pfrederi 17,734 #1 Posted September 3, 2023 I had always assumed (and you know what that can mean) that there we two styles of S/G belt Guards for small block Kohlers...one for the older units with 2 sheaves and one for the newer single sheave pulleys...Wrong. There are two different sizes. They both fit on the air shroud OK but the smaller one is very difficult to get aligned to avoid the belt (or pulley) from contacting it. All of my S/G units are hand me downs and all have different drive pulleys so I do not know what original sizes were. My pulleys range from 2-3/4 to a bit over 3". Any one know for sure the original pulley diameters??? New smaller pulley might be easier to find cheaper than the larger belt guard... 1 Share this post Link to post Share on other sites
ri702bill 8,316 #2 Posted September 3, 2023 But wait, there's more!! Do not forget the 1962 version that had a small raised dimple at the S/G instead of the raised "Button" shown..... 2 Share this post Link to post Share on other sites
953 nut 55,198 #3 Posted September 4, 2023 17 hours ago, pfrederi said: All of my S/G units are hand me downs and all have different drive pulleys so I do not know what original sizes were. My pulleys range from 2-3/4 to a bit over 3". Any one know for sure the original pulley diameters??? I don't know this as being factual but since the flywheel pulley on the eight horsepower engines was smaller than the ten and twelve horsepower pulleys they may have used a larger pulley on the ten and twelve horsepower engine S/G to compensate for it. 1 Share this post Link to post Share on other sites
Handy Don 12,216 #4 Posted September 4, 2023 I’ll go out on a limb here and speculate that the differing sizes was at least in part because the early small blocks used spark advance and not ACR. They needed more “oomph” to be turned over against the compression and the smaller pulleys on the SG and flywheel worked out to a better ratio. 3 Share this post Link to post Share on other sites
ri702bill 8,316 #5 Posted September 4, 2023 43 minutes ago, Handy Don said: I’ll go out on a limb here and speculate that the differing sizes was at least in part because the early small blocks used spark advance and not ACR. They needed more “oomph” to be turned over against the compression and the smaller pulleys on the SG and flywheel worked out to a better ratio. Over here, "oomph" sounds like you just burped, so we use the work "cookies" instead... yes, the 1961 701 did not have ACR, later models did (that is what gives the small K Series engines that wonderful "putt-putt" sound at idle - but don't idle too long....) Share this post Link to post Share on other sites