Damaged cam

[SilverXJ]

I am 100% familiar with the issues involving flat tappet cams and have done everything possible to prevent this. I used the cam break in grease on the lobes and lifter foot, standard engine assembly lube on the lifter body and cam bearing journals when installed. I broke the engine using Joe Gibbs break in oil and a bottle of GM EOS, running the engine for 30 minutes between 1800-2500 RPM. After the break in I changed the oil and filter to Valvoline VR1 with about half a bottle of Crane's break in lube. Then change the oil and filter again after 500 miles. I had the Mopar performance springs installed at 100# seat load, instead of the usual 113#. The lifter bores have been grooved and I had Plasma Nitriding done to the cam. I wanted to put in a crank scraped, but decided against it to keep the the oil slinging properties of the crank. I bought the cam and lifters from Comp, which I though had higher quality components.

I don't know what went wrong. Maybe the lifters were damaged from cranking the engine with no oil and they couldn't hold their preload under higher RPM. Maybe the cam wasn't heat treated correctly... don't know.. the cam is off to Comp for their diagnosis.

[hatem61]

SilverXJ, Sorry about devastating news.
Oil, additives, camlube and break-in procedures are all extremely important.
I did not read each an every word in the whole post but would like to highlight a couple of things... maybe .... maybe it will help identifying a possible cause?
1) pumping the lifters solid before installation is a NO in my opinion
2) have you checked coil bind at max cam lift ?

[SilverXJ]

1) The lifters were never pumped up before installation
2) There is no coil bind.

[dwg86]

Hey Silver, I've followed your build, so I know you took all precautions when you built your engine. Did you check your pushrod length? Mine ended up being 9.350 using the crower roller rockers. That is a lot shorter than stock, but that is the length I needed to keep the roller centered on the valve stem.

[SilverXJ]

Yes, I went with shorter hardened one piece push rods from Smith Brothers. However, with the Harland Sharp roller rockers id don't make a whole lot of difference as the adjuster is above the push rod, not on the pedestal bolt. The stock push rods were too long and started to preload the lifter before the rocker was torqued down with the adjuster backed all the way out.

[1bolt]

Man you have the worst luck, I thought mine was bad. IMO your culprit has to be tied in with what was making the noise. You either have springs binding, rockers binding on their saddles, rocker noses coming slightly off the valve tip, causing side loading of the stem (and thus binding everywhere else), push rods that are too long, or lifter pre load that is too high. Or (gulp) maybe the machinist line bored your cam tunnel off center closer to the deck of the block accidentally, causing stock push rods to be too long...

Wear only on the nose of the lifter seems like a binding issue, measure everything in your valve train, including push rods and even the lifters themselves confirm that everything is actually what its supposed to be and not some slip up like someone sent you lifters that are taller by mistake or longer pushrods, or taller springs would be easy to mix up. Also who makes the cam?

I know you've gone through some serious stuff and although I've read a whole lot of it; I'm kinda lost now. Can you give us a little recap on whats going on post titan debacle? Is this a third stroker build or the "post titan" one you did yourself that you had running and were tweaking A/F ratios last I saw? How many miles are on the engine as assembled? Did you have the cam out (and measured) before the 100 miles with noisy valve train?

How much ZDDP does VR1 have? Maybe the odd wear is just the beginning of failure, and once the nose of the lobe was rounded the lifter face would have been headed for dishing? Still I think somethings binding at full lift.

[dwg86]

Yes, I went with shorter hardened one piece push rods from Smith Brothers. However, with the Harland Sharp roller rockers id don't make a whole lot of difference as the adjuster is above the push rod, not on the pedestal bolt. The stock push rods were too long and started to preload the lifter before the rocker was torqued down with the adjuster backed all the way out.

OH, ok.

[1bolt]

doh I see now that you have aftermarket pushrods and adjustable roller rockers... I definitely think it's a valve train geometry thing now, you've got binding somewhere when there's actual oil pressure pumping the lifter... so what you need is to substitute in a solid lifter or take a used lifter that's not too worn and alter it so its spring wont compress, and use that to see where the bind is occurring. I bet the roller tip is coming off the valve at full lift, or close enough to it that side loading is causing the valve stem to bind... How do the valve stems look BTW?

[SilverXJ]

I know you've gone through some serious stuff and although I've read a whole lot of it; I'm kinda lost now. Can you give us a little recap on whats going on post titan debacle? Is this a third stroker build or the "post titan" one you did yourself that you had running and were tweaking A/F ratios last I saw? How many miles are on the engine as assembled? Did you have the cam out (and measured) before the 100 miles with noisy valve train?

