M18 and M20 engines...

[sblunier]

M18 oil pressure. There is a 1/16" MNPT tap right above the oil filter base, beside the dip stick, that should have an idiot light sensor installed in it with a 1/16" x 1/8" adapter. Idiot light goes on right around 5 psi. You can tee in an oil pressure sending unit (electric gauge) our use COPPER tubing to pipe in a mechanical gauge (don't use the nylon tubing on an air cooled, especially so close to the exhaust manifolds). Add a compression union near the fire wall to allow for future engine removal.

Cold oil will produce 50-65# oil pressure on my tractors (M18 and M20), very hot (summer mowing) the M18 holds 25-30 at WOT and 10-15 at idle...it's got a ton of hours on it.....M20 drops to 40 hot WOT and 20 at idle.

The oil lines and mag are worth it to get smooth vibration free power and full pressure lube to EVERYTHING.....

Bad Mag:

My loader with the M18 would start to fart and miss when hot, got really bad when I would load a trailer full of dirt and then come back 10 min later after dumping. Plenty of liquid gas at carb (not vapor locking) and iffy spark lead me to the coil replacement. Oil leak and need to split the case lead me to the accidental discovery of the burn piston. Isn't too bad, but I don;t feel like putting all of the effort into tearing it down without fixing it...it is all the way down to the first ring grove...

This is how I made sure the main governor shaft didn't back out on the last one I worked on...right or wrong, I drilled a hole for an 1/8" roll pin through the case and part way into the shaft. Left if long on the odd case I would ever have to pull it back out.

 

[wcompton]

That's a good move on the governor shaft. My 682 BLEW out that governor shaft (I thought I ruined the engine). Luckily I had a very low hour M18 on hand. I've still got that KT17SII engine, can't figure out whether to go through it or to assume this will be another Command swap in the future. For some reason the M20 seems like a totally different beast than the M18, strange that its only a little bit of stroke that is the only dimensional difference.

 

[wcompton]

The table of opposed twins and grease. I need to salvage spare parts and send the rest off to the recycler.

 

[jchamberlin]

Wyatt: Curious to know how you think the M18 and M20 are different. I've experienced the M18, how does it compare to the M20?

 

[sblunier]

M20 has LOTS more torque (when measured by the "butt dyno"). When you pull down a 20 hp she just barks and asks for more, 18 doesn't have the same "hit".

I have 2ea M18's, 1ea M20, 1 656cc Briggs 16hp twin, and a Kubota D600 Turbo.......

Haven't pulled the turbo'ed diesel hard enough to form an opinion......but right now, the M20 in the SGT frame is my "go to" for pure fun power!!!!!

And......that little "bark" from the governor when you hit a big drift with the blade moving snow with it brings a HUGE smile to your face!!!!!!

 

[wcompton]

I'd agree 100% with what Steve said about the M20. For an engine that's supposedly just a stroked version of the M18, you can really tell the difference. Additionally if you replace the Walbro with an older #26 or #30 carb you'll be in for a pleasant surprise. My 2072 has been my go-to power for well over a year now, it's really surprising how it just manhandles the Haban 60" deck I have under it. We'll see this spring how the CH20 in my IH782 stacks up against the M20 in the 2072.

Three years ago I was using a 169 as my "daily", now that I've stepped up to a 782 and 2072, both with 20hp engines and power steering, I don't miss that unbalanced rattletrap one bit!

 

[sblunier]

Unbalanced Rattle Trap......Amen......that K341 is BRUTE power.....but BRUTE also sums it up!!!!!!

Boxer twins are smoooooth power!

Dual hyd, power steering, 20hp Mag, long frame.......lots to LOVE about a 2072 (or a 2072 rebadged as a 982 "Special")!!!!

 

[sblunier]

My Red and black SGT's...

 

[mhomrighausen]

Steve B. Fancy says that he needs a plow like yours for HIS 782D. Very nice tractors and plow.

 

[wcompton]

Steve-
That 982 Special is what spurred on my "Super 72" project....
http://youtu.be/spWUd3Ky_ko

 

[wcompton]

 

[mhomrighausen]

Wyatt C. SIMPLY BEAUTIFUL!!!!

 

[shunt]

Wyatt,

You mentioned swapping a CH20 into a 782. Any special magic required to make this work? I'm considering a similar swap to replace the very abused and tired Series I KT17 in my 782.

 

[wcompton]

Steve-
So easy that if you leave it in the shop by itself it may start to put itself together.

Parts:
* Engine plate from a 1440, 1641, 1863, 1864, 1882, 2082, 2284 (any of the series, the engine plate is drilled for a Vanguard, Command, AND Kawi)
* Muffler and heat shield from a 1863, 1864, 1882, or 2082 - you'll need to trim back the exhaust tip and an inch off the forward edge of the heat shield
* You really could use any Command engine, however I may have accidentally used the easiest one, a CH18/CH20 from a 2186 or 2206 respectively.
* If you use the engine from the 2186 or 2206 grab the driveshaft too. I cut the driveshaft in half, the stock 782 driveshaft telescopes very nicely inside without play, simply drill a few holes and plug weld at a suitable length.
* Keyswitch, again, I got the 2186/2206 key switch (I can't remember exactly why, I'd have to refer to a wiring schematic why)

Finer points:
* Keep your engine spacers for under the engine's feet, you'll reuse them
* There will be a big gap between the "firewall" and the fan shroud. I still haven't addressed this, but will assume that I'll need some sort of automotive foam to fill the gap.
* To keep the stock air cleaner, cut the rearward-facing "wall" off the housing otherwise you'll have to take the fuel tank support out to get the air filter out.
* The PTO off the KT17, at least in my case, bolted right onto the Command engine.
* The oil drain will need to be addressed, I used a combination of pipe nipples and elbows and gave myself a drain plug just to the left of the PTO
* Remember that the oil pressure switch and the fuel shutoff solenoid need to be accounted for when wiring.
* You'll need to trim out one of the small black vertical bars from the grille to make room for the exhaust outlet.

Wiring; you'll need to make some sort of adapter harness, repin the stock harness, or make your own. I did the latter since I keep a supply of woven loom, 12ga wire, and Packard 56 (delphi) terminals. The latter of which are available from most good automotive parts stores or online at www.waytekwire.com.

 

[shunt]

Thanks for the info, Wyatt. Unfortunately I've tried the "just wait for the project to assemble itself" thing many times before with disappointing results.

I was counting on the motor plate and ignition switch changes, especially since I'd be going from a breaker point ignition to magneto fired. A little concerned about the driveshaft since I don't yet have a donor tractor but it doesn't sound insurmountable either.