High top dome Pistons

Wed Jun 23, 2004 4:46 pm

Hello all:
I rebuilt my tractor (57 lo-Boy) around two years ago.
We used High top dome pistons to increase the H.P.
I think that is what they are called. Anyway, I was wondering if anybody else here has rebuilt thier Cub with these? I did note a pretty big increase of power with my 42" woods mower. I can now mow up a steep grade in second gear, when previously could only do it in first. I did not run a compression test. Maybe someone else has?

Thu Jun 24, 2004 4:44 pm

Where did you find these pistons? It's a good Idea; however, they must have been adapted from another engine. As far as I know, IH didn't offer any other pistons for the C60 engine otherthan the standard flat top type.

Any problems with pre-ignition(Pinging)? What about timing? Do you have a magnito ignition?

Got them from I.H.

Thu Jun 24, 2004 7:46 pm

Dome-top aluminum pistons were introduced with engine number 264568
My cub # is 200691
It has been a few years, but as I recall, the head was also shaved down slightly, and also called for a Zenith carb.
I believe the H.P. is now around 12 H.P.
Google returned a hit on the ATIS board on this subject, but it seems the board is down now.

Fri Jun 25, 2004 3:20 am

Our local IH dealer did a rebuild on a cub using domed pistons.......he estimated an aprox. 5 Hp gain. I was also wandering about any problems from using them. Any noticed?

Fri Jun 25, 2004 5:38 am

I have not noticed any differance except an increase of power. I will do a compression test next week and let you know the results.

Fri Jun 25, 2004 10:46 pm

tdevery, speaking of compression......Where should a cub in good shape be compression wise? Did mine a few days ago.....124-124-124-124. is this average?

Sat Jun 26, 2004 9:15 am

splicer wrote:Did mine a few days ago.....124-124-124-124. is this average?

Splicer, I would say you could not hope for a better compression condition than what you have. :P

Tue Jun 29, 2004 9:16 pm

If you rebuild an engine you SHOULD notice an increase in HP even if you didn't use Domed pistons. :-)


Wed Jun 30, 2004 5:03 am

The same basic c 60 block was used in the numbered series lo-boy's. Domed pistons +

IH carb- 15 hp

Zenith carb- 18 hp

Dave H

Wed Jun 30, 2004 9:09 am

I am going to rebuild the C60 in my '55 lo-boy this winter. I plan on boring oversize and using the high-top aluminum pistons. I have a 3160 mower under this lo-boy and I need all the horsepower I can get. Is there anything special that needs to be done to the head or block to accomodate the change :?:

Sun Jul 04, 2004 7:42 pm

I had to use a die-grinder to get clearence for the domes on the pistons. However, the machine shop felt the head had been shaved sometime in the past, even thought it had standard bearinds and pistions in it. I ground it until the pistons just cleared with no gasket and then the gasket thickness added a little margin for error.