This is the first stroker post Titan that is in my Project thread, in my sig. It was running fine except trying to find a knocking noise that seems to be coming from the transmission tunnel (which was one of the sounds on the Titan engine, but that sound stayed with the new engine... hence probably the transmission). In looking into it I found excessive crank end play. I found that the thrust bearing was worn due to the flange surface on the crank not being correct. I then tried to correct this by sanding the flange on the crank with 600 then 1000 grit paper. I also used the old thrust bearing with small pieces of sand paper attached to it to give a final finish on the crank. That is where I rotated the engine with the starter w/o oil, but the engine was not fired, just turned with the starter. After that was put back together I had the hesitation issue which I never got around to correcting before I pulled the engine. And the valve train also seemed quite a bit louder, and the machinist said that the lifters were actually bleeding down at higher RPMs. Perhaps the lifters were damaged from being bleed down and then pressure put on them? Also, the engine felt down on power, but I attributed that to the hesitation issue, which I though was a PCM/sensor/electrical issue.

Also, on tear down nothing was found in this engine that would make a knocking. There is plenty of room on the back of the cam before it bottoms out on the freeze plug.

How much ZDDP does VR1 have? Maybe the odd wear is just the beginning of failure, and once the nose of the lobe was rounded the lifter face would have been headed for dishing? Still I think somethings binding at full lift.

1300 ppm of Zinc and 1200 ppm of Phosphorus, with the half bottle of crane lube it is enough ZDDP. Even if I didn't have enough ZDDP I don't think it would have failed this early. There is around 2000 mile on this engine.

doh I see now that you have aftermarket pushrods and adjustable roller rockers... I definitely think it's a valve train geometry thing now, you've got binding somewhere when there's actual oil pressure pumping the lifter... so what you need is to substitute in a solid lifter or take a used lifter that's not too worn and alter it so its spring wont compress, and use that to see where the bind is occurring. I bet the roller tip is coming off the valve at full lift, or close enough to it that side loading is causing the valve stem to bind... How do the valve stems look BTW?

The valve stems look fine. Wear pattern is about right in the middle. The springs are the Mopar Performance and have enough range for the CC 231-4 cam. This head was the one that I used on the previous engine with the same rockers, springs, valves, etc. The previous engine also had a CC 68-231-4 cam. I just had the head checked over before I put it on this stroker.

I just realized that this is the block that I got from you with the stock cam completely dead. However, from what I see I don't see anything wrong with the block... the cam rotates freely, no weird wear on the cam bearings, and the cam gear is flush with the front of the block.. could the lifter bores be offset? How do I go about checking that?

[dwg86]

Although there shouldn't be any camshaft wear after 100 miles, I wouldn't think .007 would be enough to make valve train noise. I am curious to see what Comp has to say.

[1bolt]

Man I hope it's not the block I sold you, but I doubt it is, I think it's more likely whatever was causing the noise... maybe the lifters, but all 6 at the same time? that seems unlikely. I think there's got to be some binding, and I would double check Mopars work, and also make double sure that are seated all the way and not up on some raised machining lip... you never know with a big company like that if some mix up or error caused the wrong springs to be in the package, or the label to be wrong. I wouldn't know how to check the lifter bores or if that's likely enough to bother checking, but I'm sure the specs exist somewhere... If you have a hard time finding the correct specs let me know and I will put a straight edge down the tunnel of one of my spare blocks and another down the lifter bore wall and see if I can find an angle... Maybe it's a bad block from the factory that wiped the factory cam that you found on tear down...

I think it's binding somewhere but I'm like 1 or 2 for 100 in Internet long distance text based diagnostics so what do I know

Although there shouldn't be any camshaft wear after 100 miles, I wouldn't think .007 would be enough to make valve train noise. I am curious to see what Comp has to say.

I agree its not wear, and obviously not ZDDP related that oil is good.

Damn Chris whats with you and Cams anyway?

[SilverXJ]

Man I hope it's not the block I sold you, but I doubt it is, I think it's more likely whatever was causing the noise... maybe the lifters, but all 6 at the same time? that seems unlikely. I think there's got to be some binding, and I would double check Mopars work, and also make double sure that are seated all the way and not up on some raised machining lip... you never know with a big company like that if some mix up or error caused the wrong springs to be in the package, or the label to be wrong.

I've had those springs for a while. I installed them back in 2006 when I swapped out the stock cam for a 68-232-4. They ran at the stock height for 7864 miles. Then the head, springs and the same cam was transferred to my first Titan. I then ran them for another 8334 miles on the Titans. They were then transferred to my polished and ported head, and installed at a greater height to give me 100# seat load. So, the springs have been on the first 68-232-4 cam, which was fine and I would have used again if Titan hadn't scratched it by mishandling it. Then they ran on a CC 68-231-4 cam which again showed no wear. I checked the for load when I had the head work done at the machine shop. They have about 16198 total miles in them, this is the first instance of a cam damaged that wasn't explainable.

I wouldn't know how to check the lifter bores or if that's likely enough to bother checking, but I'm sure the specs exist somewhere... If you have a hard time finding the correct specs let me know and I will put a straight edge down the tunnel of one of my spare blocks and another down the lifter bore wall and see if I can find an angle... Maybe it's a bad block from the factory that wiped the factory cam that you found on tear down...

