Welcome! Please use the navigational links to explore our website.
PartsASAP LogoCompany Logo (800) 853-2651

Shop Now

   Allis Chalmers Case Farmall IH Ford 8N,9N,2N Ford
   Ferguson John Deere Massey Ferguson Minn. Moline Oliver

Attention Forum Users: On the 28th of December 2023 at 9:00am Central Time, we will be taking the forums down for maintenance while we prepare the new forums for your use. Please click here for more information.

Discussion Forum
:

Dumb Question

Welcome Guest, Log in or Register
Author 
rooster in tenn

03-19-2002 17:49:34




Report to Moderator

This is a dumb question, but can someone please explain how you get a burnt valve? I have worked on a lot of tractors and have seen burnt valves, but I really don't know how it happens. Anybody's opinion would be helpful.
Rooster




[Log in to Reply]   [No Email]
Bryan

03-20-2002 07:06:30




Report to Moderator
 Re: Dumb Question in reply to rooster in tennessee, 03-19-2002 17:49:34  
Running too lean with a hard load for an extended period of time can burn a valve.



[Log in to Reply]  [No Email]
Ron

03-20-2002 04:56:58




Report to Moderator
 Re: Dumb Question in reply to rooster in tennessee, 03-19-2002 17:49:34  
I like to have valve spring tension a little on the "High" side, to be sure the valves don't "bounce", and to close them with a little more pressure.... A valve that leaks is subjected to a jet of fire that is like a Torch..!!! A seat of proper width , properly positioned, with good stems will give a "Perfect seal"... Then the valve COOLS against the seat, likt it is supposed to...Good valve rotators help, too...

[Log in to Reply]  [No Email]
G Taylor

03-19-2002 18:15:33




Report to Moderator
 Re: Dumb Question in reply to rooster in tennessee, 03-19-2002 17:49:34  
Too tight valve lash, extended max HP operation & detonation on spark ignition engines. The single largest cause is something that causes the valve/seat to be out of alignment. Bent valve stems, crooked valve jobs & the worst offender, worn valve guides. Common to have "Billy Bob Budget" come in with a head to be "rebuilt" and only the valves & seats are to be ground but no new guides/valves. He's back soon and mad with more burned valves as the wobbling ruined them again.

[Log in to Reply]  [No Email]
Bill from up north

03-19-2002 20:15:05




Report to Moderator
 Re: Re: Dumb Question in reply to G Taylor , 03-19-2002 18:15:33  
I agree with the others to a point - Sometimes it because the valve lash was too great, the valves and seats pounded out to wide and then a piece of carbon held up the valve and it burnt. If the seating surface of the seat is left too wide when grinding them ,then the impact of the valve on a loose piece of carbon is not great enough to break it up so it gets blown out the port. Also pulling an engine harder than it was designed for -ie: putting a pickup engine in a medium duty truck. the pickup engine won't have sodium valves and stellite seats and can't stand the heat generated-so the valves warp and then burn out the valves and often the seats too. I often have to do a two angle grind on even stellite seats to get the seat narrowed-up properly. Worn guides is not a good thing either. I changed 11 out of 24 on a set of heads the other day.

[Log in to Reply]  [No Email]
another doug

03-19-2002 18:14:28




Report to Moderator
 Re: Dumb Question in reply to rooster in tennessee, 03-19-2002 17:49:34  
burnt valves as i understand are caused when a valve does not close all the way, it cools(ever so slightly) when it contacts the valve seat(heat disipation) these parts run a dull cherry red at times when under load ,so when valve lash adjustment goes south ,and it doesn't allow valve to close and make contact for the short time that is allowed, then the heat stays in the metal and it burns,and the sealing capability of the valve is compromised, also a valve will warp if you shut off an engine that is HOT, so if you are plowing or mowing and too proud to drop it down a gear and lug your engine down and kill it, well you might get to see your engine apart very soon

[Log in to Reply]  [No Email]
Steven M

03-19-2002 18:14:19




Report to Moderator
 Re: Dumb Question in reply to rooster in tennessee, 03-19-2002 17:49:34  

I think that comes for carbon,getting between the valve and valve seat.The carbon gets so hot in that one place that the steel(valve) melts.



[Log in to Reply]  [No Email]
Tye

03-19-2002 18:00:08




Report to Moderator
 Re: Dumb Question in reply to rooster in tennessee, 03-19-2002 17:49:34  
I am not sure but maybe back fires can cause burnt valves.



[Log in to Reply]  [No Email]
[Options]  [Printer Friendly]  [Posting Help]  [Return to Forum]   [Log in to Reply]

Hop to:


TRACTOR PARTS TRACTOR MANUALS
We sell tractor parts!  We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]

Home  |  Forums


Copyright © 1997-2023 Yesterday's Tractor Co.

All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy

TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.

Yesterday's Tractors - Antique Tractor Headquarters

Website Accessibility Policy