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Discussion Starter #1
This may belong under the builds section not sure... I was intending to start a build thread tonight but... oh well.

So I recently bought a 350 short block new off ebay, it looked absolutely fantastic, turned by hand nicely. 4-bolt main, bored .060, forged pistons, decked to 0, melling HV pump, stock crank and rods, aluminum heads with dual springs and a rubberized gasket, ARP head bolts, moly pushrods .2+, aluminum 1.3 roller rockers (for break-in, 1.5's for later), comp cams additive, comp cams assembly lube, .480 lift 230 duration, hydraulic lifters installed dry (as instructed by the paper which came with the cam) 10w 30 oil, bypass blocked, primed with electric drill, then primed again by cranking with the starter, fired it up, 70psi oil press, kept idle at 2000rpm's, within 5 min. CLACK CLACK CLACK CLACK!

Thought it was just a rocker which came loose, one was loose, tightened it up, (zero lash, then 1/2 turn, then tighten the center lock) and the sound was still there, just now it sounds like a grind then a clack 10 times a second, and one cylinder sounds flat... I believe it just chewed a lobe...

So here I was thinking I could just toss in a new motor into my 52 and be able to go to college, and get a better job, without buying a whole other car, but I guess some people just don't have that kind of luck. Not to mention, this is the 3rd motor, none of which I could get any sort of luck with, and now im completely broke...

Thinking on the bright side, It was my first motor I have built myself, it was worth a shot, achieved something that most could not, and it was a thrill hearing it fire up. Too bad the noise just sounds way too nasty to be anything normal for a fresh motor.

Who wants to see a build thread anyways? I took a few pictures along the way.
 

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I will move tis if you like. Sounds like a crap cam, have you spoke to the seller yet? Maybe you can use a warranty.
 

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Discussion Starter #3
I will move tis if you like. Sounds like a crap cam, have you spoke to the seller yet? Maybe you can use a warranty.
Yea, you can move it if you like, I wont mind.

Has to be the cam, it was Comp Cams too, I thought they were good! Maybe I can see if there are some roller cam setups that you can get for these old blocks (if they exist). Ill look at what is in the oil filter, luckily I blocked the bypass, I had the strangest feeling that the cam might wipe a lobe for absolutely no reason.

I am getting tired of it though, I have never heard of anyone else having so many problems with their engines before... this is my 3rd one, all died from the strangest of reasons, all of which catastrophic.
 

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Bummer man!!
Your first sentence said it all.
Bought on ebay, looked fantastic and turned by hand easily. Should take a breaker bar to spin it over.
Low ratio rockers for break in of dry lifter's. What about the springs. They're the cam killer.
And you think it's the cam gone away and you'll just put in a new roller. Not so lucky with all those fine pieces of metal all thru the motor and not in the filter that you bypassed.
Oh well, if you did get it running good then the fire started by that aircleaner would have ended it all.
JMHO
 

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Comp cams are notorious for this problem, and the second thing to remember is always run Rotella T diesel motor oil in a fresh motor with a wix filter.
 

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Comp cams are notorious for this problem, and the second thing to remember is always run Rotella T diesel motor oil in a fresh motor with a wix filter.
That's a pretty broad statement.

Are you running dual valve springs on the heads? Did you take out the center spring?

With that engine a standard Melling pump would be fine. Why the high volume pump? Only race engines with looser tolerances need a high volume or high pressure pump.
 

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That's a pretty broad statement.

Are you running dual valve springs on the heads? Did you take out the center spring?

With that engine a standard Melling pump would be fine. Why the high volume pump? Only race engines with looser tolerances need a high volume or high pressure pump.
Know 3 people that have had comp cams get wiped out on intial break in run time. Now this guy too, coinsidence, you decide. Have never heard of this myself with others such as lunati, isky, ect. Not one myself for the high volume pumps as you say a stock pump would be just fine. Quite a while back ran a stout 350 that would hold 9000 rpm's and not miss a beat with a stock pump. At idle it would have around 15 pounds hot and around 35 under throttle, and never had a single problem. Raced this motor for three years without ever coming apart. Ironically this motor had a 660 comp solid roller cam.
 

