There's really no good commercial tool I've found to do this. I own the tensioner pictured above - perhaps the most common. It worked well once, then failed at a weld the second time I used it. You'll see that's extremely common with this tool when you look at the reviews. when it works its VERY handy. I had someone re-weld it for me and am hoping that fixed it. We'll see. I'd much rather use something like this than a crowbar or screwdriver which could damage something if I crank too hard. Breaking a casting on an engine that you couldn't see when you thought you were levering safely would be a bad day.
You can make your own tool for pennies. A piece of ⅜" threaded rod, a few washers and nuts, and some scrap hardwood. See the article I posted earlier. If you to get fancy, use a turnbuckle instead of the threaded rod.There's really no good commercial tool I've found to do this. I own the tensioner pictured above - perhaps the most common. It worked well once, then failed at a weld the second time I used it. You'll see that's extremely common with this tool when you look at the reviews. when it works its VERY handy. I had someone re-weld it for me and am hoping that fixed it. We'll see. I'd much rather use something like this than a crowbar or screwdriver which could damage something if I crank too hard. Breaking a casting on an engine that you couldn't see when you thought you were levering safely would be a bad day.
In the article, if you click on the one picture you'll get this photo. The blocks are cut to roughly match the curve of the pulleys. There is ⅜" hole drilled through the blocks to accept the threaded rod. Specific dimensions will depend on your engine. When tensioned the end of the threaded rod should be about half way or a little more through the blocks on both ends.In the one of the articles mentioned above the DIY tensioner is 2 blocks of wood, 2 nuts and a 3/8" threaded rod. You can likely picture the way that's all put together to make a tensioner.
Got Picture?I replaced the slotted bar with a turn-buckle. Works very well and you get one handed adjustments.
@Rich Stidger , I did a bit with pics in “engines and propulsion “ Nov. 2017. Not sure how to move that pic and am having trouble finding it in my libraryGot Picture?