1872 Refurbish/Command Swap

[mgonitzke]

This tractor was dragged onto the trailer and in no condition to run. One of my coworkers has a couple of supers and has also rebuilt one of the steering columns. I think that the noise is due to low charge pump pressure, but there may be something else. I'll ask him tomorrow.

 

[mpatterson]

Matt any insight on the charge pump?

 

[sblunier]

Charge pump pressure is easy to check via manual instructions....I would start there,....

 

[mgonitzke]

Getting a bit further. I finally got the super output shaft in the donor hydro unit, and all of the hydraulics reassembled. I removed the rear cover and cleaned all the gunk out of the transaxle, and also flushed all of the steel hydraulic lines out with mineral spirits. Almost ready to put Hytran in and pray it doesn't leak anywhere. I also finished modifying the 2000 series rear coupler for use on the Sundstrand hydro unit. This involved annealing the coupler, boring the taper in it to a straight 5/8" bore, then machining a couple flats on it and drilling the spirol pin hole. I didn't get the spirol pin hole aligned perfectly, but it's going to work. Engine is sitting in the tractor while I think about control cables, oil cooler installation, and a few other things.

 

[mpatterson]

Nice progress Matt! So you’re using a different engine for this project- what you need to different to cool it compared to Mag engine?

 

[mgonitzke]

Mike,

The Kohler Command (and basically every other newer V-twin engine) was subject to more strict emissions regs than the Magnum and previous engines were, so they have a fixed jet carb and run lean, which means they run hot. The heads also don't have a ton of cooling fins, so the engine is relying mostly on intake air charge and oil to cool the heads.

To accomplish this, the firewall needs an additional piece to close out the bottom of the frame such that when the foam seal between the flywheel shroud and firewall is installed, the flywheel can only suck cool air from behind the firewall. Without the firewall sealed off well, hot air can wrap around and heat the intake air, which lessens the cooling of the heads. A lot of people cut the air filter cover on these installations so that the cover can be removed, but this will cause the air filter to draw in hot air from the engine compartment instead of cool air from the flywheel inlet. I will either not cut the air cleaner cover and deal with removing the gas tank to service the air filter once a year, or make a new cover with a snorkel up to between the headlights to draw cool air from outside the tractor through the headlight panel.

I also bought an oil cooler for the larger Command engine that I am planning to install with a separate duct and a small electric fan to blow cool air through it. Most of the oil cooler installations I have seen on these engines are more of an oil heater, as they are just relying on passive cooling in a hot area of the engine compartment.

 

[mgonitzke]

Today I got the engine mounting holes drilled. The spacers were MIA with the original engine, so I bought some heavy-wall, 1/2" long bushings at ACE and slightly modified them. The OEM bushings are like 1/32" less than 1/2" long, and I haven't decided if that's going to matter or not. Both the Magnum and Command service manuals have some overall dimensions that were useful for locating the engine. I made a template to locate the new holes so that the PTO end face of the engine (and therefore PTO clutch) end up in the same location as with the Magnum engine. I also started working on the firewall extension, rebuilt the carburetor, and thought about the oil cooler installation a bit. I think I will just mount it the way it is supposed to be on the flywheel shroud (after cutting a hole so it gets air) and then maybe just adding a little duct to turn the airflow towards the front to encourage it to go out the front grille.

 

[kmcconaughey]

Matt, nice use of CAD (Cardboard Aided Design) there on the firewall.

 

[mgonitzke]

Thanks Kraig! About the only way to do something like that is to whittle away at a piece of cardboard for awhile

 

[slufkin]

Hey Matt, There is a way to add an adjustable Jet to that carburetor. Drill and tap a hole in the back of the carburetor where there is a welch plug now- just above the shutoff solenoid. Drill out your main jet a bit, then thread an adjuster into the tapped hole. Adjusters can be bought from any of the major GT Pulling vendors, or an old one laying around could work, just tap accordingly.

 

[mgonitzke]

Scott-

That is very interesting. I've got an adjustable jet for an old briggs carb laying around that would probably work. I may try to find a spare carb to try this on first so I don't screw up an otherwise functional one. Thanks for the tip!

 

[mgonitzke]

I went through several different ideas for a muffler since I am not a fan of paying $60+ for a used muffler or $280 for a new one, so, $25 new Surplus Center muffler, $13 mandrel bend, a short piece of 1" conduit, and three nights of cutting and welding later, I have a brand new muffler. I am going to put an 1/8" NPT bung in each exhaust pipe so I can temporarily install EGT probes and assess how lean this engine runs. I will probably try Scott's adjustable carb mod on a spare carb and use the EGT probes to see how much of an improvement I get. I also added a sender for an electric oil pressure gauge, in addition to the idiot light switch. I have replaced the ammeter and hourmeter with a voltmeter and oil pressure gauge, and the hourmeter is moving to under the hood somewhere. Next up is remote air cleaner installation and muffler shroud. Still a couple weeks away from being able to fire it up, but there is light at the end of the tunnel, I think

 

[mgonitzke]

Haven't posted an update in awhile. Tractor is wired, muffler heat shield made and painted. Since I installed a voltmeter in place of the ammeter and added an oil pressure gauge, the hourmeter got moved off of the dash.

Wiring is from scratch except for the oil pressure idiot light. I can't believe how many wires are in this thing. It looked so much simpler on the diagram. Waiting on a new Packard connector plug and a ground cable and I can install a battery.

I still need to finish cutting down the 2000 series driveshaft and weld the end back on so I can install that. First run attempt is scheduled for this weekend.

 

[mgonitzke]

Wrong wiring picture. I did not leave it in a rat's nest

 

[mgonitzke]

It's alive! I polished up all the paint and replaced a few of the decals. Looks a LOT better now.

Down to one leaky hydraulic connection from three (should be an easy fix, need to get the tractor out of the garage so I have some leverage to tighten it) and I need some hardware to finish the 3-point and I can start working on the 60" Haban. Grass is growing

Before all of this, installed the cut-down 2000 series driveshaft and finished up the air cleaner "snorkel". I need to run the tractor for a longer period, but it seems to be effective; the aluminum elbow just before the carb stays fairly cool to the touch.

 

[mpatterson]

Nice job Matt. I like it.

 

[kmcconaughey]

Matt, that turned out nice!

 

[wshytle]

Matt-

That's a big improvement over what we all saw on the trailer.

Nice Job!

.

 

[mgwin]

 

[aaytay]

Nice Referb Matt!

When you have some time, would you be willing to post some pics of that SGT axle reinforcement kit? I'm curious to see what it looks like installed.