Lunati Cam/lifter went flat during break in

hunt2elk

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The other thing I've read is that our fine far eastern manufacturing friends like to skip the hardening part of the process...
There was a video made not that long ago where a shop tested like 12 cams and lifters, old and new, from several different manufacturers for Rockwell hardness. The hardness was surprisingly good on all of them. That's when they started to look at the crown of the lifters and the taper on the cams.
 

moparedtn

Ed on the Ridge
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There was a video made not that long ago where a shop tested like 12 cams and lifters, old and new, from several different manufacturers for Rockwell hardness. The hardness was surprisingly good on all of them. That's when they started to look at the crown of the lifters and the taper on the cams.
Ok, so given that....it does just get down to sloppy manufacturing processes then?
The usual suspects in this case are famous for cutting "unnecessary" steps out of the manufacturing
(not to mention, QC being non-existent) in order to deliver on the cheaper cost to the retailer?
 

River Rat

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Ok, so given that....it does just get down to sloppy manufacturing processes then?
The usual suspects in this case are famous for cutting "unnecessary" steps out of the manufacturing
(not to mention, QC being non-existent) in order to deliver on the cheaper cost to the retailer?
I’m running a Hughes FT cam and lifters in my GTX, a Comp FT cam and Hughes lifters in my Coronet, and prior to this issue a Lunati FT cam and Hughes lifters in this engine. The engine is fresh, only had 100miles when i decided to change heads and cam, wanted to bump up compression and go with the bigger cam.

Like Don said earlier, my spring psi may have been a touch high for the .533 lift during break-in, but given my other projects…the Lunati lifters may have been a factor as well.

Thanks for the help guys, I don’t post very often but have been following this site for quite awhile. There is some great information on here.
 

moparedtn

Ed on the Ridge
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I’m running a Hughes FT cam and lifters in my GTX, a Comp FT cam and Hughes lifters in my Coronet, and prior to this issue a Lunati FT cam and Hughes lifters in this engine. The engine is fresh, only had 100miles when i decided to change heads and cam, wanted to bump up compression and go with the bigger cam.

Like Don said earlier, my spring psi may have been a touch high for the .533 lift during break-in, but given my other projects…the Lunati lifters may have been a factor as well.

Thanks for the help guys, I don’t post very often but have been following this site for quite awhile. There is some great information on here.
Well, now you're a contributor too! Thanks for sharing what happened with your situation, which now will
add to the "database" for others to search for and find in the future on the site. :thumbsup:
 

hunt2elk

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Ok, so given that....it does just get down to sloppy manufacturing processes then?
The usual suspects in this case are famous for cutting "unnecessary" steps out of the manufacturing
(not to mention, QC being non-existent) in order to deliver on the cheaper cost to the retailer?
Yes, incorrect machining process. I'm trying to find the video I watched, but am having trouble locating it. If you go to post #26 in this thread If you are building an engine today (~2023), Professionals are not building Hydraulic FLat Tappet camshaft engines? Don't try?, I'm pretty sure this is the guy who made the video. This is his 1st video on the subject. In his 2nd one, he shows the actual testing. That is the video I can't seem to find.
 

DanielSlocum

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same thing happened to me a couple of years ago. same brand cam,lifters,valvesprings. i also verified lifter rotation before installing the intake.
had good results with same springs and other camshaft brands prior. now i always break-in using old soft springs as mentioned above. nevertheless, we have been sold junk parts at high prices. such b.s. should not be happening in america,and heads should be rolling somewhere!
 

qkcuda

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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.
When I took mine apart I had the same issue with the wrist pins being tight. I wasn't so lucky on the pistons. The number 8 piston, which was right under the lifter that ground itself to dust, had metal imbedded in the skirt. Luckily the cylinder wall had only light scratches, most of which we were able to hone out.
 

PRHeads

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That’s pretty ugly for only 15mins run time.

I’m not really the “sky is falling” type, but if I was still building engines for customers....... I wouldn’t be using flat tappet cams in them anymore.

Not until they get a better handle on the manufacturing issues.
 

Curiousyellow71

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Metal from the bad lobe gets on the wrist pins and galls them enough that they feel tight. A good shop will have no problem cleaning up the pistons and putting it back together with out new pistons in most cases.
We have the same 704 cam and micro-trol lifters in a engine, probably even the same springs. I am not a fan of the single spring recommended and the over the nose presssures. Been concerned and haven't started it for the break-in yet. Looks like my concerns were real. We bought old stock Johnson lifters to switch.
 
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Don Frelier

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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:)
Well you could put the old cam back in
 

lewtot184

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i'm not one to write off flat tappet cams ,...yet. aggressive lobes that i don't think a hydraulic was ever designed to take, aggressive springs, higher ratio rockers equals problems. i have a new set of edelbrock springs and they tested 132lb at 1.90, [email protected], 380lb spring rate. couple this with a 1.6 rocker (never had a 1.5 rocker that didn't check right at or very near 1.6) and real lift at the valve of almost .570 and open pressure will be around 350lbs. is that enough to kill a hydraulic tappet? been there, done that and never went back.
 