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Know 3 people that have had comp cams get wiped out on intial break in run time. Now this guy too, coinsidence, you decide. Have never heard of this myself with others such as lunati, isky, ect. Not one myself for the high volume pumps as you say a stock pump would be just fine. Quite a while back ran a stout 350 that would hold 9000 rpm's and not miss a beat with a stock pump. At idle it would have around 15 pounds hot and around 35 under throttle, and never had a single problem. Raced this motor for three years without ever coming apart. Ironically this motor had a 660 comp solid roller cam.
Couple things wrong with your statement fella, Rottela no longer has enough ZDDP like it used to, it was reformulated a couple years ago. I still use Rottella myself, but have been using a bottle of comp additive PN# 159 at break in and every oil change and so far zero failures and I'm rough on equipment and not all my cam break ins have gone as smooth as they could. For $8 its good insurance.
As for Comp Cam having a high failure rate, what your actually hearing about is 2 issues. #1 comp is the biggest seller hands down. So it stands to reason that you will hear about their failures more often because there are more comp cams in the market then anyone else.
#2, because comp is such an accessible product, and everyone auomaticaly buys the name they hear about, and the price is right, every ham fisted moron buys a comp cam, then installs it wrong, breaks it in wrong, then complains to their 12 cousins when It goes sideways.
I have used their cams, and been happy with them, the last couple cams I purchased were actually Lunati and both performed better then I had hoped for and I will use them again.
But I certainly wouldnt bash comp cams without seeing the big picture.....
All that being said, go buy a Howard's Retro Fit roller and be done with it. :D
 

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More machine than man
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First, I am sorry to hear the bad news. Hopefully it is something else like a rocker hitting the valve cover, or an exhaust leak, or something easy like that. Have you pulled a valve cover yet and watched the lifters move while the motor is running?

hydraulic lifters installed dry (as instructed by the paper which came with the cam)
Are you saying there were not pre-filled with oil? Or you didn't put any moly paste on the faces of the lifters?

What lube if any was used on the cam and lifters? Comp includes a crappy red gel lube with their cams. It is not intended to sit for any length of time after it is applied (I think 24 hours max because it drips off). Was the shortblock shipped assembled or did you do the work? I just broke in a Comp flat tapper cam myself and have 400 miles with no issues so far and I used thick grey moly paste.
 

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Couple things wrong with your statement fella, Rottela no longer has enough ZDDP like it used to, it was reformulated a couple years ago. I still use Rottella myself, but have been using a bottle of comp additive PN# 159 at break in and every oil change and so far zero failures and I'm rough on equipment and not all my cam break ins have gone as smooth as they could. For $8 its good insurance.
As for Comp Cam having a high failure rate, what your actually hearing about is 2 issues. #1 comp is the biggest seller hands down. So it stands to reason that you will hear about their failures more often because there are more comp cams in the market then anyone else.
#2, because comp is such an accessible product, and everyone auomaticaly buys the name they hear about, and the price is right, every ham fisted moron buys a comp cam, then installs it wrong, breaks it in wrong, then complains to their 12 cousins when It goes sideways.
I have used their cams, and been happy with them, the last couple cams I purchased were actually Lunati and both performed better then I had hoped for and I will use them again.
But I certainly wouldnt bash comp cams without seeing the big picture.....
All that being said, go buy a Howard's Retro Fit roller and be done with it. :D
You just misunderstood, was not talking about a 16 year old that just slapped in a new comp cam in his moms firebird. Referring to the type of guys that live breath and eat this type of thing on a daily basis. Build cars all their life to go to the local ( or not so local) dragstrip to see how their changes made a difference, those type of guys. These are the kind of guys that have had issues with comp. Just stating a fact, however have I ever had trouble with a new comp cam, it has been a while but the answer is no. You are correct as they are a giant in the performance cam market that is not debatable. My next cam purchase will most likely be a lunati or crower. I will admit was not aware of the change in rotella at the time that was the best oil to run in a performance motor. Thanks for the tip with the additive.
 

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Are you saying there were not pre-filled with oil? Or you didn't put any moly paste on the faces of the lifters?
This was the question I had as well. Not that it matters now, but if the cam and lifters weren't given moly break in lube that's death to them. If it's not pumping the lifters full of oil prior to assembly, that's fine.

Some valve train info:
Adjusting hydraulic lifters
Cam break in
Valve train points to check
Valve train geometry
Valve spring installed height
 

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Discussion Starter #12
I read all the responses so far, and all I can say is WOW, so much that I did not know.

