Lunati Cam/lifter went flat during break in

[River Rat]

Well it finally happened to me. I have been breaking in cams in for years without issue. 15 minutes into break-in engine started hammering. Pulled intake and found this on #5 exhaust. It went down fast, sent shavings throughout the engine. I used Driven break-in oil and assembly grease. Engine fired pretty quick and I went straight to 2200rpm.

440 .060
Icon pistons
RPM heads
Lunati Voodoo 704 cam
Lunati Micro-tol lifters

 

[hunt2elk]

Looks like it wasn't spinning?

 

[qkcuda]

I feel your pain. It happened to me years ago with a MP cam and lifters. Same thing, wore right through the bottom of the lifter.

 

[River Rat]

Looks like it wasn't spinning?

It wasn’t, I ran a burnishing ball through all the lifter bores, and it rotated during mock-up.

 

[Don Frelier]

What is the spring pressure?

 

[pnora]

Never seen one go down that bad in 15 minutes. As said not spinning or something drastic on the springs.

 

[River Rat]

What is the spring pressure?

Flat tappet RPM heads, I think they are 134# on the seat. Had these heads on a 383 for a while last year with no issue.

 

[hunt2elk]

There have been a couple of good articles recently about cam/lifter failures. The thinking for the past several years has been that the cheap Chinese metal was the problem, but now some are claiming that the crown on the lifters and the taper on the cams is the issue. These not being cut correctly are not letting the lifters spin in the bores.

 

[River Rat]

There have been a couple of good articles recently about cam/lifter failures. The thinking for the past several years has been that the cheap Chinese metal was the problem, but now some are claiming that the crown on the lifters and the taper on the cams is the issue. These not being cut correctly are not letting the lifters spin in the bores.

Makes sense. This was a fresh engine that i actually had running pretty good with 440 source heads, Lunati 703 cam, and Hughes lifters. Wanted to step it up a little…now I’m back at square one.

 

[pnora]

Were these new cam and lifters?

 

[River Rat]

Were these new cam and lifters?

Yes, purchased directly from Lunati. They are not far from me.

 

[pnora]

Yes, purchased directly from Lunati. They are not far from me.

Might as well call them. Might go direct to tech. My buddy on a recent Chev Hydraulic roller had issues. They were of no help. They acted like solid lifters and he could not get the preload set. They must of loaded them with STP. After a couple 2 hour run sessions they must of cleaned out the cement and he was able to set the preload. Not good and it drove him nuts.

 

[qkcuda]

Sounds familiar. I had a good running 400 with a Crane cam, and decided to upgrade to a MP 292/509. Oh well, that's when I decided to stroke it.

 

[Don Frelier]

At .533 the spring pressure is likely pretty high.
Break in springs may have helped?
But unfortunately you'll never know.
Pretty much sucks

 

[River Rat]

At .533 the spring pressure is likely pretty high.
Break in springs may have helped?
But unfortunately you'll never know.
Pretty much sucks

Thanks, makes sense. I’m looking at hyd roller options now. This my wife’s 72 D-100…need to get it running…she’s not happy that I tried to “hop it up” a little bit for her

 

[QuickBpBp]

When you tear it apart. Please follow up on what it looks like as many years ago had a cam wipe a few lobes. I will be honest that I should have left it in the car and just put a new cam in it. Everything looked great and the filter and magnet in the pan caught it all BUT i was expecting it to be a mess... Peace of mind has it's value too.

 

[Kern Dog]

Might as well call them. Might go direct to tech. My buddy on a recent Chev Hydraulic roller had issues. They were of no help. They acted like solid lifters and he could not get the preload set. They must of loaded them with STP. After a couple 2 hour run sessions they must of cleaned out the cement and he was able to set the preload. Not good and it drove him nuts.

Good idea. Maybe the rest of the lifters could be examined to see if they have adequate crown to them.

 

[River Rat]

When you tear it apart. Please follow up on what it looks like as many years ago had a cam wipe a few lobes. I will be honest that I should have left it in the car and just put a new cam in it. Everything looked great and the filter and magnet in the pan caught it all BUT i was expecting it to be a mess... Peace of mind has it's value too.

Already tore it down, had minor scratches on the #1 crank journal, machine shop was able to polish out. Strangest thing was all the pistons were very tight on the wrist pin. Shop presssed out the pins and just cleaned up, everything was still in spec. Hope to put the shortblock together this weekend.

 

[moparedtn]

There have been a couple of good articles recently about cam/lifter failures. The thinking for the past several years has been that the cheap Chinese metal was the problem, but now some are claiming that the crown on the lifters and the taper on the cams is the issue. These not being cut correctly are not letting the lifters spin in the bores.

The other thing I've read is that our fine far eastern manufacturing friends like to skip the hardening part of the process...

 

[dvw]

Two things. I’d make damn sure the lifters rotate. Mark them with a sharpie. Lube with oil only. Spin the can by itself and watch. I’d use an old set of stock springs on break-in. Cam lube on the bottom of the lifters only. Oil on the sides.
Doug