Branson 4720h Engine replacing rings

[bobmisi]

I get my parts from Cummins with no problems. I would say the prices are average for todays world.

 

[Bob Nelson]

Can you tell me exactly where your supply is and their name and phone number or address? It would be greatly appreciated!

 

[IH3444]

2900 hours. You sure you need pistons. Maybe just a cylinder honing, new rings, and a valve job. I'm not a grind the valve believer, but in your case I would to save money. Check the bottom end for bearing clearance, and new rod bearing for sure if the crankshaft mics out good. This is why you use good quality oil, and change it regularly. These diesel engines are usually good for 10,000 hours. Post some pictures of your pistons when you get them out.

 

[Bob Nelson]

2900 hours. You sure you need pistons. Maybe just a cylinder honing, new rings, and a valve job. I'm not a grind the valve believer, but in your case I would to save money. Check the bottom end for bearing clearance, and new rod bearing for sure if the crankshaft mics out good. This is why you use good quality oil, and change it regularly. These diesel engines are usually good for 10,000 hours. Post some pictures of your pistons when you get them out.

Yes. I bought the tractor at a very good price. The dealership was not a Branson but I have purchased used stuff from him before. He sold the tractor as is and I drove it all around for 1/2 hour. Lots of smoke, but everything worked as it should. It actually surprised me as the thing was just full of dirt up to the dashboard and packed everywhere. He thought it had sucked some dirt. No leaks.

So, I have the head off and mic'd the bores and you are right, the bores, top and bottom are within specs to just be honed. I am taking the pistons out today. A local shop will do the head for $275, clean, valve grind, etc. Unless it needs guides, etc.

 

[IH3444]

Branson tractors have a stellar reputation. Looks like this one was just rode hard, and not taken care of. The cylinders mic-ed out good, so a top notch piston clean up, cylinder honing, and new piston rings should get you back up and running well. I would still mic the crankshaft to be sure its OK, do a micro polish of the journals, and install new rod bearings, as well as mains if you will go that far. Disassemble the oil pump and check it for wear, and backlash.

 

[Bob Nelson]

I would do those things, but I'm doing an "in frame" job. I don't want to pull the engine. I will plastigauge it, though.

 

[Bob Nelson]

Got the piston out of the worst cylinder compression wise. It had 240PSI. The manual says 495. The top ring is broken and the second compression ring has little spring to it.

 

[LouNY]

That will ruin the compression for sure,
the most common reason I've seen for broken rings in a diesel has been starting fluid.

 

[sd455dan]

Yep. looks like it also pounded top ring land out of the piston

1 New piston for that hole needed for sure.

 

[IH3444]

Rod bearing insert worn down to the copper. Looks to be dry started with too much starting ether, and bearings were dry on harsh startup in dead of winter before oil got to the bearing. This is where full synthetic good quality oil shines. Cold winter start ups, synthetic oils flow better and quicker. They also have a better clinging to the metal surface ability. Most likely a regular 15w-40 oil was used, instead of a better suited for cold winter full synthetic 5w-40, like Rotella T6 5w-40.