after I primed my LS1's oil system up, I heard very faint metallic noises coming from the motor that sounded very much like a hot motor "heat sinking" after shutting down!! You know, a light "tink" here and there, like hot metal contracting as it cools!!! Again, this is happening as the motor is on the engine stand(!) and has NOT been fired, only primed with oil. I watched carefully as all 16 rockers started drooling oil down to the head, and thought all was well. Maybe it is, but then I started hearing these noises!!! Well, I still had 2 quarts of oil left to go, so this time I was waiting for the noises to start as soon as I cut the oil pressure. Sure enough, they started within 10 or 20 seconds after the oil pressure started to drop!! This time, I put my fingers on the rockers and could feel a very light "tap" as the sound occured from inside the motor. It appears that the lifters are "bleeding down" and the plungers must be slightly hesitating before they move again. This movement is very slight, and maybe is normal for these lifters, but it sure has hell is disconcerting at the least, and could be a sign of trouble to come at the worst!! Has anyone else ever had this happen? In all my years of building motors, I have NEVER heard this before. I would be more concerned if only one lifter was doing it, but it appears that any one that bleeds down is doing it, also. What do you guys think? I know that when these lifters came out there were some issues for some people, but not too many. And I have never heard of this one before!!! I hope you can shed some light on this, guys. Thanks.

vettenuts

iTrader: (4)

There was some discussion on these lifters on another board. Some of the internals are ceramic to reduce mass. Might be more of a start-stop on the bleed due to the lighter components but this is simply a guess on my part.

How did y ou make out with the block issue?

16floz470ml

iTrader: (2)

It is probably just your valves closing. Assuming of course that it is all put together correctly. I have these lifters and have not had any problems yet.

stock48

iTrader: (17)

The sound you are probably hearing is air bleeding out of the lifters. What are you using for a primer?

grinder11

iTrader: (1)

This is NOT the cause, for sure, as the valves are still open, some halfway, some less, some more. And, again, I have NEVER heard a noise like this before on any motor I have built in the past. But then again, I have never used these lifters before, either!! Thanks for your .02.

grinder11

iTrader: (1)

You may have pinpointed this problem. As far as a primer, I am using..... compressed air! In an accumulator that I built myself. It may be that there is still some residual air within some of the lifters that is trapped until they are actually warmed and the motor is running. Thank you very much for your help. I know air can, and does, make some weird noises sometimes. By the way, that must be a strong motor you have to run times at that DA. Not being a wiseguy or doubtful, just envious!! Thanks, again.

stock48

iTrader: (17)

Thank's for the good words! It was a stock internal 6.0L, it finally took itselfe apart in Vegas a couple months ago Working on a forged 370 right now, should be assembling it next week I hope that's what you have going on. I hear a noise like that almost every time I prime a engine.