Setting Valve Clearance

Depends on the engine and how it expands. Some close up when hot, some open up. That just depends on where the valves and cam shaft and rocker arm are anchored and what material holds them and they are made of. If the book says hot, you'll do best to do them hot.

You may not have to do them running, but I've done valves that way. Its possible, but a little messy, at least with an overhead valve engine.

Gerald J.
 
Looks like the answer is .022 but you'll find greater differences than .002 if you don't set the clearance at exactly 180 camshaft degrees from open.

In other words, check your valve clearances at other than one place in your engine rotation. Most folks believe that the clearance should be set at the 180 degree point from the wide open part of the camshaft. When I tried it there, I found another .010 of clearance when the flywheel rolled on further just a bit. So was I setting it to .030 or .020 by the book? I'm not sure, but I didn't like the valve clatter and set it tighter which got rid of the noise.

Another fellow chimed in once and said "me too on mine", I suspect that they are all this way, but not enough people care to shave these thousandths often enough to make it an issue or common aspect of valve setting, at least so far.
 
The very best practice is to set tappet clearance at combustion TDC. This is about a low-cam as you can get! (PatB)
 
Deere's recommended procedure for setting valve clearances when there is a chance of wear in the system, given in the owner's manuals, shop manuals, and Field Service Bulletins, is to turn the adjusting screw until a slight drag is felt when the push rod is rotated, then turn the adjusting screw out 1/3 turn which will provide 0.020 clearance. There are normally hex nuts involved, so 1/3 turn is two hex points. This process covers all wear in the tappet levers, tappet rod, cam gear wear, etc.. Using a feeler gauge can be particular problematic if the tappet levers have not been ground and have worn grooves in the heads - and this groove is masked by too wide a feeler gauge. This method is easy to do, and accomodates all wear in the system. Works fine for me.
 

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.

Back
Top