Worn Cam lobes?

[4door64]

Anyone ever loose a cam lobe with a new cam? I put about 500 miles on my new motor and I figured that I lost the cam lobe after I had "glitter" in the oil and I pulled the valve cover off and the #5 Intake rocker was only moving about 1/2 of what it should. I was just wondering how good the chances were that I wiped out the bearings too? After break in I put about 6 miles on the oil and I looked and it had glitter so I changed it and put about 500 miles on it (I kept driving it cause I thought the glitter was normal and my rocker arms kept backing off). I dident see anymore "glitter" in the oil after I changed it the first time. I guess the only way to figure out is to pull the pan and check but I just thought I would see if it happened to anyone else?

:chev:

[loneagle]

I had it happen a few years back on a fresh engine I built. I always plug the bypass on the oil filter adaptor, so I was good. I just changed the oil a couple of times after replacing the cam and lifters and the glitter was gone. I hope you're OK!

[Paul Wright]

If the cam has wiped a lobe, all the oil changes in the world won't help. It's time to pull the cam and replace it and all the lifters.
The first 20 minutes of cam break-in is very important. If the lifters aren't spinning then cam failure is going to happen.

[4door64]

Well the "glitter" was in the pan when I first changed the oil and the 2nd time it wasent in the oil (im guessing it all got traped in the filter) which is a good thing but im just worried I trashed the bearings and I was just wondering if its that easy and if anyone else trashed the bearings from loosing the cam lobe.

[69NovaSS]

If its going to bother you or you want to be careful then pull the pan off and check them out...if they look good then your likely good to go...if not then they will need replacement...(you might want to really look at the journals too)...

If you like to take chances and or enjoy gambling or its not bothering you then you can just run it and hope for the best...

Both options have their pros and cons...:)


I tend to be overly cautious with these types of things...I would check them out...BUT that is just me

[BRETTZER]

I had 2 lobes wiped off, and 2 more had started on a fresh rebuild, along with 2 bent pushrods after 150 miles. We dropped the pan and cleaned it out best we could and pput new cam & lifter set in. All seemed fine but oil pressure got really bad. Pulled motor again and it had wiped out 2 main bearings, brass completely covered the screen. All that metal running through there can plug oil galleys,etc. Should have torn it all apart and hot tanked it. Well we did that and put new main bearings in, and the cam went out again in another 150 miles. There was a bunch ground off of the lifter again. I would pull it all apart and have it tanked so it doesn't toast anything else.

[Scooter]

Wow how does this type of thing happen? I've read so many stories about people with brand spankin new engines that wipe lobes or bearings. What causes this type of thing? Do ya just have to sit back hope everything goes ok? Does it all rely on the spinning of the lifters? I can't imagine what it would feel like to find out a brand new engine is already messed up.

[Paul Wright]

Wow how does this type of thing happen? I've read so many stories about people with brand spankin new engines that wipe lobes or bearings. What causes this type of thing? Do ya just have to sit back hope everything goes ok? Does it all rely on the spinning of the lifters? I can't imagine what it would feel like to find out a brand new engine is already messed up.

It happens because the cam isn't broken in properly! A flat tappet cam shaft isn't flat. The lifters have a very slight spherical shape and the lobes are slanted to one side. This causes the lifter to spin so it doesn't wear in one spot.

The lifters must spin or they will wear the lobes off in a very short time. Here's a tip: Put a white paint pen dot on the pushrods and lift the valve covers to see if they are spinning.
If any aren't then you need to replace the lifter.

The cam must have protective lube on the lobes and lifters to protect them during initial fire up. The engine must be ready to run because the lube comes off in first few seconds.
All too often fire up becomes a "starter durability test" because the distributor isn't in right and or the carb isn't adjusted right. Every time I see this problem it's due to someone being in too much of a hurry to start the engine and skipping essential steps and or not being familiar with setting up the distributor to fire right away.

Being in a hurry will hurt your engine.

There is also the theory of low zinc in the oil. Read here in Best of Tech (http://www.stevesnovasite.com/forums/showthread.php?t=31735).

