Bad lobe on break-in...now what? Metal shavings + New cam

[~7879landau]

I had one lobe go bad on the break-in of my new engine. I don't know the condidtion of the others lobes till I pull the cam.
I'm getting ready to put in a new cam and start over.
My questions are:
Now that there is a bunch of metal in the engine, how do I clean it all out with out dismantleing it completely? What chemicals should i use to flush it as clean as I can get it? Any advice on this will be helpfull since this is a first for me with a completely rebuild engine. If it was and old engine I'd just rinse it with some new oil and hope for the best. I have alot of money tied up in this one though.

I have an idea why the first cam didn't last break in but I'll also double check for these things too.
What "oil" to use with the Comp Cams breakin in stuff?
When it first starts and runs, should it be ran at a steady rpm or should the idle be fluctuated and ran at different speeds? If its steady, what RPM should the enging be turning during the break in?


Jim

 

[Ed Cannon]

I had a lobe go out on my 383 a few yrs ago. The only way to really get it all cleaned out is to completely disassemble and clean all the parts and then check for damage if any. In my case It killed my rod and main bearings. You might get lucky and not have damage but when there is small metal particles in the oil you can almost guarantee there is or will be damage. Also that was the last flat tappet cam I ever used its roller from there on for me. Just my .02

 

[bowtie81]

Jim
I had the same problem, i know the best way to clean it out is the take it all apart but i was lazy and put another cam in it and tried again. when i did have to take the motor apart the bearings were fine.
Whe you do break a cam in i used shell rotella with comp cams break in fluid and when it does fire up keep the rpm's around 2000-2500 for atleast 20 min.
By the way how do you know the cam lobe is gone?
shaun

 

[455_82malibu]

I had a pontiac motor that took 3 lobes and 1/2 the lifter with it, lots of metal, I got a case of carb cleaner and shot the heads down.... getting in all the end pockets, cleaned the valley area and then ran it with cheap oil and changed oil 2 times, motor still runs fine.

it has more to do with spring pressure than the oil, using zinc additive helps but if the springs in the heads are strong it will eat the soft new cam. Also make sure your cam is indexed so the lobes are 1/2-3/4 in the lifter bore, not centered, you need this to help spin the lifters, honing the lifter bores is a good idea too.

 

[~7879landau]

Jim
I had the same problem, i know the best way to clean it out is the take it all apart but i was lazy and put another cam in it and tried again. when i did have to take the motor apart the bearings were fine.
Whe you do break a cam in i used shell rotella with comp cams break in fluid and when it does fire up keep the rpm's around 2000-2500 for atleast 20 min.
By the way how do you know the cam lobe is gone?
shaun

I guess i don't know for sure but after a couple heat cycles i drove it only about 20-30 miles and the whole time it made a heck of a tiking racket. sounded like many were out of adjustment. I pulled the covers and found one with a very loose pushrod. I guess it could be a collapsed lifter but my bet is on a flattened lobe since there was so much ticking. The cars been sitting for about 2 years like that. To tell the story what I think happend was, I had a bad carb on there and kept cranking the engine around to many times before it fired and it lost all the assembley lube. Each time I retried to start it I kept thinking that isn't good to be doing and not fireing right up for the cam. I bought a new carb and it fired. I took my chances with all the lube possibly having been scraped off and tried breaking it in anyway. I'm no expert and everyone I talked to about it said it would be alright. They said there would still be enough on the cam to not harm it. I hope it was that reason because I can't figure out any other. I have a single spring with a damper, otherwise i'd take one spring out to lighten the pressure.

I guess if I can get the next one broke in i can take it all apart and replace bearings. I don't want to do that before i do get a good breakin though. I do understand with a new engine(tight clearances) that any debree is worse that on a old engine. I wouldn't think it would hurt the crank any just the bearings. If I have to replace them I might as well wait till later. never know this could become an on going trend :roll: Lol! hope not

By the way I did use shell rotella with comp cams break in fluid. I read a few topics on here about that around the time I was assembling the engine and went with that. Its good to hear someone say that again. At least I did that right.

Jim

 

[~7879landau]

Also make sure your cam is indexed so the lobes are 1/2-3/4 in the lifter bore, not centered, you need this to help spin the lifters, honing the lifter bores is a good idea too.

I'm gonna sound real stupid here..... at what point do they need to be 1/2 to 3/4 in the bore? are you saying to spin them in the bore while they are part of the way out? I didn't hone them I probabley should have.....and possibly can. Do you think there is a lip?

 

[455_82malibu]

no, when the cam is in, look down the lifter bores at the cam lobes, they should be off center, the lifter will not ride fully on the lobe, it will hang off to one side or the other, this is what makes the lifter spin, if it doesnt spin it will wear .

 

[bowtie81]

You can try firing it up and try adjusting that lifter that is loose. if it keeps coming loose it's a bad cam lobe. What i did with my cam i didn't use the assembly lube i used lubriplate.

 

[~7879landau]

It is bad. heres the lifter in question. I got it out today I also removed all of them from the same side as this one and all are looking good. I can see that they all were rotating as there is a small circle apearence. Could this one have been hanging up? When i assembled the engine I spun them partly out of the bore to see if anything was to tight. All seamed good. Does that look like normal wear on the side? I never seen one out with such low miles. It is dished pretty bad it doesn't show up as much it the pic.

 

[~7879landau]

no, when the cam is in, look down the lifter bores at the cam lobes, they should be off center, the lifter will not ride fully on the lobe, it will hang off to one side or the other, this is what makes the lifter spin, if it doesnt spin it will wear .

I shined a light down in there and the cam looks off center.



Jim