Only Cub Cadets

PLEASE PATRONIZE OUR SPONSORS!

CC Speciaalties R. F. Houtz and Sons

Patton Acres IH Cub Cadet Parts

Cub Cadet Parts & Service


If you would like to help maintain this site & enhance it, feel free to donate whatever amount you would like to!




Attention Folks we have a new owner!
Greg Rozar AKA- CubDieselFan


Go Back   Only Cub Cadets > Cub Cadets > Cub Cadet Engines > Kohler Engines

Notices

Reply
 
Thread Tools Display Modes
  #1  
Old 08-22-2021, 04:27 PM
RustyShackleford's Avatar
RustyShackleford RustyShackleford is offline
Senior Member
 
Join Date: Dec 2020
Location: CA
Posts: 140
Default Piston/Bore Clearance - K241

Hi all,

Back with another engine question. I’m rebuilding a K241 and am using a NOS piston, style A specifically. When I dropped it all off at the machinist I brought the Kohler rebuild manual, but read it incorrectly when I told him what clearance to go with. The manual lists one clearance for the K91 (3.5-6 thou) and 7-10 thou for all the other K-series engines. Well, in my rush to get it all dropped off I mistook the K91 clearance for what I needed, and ended up with about 4 thousands clearance (measured with a feeler gauge).

Now, obviously I need to have that widened up some. My question is, I have read on here (from J-Mech, I believe) that he usually shoots for 5 thousands clearance on Kohler K’s. That’s not spec, so I just want to verify…should I stick with the Kohler rebuild manual recommendation of 7-10, or is 5 better for some reason? And if so, why?

Thank you!
__________________
102
Reply With Quote
  #2  
Old 08-22-2021, 06:03 PM
ol'George's Avatar
ol'George ol'George is offline
Grand Member
 
Join Date: Oct 2009
Location: MI
Posts: 6,610
Default

Put that feeler gauge away and use a dial bore gauge or at least a mike with telescoping gauge.
Better yet, take it to the machinist that did the work, if you don't have the precision tools.

You just might find you have the correct clearance.
Guessing is not what you want to do.
Reply With Quote
  #3  
Old 08-22-2021, 06:17 PM
RustyShackleford's Avatar
RustyShackleford RustyShackleford is offline
Senior Member
 
Join Date: Dec 2020
Location: CA
Posts: 140
Default

Will do! I’ve read conflicting things on using feeler gauges before. Some say they do it, others say to never do it. Figured it’s better’n nothin’. I was planning on taking it into the machinist tomorrow either way, so I’ll have him check it out.

At least it’s not too loose!
__________________
102
Reply With Quote
  #4  
Old 08-22-2021, 06:37 PM
finsruskw finsruskw is offline
Grand Member
 
Join Date: Mar 2013
Location: Iowa
Posts: 2,984
Default

You are going to put an NOS piston in a hole that has not been bored??
In effect a worn cylinder bore.

Best to let your machinist tell you whether that is a good idea or not.
My guess is that he will advise against that depending on his findings as to the taper and/or out of round current bore.

May I ask as to just why you are considering that?
To save a buck or two?
Reply With Quote
  #5  
Old 08-22-2021, 07:47 PM
Billy-O's Avatar
Billy-O Billy-O is offline
Grand Member
 
Join Date: Jul 2012
Location: New Jersey
Posts: 1,752
Default

Quote:
Originally Posted by RustyShackleford View Post
Will do! I’ve read conflicting things on using feeler gauges before. Some say they do it, others say to never do it. Figured it’s better’n nothin’. I was planning on taking it into the machinist tomorrow either way, so I’ll have him check it out.

At least it’s not too loose!
I agree with ol'George.... Another thing about pistons is that it is often slightly barrel shaped at the skirt... That would make the using the feeler gauges difficult and inaccurate.
__________________
Two 125's and a 124 all with 42" decks
Plow blade
#2 Cart
QA36 snowthower
Reply With Quote
  #6  
Old 08-22-2021, 10:56 PM
RustyShackleford's Avatar
RustyShackleford RustyShackleford is offline
Senior Member
 
Join Date: Dec 2020
Location: CA
Posts: 140
Default

Quote:
Originally Posted by finsruskw View Post
You are going to put an NOS piston in a hole that has not been bored??
In effect a worn cylinder bore.

Best to let your machinist tell you whether that is a good idea or not.
My guess is that he will advise against that depending on his findings as to the taper and/or out of round current bore.

May I ask as to just why you are considering that?
To save a buck or two?
Sorry I should have been clearer. The block was gone through already. Bored & honed, valve seats ground and valves lapped, and all that. I was just mistaken in telling the machinist the wrong piston/bore clearance to use. Totally my mistake. I actually have darn near NOS everything for this rebuild, even a NOS crank! Just want to make sure it’s all as “correct” as it can be while I’m rebuilding it. Part of the fun, I suppose. I’ll actually be taking your advice from an older thread where you suggested cutting a 1” nipple in half and welding it onto the exhaust elbow in place of the worn out threads that are currently on the elbow. Hoping it will work nicely!
Quote:
Originally Posted by Billy-O View Post
I agree with ol'George.... Another thing about pistons is that it is often slightly barrel shaped at the skirt... That would make the using the feeler gauges difficult and inaccurate.
Gotcha, that makes sense.

