NEXT PROBLEM: Timing Belt Tension Pulley

Red Bull 78

Red Bull 78

True Classic
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Bracket worn so Pulley rubs. No brackets available.
Q#1 How can you shim that compound mating surface?
Q#2 Can the Pulley be '"Shaved" on the back Side to gain Clearance?
Q#3 If so, how much Clearance? .005 in /.127 mm or .010 in /.254 mm?
 
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is what your referring to as a "pulley" actually the tensioner bearing? what are the dimensions of the "pulley/bearing you're using? the 1300 (which I'll guess your 78 is) and the 1500 use a different sized tensioner bearing, and also a different tensioner bearing support bracket (the shoulder heights are different)

SteveC
 
fiatfactory said:
and also a different tensioner bearing support bracket (the shoulder heights are different)
Click to expand...
This brings up a good point. When the head/cam box are milled, the 1300 tensioner bearing is often used on a 1500 to take up the difference in belt length. So I guess the bracket needs to be changed to a 1300 item also? And which belt is used, 1300 or 1500?
 
Dr.Jeff said:
This brings up a good point. When the head/cam box are milled, the 1300 tensioner bearing is often used on a 1500 to take up the difference in belt length. So I guess the bracket needs to be changed to a 1300 item also? And which belt is used, 1300 or 1500?
Click to expand...

I used 1300 bearing with 1500 bracket when I had the shaved head / cambox combo on my 1500
 
I don't think that bracket can "wear" to cause that interference, obviously something else is going on here.
 
Yeah... never seen a tensioner rub the bracket. Something's not right.

The only thing I can think of is the tensioner might have locked up and spun on the bracket and worn it down some. I would want to inspect it more carefully to see what was going on.
 
Could you just make a shim out of very large washer and slide it on the shaft before the bearing is installed?
 
Late Friday, I left it with a Machine Shop, with all the parts. Showed them how it fits together and told them to Shave .005 inch, at a time, off JUST ONE Side of the "Pulley", until when torqued to 32.5 lbs, the "Bearing" didn't rub the bracket.
I'll find out later today, if it works and how much it cost.
 
When you reassemble it on the block, check to make sure the belt rides on the center of the "pulley". Between the worn mount and the machining it might end up off center. A slight difference won't hurt but the belt should be well supported to avoid excess wear on it and the bearing.
 
question - where did you get that tensioner bearing? If it's not new, replace it. If it's a dodgy source, don't use it. They're cheap, and that's one part you don't want to fail.

Can you provide an axial pic (front of the bearing?). You shouldn't need to modify anything to fit to be honest. I'm hoping to save you some heartache later! :)
 
UPDATE: With .010 inch shaved off one side of the Bearing I got from Vicks. (He sent wrong belt, for a DOHC. That & Distributor Issue is what took so long.)
With Bearing Race seated to run with belt and torqued to 32.5 ft lb, it has .005 Clearance.
First Start UP. Timed by Ear. I wanted Video of whatever happened.
I have Invoice for Timing Belt job from 2009, no mention of Bearing, so it must have been OEM and must have been doing more than just making NOISE, because the engine already sounds so much smoother.

https://www.facebook.com/video.php?v=2330769897150129
 
Red Bull 78 said:
UPDATE: With .010 inch shaved off one side of the Bearing I got from Vicks. (He sent wrong belt, for a DOHC. That & Distributor Issue is what took so long.)
With Bearing Race seated to run with belt and torqued to 32.5 ft lb, it has .005 Clearance.
First Start UP. Timed by Ear. I wanted Video of whatever happened.
I have Invoice for Timing Belt job from 2009, no mention of Bearing, so it must have been OEM and must have been doing more than just making NOISE, because the engine already sounds so much smoother.

https://www.facebook.com/video.php?v=2330769897150129
Click to expand...
No Disrespect for Vicks but I have seen some bad parts come from them. The Bracket is at MWB and the X1/9 belt is only 13.95 I bought a new bracket for 27.95. Vicks has some stuff but I buy all my maintenance from MWB.
 
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