Valves question

[Britcheflee]

Is it possible for the valve adjustment to move once set on an 8n? If valves need re-checking is it more likely they have become too loose or is there any way the gap could become smaller? What are typical symptoms of incorrectly adjusted valves on these tractors.

Thank you

Lee

 

[Dell (WA)]

Lee........you ask......."do valves need re-checking".......as a general rule, they seldom move and when they do the gap gitts NARROWER. Too narrow a gap on yer exhaust valve and you will BURN yer valve and loose compression. Too narrow on yer intake and it will "pop" thru the carb. But to answer yer original question, yes, valve gaps do change over time but usually they do not need re-adjusting after installation. Don't fergitt, there are 2-types of N-Engine valves. Early valves have "trumpet" ends and you actually haffta "grind" the end of the valve for clearance. Later 8N's have adjustable valve lifters and you need "knuckle-buster" wrenches to adjust them. Personally, I prefer blonde wrenches 'cuz I don't like to squeeze blackheads .......Dell, the wrencher

 

[TheOldHokie]

(quoted from post at 10:57:11 07/31/12) Lee........you ask......."do valves need re-checking".......as a general rule, they seldom move and when they do the gap gitts NARROWER. Too narrow a gap on yer exhaust valve and you will BURN yer valve and loose compression. Too narrow on yer intake and it will "pop" thru the carb. But to answer yer original question, yes, valve gaps do change over time but usually they do not need re-adjusting after installation. Don't fergitt, there are 2-types of N-Engine valves. Early valves have "trumpet" ends and you actually haffta "grind" the end of the valve for clearance. Later 8N's have adjustable valve lifters and you need "knuckle-buster" wrenches to adjust them. Personally, I prefer blonde wrenches 'cuz I don't like to squeeze blackheads .......Dell, the wrencher

Funny - I always thought the gap widened and they got noisy as the lifters/rockers/stems wore. That's why they are adjustable :idea:

TOH

 

[carolina don]

Yeah Dan.....we learn more about these tractors every day.Something special about how tractor valves work.Huh? don b

 

[carolina don]

If you have adjustable lifters...the adjusting screw threads may be worn and letting it back off.May need to check them and replace lifter if necessary. don b

 

[Roger in Iowa]

The gap gets narrower because the valve/valve seat area wears.

 

[TheOldHokie]

(quoted from post at 12:19:58 07/31/12) The gap gets narrower because the valve/valve seat area wears.

That's an interesting concept Roger and I am sure there is some slight face/seat wear. But valve seats often carbon up and don't fully close increasing valve lash. And which wears faster - valve seat/face or the face of the cam lobes/lifter/stem end? I have adjusted a lot of valves on many different vehicles when they started getting noisy because the lash was excessive. ABICR the only time I have ever seen the gap too narrow is when someone screwed up the adjustment.

TOH

 

[Hobo,NC]

(quoted from post at 20:41:30 07/31/12)

(quoted from post at 12:19:58 07/31/12) The gap gets narrower because the valve/valve seat area wears.

That's an interesting concept Roger and I am sure there is some slight face/seat wear. But valve seats often carbon up and don't fully close increasing valve lash. And which wears faster - valve seat/face or the face of the cam lobes/lifter/stem end? I have adjusted a lot of valves on many different vehicles when they started getting noisy because the lash was excessive. ABICR the only time I have ever seen the gap too narrow is when someone screwed up the adjustment.

TOH

I have seen it work both ways,,, I would say allot depends on if it has harden seats then it would depend on how hard they are... I would venture to say the more moving parts in the valve train the more apt you will find them lose... You will still find it both ways across the board on different engines...

 

[JMOR]

(quoted from post at 15:14:51 07/31/12)

(quoted from post at 20:41:30 07/31/12)

(quoted from post at 12:19:58 07/31/12) The gap gets narrower because the valve/valve seat area wears.

That's an interesting concept Roger and I am sure there is some slight face/seat wear. But valve seats often carbon up and don't fully close increasing valve lash. And which wears faster - valve seat/face or the face of the cam lobes/lifter/stem end? I have adjusted a lot of valves on many different vehicles when they started getting noisy because the lash was excessive. ABICR the only time I have ever seen the gap too narrow is when someone screwed up the adjustment.

