Marc Arnold GRAY 12hp Engine
Marc Arnold's GRAY 12hp Engine
I would appreciate some help on an engine I just aquired.
It is a twelve horse GRAY. I would like some help with getting
pictures of some things that are missing and broken, so that
I can get them fixed and this engine doing it's thing again.
I recently purchased the engine in Quebec, it had been outside
during a rather impressive ice storm about nine years ago.
The storm was so massive that many parts of Quebec didn't
get power back for many weeks, the military had to go in to
help out. Emergency workers and gas and electric workers
brought in from many different provinces to work.Any way the
engine took a bit of a beating and got bombarded by massive
chunks of ice resulting in a broken carb, mag trip arm and
mag bracket,and three cracked flywheel spokes.
Any info would be greatly appreciated.
UPDATE from Marc - Sept 2008
Hello there - Here are some pics of the engine. I have it listed on Engine Ads at $4000.00,
but as always that's "or best offer". I've had it running probably a total of three or four hours
and it seemed to work Ok... thats when I think it must have picked up something from the tank,
as it started to act like it was out of fuel.. runs fine on the primer bowl, but spits and coughs off of the
tank...gotta probably clean out the check valve. When this engine hits, it hits hard, that's why I had to
put on the muffler... still not quiet but it was actually so loud you couldn't stand near it.
6- 3/4" bore x 13-1/2" stroke.. thats 482-3/4 cubic inches. It was stuck when I got it, pressed out piston.
Two rings out of the four broke coming off. Oddball size rings, turned two of the ring grooves bigger
and put in two sets of two new rings back to back in those grooves and two originals back in the
other two grooves. Honed out cylinder, still a little pitting in a few places but it had stuck basically
in the middle so the little pitting isn't really where the rings even ride. And there is so much
compression you can stand on the flywheels and it will not go over compression, thats why I put
the starter pup on the back. You start the Clinton, go up front, hold the intake open, pull the lever, & the
Clinton's rubber tire rolls on the flywheel, and once she gets rolling, release intake and Bob's your uncle.
I cut the valve seats and gave it new valves, (John Deere AR valves are the same size just too long).
There was a freeze crack down the cylinder and across the head, bronzed those and then JB weld for
body filler. Looks ok, hard to get a shot of that because of where it is sitting.That break is on the
opposite side to the mag. Had to make a new air control poppet for the carb.The large timing gear
has at some time been broken and a plate riveted into it, but works fine.This poor engine went
through the Quebec ice storm about ten years ago sitting outside and was hit by a large amount of
falling ice which broke lots of parts. I have repaired or have had repaired lots of the castings.
All of these now look good but I like letting people know these things. I have brazed the governor
weights where the little tabs had broken off, the the governor slide collar & the mag braket.
The flywheels were sent out to be repaired by an industrial cold casting repair facilicty that specializes
in this.They table the wheel, and then going across the crack every 3/4 of an inch or so they machine
out what looks like a a path way of dog bones laid end to end. Then they press fit in keys of the same
shape about 2 thousandths larger for an interference fit and then all along the crack they machine out
and thread and tighten in rod. All of these materials are made of some fancy alloy of rediculous strength.
They then chuck it in the lathe and if need be, bore and sleeve it to make it runs true. None governor side
had to be sleeved, governor side didn't, but the key slot had to be broached oversize so I had to shim the
key afterwords.Very interesting process, works great---not cheap. I'm located about an hour from the
Niagara Falls / New York border and about 2-1/2 hours from the Sarni / Michigan border.
Any other questions, just contact me.
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