Thank you guys! I appreciate the help, as usual
__________________
102
Reply With Quote
  #7  
Old 08-23-2021, 08:08 AM
RustyShackleford's Avatar
RustyShackleford RustyShackleford is offline
Senior Member
 
Join Date: Dec 2020
Location: CA
Posts: 140
Default

I’ll be taking it by the machinist’s place after work today, hopefully. Should we shoot for .007-.010 clearance as per the manual?
__________________
102
Reply With Quote
  #8  
Old 08-23-2021, 08:23 AM
ol'George's Avatar
ol'George ol'George is offline
Grand Member
 
Join Date: Oct 2009
Location: MI
Posts: 6,610
Default

Quote:
Originally Posted by RustyShackleford View Post
I’ll be taking it by the machinist’s place after work today, hopefully. Should we shoot for .007-.010 clearance as per the manual?
Most engines of that bore size use less than 1/2 of that clearance, of course it depends where one measures the piston.
I prefer to measure the piston skirt at right angle to the pin, and below the pin at the biggest part of the skirt.
If one truly has .007-.010 measured in that situation, it will rattle like a marble in a bottle.
Reply With Quote
  #9  
Old 08-23-2021, 10:29 AM
RustyShackleford's Avatar
RustyShackleford RustyShackleford is offline
Senior Member
 
Join Date: Dec 2020
Location: CA
Posts: 140
Default

Quote:
Originally Posted by ol'George View Post
Most engines of that bore size use less than 1/2 of that clearance, of course it depends where one measures the piston.
I prefer to measure the piston skirt at right angle to the pin, and below the pin at the biggest part of the skirt.
If one truly has .007-.010 measured in that situation, it will rattle like a marble in a bottle.
I was thinking the same, but...all of the Kohler manuals say .007-.010? Perhaps these old Style A pistons really expand that much when they run? I would hate to lock up a shiny "new" engine

I certainly trust the collective experience of everyone on here - amd I do find it odd that Kohler would spec such a loose tolerance. Maybe these engines just run stinkin' hot

Edit: Here is the post/thread I was referring to regarding reading on here about using feeler gauges: https://www.onlycubcadets.net/forum/...d.php?p=464530
__________________
102
Reply With Quote
  #10  
Old 09-24-2021, 01:42 PM
RustyShackleford's Avatar
RustyShackleford RustyShackleford is offline
Senior Member
 
Join Date: Dec 2020
Location: CA
Posts: 140
Default

I had the machinist widen the bore just a hair to hit .007 clearance, since this is what every Kohler manual and resource says to go with, as well as Norman over at iSaveTractors (who was very helpful via email, by the way).

All well and good, until I go to check the piston ring end gap last night...and find that the top ring has a .022 gap and the second ring has .021. Spec is .010-.020 for new bores, up to .030 for used bores. Dang! Not sure what the deal is. Using a Kohler piston and Kohler rings.

At this point, it seems like the only options would be
  • Buy another set of STD rings and see if the gaps are a little tighter
  • Buy a .010 over piston/ring set and try again (yuck)
  • Slap it together and run'er

At this point, I am leaning towards option 3, and don't think I could stomach option 2

Edit: Quick update, I emailed Norman again asking him what his thoughts were. He suggested trying another ring set, so I figured what the heck. Ordered a set of rings from him. We shall see what the gap is like once they arrive. Worst case, I have an extra set of rings, and Norm has a few bucks in return for his advice
__________________
102
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 01:14 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.

Cub Cadet is a premium line of outdoor power equipment, established in 1961 as part of International Harvester. During the 1960s, IH initiated an entirely new line of lawn and garden equipment aimed at the owners rural homes with large yards and private gardens. There were a wide variety of Cub Cadet branded and after-market attachments available; including mowers, blades, snow blowers, front loaders, plows, carts, etc. Cub Cadet advertising at that time harped on their thorough testing by "boys - acknowledged by many as the world's worst destructive force!". Cub Cadets became known for their dependability and rugged construction.

MTD Products, Inc. of Cleveland, Ohio purchased the Cub Cadet brand from International Harvester in 1981. Cub Cadet was held as a wholly owned subsidiary for many years following this acquisition, which allowed them to operate independently. Recently, MTD has taken a more aggressive role and integrated Cub Cadet into its other lines of power equipment.

This website and forum are not affiliated with or sponsored by MTD Products Inc, which owns the CUB CADET trademarks. It is not an official MTD Products Inc, website, and MTD Products Inc, is not responsible for any of its content. The official MTD Products Inc, website can be found at: http://www.mtdproducts.com. The information and opinions expressed on this website are the responsibility of the website's owner and/or it's members, and do not represent the opinions of MTD Products Inc. IH, INTERNATIONAL HARVESTER are registered trademark of CNH America LLC

All material, images, and graphics from this site are the property of www.onlycubcadets.net. Any unauthorized use, reproductions, or duplications are prohibited unless solely expressed in writing.

Cub Cadet, Cub, Cadet, IH, MTD, Parts, Tractors, Tractor, International Harvester, Lawn, Garden, Lawn Mower, Kohler, garden tractor equipment, lawn garden tractors, antique garden tractors, garden tractor, PTO, parts, online, Original, 70, 71, 72, 73, 76, SO76, 80, 81, 86, 100, 102, 104, 105, 106, 107, 108,109, 122, 123, 124, 125, 126, 127, 128, 129, 147, 149, 169, 182, 282, 382, 482, 580, 582, 582 Special, 680, 682, 782, 782D, 784, 800, 805, 882, 982, 984, 986, 1000, 1015, 1100, 1105, 1110, 1200, 1250, 1282, 1450, 1512, 1604, 1605, 1606, 1610, 1615, 1620, 1650, 1710, 1711, 1712, 1806, 1810, 1811, 1812, 1912, 1914.