3 53 detroit rods bent and broken?

[scorpion6]

Purchased 2 - 3 53 detroits for my goat. 1 has been rebuilt. The other appears to be a low miles motor lacking a few parts. The rebuilt motor would not turn over all the way. I opened her up and found that 6 of the 9 push rod poppits had been bent or broken. all valve related rods not the injector rods. Took the head off to find no damage at all not even a scratched piston or bent valve. The cylinder still has the hone swirls in it. So the Question is what may have caused this catastrophie? I did notice that the rod locks were loose.

 

[RANDYDIRT]

Bad blower seals may have leaked oil into the supercharger and caused a run-away.

Dirt

 

[Gamagoat1]

High RPMs for sure.....This is a hellish stout engine! The weak point, aside from improper maint., is the valve train.

 

[scorpion6]

Well, I finally got to the bottom of the bent rods. It seems some mech. at the depot did not know his @#@#$ from a hole in the ground. As I said every thing in this motor is new, but the mechanic did not set up the valve train correctly. He did not even set the gear marks so that the timing would match the cam. The injectors were set wrong so one was coming in contact with the piston slightly. All in all not much damage for the incompetence. The 3rd cylinder valves were new, and now are bent. So I have now readjusted the timing, swapped out the rods and am in the process of changing out the springs and valves. Amazing just amazing! Thank you for the places to start.

 

[johnsr]

and this would be why i have so many repair manuals (and want more) and have a few mech's on speed dial. my daddy alwas said " Son if you don't know just ASK."

 

[davidkroberts]

i was talking to some of the diesel mechanics at work a few years ago when i was just buying my goat they were talking like the detroit diesels were a bit difficult during the rebuild and running the rack on them was a pain. I never tore into mine so i never got to find out.

you sound like you have torn into one before today how difficult overall do you think they are to work on?

 

[scorpion6]

Well as far as working on one before.....never have. The overall mechanics of the 353 is just like any other motor. I have worked on many gas motors and a couple cummins diesels. I feel that the 353 is overall pretty simple to work on. There are a few differences that merit mentioning.....valve train is different as there are 4 exhaust and no intake valves, and the injectors are self priming with no lift pump. To answer your question the motor is easy to work on , but get yourself a manual for all the specifics of the valve train. Setting the rack is the most temperamental part and can be a pain and cause damage if not set right eg. piston damage due to the injectors being set too deep or running too rick or lean in one cylinder. This will cause a melt down of the aluminum piston in a short time ( I mean hours not days of run time). The valves need to be set right. If the exhaust opens at the wrong time funny things like the motor running away with its self happens because it is running backward and pulling through the exhaust. The motors are the overall best diesel on the market as they produce more torque with less RPMs. They are less expensive to repair, and there are plenty of parts available.
So now don't you wish you hadn't asked. I just jump into the motor and let the chip fall where they may......you learn more that way. Besides there are always phones handy when you get too deep to cry for help.