All valve systems change dimensions as the temperature of the engine goes from ambient, to full running temp. As this happens, the metal of the engine changes size with temp. (hot bigger, cold smaller) Not all metal changes at the same rate in inches per inch per degree. The valve is made from very different metal than the head. The pushrod and valve rocker are also different. The result is that the valve train expands with heat farther than the head and block. This engine has mechanical valve mechanism that is different than those found in new cars in that those have automatic adjusters which keep the clearance correct. Your tractor has "looseness" that is designed into the system to allow correct operation. This looseness is the clearance. The clearance is more when the valves and engine are cold. The Two ways of setting the valves are when it is cold, and when it is well warmed up. To get it warmed up, and then remove the valve cover and adjust them (while toasting your fingers/hands/and tools) is more difficult, and is usually not done except at repairs that also require the removal of the head. Adjusting cold is a bit less accurate, but no real problem. Setting clearance cold is done as follows: A feeler gauge (a multi-blade tool with 2.5 inch long "feelers" that are in different thicknesses, measured in thousandths of an inch (or mm if Metric) There will be 15 to 25 blades in the tool. The measurement is between the rocker arm and the butt end of the valve. (Adj. Gap in illustration). This gap can have wear between the tip of the valve, and the rocker arm tip. this wear can interfere with correct reading of the clearance if the rocker is cup shaped. Look carefully at a rocker tip to assure it is not grooved. If grooved, it will be necessary to have the tips reground at an auto machine shop. The positioning of the valves is as described in the post. The feel on the feeler gauge is judged good when the gauge has a slight resistance to removal, but is easily inserted. Be careful to keep the feeler flat on the valve butt. The lobe of the cam in the illustration is pointing away from the lifter. This is the position ov adjustment. You cannot see the cam at all, so looking at the opposite valve as directed in the former post is the idea. A valve is open when the lobe pushes all parts and compresses the spring. When it is closed, it is up, and the pushrod is looseish. If this is insufficient instruction, you will need to feed a mechanic about 1/2 pound of steak, and a bottle of 25 dollar Scotch. Jim
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 ]
Today's Featured Article - The Cletrac General GG and the BF Avery A - A Bit of History - by Mike Ballash. This article is a summary of what I have gathered up from various sources on the Gletrac General GG and the B. F. Avery model A tractors. I am quite sure that most of it is accurate. The General GG was made by the Cleveland Tractor Company (Cletrac) of Cleveland, Ohio. Originally the company was called the Cleveland Motor Plow Company which began in 1912, then the Cleveland Tractor Company (1917) and finally Cletrac.
... [Read Article]
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.