If you don't have one for sale,,,, maybe you could point me to a source?

I went to NAPA and got some Gates belts. I think for big trucks or industrial. I got several lengths so I could change to a smaller pulley at times. I think they are all stored in the trailer but let me take a look. I should be able to come up with some numbers. I'll check tomorrow as I'm leaving for Louisiana Friday. Chuck in NH

Dan, i got mine from craig conley- paradise wheels.

I guess I could just measure everything out, buy a couple, fit them, etc. But my main concern is the spring pack. I could get a belt to "fit", but doesn't the spring pack keep a certain amount of load on the blower pulley so that it will separate/come together appropriately? In other words, I would assume that the more tension on the spring, the more force on the belt that would in turn put more tension on the main blower pulley.

Am I nuts? Or am I thinking along the right line???

I found one of my spare belts in the shop. It's a Dayton #37228 1 56027 . They should be able to cross reference from that. If that dosen't work when I get back I'll check in storage for the Gates numbers. Nobody up here could help me except the guy at NAPA. He went straight to them. There are several lengths available and you just have to measure and try. Set the idler so it's an inch or two in from full extension. There is not a lot of pressure on these belts but they don't seem to slip any. Hope this helps. Chuck in NH

Dan, i have asked that same "what belt tension or deflection should there be at the tensioner pulley" on several forums over the years and cant get an answer. like you, i figure it has to be a known setting as to impart correct load on main pulley, etc, if you get any info, i,d love to know. thanks.

Bill - I will keep you posted. I guess we think along the same lines. And of course, you and Chuck tend to be the fellas that answer my questions about the VS57 the most. Guess not too many are running that particular blower. I know there are a few well known fellas that have the VR57. John Harding, back when I bought an isky blower cam from him, gave me the names/contact info of a few fellas that have good knowledge of these blowers. It is probably about time I looked them up. Unfortunately my project has been on hold because of my new garage, all of the moving and setting up, etc.

Maybe I should have started posting in the this and that section, but I thought that maybe somebody would have a good belt for sale.

johnerb@sbcglobal.net

Chuck in NH

I would think that with the blower pulley at it's maximum diameter, that is opened fully, the idler should be compressed all the way.  The spring and belt do not determine the opeining of the variable pulley, the piston inside the blower does.  The spring merely maintains tension on the belt so it won't slip, regardless of pulley position.

Having just a little "working" knowledge of these things can definitely lead to false conclusions. So, I assume that the blower pulley itself has enough tension/pressure on its actuation (closing and opening, going from large diameter to small diameter) from the drive inside the housing, that the tension on the spring pack really plays no role in its movement, etc.

Therefore, I would also assume from what you are telling me that I need to get a belt that will fit the unit as close as I can get the spring pack to compress...upon initial installation (allowing for the minimum diameter of the blower pulley to have good friction on it because the spring pack is still holding it snugly around all of the pulleys in question)...now that's a mouthful!!

I will check out Chuck's belt first and go from there.

Thanks john, Dan and I both had same question re belt tension, you have made it clearer, guess i,ll go and try some belts. Thanks for the information. Regards bill.  

Just a bit of added information.  When the blower is told it needs to put out more boost, it reduces the pressure against the piston that actuates the variable speed pulley.  The belt then tries to wedge itself deeper in the pulley, thereby pushing the piston out of the way so the blower will spin faster.  When boost reaches the preset value, the piston again closes the pulley and the belt has no choice but to ride higher in the groove by compressing the tension spring.  Hope this makes sense.

John, thanks for your vast knowledge on this subject and expeirence racing these units. So if i had a belt too long, it would not place enough tension on blower pulley, then one too short would overload the bearings and pulleys, then to be in the ballpark would i be correct with a belt that compressed the tensioner spring about 3/4 of its travel? Just need a starting point, thanks again. regards bill.

Your plan sounds like a good one.  And Paul, I had one of those combines, and my present Gleaner also has variable speed pullies.  But my variable speed belt drive experience comes from several years of maintenance supervision in an industrial plant.