More bad luck!

[mattsmopars]

Well today i pulled the intake off my 340 in the duster that a bought a few months back to change it and the carb. Got to looking at the cam and found two bad lobes and lifters. I did not build this motor, and it seemed to run well, but i drove it to Livingston, TN a couple months back ,and when i got back i noticed a little valve train noise, but wrote it off as the rockers. Well i guess that i was wrong! I am guessing that it has to big of valve springs on it, is way it done this damage. It was only on two lobes that were next to each other, with the cylinders across from each other.It is the 3rd cylinders back on both sides. I have not driven the car any since the cruis in and have only started it a few times since. I did notice some fine silver coloring in the oil on the lifter valley. So i know that i am going to have to have a cam, lifters, springs. I am wondering if i should just go on and pull the motor to inspect the bottom end or flush it out good by changing the oil good a few times? It does seem to still have good oil pressure at last run. I don't want to put new cam and matching componets in just to ruin them. I pulled all the other lifters out and they are all o.k. So let me know what ya'll think i sould do?
Matt

 

[TheCrackHead]

Flush the oil and change the cam and lifters then check spring pressures on both side where the lobes went flat.

They don't look like they left a lot of trash behind so you should be good.
If it makes you feel better and are taking the motor out anyways then check the bearings-journals.

 

[mattsmopars]

Thanks for the reply, i am hoping that i cought it before it did any major damage. I do not have intention of pulling the motor unless it is needed. I had rather change cam and lifters and check the valve spring pressure. Maybe the cam was not broke in right? I am not for sure, it does not have that many miles on the the rebuild. I think that i will drain the oil good and check it for shavings or anything and go from there.
Matt

 

[retsud_043]

I hope everything turns out alright for you Matt[-o<.... I haven't seen lifters like that since the 305 chebbies of the middle 80's. We changed out tons of cam& lifters (I worked at a G.M.ukeleft: dealership) with just a good crankcase flush, most of the engines had no issues from filings.

 

[67valiant]

i had the same problem on my 318, and on a 360 i bought i tore it down to rebuild it and 2 lobes on the cam were worn off and a bunch of lifters were dished shaped like that, i have heard that cheap oils and some other brands make this happen because of the different additives in the oils, i would research more on it so it does not happen again

 

[clifftt]

A friend of mine had a new cam go bad in a 360 during break-in. He replaced the cam and lifters, flushed the engine, and no more problems.

 

[moper]

It's a crapshoot if you dont clean it all out. I agre, not much went thru. It's probably not worth teraing it all down to bare block. but, if you drive it and there is damage, it will more than likely require some major parts to and work to fix. The reasons cams go flat are many, and it only takes one to kill it.

 

[340sFastback]

I'd cut that oil filter open and see if its full of metal. If too much junk goes into the filter the by pass could open and send the metal all through your bearings then eventually you will have major problems if that occurs.

 

[lenweiler]

Same thing happened years back to a 451. New engine. Changed the cam and lifters. Didn't like the cam anyways. Engine still runs strong today.
I'd suggest that the cam was never broke in properly, or used lifters, or bad oil, or all three.
That's why I run rollers now.

 

[mattsmopars]

Thanks for the replies! I am going to check to oil and the filter when i tare into it. What is the best way to flush the motor out? Or would you just clean what you can get to and change the oil a few times fairly quick?
Matt

 

[ocdart]

Hey Matt -
Even the 'good' oil today has a definite lack of zinc and break-in of ALL flat tappet cams is going to be suspect unless you use an additive with high amounts of zinc (ZDDP). There's been a bunch of articles is all the magazines about this issue.
One of the major cam manufacturers is now plating their cams to help combat this break-in issue (sorry, I'm at work now and don't have my "library" for reference - I'll check it out further when I get home add add the information to this).

 

[72bluNblu]

Make sure you run some zinc additives after you install the new cam. New oils have almost no zinc at all, and it kills non-roller lifters/cams. Although I'm not using it now (I should be) I'll be running amsoil in my new engine (not in the car yet) after break in. It has oils that still contain zinc and other things needed for the older engines. If your oil doesn't have it, you'll need additives in the future. The cam should come with its own break in additive.

As far as flushing it out, I'd pull the pan during the oil change and clean it up. Most of the metal should be down there or in the filter, and I wouldn't count on it all draining out just with the oil change. Then I'd change the oil again after the recommended cam break in.

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whoops, looks like ocdart beat me to it!

 

[moper]

I run a large magnet on the oil filter when I fire new engines... It traps the metal that I may have missed during cleaning. You may try that, and change the oil a few times, with only a few minutes of runn time between them.

 

[JohnRR]

The oil goes thru the pump FIRST before the filter , I would be changing the pump out if the filter shows alot of debris . Also GRAVITY is a funny thing , the metal off that can goes STRAIGHT DOWN and deposits itself on the piston skirts right below it .

Personally I'd be pulling it out an tearing it down instead of half assing it by just doing a few oil changes , I spun a bearing in a 383 , maybe drove it 9 miles after it happened at slow speed , when I took the hyd. lifters apart to clean them out EVERY single lifter had fine metal particles in them .

 

[intimidator]

Every motor that I have ever seen that had a cam go flat also had some damage to the rod bearings as well as the oil pump and cylinder walls. If I was keeping this motor I would check it over from top to bottom. Spun bearings get very expensive later.