mc cormick c

[D&Dservice]

Starting new project, mc cormick c, engine runs but boils over after running for short time, rad is clear with no obstructions, I am thinking head gasket or water pump, however there does not seem to be a water pump on this engine, but it does have a pressure cap, whats the deal is the pump in the timing case or is it just a convection circulation. engine runs good and does not seem to be burning any water, no steam or miss at startup. Thanks!

 

[Steven f/AZ]

The A, B, and C used a thermosiphon system... no water pump. It should not have a pressure cap, pressure in the system could be the cause of overheating.

 

[D&Dservice]

If i remove the cap completly would that answer the question if that was the problem?

 

[ScottyHOMeY]

A very few of the late Cs had water pumps that ran off a pulley at the bottom left below the timing cover, left side, as on the SuperCs. I don't expect that's your problem.

Other things I'd look at:

Timing off -- I have a SuperC and the only problem it's given me in this regard was the first time I worked it after the rebuild and I had the timing too hot.

Crud -- both 113/123 blocks I've rebuilt had a serious buildup of sediment in the head, the worst being a slow buildup from around #2 to being full to the top back behind #4. I had it apart anyway and scoured it out with a pressure washer and, in both cases, flushed it after the rebuild with a washing soda solution like the Owner's Manual suggests, and they've both been fine since.

Where is the vent on your radiator, above or below the gasket on the cap? If below, and you're confident that the radiator is clean, that won't be your problem.

What are you running for coolant?

 

[El Toro]

I would double check that timing, but you may have a buildup of dirt and rust around those sleeves. Hal

 

[ScottyHOMeY]

It might, IF your cap is sealing the system below the overflow. On the thermosiphons the sytem was open. The radiator cap was just like the gas cap (Never tried it, but I think they would interchange, or at least look like they would!) and sealed against the top of the opening, leaving the overflow, which was below that, to vent any pressure (any pressure at all).

Start with your cap and work backwards.

And just thinking of oddball things, the front of your radiator and grille are clean? And you don't have anything like radiator shutters that might be closed? Or stuck closed even if the lever looks like they might be open?

 

[ScottyHOMeY]

The crud I made reference to was in the block behind the sleeves, like Hal said, and in my experience from #2 back to #4, not in the head.

Thanks, Hal.

Gittin' laaaaate. Time fer bed!!

 

[D&Dservice]

no external obstructions that i can find, I have the sheetmetal off the front, there are no shutters on the tractor, i have used it off and on over the past few years on a sickle mower, It has worked fine until this spring, then it started this problem. It has glycol coolant in it and it is good to -20, Timing may be an issue but as far as i know nobody has had the mag off. I should have given more history in my first post. this tractor has not been dissasembled and has been used lighly every year

 

[Will Sick]

Is the fan belt tight enough to turn the fan?

 

[ScottyHOMeY]

If there's no water pump, it couldn't hurt to pull the elbow on top and make sure nobody tried to put a thermostat in there that might be stickkng on you.

Also lube your mag through the forward oil cap. If the impulse coupler in the mag is sticking, it could screw up your spark timing and make her run hot. Drop some light oil (like 3-in-1) in there and let it sit and dump some more in after you next start it up. Worst case (not all THAT bad) would be the owner's manual procedure for pulling the mag, flushing the impulse coupler with kerosene and resetting and retiming the mag, if that turns out to be the problem.

If that coupler has just got dirty or dry and stuck, it might very well be your problem

 

[James Williams]

CLEAN THE FINS IN THE RADIATOR WITH A WATER HOSE OR AIR

JIMMY

 

[D&Dservice]

thanks for the info, I will try checking the mag, that sounds most likely since it has done fine in the past if that does not help i will pull the head, maybe it has gotten crud settling.

The fan belt is tight and I can see through the radiator from top to bottom, Thanks for the replies

 

[dave guest]

Fellow told me to run straight H20(water) for better heat transfer and cooling. Tight belt. No pressure cap. Don't fill up to top, down about 2". Radiator clean inside and out. Most cannot hold hand on radiator when working hard.