[Lear35A]

I had been searching for a whistling noise at the front of my engine. I asked about belt noise in another thread. However, after searching around using a mechanic's stethoscope, I discovered the upper pulley (passenger side) was causing the noise. After experiencing belt slippage during a dyno run, I had tightened the belt (which solved the slipping problem), but apparently the new, improved tension was too much for this pulley and the bearing inside crapped out.



After a phone consult with Flash I ordered a Dayco 89095 pulley on Amazon. It arrived yesterday, so I blew about 4 hours this afternoon replacing it. Just doing the pulley wouldn't be too bad, but I elected to also replace the belt to take one variable away. IMHO (and I guarantee a dissenting one in a following post) we have a balancing act between enough tension to prevent slippage at top rpm and boost and the life of these pulley bearings. For the number of units out there, there have been a significant number of failures of these pulleys. Without a quantitative way to set the tension those of us out here in the field are vulnerable on this. The pulley has to be modified a bit by removing 0.035" of material (it's plastic) from one of the outside flanges for clearance. Since I have a small belt sander, this was easy to do.



Anyway, it's a lot more work to change the belt. That's just the way it is. But with minimum loss of blood it's done. When I started up the car and the noise was gone, I was quite relieved.



I did not replace both pulleys because Amazon only had one in stock. Another is on the way just in case. Also, I left the middle pan off for now to make it a little faster to adjust tension. Right now it's at the minimum tension the tension bar will allow. Maybe this new belt will stretch a tad, and I will tighten a little bit. Then do a dyno run.



Heck, it was too hot here to play golf anyway.

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[rxter]

So what happens if the belt or a pulley fails? Do we detonate the Rotrex?



An unrelated question, but what happens to the engine if the Rotrex blows up? Is it starved for air or does it simply become a NA engine at that point?



Clearly if either of these things happened I imagine that we would be able to hear it and would pull over asap, but curiosity has me on this one as sometimes I am a long, long way from a flatbed...

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[flash]

if you blow the belt, the rotrex stops turning. the engine will be starved of air, but it will still "run". obviously you would also have no alternator or ac. i see no reason anything should be damaged, other than the belt whipping around and buggering things.



as for the pulley, if it freezes up, you'll toast the belt. it should let you know well in advance of that though.

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[rxter]

So its basically just parts and inconvenience then.



Does the engine starve if you detonate the Rotrex as well? More expensive part failure for sure, but protecting the engine is what I am trying to get at.

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[flash]

if you detonate the rotrex (not sure how you would do that) as i said above, it will "run" but be starved of air.

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[gbarrier]

If something locks up, as in the Rotrex, then the belt has to figure out whether it wants to stop or go, It will get very hot and pour a lot of smoke out from under the back. It will also melt all four non metallic pulleys supplied with the SC kit. No other damage.

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[968forums]

Once again off topic posts have been removed to return this thread back on topic.



This is important technical information. Readers should not have to wade through off topic banter, no matter how clever, witty, or entertaining, to find important information that may affect them.

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