V Belt Tensioner for the Type 1

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Jadewombat
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Joined: Sat Jun 22, 2002 2:01 am

V Belt Tensioner for the Type 1

Post by Jadewombat » Sun May 17, 2020 9:51 am

I truly hate seeing belt flop on these engines. Before we get into operator "error", I have a German made pulley on my engine, high-quality crank pulley, Continental belt, and everything is adjusted correctly. So, no. That's not the issue.

With the choice of forking out $250 for a ribbed belt/tensioner system, then having to redrill the crank pulley for the magnets my crank sensor needs, also having to modify my crank sensor bracket, changing out the studs on the alternator stand because the ribbed belt system would need longer studs, etc--I opted to buy a compact tensioner and fab. up my own for less than $50. :lol:

Got a tensioner designed for motorcycle chain tension from Amazon on the interwebs along with a pack of v-groove 3/8" wide PGN industrial bearings. Amazon only sells these bearings in an 8-pack but I found out later you can buy them direct from PGN directly in whatever quantity you want.

Anyhoo, make a short story long, I had to figure out where to mount the tensioner and what to mount it to. No surprise there's not a lot of space. Wasn't going to fit on the inner area of the belt pushing it out, so it was going have to ride on the backside of the belt for tension. The bearings have a v-groove in them which is fine for what I needed because I simply take two of them and stack them side by side, however on of each of the grooves needs to be machined flat. It took about 1/2 hour on the lathe to machine each bearing.

The shaft that the bearings ride on and sits in the tensioner also needed to be machined down which took another 45 minutes. Also had to cut, machine and weld a little collar clamp to hold the bearings on the shaft, drill the shaft for a cotter pin as extra failsafe, then turn my attention to fabbing up the mounting bracket.

The tensioner fits nicely riding against the alternator using two of the alternator housing screws for securing and the rear bolt on the throttle body as a third mounting point. Drilled some flat bar for speedholes and bent it on my tubing bender. Did a test fit and test run then pulled everything off and powder coated it silver.

The whole thing works great, couldn't be happier with it.

No, that's not Megasquirt BTW.

https://youtu.be/zHHZ0HiHM2U
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