icanfixall
Official GMM hand model
A member asked me about the different belt lengths I have used so I felt others could pick up some information from this too. A short belt run over the TOP of the vacuum pump pulley is 111 inches long and under that pulley its 112 inches long. Now for the fun part of knowing what the numbers mean on the belts. My Goodyear belt part number is 4061110. I'm no expert but this is what I do know about that number. The 6 tells us the belt has 6 ribs. This is important because there are 6, 7, and 8 rib belts. Only the 6 rib works on our systems. the numbers 111o tells us this belt is 111 inches long. Had it been 111 1/5 inch long the zero would be a 5 for 1/2 inch fraction. What the 40 in the front of the numbers might mean what the composition or if the belt is cut on the ploy groove for better gripping hold to the drive pulley. And by the way the drive comes directly from the crank shaft pulley. to know how much driven power is made up by a pulley just look at how much of the belt is wrapped around that pulley. Also the pulley that needs very little drive pressure will have the belt running on the smooth side of it like is done with the vacuum pump pulley. Feel free to add what you might know about these numbers. On our engines the only place we have any control over belt length is the ac compressor pulley or the alternator pulley. Most of the time the alternator pulley decides what belt we need. My alternator pulley is 2 9/16 inch diameter and my ac comp is 5 inch diameter. The other pulleys can't be changed bigger or smaller. We run what we have.