[RED67]

Plenty of assembly lude on the cam,,like GM EOS.
High zinc "break-in" oil like Kendal GT-1.
Prime the oil system with a drill motor before you install the distributor.
Be absolutely sure your initial valve lash adjustments are correct.
At fire up bring the idle up to approx 2000 rpm to keep plenty of oil circulating on the cam.If the engine won't start right away don't just crank on it,,,find the problem.
Some engine builders recommend light weight "break-in" valve springs to allow the break-in oil to burnish the zinc and paraffin into the cam lobes and lifters before the heavier racing springs are installed.
Glitter in the oil is not the kind of "Bling" you want to see from an engine.

Good Luck,
RED67

[Dan_Lebherz]

This happened on my fresh engine with the Comp XE268. While trying to figure out the problem I swapped all the bearings with the engine in the car, then finally figured out it was the cam. I swapped cam and lifters and had the Vortec valve guides cut. Oil got changed and pan cleaned in the process. I probably have around 25-30,000 miles and 275 total passes on the car now. Runs fine. No indication it won't go another 100,000 miles (knock on wood). I had a completely new setup with an old HEI that was bad and I probably cranked all of the lube off of the lobes b/4 finally figuring out why the engine didn't fire. Ran great for about a year b/4 it didn't anymore.

Somewhere, I have a cam just like that one that Paul put in his picture. Mine was the #1 exhaust, if I remember correctly. Car started to pop back through the intake because it was getting a compression stroke when it was supposed to and also when it was supposed to be on the exhaust stroke.

[62bandwagon]

If you check out Comp Cams website they have a tech article on todays engine oils & how they are lacking the zinc & other minerals that oil used to have in it. Now, with all the roller valvetrains in todays cars the newer oil isnt designed to protect a flat tappet cam at break-in. I learned the hard way, lost a lobe, installed a new Comp cam with their lifters, used Rotella HD oil with a break-in additive...no problems. This was the first time in 6 builds that I ever had a problem.

[Ron Slabaugh]

After a successful flat tappet break-in, will any dinosaur oil suffice, or should we stick with a high-zinc oil like Rotella T?

[4door64]

Rotella HD oil with a break-in additive...no problems. This was the first time in 6 builds that I ever had a problem.
I'll pick up some of that oil. Is it hard to find??

Thanks for all the tips guys

[Paul Wright]

I think Walmart has it, otherwise try Napa or a truck stop. It's not a substitute for proper break-in.

[4door64]

Well I know what went wrong with the last cam, a friend was helping me (he has built a few engines before) and when it was time to fire it up it wouldent start so we would try to crank it over to find out what was wrong and we wernt getting any spark and I guess we turned it over too much.... I was just odd cause the dist was working right when I pulled it off of my old motor and why it was just sitting there for a week the coil or ignition module went out...

[4door64]

Well I droped the pan lastnight and pulled the #2 main cap and the bearings are trashed and there is scratches in the crank........:(

[4door64]

http://i46.photobucket.com/albums/f139/1badd64nova/100_0483.jpg

Look bad? :(

[Dan_Lebherz]

Doesn't look good, anyway.

[MuscleDreams]

I lost 3 cams in a small block about 10 years ago.
The engine was assembled by a professional well known builder.
In all 3 cases I primed the oiling system, and carb and the engine fired right off the bat and ran good enough to run according to break in procedure.

One cam lasted about a month before I noticed something was wrong. The other 2 didn't last at all. In all 3 cases the metal ruined my bearings.
I used Lunati BM II cams 300/515 and a comp cam 305/525.

After all of that I got all of the advice I could and took the block to Rowlette Racing engines. Doubt if any of you heard of him but he is near Memphis and has a good reputation for building engines. Anyway he said that there was a problem with my lifter bores.
Unfortunately I ran out of money and never finished the engine again and sold that car so I'll never know if that would have resolved it.

Fast forward 10 years. I got my 71 with a 454 in it. I was told the valves needed set when I bought it. I brought it home and found that 5 lobes were flat. Tore the engine apart and of course the bearings were rubbish.

Rebuilt it using a roller cam. I'll never run another flat tappet period.

[strtlegal]

happened to me two months ago..car ran like crap, a real dog off the line...it felt real rich..finally decided to switch to a crane cam.. my #5 cylinder lifter was gone..it was so bad you could see the spring inside the bottom of the lifter