This site is not affiliated with AGCO Inc., Duluth GA., Allis-Chalmers Co., Milwaukee, WI., or any surviving or related corporate entity. All trademarks remain the property of their respective owners. All information presented herein should be considered the result of an un-moderated public forum with no responsibility for its accuracy or usability assumed by the users and sponsors of this site or any corporate entity.
The Forum Parts and Services Unofficial Allis Store Tractor Shows Serial Numbers History
Forum Home Forum Home > Allis Chalmers > Farm Equipment
  New Posts New Posts
  FAQ FAQ  Forum Search   Events   Register Register  Login Login


XT Valve lash results may we
 Post Reply Post Reply
Author
Message
  Topic Search Topic Search  Topic Options Topic Options
captaindana View Drop Down
Orange Level
Orange Level


Joined: 14 Sep 2009
Location: Fort Plain, NY
Points: 2373 		Post Options Post Options   Thanks (0) Thanks(0)   Quote captaindana Quote  Post ReplyReply Direct Link To This Post Topic: XT Valve lash results may we
    Posted: 10 Mar 2012 at 5:32am
discuss my findings from yesterday? The engine was not up to operating temp. It was 35* in the pole barn shade. Cyls 1 through 5 all had exhaust valves which measured from .018 at the narrowest to .027 for the worst which was cyl #1. Cyl 6 specked .016 on both valves and every other intake valve specked .016. So what do these 5 exhaust valves have in common? If some carbon/rust/junk/fod was in their seats causing them to not fully seat I believe when I got there and measured the lash the measurement would read as I found...too wide, correct? Also if the five exhaust valves were not fully seating my compression would be low. The other day when I was compression testing cyl#1 which had shown 300 psi the previous day showed about zero. That is why I took the gauge to be caliberated. But now that I found it's exhaust valve had .027 clearance to the tappett I do believe it must have been not seating, correct? Yesterday before I adjusted any tappets after the initial measurement I would pry the valves down quite far and let them spring back quickly trying to dislodge anything which may have been in their seats. I believe as I progressed in sequencing I could hear the increased compression as I bumped the starter. Any input is greatly appreciated guys. I am learning and I love it!!! Thanks, Dana
Back to Top
Sponsored Links


Back to Top
MACK View Drop Down
Orange Level
Orange Level


Joined: 17 Nov 2009
Points: 7664 		Post Options Post Options   Thanks (0) Thanks(0)   Quote MACK Quote  Post ReplyReply Direct Link To This Post Posted: 10 Mar 2012 at 7:11am
.018 is about right cold.  MACK
Back to Top
skipwelte View Drop Down
Orange Level
Orange Level


Joined: 29 Oct 2009
Location: Anthon, Iowa
Points: 723 		Post Options Post Options   Thanks (0) Thanks(0)   Quote skipwelte Quote  Post ReplyReply Direct Link To This Post Posted: 10 Mar 2012 at 8:43am
Warm it up real good,  set the lash at what ever the spec is hot then use it as hard as you can.  You may just have worn parts causing excessive lash.    Valve lash should be adjusted every couple thousand hours, nobody probably did, now is a good time to level the field.  Good luck.

Edited by skipwelte - 10 Mar 2012 at 8:44am
Back to Top
Gerald J. View Drop Down
Orange Level
Orange Level


Joined: 12 Sep 2009
Location: Hamilton Co, IA
Points: 5636 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Gerald J. Quote  Post ReplyReply Direct Link To This Post Posted: 10 Mar 2012 at 10:10am
Banging the valve closed with the spring may feel good but its not going to nearly as effective at crunching carbon deposits as working the engine hard.

The spring probably has 120 pounds force with the valve closed. Combustion pressure is probably more like 1500 psi in a diesel, spread over the about 3 square inches of a 2" diameter valve makes 4500 pounds on the valve head to make it close. Then when the valve lifts for exhaust there's a bunch of combustion product flow to blow the crunched crud out.

Gerald J.
Back to Top
BrettPhillips View Drop Down
Orange Level
Orange Level
Avatar

Joined: 11 Sep 2009
Location: Strasburg, VA
Points: 808 		Post Options Post Options   Thanks (0) Thanks(0)   Quote BrettPhillips Quote  Post ReplyReply Direct Link To This Post Posted: 10 Mar 2012 at 5:56pm

Originally posted by skipwelte skipwelte wrote:

Warm it up real good,  set the lash at what ever the spec is hot then use it as hard as you can.  You may just have worn parts causing excessive lash.    Valve lash should be adjusted every couple thousand hours, nobody probably did, now is a good time to level the field.  Good luck.


I'll second that.  Warm it up, check the valve clearances, then warm it up again gently and thrash it as hard as you dare for an hour or more, then gently cool it down afterward.  If the symptoms persist after that, you may be in need of a valve job or ???
Back to Top
 Post Reply Post Reply
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 11.10
Copyright ©2001-2017 Web Wiz Ltd.

This page was generated in 0.055 seconds.


Help Support the
Unofficial Allis Forum