Just completed a conversion back to a newer gas engine on my D2. If anyone is interested I have parts for sale from old pony motor and can give info on how it worked out.
I would be interested in seeing pictures and hear about the conversion. I know the fellows over on the ACMOC site would be interested also. That site is also a good place to sell your old pony parts. Folks always looking for pony parts there.
to old-iron-habit Thanks for the interest, here's the basics. I used the rear motor cover from the original pony motor so that I could use the original 40 tooth gear and have it in the correct position. Then made a plate to cover water jacket port and hold a carrier for the other side of the 40 tooth gear shaft. The motor is a 13hp electric start predator from Harbor Freight ($300) and a 12V generator battery ($40). The gear I used was similar in size to original drive gear, but made for a 1 inch shaft. I purchased it on ebay for $32. In order to set motor in place I had to raise the hydraulic line blocks 1 inch. When to motor was in place and aligned, I marked the motor mounting holes, removed the motor, drilled and tapped two holes in the flat part of bell housing, two in the rounded part and made spacer blocks to go between the rounded part of bell housing and motor base. (I used the spacers that had been under the battery box) The motor was then put back in place and bolted down. Then the real modifications came. Cut out dash to clear motor, modify the exhaust from motor to diesel intake manifold, change gas engine air cleaner housing, and seeing as there was no longer room for the monster air cleaner run new throttle rod through dash and install a air cleaner right at the intake manifold. I also built a guard for the open gears and tie the original rear motor cover to the new gas motor. (for stability) If I was to do it over I would have used the original drive gear with a shaft adaptor and the plate for the water jacket and shaft carrier would have been big enough for the whole motor base. But seeing as I couldn't find anyone that has did this it was a try this process. As far as how it works, it has no problem turning the diesel motor (it would probably turn it under compression when the pinion clutch is engaged)
to old-iron-habit More pictures
That is amazing
Interesting solution to a bad pony motor. Couple of question I have. When you say you believe it would turn the engine under compression. I assume you mean while starting the gas starter engine? Am I correct to assume that you go to compression on the main after you have it running. The other thing I note is that you no longer have any water running thru the main to warm it up for starting when cold out. A word of caution in that repeated use of ether is hard on piston tops on the diesel engine. Many of them have been pulled apart to reveal the piston edges broke between the top ring and the top of the piston. Just curious how you preheat the main. Compression will provide some heat while turning before you put the fuel to it. I suppose a tank heater or similar device would work if electric is available. A small water cooled gas engine would be awesume as a starter motor. Lots of food for thought here. Thanks for posting.
Yes I could start the gas engine while diesel is under compression, but I don't. I start it as if it had the original pony motor. As for the motor heat up the big key is I kept the starting motor exhaust going through the intake manifold. Fiqured if I went with electric start I wouldn't even have that. Used to have a JD 2010 backhoe that when the glow plugs would go bad I stuck my heat gun in the air intake to start it. I did make a home make ether injector for it, but because the starting motor turns the diesel over faster then the old one. I've only tried to start out with ether one time and it only took a wiff past the air cleaner and it started.
I don't see any mention of him using either to get the diesel started, or did I miss something? I do see where the exhaust from the "new pony" appears to be routed through the intake, like the original pony, so that will pre heat the intake air to the diesel just like Cat designed it. Heating the water would also help but this set up should do just fine in Virginia, maybe not so good in Moose Lake Minn!
You are correct Ken. He did not mention using ether. For some reason I was thinking Vermont. Virgina is certainly warmer. Not necessarily for the OP as he is probably very educated about his machine based on how it looks, but I just like to educate new folks to old Cats about the dangers of using much ether in these old engines. They last forever with a little care and proper starting and shutdown procedures. I really like the whole conversion and it looks to be very well done. I do believe that exhaust alone will not work in Moose Lake for at least part of the year.
Compression provides a LOT of heat, not sure how much you're losing with the loss of the water circulation but a couple more minutes at full compression should suffice to offset it. Compression heats the piston top directly, which is where you want heat for igniting the fuel charge. From an engineering standpoint I think CAT probably used water cooled ponies for compactness and efficiency as much as for circulation of hot water, though it probably helps a lot with thermal shock. But then when you fire off dead cold with ether or glow plugs on direct electric, it's dead plant freezing so.....
first off, i admire your ingenuity, i thought this out many ways and what it really takes is a fearless pioneer to make it happen. now my big question is... how do you keep the pony pinion clutch/40 tooth gear lubricated?
Two ways, I drilled, taped and installed a grease fitting in the original rear cover where the shaft sets in and installed a small oiler in the top of the guarding I made so that I can spray what they call opened gear lube on to the gears. The opened gear lube is very tacky and sticks to the gears.
i would like to see more pictures as my old pony exploded broke a connecting rod and piston and broke the block my email is [email protected] thanks
When you have a chance would you mind posting a video of your start up? I'd be very interested to see this ion operation!
The OP was last on here in 2016.
Welcome to HEF, D2 man !
Here is how we started a D7 that I have access to. It belongs to my deceased uncle...now to his children. They gave us permission to see if we could start it...it had been sitting for about 5-10 years at the time. It is still where we parked it 11 years ago after we got it running...have not had a reason, time or money to mess with it since. Although this year I started draining, dredging, and recovering our 70-year-old 20-acre pond and may need to use it to move all the dirt we are starting to dredge with our CAT 320C.
Didn't notice that!