How common is a wiped cam lobe?

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DartVadar

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I've been reading alot about the initial break in period of a cam and how it is very important. I agree with it all and will be following the procedures that are laid out. But in the end how many mild flat tappet camshafts actually end up being wiped or damaged if the person follows these procedures? (Use break in oil, prime oil pump, start up immediately or with only a few cranks ..)

I was talking to my grandpa and he's build alot of flat tappet cam motors and never had one end up wiped, maybe he is just really lucky. He told me I'm worrying about this too much! lol

I know another guy that just used rotella oil and no break in additives for a stock-ish replacement cam in his car and then switched over to better oil after he changed the oil for the cam break in. Never had a problem and that was years ago.

I even did a few searches on here and only came up with a few posts about a cam failure/wiped lobes, and most of the time the problem was caused by something else, or a defective part. Or maybe I didn't look hard enough...
 
Your engine, your time, labor & money! Just use Rotella then.

As for me, I always use cam lube and break in oil!
 
What KIND of "motors" did he build? Maybe you could get away with this with a fairly stock grind and factory "weak" springs.....................

First time I'd heard of cam break in was when I bought my Erson 480 lift back around 72 in the 440. I'd installed a few (with friends) the Chivvie 350hp factory hydraulic cam, and we never broke them in, nor had we heard of doing so in the late '60's
 
Lube upon assembly, use a good breakin oil with additive.

Make sure you have a good know carb, something that will make the engine fire up as quickly as possible.
 
What KIND of "motors" did he build? Maybe you could get away with this with a fairly stock grind and factory "weak" springs.....................

First time I'd heard of cam break in was when I bought my Erson 480 lift back around 72 in the 440. I'd installed a few (with friends) the Chivvie 350hp factory hydraulic cam, and we never broke them in, nor had we heard of doing so in the late '60's

My grandpa has been building motors since the late 60s and 70s, he does the break in procedures on the ones he builds now though, don't know how long that's been. He was big into drag racing, had a few 440 and 426 cars, he did really well with them.

As for the guy I know, I think he just put a cam in an old 318, and just fired it up to break the cam in, he didn't really take many precautions and wasn't worried at all.

So why all of a sudden is everybody so worried about the cam then? Lack of zinc on modern oil? or is it the more aggressive cams out there now?
 
Lobe failure on a cam was almost unheard of before the early 80s. Then things changed and it became common. Oil changed and I think camshaft materials and hardening processes changed too. Of course lifter bores on most engines are many years older too.... As folks became aware of the situation and took precautions to prevent issues by using a good assembly lube, break in oil, prime the oil pump, start up immediately, using oil with proper zinc levels etc. the problem was minimized. I personally had a couple of cams develop bad lobes in the early 80s even with all precautions, but then did not have a single failure for many years. I did recently have a 268 hydraulic cam get a bad lobe even following all precautions so I pulled it and replaced with a different manufacturers 268 cam and that one worked perfectly. (Odd that I would have a problem with such a mild cam but it did lose a lobe.) No other failures since that one though. I think there is still some risk with flat tappet cams but it is minimal if cam manufacturers installation procedures are followed. I would say it's not really a worry but something to consider any time you deal with a FT cam.
 
So really if you are paying attention and use good oil there should be no issues.

Is a complete tear down required of you wipe a lobe? or can you throw in a new cam/lifters and be good?
 
Your engine, your time, labor & money! Just use Rotella then.

As for me, I always use cam lube and break in oil!

There's nothing to squawk about with Rotella oil. Rotella oil for diesel engines, as far as I know, still remains one of the only oils in the industry with higher than normal Zinc content. Its been about 5 years since my last engine build though, and they could of reduced the Zinc content as of recent due to new diesel emission laws (stupid regeneration systems). I used Rotella for initial break-in in my last 5 chebby 350's in combination with good sticky assembly lube. Then I would just change out the oil after a couple hundred miles.

So why all of a sudden is everybody so worried about the cam then? Lack of zinc on modern oil? or is it the more aggressive cams out there now?

When catalytic converters were introduced to the automotive industry in the late 70's/early 80's, manufacturers realized that the zinc in the oil was causing the cats to fail prematurely. The oil companies started to produce oil with reduced Zinc content at the request of the auto manufacturers. This paved the way for the manufacturers to go to roller cam setups and low tension piston rings. Now there was no need for a high Zinc content, but that left all of the classic car owners in the dark. Now we have to pay nearly double for the proper oil to run in our vehicles.

I'll have to look into Rotella, and see if it still has a high Zinc content or not. I wouldn't doubt that the feds put the kibosh on that too.
 
Just break the engine in with weaker springs....then after "break in" put the heavier springs in there and everything will be fine!!


