camshaft failure

[big gear head]

I'm going to be building a 327 for my dad's '55 Chevy. We are using a Comp Cam and some of their new coated lifters. The coating is supposed to fix the problem. It's not just Comp. Most of the cam cores and lifters come from the same place and are sold by many brands. Use oil with a lot of zinc, even after break in, and break it in with low pressure valve springs.

[BCreekDave]

Neighbor just finished an engine with a Comp Cam and their lifters and lost two lobes on the 20 minute startup. Called Comp and they sent him a new cam and recommended the DLC coated lifters. Said the issue is really with lifters and not the cam. He totally rebuilt the engine and used the DLC lifters and all is well after run in and several hundred miles. The DLC lifters have a mirror finish on the bottom and don't really seat in to the cam. This was a small block with Z28 level valve springs so nothing over the top on spring pressure.

[RALLY]

Originally Posted by thehornworks

I been reading a lot about new solid camshaft and lifter failure on start up. I have a new Comp cam in my 69 Z28. Hasn't been fired yet. A engine builder I know said he won't build a motor with a solid cam because of all the failures. Any input is appreciated.

Great oil engineer online who has a blog full of great info on motor oils, cam breakin oil too. Its called 540ratblog. Go on google search and type this in 540 Rat. This guy is very good.
n recent years there have been entirely too many wiped cam lobes and ruined lifter failures in traditional American flat tappet engines, even though a variety of well respected brand name parts were typically used. These failures involved people using various high zinc oils, various high zinc Break-In oils, various Diesel oils, and various oils with aftermarket zinc additives added to the oil. They believed that any high zinc oil concoction is all they needed for wear protection during flat tappet engine break-in and after break-in. But, all of those failures have proven over and over again, that their belief in high zinc was nothing more than a MYTH, just as my test data has shown.

.
A high level of zinc/phos is simply no guarantee of providing sufficient wear protection. And to make matters even worse, excessively high levels of zinc/phos can actually “cause” DAMAGE your engine, rather than “prevent” it. Motor Oil Industry testing has found that motor oils with more than 1,400 ppm ZDDP, INCREASED long-term wear. And it was also found that motor oils with more than 2,000 ppm ZDDP started attacking the grain boundaries in the iron, resulting in camshaft spalling (pitting and flaking). The ZDDP value is simply the average of the zinc and the phosphorus values, then rounded down to the nearest 100 ppm (parts per million).

.
From those failures where I was able to find out what specific oils were used, it turned out that those were oils I had already performed my Engineering Wear Protection Capability tests on. And all those oils had only provided poor wear protection capability, meaning that if they had looked at my test data before using those oils, they would have known in advance that their engines would be at significant risk of failure with those oils. And that is just what happened.
.
A number of people who have had those failures, and some had repeated failures, have contacted me, asking what they can do to prevent that failure in the future. I tell them to forget all that high zinc nonsense and look at my Wear Protection Ranking List. And to select any high ranking oil there, no matter how much zinc it has, because zinc quantity simply does NOT matter. The only thing that matters regarding wear protection, is the psi value each oil can produce in my testing. The higher the psi value, the better the wear protection. I recommend they use the SAME highly ranked oil for break-in and after break-in. It’s that simple.
.
WHEN PEOPLE HAVE TAKEN THAT ADVICE, NOT ONE PERSON HAS EVER COME BACK TO ME TO REPORT THAT MY RANKING LIST DID NOT WORK FOR THEM. Since my ranking list has worked in every case to prevent wiped flat tappet lobes and lifters, it can also work for you to provide the best possible wear protection for your engine. My test data is the real deal, it exactly matches real world experience, and it is the best and most complete motor oil comparison data you will ever find anywhere.
.
And for those people who have been able to use various high zinc oils without having trouble with their flat tappet engines, that only means that the oil they used had enough wear protection capability for the loads their engines saw at that time. It does not mean they were necessarily using a great oil. And it does not provide any information about how much reserve wear protection capability their oil provided, nor how their oil compares to other oils on the market. Rat Recommends Quaker State 5W30 Full Synthetic oil. Best oil on the market today.

[Crossbreed383]

The issue IMO is more to do with insufficient case hardened depth on the cam cores being used. The issue is when the case depth on the nose isn't enough and this is magnified because of spring psi being highest at over the nose of the cam, than on the base circle of the cam .
Certain companies use the same UGL( unground lobe ) cam cores for a multitude of cam valve events, pt numbers , etc . The issue lies in that you harden the lobes during heat treat, but when you try to cut the more than one cam profile, using multiple centerlines or lobe lift( base circle) on the same core ,you end up grinding away too much or even going through the heat treat in some spots.
If the use a specialty UGL for each specific cam then the case depth is set at XX mm of what it needs and you after final grinding you are left with sufficient heat treat depth.
We see it all the time here .
Thanks

[jl8z28]

I have a nos 350 Lt1 cam has their been any issues with them

[Lynn]

I run a stock LT-1 cam in my Camaro. I have had no issues. I use the stock springs. I think if you use heavier springs you will have issues.

Getting ready to put the original engine together for my 70 LT-1 Corvette, and am using EDM lifters just as a precaution.

[thehornworks]

Thanks, great information. The thread went as I hoped. I have also looked at the New DLC (Diamond-Like Carbon) coated flat tappet lifter . gary

[Tuna Joe]

I’m in the process of doing the engine build on my L89 and am trying to put the car back to original.
Very discouraging to read of all the cam failures.

[Too Many Projects]

There are solid roller conversions that will minimize the risk of failure and still have the "sound" that the tappets make. Find, or have made, a grind that is very similar to original and use that instead. Is anyone going to know if it's an original style tappet or roller lifter making the ticking noise?

[Tuna Joe]

Originally Posted by Too Many Projects

There are solid roller conversions that will minimize the risk of failure and still have the "sound" that the tappets make. Find, or have made, a grind that is very similar to original and use that instead. Is anyone going to know if it's an original style tappet or roller lifter making the ticking noise?

My other 69’ Corvette 427/435 has a roller installed by the PO. But he had to put these wonky valve cover spacers on that I really don’t want on my new build.
I just assumed that the rollers needed more vertical space but maybe they don’t? Perhaps it was just the brand or make of the rockers?