Pony cooling system on D2 5J

Hi Jack,
Ain't that easy...never is😄
The connecting passage is at the bottom rear of the sump but it has two or three 90 deg. turns so direct access doesn't work............and that's one of the candidate places that plugs up. Usually takes a combination of air blast and mechanical cleaning. I use 1/4 inch cable, brazed near the end so it splays out into a wire brush but you sill can't go through the connecting passage. Both head removal is a must. Worst ones require chemical dip.

Thanks O.M. I was afraid it would look something like that.😮 Guess I'll wait for warmer weather and then spread the pieces all over the shop.

Jack

You may have some restiction in pony but it is cooled by thermo movement and that cant happen til it gets pretty warm. I hope you dont think that the water from pony circulating thru the main engine is what warms it up because thats not what happens there is no circulation between motors except what is done thermoly the main thermostat is close the water pump is not circulating water. The warming of main is created by turning over under compression and the pony exaust going thru the main intake warming the air going tru the main.

It's more an observation of the pony getting hot and the diesel head next to it not warming up as it used to, like I don't think the pony is being cooled much. I can start the diesel but it is a lot cooler at the back of the head than was it's custom. It's more like starting with an electric starter in cold weather now. Let it blow a lot of smoke and shoot in the ether. It runs good, starts OK, but I never used that much ether before and don't like to.

And don't kid yourself. The heat exchange isn't the whole story but it helps, just like turning a space heater onto the side of the engine helps. It's all about heat, wherever you can get it.

Jack

Ive found crud setles in the pony and also blocks the passage under it to the main engine ive ended up removing the pony , then taking the heads off and using a jet wash to clean it out, you may get away with just taking the heads of and giving it a blast out , when its circulating corectly the pony runs cool and the heat transfers to the main engine, hope this helps............

Do I understand you, the passage from RH to LH is the space between the pony crankcase and the top of the main clutch bell housing? I've looked at every picture of a pony I could scrape up and havn't seen one of the bottom of the pony block. I assumed that there was a passage cast into the block across the front or back of the crankcase. Maybe I assumed wrong?😕

The up side is that I've had good luck with pony motors, have never had to remove one in last 39 years.😊 😊 😊

Jack

Hi Jack,
The passage from left to right is internal to the pony block casting. If you flip it upside down you can't see it....all you see is the connecting hole between the block and the bellhousing. You have to look in the sump to see the route of the casting/passage. You can see one of the openings if you look down the cooling water passages from the head on the LH side but it is a 90 degree turn at the inlet and appears to be a couple more 90 degree turns internally. What you can see from the bottom is a welch (casting) plug that intersects the main passage.

I did leave out......connecting that cable gizmo to a variable speed drill in my original post.

OK, that sounds more like what I immagined it to be, except I never dreamed there would be so many twists and turns. So if I can see the entry port through the head water openings, maybe I can get a tube into it with air or water to flush it out? I pretty well know what I'm up against now, but I'm going to wait for warmer weather because this is going to be messy; I'd rather do it out of the shop.

I like the idea of twisting the cable splayed out on the end. I'll remember that one, could have used it on other things times past. I use a speedometer cable that way a lot for fuel lines, but they unravel if you try to splay them.

Thanks, O.M. and others. I get more good info from you than you will ever know just reading other folk's threads. When you run a tractor that's older than I am, you need all the help you can get.😉

Jack

I'll take another look at my empty block again in the am.....I'm thinking if you back flush while the thing is mounted you'd dump the crud into the main engine passage. More later🙄 🙄