Head Milling for a little more power out of a C-60 Engine

[b52c130]

Got a little more power out of the C-60 engine by shaving .085" off the head.

This is a C-60 engine installed in a Loboy 184. Later model engine with aluminum dome topped pistons.

Removed head and measured piston dome to head clearance of approximately .120" using balled up aluminum foil to crush as the piston was manually run threw top dead center. Valve clearance was so great that it did not needed to be measured. Had machine shop remove .085" from the head.

Got new Grade 8 head bolts from an on-line hardware store (About $10 -$15) and installed newly milled head using Teflon plumbers pipe dope on the head bolt threads.

By the SOP (Seat of Pants) dynometer, the tractor seems to have more power than before. Total cost was between $100 and $125.

The only other adjustment that needed to be done was that the idle mixture screw had to be made a little richer after the compression was increased.

This was done to a 184 tractor running at 7,300 foot elevation in Colorado. Since the air is so thin at only 11 PSI verses 14.2 PSI at sea level, this change certainly wouldn't overtax the design limits for the engine.

Just thought that I would pass the results along to anyone on the forum that might be interested. NJDale

[Bob McCarty]

Where in Colorado?

Bob

[beaconlight]

There was a high altitude modification of a Cub. Guess you did one for a number series.

[b52c130]

Bob,
In Aspen Park, one of the 'Homestead' subdivisions.
Dale

[b52c130]

Bill,
Yes, there was supposedly a different head number offered for the 'flat-top' cast iron piston engine - good luck on ever trying to find that head in the 'used' market place. No 'high-altitude' head number was ever offered for the aluminum dome topped engine (as far as I can tell).

At the 7,300 feet elevation the C60 is very anemic; of course the engine needs a ring and bearing job, but that is a 'next year' project.

Thanks, Dale

[BigBill]

I also notice with these tractors sitting for long peroids of time the valve guides can get dry along with the piston rings sticking. This can suck gobs of power from a good engine. I run seafoam and high test gas and after one tank full the rpm is much higher at an idle. This tells me the engine is happy, happy with the seafoam treatment. They respond much better too.