Autopsy Completed: Results #2

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FASTBACK340

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Pulled apart my lump today. I found some cooked main bearings, clean crank, and a beat-to-death camshaft. I tried to post 5 pictures in a previous posting but wasn't allowed to post that many pics at once. Here's the first of 3 sets.

teardown5.jpg

Chunk missing. Too tight? Crappy material?
teardown1.jpg

Crank looks clean. But then there's the bearings....
teardown3.jpg

#2 & #4 not longer seat in the saddles. Line bore?

Any & all input appreciated here gang.
 
Should the pins be this tight in the pistons? I don't remember them standing straight up like this....
teardown9.jpg

And here's the object of my frustration: One wiped-out Mopar Performance camshaft......
teardown12.jpg

teardown13.jpg
 
John I merged them together for you.

Now lest get thyis motor together for good.

Its sounds like its time for some good machine work. Line bore and hone the main, Add a timing chain tensioner to take out the slack in the chain that it will cause, Check the deck and make sure its flat, and hone the bores. CLEAN, CLEAN, CLEAN ! Did you pick a new cam yet ?
 
From what I remember pistons should not stand on their own like that! BTW Love the FABO sticker on the tool box! Did you cut the goofy arrows off the F and M?
 
John do you have a good aftermarket oil pressure guage in the car ? I'm thinking you have some oiling issues, Bad bearings, flat cam and possibly bad rist pins.
 
AdamR said:
John do you have a good aftermarket oil pressure guage in the car ? I'm thinking you have some oiling issues, Bad bearings, flat cam and possibly bad rist pins.
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I had no problem with the rockers galling or any knocking/tapping when it ran. I also primed the motor before initial start-up with a priming rod in the oil pump with the distributor out. I had the valve covers still off to verify that oil was getting up in the heads. I (had...) a new Melling stock volume oil pump. The pressure switch is new with a working factory gauge. Plus it never ran hot and the oil looks like new. Except for all the shiney stuff in it.

I'm into this thing for my lungs at this point..... Me thinks I need to re-do the block. At this point I'm ready to cry. :(
 
What does the back side of the beraring shell look like? also, the main cam mating surfaces, on the block and caps?
 
Fastback John
What brand of Cam was it ???.
I have been reading threads of M.P. Cams grinding down. I have a new 340 With an M.P. hyd cam I hope to get in my 69 and fire up,this week end, but now I'm worried about the cam takeing a dump.
I hope your truoble didn't start with the cam.
 
Bad news it was a Mopar 292-508" cam. Good luck with your fire up.
 
I hope it did not start with the cam. I have a MP 292-509 cam in my 400. :scratch: Thinking about it almost everything in my motor is MP.
maybe time to change the cam befor I put everything together. I still have alot of time before that times comes.
 
It's looking more & more like the cam **** the bed and took everything else with it.... The oil pump rotors look like something an angry pit bull cound have chewed up. The backs of the bearing shells are clean, the saddles are good, and the caps didn't shuffle. There's no sign of heat damage either. I think I opened it up just in time before this thing totally seized up.

I sent the pistons/rods & crank out to a machine shop for evaluation. The block gets hot tanked at work this Saturday and I'll start measuring bores & mains. The block will probably go the the shop next week.

The cam was a MP. It's now in 3 pieces.....:angry5:
 
Interesting tho..Cam garbage doesnt usually cause bearings to loose crush..that's usually begine hammered, detonation, and you'd see it elsewhere like the cap surfaces..Are you sure the bearings are the correct application? Something seems "fishy" (sorry for the pun) there. MP cams have just as much chance as anyone else these days. The installer/first start guy has to be on top of their game to get it right with low/no zink oils, higher spring pressures, and high rates of lift.
 
Wow...one cam goes bad so now everyone jumps on the mopar cams suck bandwagon. get over it people, I had a friend have an Eagle rod go bad on him...does it mean ALL eagle rods suck? NO. It means he got a bad part, things happen during machining.

Sorry about your loss on the motor, parts do go bad, I have broken a few parts in my day (still have a truck sitting due to it), it happens when you want to go fast or do anything. Clean that puppy up, make sure its still safe, and rebuild it.
 
threefortyduster said:
Wow...one cam goes bad so now everyone jumps on the mopar cams suck bandwagon.
Click to expand...

Do a search on the board or any other mopar board for Mopar performace cams going bad. This is not even close to being the first one.
 
The machinist called and told me the crank and rods/pistons are salvagable. After a brief chat he said yeah, MP cams do have a bad reputation, and also explained that when you stud a block the mains should be honed. Mine weren't.....

I bring the block out Thursday night and talk it over with him. Looks like about $400 in machine work. I'll let you all know "real world" costs for this disaster and what is done.

Here we go again.......:cussing:
 
I used the GM EOS on assembly. I primed the engine using a drill and a priming shaft. I had all settings correct for immediate fire-up. It started and I held the idle between 2,000-2,300 RPM for a half hour (the neighbors LOVED that with the 2 chamber Flowmasters.....) Returned it to idle and set the carbs. Shut it down and changed the oil & filter and double checked the valve lash (adjustable hydraulics.....) Started it up and took it easy driving it until it started tapping from the lobes disappearing.... Grand total: 20-25 miles.

So far I'm having a sense of humor over all this......:|
 
What valve springs were you using on your initial break-in? It is not good to break in a cam with high spring pressure.
 
GotDart said:
What valve springs were you using on your initial break-in? It is not good to break in a cam with high spring pressure.
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I've heard pro's & con's over this issue too. I'm using Comp double springs, which were in the motor on break-in. I was planning on swapping the springs if the cam I select recommend something other than what I have. Otherwise they stay...

I still say it was a bad cam....
 
I bet spring pressure helped kill it. You should pull the inner springs for break in.
 
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