TOH

I have seen it work both ways,,, I would say allot depends on if it has harden seats then it would depend on how hard they are... I would venture to say the more moving parts in the valve train the more apt you will find them lose... You will still find it both ways across the board on different engines...

n all the old Ford & Chevy OHV engines I have worked on they seemed to grow the gap, BUT two different Honda 200X ATCs, they would close up & eventually hold the valves open. Maybe something to do with aluminum or OHC or the large amount of moving parts in those old OHV engines.
By the sounds of my 8N right now, I say that its gaps have opened up.

 

[ZANE]

That is the correct answer!!!

Zane

 

[TheOldHokie]

(quoted from post at 17:55:56 07/31/12)

(quoted from post at 15:14:51 07/31/12)

(quoted from post at 20:41:30 07/31/12)

(quoted from post at 12:19:58 07/31/12) The gap gets narrower because the valve/valve seat area wears.

That's an interesting concept Roger and I am sure there is some slight face/seat wear. But valve seats often carbon up and don't fully close increasing valve lash. And which wears faster - valve seat/face or the face of the cam lobes/lifter/stem end? I have adjusted a lot of valves on many different vehicles when they started getting noisy because the lash was excessive. ABICR the only time I have ever seen the gap too narrow is when someone screwed up the adjustment.

TOH

I have seen it work both ways,,, I would say allot depends on if it has harden seats then it would depend on how hard they are... I would venture to say the more moving parts in the valve train the more apt you will find them lose... You will still find it both ways across the board on different engines...

n all the old Ford & Chevy OHV engines I have worked on they seemed to grow the gap, BUT two different Honda 200X ATCs, they would close up & eventually hold the valves open. Maybe something to do with aluminum or OHC or the large amount of moving parts in those old OHV engines.
By the sounds of my 8N right now, I say that its gaps have opened up.

Interesting - I did some research (Google is your friend) and it does seem that different vehicles/engine designs go different directions. Based on the comments/stories I found newish motorcycle engines seem to be prone to tightening for some reason and old pushrod OHV enginse seem to go the other way. I know my old Falcon and Triumphs required regular adjustment to keep them quiet as did my "modern" 73 OHC (8RC) Toyota. The 9N was a clatter box before I put in adjustable lifters and neither it or the "new" 8N have logged enough hours to judge how they will change. Since I sold that Toyota 35 years ago I don't think I have owned an OTR vehicle without hydraulic lifters. The longer I'm around the more I learn what I don't know ;-)

TOH

 

[HCooke]

My experience with 356 Porsches in the 70's. Valve
clearance needed to be adjusted every 6000 miles!
They always loosened up.

 

[Hobo,NC]

All the engines I have been into the used disk type adjuster I have never seen one get out of adjustment... I rebuilt the engine in my 93 yota cilica 250K the adjustment on the valves were dead nutzz.... I did not cut the seats are valves,,, I don't think I have anything that would cut the seats anyways they are that hard...

Engines that use disk,,, the disk rotates as the lobe enters it no hammer affects as with s-cre-w type lash adjusters...

 

[TheOldHokie]

(quoted from post at 21:46:29 07/31/12) All the engines I have been into the used disk type adjuster I have never seen one get out of adjustment... I rebuilt the engine in my 93 yota cilica 250K the adjustment on the valves were dead nutzz.... I did not cut the seats are valves,,, I don't think I have anything that would cut the seats anyways they are that hard...

Engines that use disk,,, the disk rotates as the lobe enters it no hammer affects as with s-cre-w type lash adjusters...

Yeah - my Celica 8RC engine used a screw type adjuster on the valve stem end and it required periodic tweaking. IIRC a solid foot on the other end of the rocker ran directly on the cam just like a lifter.

TOH

 

[gdstogner]

If adjusting bolts are loose could you use blue loctite after adjustig them.Thank you and have a blessed day.

 

[Hobo,NC]

(quoted from post at 18:24:37 08/01/12) If adjusting bolts are loose could you use blue loctite after adjustig them.Thank you and have a blessed day.

http://www.loctiteproducts.com/p/t_lkr_green/overview/Loctite-Threadlocker-Green-290.htm