D315 Pony Engine

Hello eveyone,

Well I am in a little bit of a tight spot. I took my D315 diesel out of my B-E crane at the beginning of the year to diagnose what was going on. Since then I have had a valve job on the head. I've got the head back on and ready to roll. My pony engine, not so much. It set with water in it for a long time and pitted the cylinders really bad. So bad that I am going to have to have it bored and sleeved and re-bored so I can use my stock pistons. Cat says the oversize pistons and rings are discontinued. All my local machine shops are not equipped to bore this block to be able to sleeve it. Does anyone have a source where I can ship this rig and get it bored and sleeved? Does anyone have a pony engine they would part with? I have an electric starter on the diesel so its not imperative that I have the pony engine. I will have to engineer something for the coolant bypass.

Hi K100, oversize pistons are available from JP Pistons in Australia. You can let them know how much oversize you want and they'll send you pistons and rings. If you want to sleeve and are East Coast, my local shop, Drake Engines on 2285 Ridgeway Ave Suite 1, Rochester, NY 14626 might be able to. Give them a call on +15857231333. I've had them bore my two pony engines, and also machine the cranks for thrust bearings as a customization. They've worked on a LOT of engines and have a lot of expertise. If they don't sleeve, they most likely know who does

Thank you Neil for the info. My name is Jason

I have a good pony I could sell you. Where are you located?

Do you still sell it? I'm at 1169 Mohr Mount Suite 884 Port Flavie. Is that near you?

Edit by geometry vibes a day ago.

I am in Ellettsville Indiana

Sounds like you’ve made some solid progress getting the D315 back together — nice work on the head! As for that pony engine, you’re right, the oversize pistons and rings have been discontinued for a while, so sleeving is your best route if you want to keep it original. A few shops still handle small vintage Cat engine work — you might try Richmond Machine & Welding (VA) or Olson’s Machine Service (WA); both have experience with pony motors and can handle sleeving jobs by mail. Another good option is to check with Florin Tractor or General Gear (tractorparts.com); they sometimes have rebuilt or salvage pony engines for the D315. Since you already have an electric start setup, you could definitely run without the pony if you rig up the coolant bypass properly. Still, it’s worth keeping the pony if you can, since it adds originality and reliability in cold starts. Hope that helps point you in a good direction — sounds like a great project! @slope rider

Still trying to get ahold of this guy that has the pony for sale. I am interested. Please call me at 317.410.9918 to discuss.