I am heading off right now to get more coolant, when I get back ill answer some questions.

Thanks everyone :D
 

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Discussion Starter #13 (Edited)
Yea, my definition of "turning over nicely" when I got the block, involved using a breaker bar to do it hahaha.

Are you running dual valve springs on the heads? Did you take out the center spring?
So, here's the valve springs that I got:
SBC Chevy 350 .600 Lift Dual Spring Cylinder Head Valve Springs Small Block - KMJ Performance

I thought, and while assembling, I believed as fact (now I am not sure), that the max press springs on the cam for initial break-in would be 330lbs, so I assumed that with low ratio 1.3 roller rockers for cam break in, that the spring pressures would never reach 330lbs. It may be that my thinking was flawed.

Are you saying there were not pre-filled with oil? Or you didn't put any moly paste on the faces of the lifters?

What lube if any was used on the cam and lifters? Comp includes a crappy red gel lube with their cams. It is not intended to sit for any length of time after it is applied (I think 24 hours max because it drips off). Was the shortblock shipped assembled or did you do the work?
I did use the red lube that came with the cam on the lifters and cam, but I installed the lifters not soaked ("dry") as instructed by the paper that came with them, and yes, it did sit for longer than 24 hours as I was grabbing an intake for the 23* heads... :(

And you think it's the cam gone away and you'll just put in a new roller. Not so lucky with all those fine pieces of metal all thru the motor and not in the filter that you bypassed.
I meant by "bypass blocked" as in, I have installed a new spin on oil filter adapter plate with no bypass valve, so ALL the oil will go through the filter, and a massive WIX filter for just in case the cam did blow. Hopefully, the mains would have some chance of survival if it did chew a lobe, whether or not this is a good thing is debatable, at least I got 80psi of oil press when cold, and 70psi when hot, so at least I can reasonably assume that everything is getting oil.

But here's the latest: Yesterday, I decided to have another look at that rocker which was loose, it turns out the pushrod for the intake was hitting up against the head, I cannot tell that there is any damage, but after I adjusted my adjustable guide plates so that it would have more clearance, I can no longer hear a clacking noise. Too bad I did not see it during mock-up, as I was specifically checking the pushrods, I guess I missed that one.

But, a new problem has just appeared, last night, before I could get past my 5min record of run time, the temps began to soar to 200* quickly enough that I could actually watch the gauge needle. (this is a newer gauge that worked perfectly on the previous engine.) The exhaust was burning hot, which gives me the impression that the cam did in fact wipe a lobe.

I don't know if it's normal, but it does appear that I may have an exhaust leak where the manifolds meet the heads at the gasket, I can clearly see what appears to be black soot, that COULD if I'm right, cause one of the cylinders to sound flat I believe. I may not have got all the previous gasket material off the exhaust manifold surface.

My gut feeling is that the 180* thermostat is stuck closed, as I used it once for a short time before changing it out for another temp thermostat. So I have another 160* laying around that I just tested in a pot of hot water, and it does in fact open, and I just came back from the store down the road (I live 40 miles from town...), with 3 gallons of distilled water and water wetter since they were out of antifreeze.

At this point im deciding if I should try the 160* thermostat, or wait for a day where there is no risk of rain to pull the intake off and look at all the lifters, just in case a lobe did fail, I should be able to see something I would think.
 

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Discussion Starter #14
I am unsure if this is a good sign or bad, but so far I have not found any chewed lobes/lifters, but it appears that I may have caught the start of it. I have only gone through a few lifters so far, but one shows signs that the lifter did not rotate immediately, but apparently is now (which I assume is ok). The lifter which was in question has pitting and has scratches in a straight lines, I googled this, but nothing really came up. The scratches are deep enough that I can feel it with a finger nail, but feels rounded off which makes me believe that the lifter was binding, beginning to chew, but started rotating, as I can rotate it very easily by hand. Looking at the pushrod, the wear marks show that the pushrod was not rotating for some time, I assume it was binding on the guide plate.

I will take some images, and go through the rest of the lifters, I am starting to feel that this may be a sign for me to STOP remove the cam, and get a new one, and find a way to remove all center springs, would that be a safe bet? If I caught the damage early and there are no actual chewed lobes, ill be happy with that result!
 
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