That a thought I have considering that stock cam was so bad... I didn't think anythign about it at the time other than perhaps poor maintenance and crappy oil.

I think it's binding somewhere but I'm like 1 or 2 for 100 in Internet long distance text based diagnostics so what do I know

Although there shouldn't be any camshaft wear after 100 miles, I wouldn't think .007 would be enough to make valve train noise. I am curious to see what Comp has to say.

I agree its not wear, and obviously not ZDDP related that oil is good.

I'll check for binding, but when I was degreeing the cam in I used some light weight springs and didn't see anything. And I never noticed anything weird any other time. I do agree that I don't think that little bit of wear caused the valve train racket.

Damn Chris whats with you and Cams anyway?

Hey! I only had 3 die on me.. one was the stock one at 113100 miles.. but I knew nothing about ZDDP at that time until I installed the CC 68-232-4. The second one was the Crane that Titan installed (which they snuck by me) and that died because they didn't do a proper cam break in. Now this one isn't clear why.

Since I have sent my current 68-231-4 I'll have to see if I have another one laying around from the Titan... maybe i'll install that this weekend and see if I see anything binding.

[SIXPAK]

I'm still somewhat bewildered by these cam failures. I've replaced many cams in these 258's/242's. Not proud of it but I have done little to nothing as far as cam break-in.
My motors are assembled using TORCO MPZ assembly lube only. Liberal amounts on cam bearings and lobes. Of course on the Rods and Mains too. Pistons are dunked upside down in regular 10/40. ONLY the last cam did I do any sort of break-in and that was only removing the inner spring from the valvetrain. Ran it for maybe 10 minutes or until the motor go to temp and shut off and repeated that 2 more times. Reinstalled the inner springs and then went racing.(190 seat and 390 open pressure & super aggressive ramps) Given this motor is not run like a street motor as far as miles but what gives here? I've used, Lunati, Comp, Bullet, and Cam Motion with zero issues.Typically these motors are started and raced with a standard oil like Valvoline 10/40, nothing special. After that I used to run Mobile One Synthetic but switched # years ago to Brad Penn amongst al the ZDDP hype and BTW I do believe that it at least does play a some roll in the matter of cam failures.
One thing I am kinda anal about is temp & RPM's. Usually the motor does not see much over idle until I see some kind of heat in it. I use a Mellings 258 HV oil pump, standard 258 oil pan and pickup. Cam gear and dist gear looks prestine. Am I just lucky? Not sure but these are my habits good or bad.

[1bolt]

Just from thinking about it, I seriously doubt it's a failure, or broken component like 6 mysteriously damaged lifters. With all six lobes having that problem I would tend to think the Cam was soft, or not heat treated properly or just didn't get work hardened on the nose during break in for some strange reason, but because you had valve train noise and I can't think how the worn noses would cause any noise... I think there's some geometry issue with the rockers, length of the push rods or something that would explain all six lobes having the same damage, done presumably from the added stress of the binding which also caused the noise.

Unless the lifter bores aren't aligned right and somehow this was causing the lifters to "toss" off the cam and smacking back down on it... but that it not a "valve trainy" (to coin a phrase ) noise. Every time I've heard lifters slapping down on a cam it sounded like solid lifters or Rhodes lifters on startup... sort of a clipity clopity old school cold engine noise. Maybe the edge of the lifter is climbing up the ramp and when it gets steep enough the actual edge was digging into the nose of the lobe.

I don't know just kinda wild ass guessing here. Is there any rounding or polishing on the edges of the lifter foot? If it does turn out to be the lifter bores, I've got another block you can have.

[SilverXJ]

Just from thinking about it, I seriously doubt it's a failure, or broken component like 6 mysteriously damaged lifters. With all six lobes having that problem I would tend to think the Cam was soft, or not heat treated properly or just didn't get work hardened on the nose during break in for some strange reason,

That is a though I had too.

but because you had valve train noise and I can't think how the worn noses would cause any noise...

That little wear wouldn't cause the noise as the preload didn't go to 0. Maybe it was the motion of the lifter moving over a less then rounded lobe?

I think there's some geometry issue with the rockers, length of the push rods or something that would explain all six lobes having the same damage, done presumably from the added stress of the binding which also caused the noise.

I doubt there is anything binding on the head as that exact head (rockers, springs, etc) was used on another 68-231-4 cam, and not a problem with it. And I can't see the push rods being a problem as there was still a bit of movement with the rockers torqued down prior to 0 lash.

I don't know just kinda wild ass guessing here. Is there any rounding or polishing on the edges of the lifter foot? If it does turn out to be the lifter bores, I've got another block you can have.

I didn't take that close of a look at them prior to being shipped off, but I didn't see anything on the edges indicating that they were bearing down on the lobes. The pattern on the lifters looked pretty normal aside from that fact that it wasn't a polished surface.