69a100

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Engine fired pretty quick and I went straight to 2200rpm.
Now for the million dollar question! Did you leave the RPM's at 2200 the whole time, or did you vary the RPM's from say, 1500-3000+?
I will hold a steady RPM, but I'll also let it slip down to say 1500, then blip the throttle to get to a quick 3 or 4K RPM and then let it settle back down, then do it again. I do this for the whole break in period! I'm all over the RPM's to make sure that they are spinning instead of just letting it sit at one speed. The quick burst in R's will force the lifter's to spin. Just my way of covering my ***!
I guess some folks think outside the box so they don't bork things up! Good Luck
 

PRHeads

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Back in the good ole days, before soft springing and break in oils were a thing....... the mid-80’s........when I was trying to learn how to make my car faster(and really didn’t know anything) I put 5 SFT cams in my 440 one summer.
Dual springs on the heads(I had no idea what the spring pressures were, and even if I had known, the numbers wouldn’t have meant anything to me. But later on after I was more informed about those things, I pulled the heads apart and tested the springs. They were set up at 150 on the seat and over 400 open)....... and I broke in and ran all 5 cams on the same set of lifters. No problems at all.
I slathered the moly paste on the cam(s) and let it rip.

You aren’t going to get away with those antics nowadays.

The old MP 933 spring has a rate of 433lbs/in.
[email protected], [email protected] lift.

Just think of how many 509 cams got matched up with those springs........ that got broken in with them on the heads.

I was working at a machine shop with a dyno in 1989......... and a cam going flat was a pretty rare occurrence at that time.
 
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River Rat

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Now for the million dollar question! Did you leave the RPM's at 2200 the whole time, or did you vary the RPM's from say, 1500-3000+?
I will hold a steady RPM, but I'll also let it slip down to say 1500, then blip the throttle to get to a quick 3 or 4K RPM and then let it settle back down, then do it again. I do this for the whole break in period! I'm all over the RPM's to make sure that they are spinning instead of just letting it sit at one speed. The quick burst in R's will force the lifter's to spin. Just my way of covering my ***!
I guess some folks think outside the box so they don't bork things up! Good Luck
I lightly increased RPMs to around 2500 a few times, the fans cut on twice and dropped RPMs a bit but never below 2000.
 

moparedtn

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Yes, incorrect machining process. I'm trying to find the video I watched, but am having trouble locating it. If you go to post #26 in this thread If you are building an engine today (~2023), Professionals are not building Hydraulic FLat Tappet camshaft engines? Don't try?, I'm pretty sure this is the guy who made the video. This is his 1st video on the subject. In his 2nd one, he shows the actual testing. That is the video I can't seem to find.
I remember watching that fellow's 440 build videos a number of years ago.
 

Tman100

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I ordered a new 704 cam and just got it. I currently have a 703 in my 440 now. I too was wanting a little more as my 440 is under Cammed…. I may now be rethinking opening my perfectly running 440 after seeing thins thread.
 

Geoff 2

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I only read the first post because I know all the crap that would follow......

If you want a FT cam to last, get some factory lifters [ or lifters that are at least 25 yrs old ] & have them re-faced.

You can put lipstick on the pig [ extra lifter oiling mods etc ]....but you still have a pig.

When the FT lifters started coming from overseas about 20 yrs or more back, Crower offered Chebby lifters in two harness grades, which I took to mean you can have crappy lifters or....or a little more....not so crappy lifters. There was even a polished version, special lipstick.
 

River Rat

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I ordered a new 704 cam and just got it. I currently have a 703 in my 440 now. I too was wanting a little more as my 440 is under Cammed…. I may now be rethinking opening my perfectly running 440 after seeing thins thread.
The reason I started this thread is to maybe get some answers. I have been researching this for 4 weeks since it happened, 2 guys on here asked the same question I asked Lunati…how could that much damage happen in 15min? I don’t believe this was your typical wiped cam/break-in issue. That lifter never rotated and had to have began transferring material instantly upon start up for it to give up like that.

The other 15 lobes and lifters are in excellent condition. Lunati told me that I had a lifter bore issue…I guess it’s possible. I’m moving on.

I’m not shying away from FT cams in the future, but you can be assured I will be using the Johnson Hy-Lift lifters that you can get from Hughes, they are in my GTX, Coronet, and will be back in this truck shortly.
 

padam

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I installed a Lunati cam a couple years ago, but didn't like the look of the lifters. They did send me 1 new one for 1 that was undersize, but I went with Rhoads anyway.

 
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