No worries!!!
treblig
 
Just break the engine in with weaker springs....then after "break in" put the heavier springs in there and everything will be fine!!


No worries!!!
treblig

just make sure the "weak' springs will handle the lift of the cam

if it is a hydraulic cam....usually the springs are not really stiff....

solid cam usually uses a dual spring....you can take the inter spring out and break the cam in....then reinstall the inter spring
 
I had a Mopar .509 cam fail five years ago in a small block. I did everything properly, used good oils, broke it in and everything was great for the first year and a couple thousand miles. The following spring I changed the oil and, "upgraded" to full synthetic. Within 15 minutes of running with the synthetic it had completely wiped a lobe.

Some people just throw another can in and go. On advice from my machine shop I disassembled the engine. He said, and was right, that the failing lobe will throw metal into the bottom of the adjacent cylinders and score them slightly. We honed it lightly, changed the bearings for good measure, polished the crank and replaced the oil pump. The pump did show signs of damage from the metal. It probably would have been just fine with only a new cam although its longevity may have been less. I also took the time to upgrade to a roller Cam. After seeing the difference that the roller can made to the engine, in addition to the peace of mind that it offers, I will never run a flat tappet cam again.

My 2 cents
 
mid 70`s up small blocks lost alot of cams due to what I believe was mentioned earlier about the zinc. I did alot of them and can tell you when they went back it was most of the lobes gone not just some. We always knew when they pulled in and under throttle they sounded like popcorn machines.
 
So really if you are paying attention and use good oil there should be no issues.

I would not gamble on that at all.

Is a complete tear down required of you wipe a lobe? or can you throw in a new cam/lifters and be good?

I would think so, the last thing you want is little pieces of metal roaming around in your engine.
..
 
I guess nothing is a sure thing, and that what I would think, probably damages the bearings pretty good.

Getting me worried here! next motor should be a roller cam.
 
IMO, it's not the more aggressive lobe ramps directly. It is the stronger springs requires for them and the loss of zinc compounds. As long as you follow the proper break in procedure for a flat tappet, using the right oil you won't have a problem.

I agree with Del though. Back when I was first getting into it myself 30 or more years ago, I can remember several weekend cam stabs where we never broke the cam in, and also never ad a problem. Most of those did not include a valve spring change, either.
 
IMO, it's not the more aggressive lobe ramps directly. It is the stronger springs requires for them and the loss of zinc compounds. As long as you follow the proper break in procedure for a flat tappet, using the right oil you won't have a problem.

I agree with Del though. Back when I was first getting into it myself 30 or more years ago, I can remember several weekend cam stabs where we never broke the cam in, and also never ad a problem. Most of those did not include a valve spring change, either.
I have to agree with the stock cam replacements years ago. lubed them stuck them in and never broke them in without trouble.
 
Cam break in has been around since the 60s with racey stuff. Chevys you ran old springs or "stockers" to brea kthem in, then repalced to "the real" ones. Oil covered a lot of potential issues years ago. It won't do so anymore unless you buy an oil formulated to do so. Like the Brad Penn, etc. Deisel oils are no longer much better than the SAE gasoline engine oils.
It's my belief that the problems that create the issues are really only two now:
1. Misalignment of the tappet on the lobe either from poor factory machining or wear in the tappet bore(s). Think how "good" the rest of that machining is in terms of the deck surafecs and bore squareness - and you'll understand how bad that can be. Factor in the higher spring pressures modern springs can develop and that faster rate lobes need and the problems are compounded. If you assemble engines or swap cams and do not check and verify lifter rotation during that process - you're asking for a failure due to misalignment. Sometimes simply swapping lifters between different bores will allow the lifters to rotate freely as the lobe cycles them. If they all rotate easilly there is a very high likelyhood that you will be fine.
2. Loss of high pressure lubricants in the oil. That's the zink. It's bad for catalytic convertors - which is why even deisels are losing it - they have cats now too. Plus modern engines are much more precisely machined and components and oiling systems are much much better.
What we call "modern" fast rates have been around for decades. The MP Mushroom cams had them in the 60s. but we didn't have great spring materials. Once the springs got better, the ramp speeds were brought up right to the edge of mechanically not working. Those are the ".904 profiles" for mopars. The closer you get to that mechanical inability to move the lifter with a flat tappet, the harder it is for the oil, and the more important lifter bore relationships are. Hence the issues Hughes had trying to push that envelope and having failures like the EM entry from Moparts. Pressure fed lifter faces are helping a lot especially for engines that have to idle. Because without them the cam is only splash fed oil from the lower end. So some builders will want a higher idle speed to keep oil on them at idle.


