Jump to content

Unofficial Home of Old Simplicity & Allis-Chalmers Garden Tractors

  • Announcements

    • Kent

      Sign In or Password Problems?   10/09/2016

      If you can't Sign In, you need to reset your password.  Use the Forgot Your Password link at the bottom of the Sign In screen, and the site will send you an email to reset it. If you have an AOL email account, use the Contact Us link at the bottom of the screen -- AOL is intermittently blocking email from the site.
    • Kent

      Feedback Please!   10/28/2017

      See News and Announcements forum.
Sign in to follow this  
StinKy

Kohler bore

Recommended Posts

StinKy
Why is .030 the largest oversize bore Kohler allows in it's K series cast iron engines? What possible harm can an extra .010 (.040 over) do to the cylinder? Can aftermarket pistons be bought in .040 over? Thanks for any and all answers. Dick

Share this post


Link to post
Share on other sites
HubbardRA
The overbore size has to do with two things. 1.) Engine balance. As the bore gets larger the piston gets heavier. The crank must then be re-balanced to compensate or the engine will suffer from tremendous vibration. 2.) Overheating. Larger pistons mean more displacement and higher compression, resulting in more heat. The cooling fins and fan are not designed for this. A friend of mine used to build pro stock pulling tractors, and he would bore a 16 Hp Kohler approximately .180 oversize. He had the engines re-balanced and they were not run continuously for any long periods of time.

Share this post


Link to post
Share on other sites
Guest
This topic is now closed to further replies.
Sign in to follow this  

×