Griptwist Belts?

[Dockhead]

I decided not to carry spare alternators for my main and genset engines. They are expensive and take up space and they are not mission critical as they exclusively charge the start batteries which can be easily charged by other means. (I do carry a spare for the school bus alternator I use to generate bulk power).

One worry I have however is what happens if the alternator bearings crap out -- I can't drive the fresh water pumps.

So what about carrying Griptwist belts to drive the fresh water pumps directly, in such a case? This seems to be a superior type of emergency fan belt which, it is claimed, will last as long as a normal one. I would be especially interested if someone has some experience with them.

https://www.regalpts.com/PowerTransm...Form_9786E.pdf

[a64pilot]

They have actually been around for a long time. They do work, but I think they are way weaker than a normal belt, I would run one a little looser than I would a regular belt. But your only running a water pump, no need for a tight belt, plus since nothing can be moved it’s not going to be tight, you can only get the belt as close as you can, then lever it over the pulley,so it’s going to be real loose.
Ideally you need an idler or tensioner pulley.

[jimbunyard]

No experience specifically with this manufacturer's product but it is refreshing to see this directly from their descriptive literature.

Disadvantages

While Premium Browning Griptwist is interchangeable as mentioned above, and is ideal for emergency usage, it is generally not a cost effective permanent replacement. Depending on size, using Premium Griptwist or a similar competitor twist belt product, the increase is on average about 300% more expensive than traditional premium quality v-belts. Given belt life and drive performance generally are equal, it is a costly option for permanent replacement. Ideally, Griptwist allows a technician to quickly get the drive running when a belt breaks and replace the original v-belt when one is obtained.


My first worry would be that the 'adjustment' would be too coarse, and the belt would be either too loose (which for coolant water might not be an issue), or too tight, which can kill bearings in pretty short order. The only way to tell for sure is to try one on...

[a64pilot]

It’s going to be too loose, you couldn’t get on any other way.
Remember the position of the crankshaft and water pump is fixed, no adjustment can be made, so if you can get it over the pulleys and it drops into the grooves, once over it will be loose, but a water pump is easy to spin, so if you keep the revs down it ought to work.

[Jim Cate]

Never used one, but it seems that if one has access to the crank pulley one could dismount it, slip on the belt and then replace t he screws that hold the pulley in place. This should allow a bit more tension than levering it over the lip of the pulley at the cost of more fiddling around to get it in place.

Jim

[a64pilot]

You could disassemble, but I bet even loose it would work, doesn’t take much to spin a water pump and a little slippage as long as it’s not excess heat won’t hurt.
I was even wondering if surgical tube would work, or a bicycle inner tube.
I have heard of using a women’s hose, nylons but I’d be surprised if it worked, but if it was all I had, I’d try it .

Of course if you were real slick
https://youtu.be/T2DSVMyTJVg

[deluxe68]

Originally Posted by Dockhead

I decided not to carry spare alternators for my main and genset engines. They are expensive and take up space and they are not mission critical as they exclusively charge the start batteries which can be easily charged by other means. (I do carry a spare for the school bus alternator I use to generate bulk power).

One worry I have however is what happens if the alternator bearings crap out -- I can't drive the fresh water pumps.

So what about carrying Griptwist belts to drive the fresh water pumps directly, in such a case? This seems to be a superior type of emergency fan belt which, it is claimed, will last as long as a normal one. I would be especially interested if someone has some experience with them.

https://www.regalpts.com/PowerTransm...Form_9786E.pdf

Your ESPN must be working, I was thinking of this the other day. I have a serpentine setup, so I am not sure if they make a griptwist to replace a serpentine belt. I may try to get a serpentine that will fit without going thru the alternator, not sure how hard it is to cram it on without any tensioning capability.

One alternative is to mount a pulley in place of the alternator to get you home.

[Almost-There]

Why not just measure how long of a belt you'd need,go to the store and get a few around that length +- a little.Try them on and keep the one that works the best and return the rest. I know you probably wont use it but in the scheme of things its cheap insurance.


Another option is to carry the bearings used in the alternator you are worried about.But if you havent had one apart or have a impact on board etc it might not be a option.


Last but least is make sure the water pump will still spin in the same direction when you bypass the alt. Otherwise the motor will most likely overheat as they tend to be directional.

[a64pilot]

Or just get a cheap alternator, you just want it to hold a belt, it doesn’t have to work.
I guess I ought to get my stock one out of the hanger

[Pauls]

Using a cheap replacement alternator as an idler pulley is a much better idea than the section belt. If you are determined to use the belt then set it up on your engine and run it and see how it fares. Or you could just carry a set of replacement bearings for the alternator you have if you really want to economize on space and weight.