Now to the OP question - if everything is followed perfectly and everything works right, you can still have a failure due to the lifter bore relationship and that is primarilly driven by the lobe design. The larger and faster the lobe, the greater the chances of failure. If you stay away from very fast rates and high spring rates with long idle periods you should be fine. I've also never lost a cam but ultimately it comes down to checking everything you can, buying the products that help you most, verifying those products are functioning properly, and being good enough with everything else so it fires right up and can run for the break in with no issues forcing you to shut it down.
 
I lost one in the fall of 2008. I had just switched cams to a Comp XE295HL, I removed the inner springs, used their Comp 159 break in oil, did everything by the book and still wiped a lobe. Metal got EVERYWHERE in the motor, destroyed the oil pump, metal shavings got slug up into the piston skirts and dragged up and down the cylinders scratching them up bad...had to tare the whole thing down and clean it, replace pistons, bore it, hone it, replace oil pump, replace bearings, etc.

I ended up going roller after that, and stroking it, and porting the heads, and getting a looser converter.....major Snowballing effect on the rebuild, LOL!. Oh well, I went from a mid 12 second car to a mid 10 second car...good times :D. No more flat tappet cams for me.
 
I lost one in the fall of 2008. I had just switched cams to a Comp XE295HL, I removed the inner springs, used their Comp 159 break in oil, did everything by the book and still wiped a lobe. Metal got EVERYWHERE in the motor, destroyed the oil pump, metal shavings got slug up into the piston skirts and dragged up and down the cylinders scratching them up bad...had to tare the whole thing down and clean it, replace pistons, bore it, hone it, replace oil pump, replace bearings, etc.

I ended up going roller after that, and stroking it, and porting the heads, and getting a looser converter.....major Snowballing effect on the rebuild, LOL!. Oh well, I went from a mid 12 second car to a mid 10 second car...good times :D. No more flat tappet cams for me.

I think I wouldda handled that the redneck way. There wouldda been a motor sized hole through the front door at Comp Cams.
 
I have never lost a lobe. However, it seems luck plays more of a role as there are many good mechanics that have failure doing the right things. A roller cam removes the worries, and no break in procedure needed.
 
The 268 cam that lost a lobe just a couple of months ago for me was properly and carefully prepped with assembly lube and checked for lifter rotation with just cam and lifters and again just before buttoning things up. I followed the break in procedures very carefully, primed the pump and ensured that it started immediately. Rpms were up and varied for the break in time. The thing started clicking almost immediately. As soon as the break in was completed I pulled the valve covers and determined which lifter was making noise with my stethoscope. The lifter was turning. I messed with it for a few days and finally pulled the intake so I could see the cam. It was obvious then that the tip of the lobe was just beginning to show signs of failure. I pulled that cam and since I caught the issue early, just ordered a different brand of cam and put it in. That cam is working fine today. I tried to claim a warranty on the failed one but, of course, the break in procedure not being followed properly was blamed as the cause. So, I think given enough flat tappet cams, every so often one is going to be a problem. That is why the roller cams have gotten so popular.
 
Lobe failure on a cam was almost unheard of before the early 80s. Then things changed and it became common. Oil changed and I think camshaft materials and hardening processes changed too. Of course lifter bores on most engines are many years older too.... As folks became aware of the situation and took precautions to prevent issues by using a good assembly lube, break in oil, prime the oil pump, start up immediately, using oil with proper zinc levels etc. the problem was minimized. I personally had a couple of cams develop bad lobes in the early 80s even with all precautions, but then did not have a single failure for many years. I did recently have a 268 hydraulic cam get a bad lobe even following all precautions so I pulled it and replaced with a different manufacturers 268 cam and that one worked perfectly. (Odd that I would have a problem with such a mild cam but it did lose a lobe.) No other failures since that one though. I think there is still some risk with flat tappet cams but it is minimal if cam manufacturers installation procedures are followed. I would say it's not really a worry but something to consider any time you deal with a FT cam.


A few years back I was talking to my guy at Mancini and he was telling me about some of the quality problems that they were seeing. They stopped carrying the MP camshafts as they changed sources and the new ones were coming out of the box in two pieces brand new and MP wasn't warranting them. Mancini stopped carrying them as they did not want to be responsible for their poor quality. Guess who he said that their "new" supplier was.... Comp Cams :banghead:

He also told me not to buy the MP piston top dead center stop tool as they were also having problems with the spark plug threads being bad. He tried to chase one with a die, and it was too hard and would not go. He took one brand new out of the package and tried it in an Edelbrock head and it didn't screw in. He took a spark plug and screwed it in and it went in fine.. MP was also trying not to warranty those also and just pass them off to the consumer (and they coincidentally were having trouble with the same Comp Camp TDC stop tool)....



Companies are trying to cut costs and make things cheaper and cheaper now days, quality is out the window. Sad.... :sad10:
 
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