Catastrophic Failure of the Camshaft Bearings

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airwoofer said:
Is the shop capable of maching the cam tunnel? If so have them do that and pay for it. there are a lot of stories about the Mopar cam tunnels being out of whack.
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Was thinking the same thing. As long as the bearing would fit afterwards. Wonder if they make a thicker OD set of cambearing for such application...I would think??
 
340_dart_power said:
UPDATE:
and the suspicion is that the tolerances between the camshaft and camshaft bearings were either too great or too small, and this is why the bearings failed.
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Anyone else have a problem with this statement? Come on now.....a machine shop telling a customer that has had a failure of sorts that we thinking the clearance is either tight or loose? To me that smells of we did not even look at it when we tore into it and are hoping that it will be right when it goes back together. I would have asked for specifics on the cam bearing specs....what they should be vs what they are on my motor.....at the very least....
 
I am glad to hear they are standing behind their work.I bought a 496 from Speed-O-Motive out of CA a few years ago and it last a whole 40 miles.They didn't even line up the oil holes in the cam bearing.AND THEY WOULD NOT STAND BEHIND THEIR WORK!!!! So from now on I build my own motors.
 
There is no correlation between the lower end living and the cam bearing clearance. The oil travels up to the right side lifter galley from the pump, then goes down individual passages to the respective main bearings and then to the rods. IMO - if the lower end has bearing issues there is one or more of three possible issues: it was not machined right, not assembled right, or not started right. But regardless - the cam had nothing to do with it. Hopefully they get what was really wrong fixed for you.
 
inkjunkie said:
Anyone else have a problem with this statement? Come on now.....a machine shop telling a customer that has had a failure of sorts that we thinking the clearance is either tight or loose? To me that smells of we did not even look at it when we tore into it and are hoping that it will be right when it goes back together. I would have asked for specifics on the cam bearing specs....what they should be vs what they are on my motor.....at the very least....
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If it was mine, I would have wanted to get straight to the bottom of it. But more likely, since I assemble my own stuff, I would have found it myself on assembly. Since it belongs to somebody else, "I" don't have a problem with it, cause I ain't got no skin in the game. As Obammy would say.
 
Gents, thanks for the input/suggestions/analyses. If you've seen any previous posts of mine, I've stated before that my mechanical knowledge of engines is very limited, so I am at a bit of a disadvantage when it comes to discussing theses issues. Unfortunately I have to rely upon the Moral Character and Ethical Code of the people working on the 340 to "Do the Right Thing" and not B.S. me when describing what may have or did actually go wrong.
I know it's difficult sometimes to detect tone in these kinds of written posts, but please understand I'm not being critical of anything anyone has contributed to this discussion. As I said before, my engine experience is very limited when compared to other Forum Members, so I'm learning as I go.
I stopped by the engine shop Friday of last week (09/27/2013) and the rebuild had not begun due to several other racing engines which came in and had to be worked on by the shop. Hopefully by mid-week of this week they'll have made progress on mine.
 
In the end when the engine runs well and stays together - it doesn't matter what was wrong and they are fixing it at their cost. If it has issues again - the education might come in handy when you're talking to them again. My purpose in posting was to educate - otherwise like Rat I got no skin in the game.
 
Understood, I appreciate it, moper.
Some progress has been made on the rebuild, but now we're looking at next week to go pick up the finished 340.
 
As of yesterday the 340 was rebuilt and ready for installation. It will be picked up today and taken to the shop where the Dart is resting comfortably awaiting its engine.
I swear if the 340 goes belly up again I'm yanking it and finding a 5.7 Hemi to drop into it....
 

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340_dart_power said:
As of yesterday the 340 was rebuilt and ready for installation. It will be picked up today and taken to the shop where the Dart is resting comfortably awaiting its engine. I swear if the 340 goes belly up again I'm yanking it and finding a 5.7 Hemi to drop into it....
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If it goes belly up again, your more than welcome to send it over here 8) lol
 
Does this shop have a run stand to test the engine before you put it back in? If the they do I would suggest you run it first on a stand.

Ian
 
Best of luck to ya. Follow "destructions" exactly on break in
 
when my dads motor was machined and assembled at Lesco Race Engines in S.L.O in CA. they had to turn down the journals on the Crower cam as it was a tick to tight. that is something that is not uncommon...
 
Cool, hope this one goes better and you get a bunch of miles with a big grin on your face!
 
68383GTS said:
I am glad to hear they are standing behind their work.I bought a 496 from Speed-O-Motive out of CA a few years ago and it last a whole 40 miles.They didn't even line up the oil holes in the cam bearing.AND THEY WOULD NOT STAND BEHIND THEIR WORK!!!! So from now on I build my own motors.
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They Did crap work..... I'm Glad there out of business.... George Sucked at what he did.
 
Some videos from today:

[ame="http://www.youtube.com/watch?v=FYCsQi7rDpw"]The Dart GT is buffed Oct 20 2013 - YouTube[/ame]

[ame="http://www.youtube.com/watch?v=azob0KnmnyA"]The Dart GT on Interstate 65 Oct 20 2013 - YouTube[/ame]

[ame="http://www.youtube.com/watch?v=mk25TrHf50o"]Coming up Mack Hatcher Oct 20 2013 - YouTube[/ame]
 
Thanks, Abody & Pettyblu; just need to get 500 miles on it before I can get on it a bit more aggressively. We were able to get rid of the electric vacuum pump which had been installed after the first rebuild due to the lack of vacuum being produced by the first camshaft used. I didn't have enough to properly activate the brake booster, but this camshaft is producing so much more that the pump became unnecessary. My mechanic pulled it and the brakes are fine w/o it. Plus, it cleaned up the engine compartment as well by getting it out of there; less cluttered in appearance.
 
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