my used cam

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muscle car mike

muscle car mike

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So, my 318 in my new dart had aprox 1" of slack.in the timing chain. The teeth were worn to little nubs. No wonder it didn't idle... so the best deal I could get was an xe268h, k kit, and some lightly ported 675 heads. The chambers looked tiny compared to the x heads I ran on the 360. But the were open chambers. I got the old heads off and found the pistons were close to the top of the bore, less than. 0125. Very cool compared to others I have seen. So any way I bought that stuff all for $245. The Cam had 16000 miles on it. I called comp cams and they said run an abbreviated break in.so I put some break in oil in there and fired it up. My 4160 started leaking out the balance tube and baseplate but I watched it and Ran it about 10 minute then... it ran outta gas. I thought I had five gallons in there! And even tho it was warm it wasn't HOT. I had it at about 36 ° total, it was running pretty good but I think the vacuum loss from my crappy Carb kept it from starting again. The cranking compression killed my battery quick, I am charging it up and thinking of running a thermoquad on it till my Holley holds a seal. But that old thing is beat and I'm outta money. So am I gonna need to run another break in? I didn't mean to write a book but I want folks to clearly know what went down.
 
Did you have new lifters in it?
 
Nope. Same ones. There was no visible wear pattern on any of them. The comp tech said even if they were out of order that they would probably be fine. They were well past break in and would probably seat just fine. It definitely seems to have a nice bark and throttle response just jolting it to 3500 from 22-2500.
 
Well, now I know for a fact that Comp has lost it. Good luck with that one.
 
This is going to sound like a bashing, but here goes...
Either you misunderstood the man or Comp cams has started hiring total idiots to answer questions. Only a fool would put used lifters on a used cam out of order and expect it to be okay. "Probably be fine" ? Really???? Do you realize that when the cam and/or lifters fail, all the shavings will pass through everywhere the oil goes, tearing the hell out of the oil pump, crank and rod bearings, valve guides....
"Probably be fine" is a terrible risk to take.
 
Let's not just seem like we're bashing, lets give the real reason. Here it is. Camshaft lobes are ground on a taper. In other words, they are not flat across the lobe. This is done to make the lifter spin it its bore. The lifter is also not flat on the bottom. Is it ground with a convex (dome) shape across the bottom. This also facilitates lifter spin. This means that the contact pattern between the lifter and the cam lobe is thin. This is why camshaft break in is so critical to a flat tappet camshaft and lifters. This is done so that the lobe and lifter will not fail when properly broken in. If the lifter did not spin in the bore, the camshaft lobe would wipe in the same place on the lifter face and soon destroy it.

For years, it has been accepted that you can run a used camshaft with used lifters, as long as those lifters were kept in order from each lobe they were run on on the same camshaft. It is also accepted practice that you can run new lifters on a good used camshaft, providing you run through the break in process just like a new camshaft and set of lifters. In this way, the new lifters wear to the used camshaft's lobes. Again, this is acceptable.

However, under no circumstances should you ever run lifters that have been run on a camshaft if they have been mixed up and you do not know which lobes they are asigned to. Not even on a camshaft that has five minutes run time, much less one that is already broken in as you describe.

You've broken a cardinal rule and WILL have a failure of either a camshaft lobe(s) or lifter(s) or both. It is simply a question of time. Why a "professional" from a suposedly "reputable" camshaft company would tell you it was fine is beyond me in light years. Rest assured, it is NOT fine.

If this engine is together and running, I strongly advise you tear it back down and closely inspect the camshaft and lifters. Drain the oil and look for metal particals. If you see none, oh happy day. Buy a new camshaft and lifter set and replace what you have. They are now worthless. Just hope that is ALL that needs replacing, because if you have metal particals in the oil, the entire engine needs to come down.
 
It aint bashing and I don't take it personal. This is my first time running a used Cam so I am in new territory. I have built 11 engines of my own but this one was to be a temporary measure while I build the other engine. I have never had a failure of anything I built except my Holley that leaks from the balance tube like my daughter leaks around the eyes when she wants $. So, I am gonna check things out today, there ain't much I can say here except that if there are no signs of damage or any chewed up lobes I'm gonna run it till it stops. I also want to ask, because I have been here for a long time and I hear it sad a lot that this or that WILL fail, how many of you have DONE this? Run a lightly used Cam? With it's original lifters? Out of order? What was your situation, circumstances, and what EXACTLY happened. ? Thanks! I don't mean to be bull headed or set myself up for a hundred lectures on Cam dynamics, you dont know this about me but I studied under Dom Elgin here at De Anza. So I am clear about cams down to the metallurgy. This is why I asked. If this Cam were nitrided and lightly run, ?? Who has tested this and what happened? Oh, and I DO TRUST COMP CAMS.
 
Disregard....I re read your post and I have nothing to add except that I know my brother wiped a used cam with mismatched lifters...and he did run a break in...but his oil was contaminated too. I'll see if I can find the pics
 
I have to get a tow truck to go out to the valley (Modesto area) and pick up the motor home that has my 360 in it. It has 11000 original miles... I am buying a 426 kit from Hughes and building that. I was gonna run a 285hl or something nice like that in it. I just need this thing to function til I can fund the new one and get er done. I have two other 318's that I can use if this one wipes. Oh well.
 
You may not be able to tell really, but the #2 intake (I think) lobe is nearly worn away. The only way he knew was the increasingly noisy valvetrain-dead giveaway.
 

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I hope it works out for you! I have heard of people getting lucky before.....but generally that's a rule that should never be broken. I can completely understand you having to do what you have to do. I am there myself. Good luck!
 
I hope beyond hope that it works for now. My friend Vic who owns victory machine said its a no-no, generally, but the three times he's ever done it in his 35 years of engine building he didnt have any problems. But he doesn't recommend it! Ha! I am not usually a gambling man but this time I guess I'm gonna just throw the dice. Put on some safety glasses and FLOOR IT.
 
muscle car mike said:
I hope beyond hope that it works for now. My friend Vic who owns victory machine said its a no-no, generally, but the three times he's ever done it in his 35 years of engine building he didnt have any problems. But he doesn't recommend it! Ha! I am not usually a gambling man but this time I guess I'm gonna just throw the dice. Put on some safety glasses and FLOOR IT.
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I love this post! Safety glasses HA!

Good luck. Giving the circumstances, I would do the same and just beat the ever living snot out of it. Your already in this deep....
 
USE GOOD OIL !!! and by that I mean breakin oil i.e. Comp, Joe Gibbs, Brad Penn, ect, and put about 30 min of 2000+ RPM breakin time on it. Good luck.
 
Interesting. You sound like the guy I talked to last week about a cam I have for sale...
 
Junk yard build run what you have, love them.
Back in college 1985 a buddy of mine had a 70 nova, 4-speed that ran real good that he did the paint, touched up the interior and drove the snot out of it, never touched the engine.
Nice car
The car ran like a raped ape, but after a few years it started to smoke a little.
He sold it to another friend, which tore the tired 350 (abused) down.
A two of the cylinders were .030 over the rest stock, it had a few dished pistons, a few flat tops and some dome ones in there.
The cam was a hydraluic but it also had a few solid lifters on it.

The person that built the motor just used what ever he had and it stayed together for years, luck yes but you dont need high dollars to go fast, do I recommend it NO.
 
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