Engine V Belt Pulleys

[AustHaflinger]

My Haflinger has the standard twin V belt system for use in starting the engine and then running the dynastarter. While there is a little wear on the belts they are all in very good condition and the system is all adjusted up correctly.

I am not sure if anyone else goes offroad much and has to ford water etc but I do - like in this pic where I went through the left track

The issue I have is that when the belts get wet either from fording or just washing the engine, the belts slip and will not turn the engine over until they dry out which takes a long time. I now carry a roll of toilet paper and when the belts are wet - roll some of the paper into 6" long 'cigarettes' and put then in the small slots in the crank pulley V where the belts meet the crank pulley - this dries out the area a little and provides a bit of friction for the belts to grip on. With the engine warm this is normally enough to start it.

This got me thinking though - why not change the dynastarter and crank pulley to toothed pulleys and use a heavy duty tooth belt - like on a cam timing belt. I have looked at toothed cogs at a industrial supplier and they would easily fit with a little modification.

Has anyone done this and how did it go?

Garry

[heinkeljb]

I don't know anyone who has replaced the V-belts with a flat toothed belt, but I have seen a few toothed V-belts.

The original system has the shims to allow you to adjust the tension on the belts to some degree. Using a toothed belt, you would have to figure out a sliding tensioner system to take out the slack. No impossible or even too difficult to do, but probably too much extra work for an unknown benefit I suppose.

Wouldn't it be easier just to leave the engine running if you have been through water that might have made the belts wet. Engine heat and the friction of the belts moving on the pulleys should dry they off quicker than toilet paper I would have thought, but that's just my two penny's worth!

John

[AustHaflinger]

Wouldn't it be easier just to leave the engine running if you have been through water that might have made the belts wet.
John

I was going to say that you must not do much offroading but I do know you do a bit of rallying when you can - yes leave the engine running is preferred but in technical sections you often stall the engine and when it is cold and damp it takes a long time to dry out. At least dunny paper allows you the engine to start straight away.

A tensioner mounted off either the oil filler mounting bolts or the governor mounts will control belt tension - maybe Steyr should have considered such a tensioner for its V belts rather than the current silly system of shims etc - or maybe just make the dynastarter moveable to tension the belts.

garry

[Tajman]

On commercial Hovercraft, we used Belt Dressing. They are subject to sea spray etc.
WD-40 do a product -Auto motive belt dressing. Be sure to check that the product is compatible with the type of belt material.
Might be worth a try.
https://bit.ly/2WvUZ4t
Jeff

[AustHaflinger]

Hi Jeff - yes I have it but it does not work quite as well as advertised when the belts are wet. Makes a huge mess as well.

I have just noted where you are located - when I lived in the Uk I lived just a bit north of you in Hambledon. Was a nice place to live.

Garry

[Tajman]

Hello Garry,
Yes I live 12 miles, well 11.6 miles according to Google Maps. 12 miles would put me in the Solent, directly south of Hambledon, "Home of Cricket"
It's a small world.
I,m very close to having a drive round the block for the first time in my Haflinger. I had to adjust my belts, they were loose enough to be making a slapping noise. Once the engine is warm, it runs relatively smoothly. But I am surprised how noisy it is even with mostly new exhaust system. I will glue on some sound deadening on the engine hatch/lid to see if that helps. Not used to air/oil cooled twins. My John Deere lawn tractor, 1990's, 178 with Kawasaki water cooled twin is much quieter, of course a more modern engine. At my age wearing hearing aids, they pick up all sorts of different frequencies.
Anyway, by the time I,m bombing along country lanes in the Haflinger, with the wind in my hair, and the warm summer sun on my back, leaving Covid behind, it won't matter!!
All the best
Jeff.

[AustHaflinger]

Sunday lunch at the Bat & Ball pub was always good but that was a long long time ago.

Yes the Haflinger engine is a bit noisy - it should have a bit of a VW dak a dak sound to it on the outside but is not too bad. What has always surprised me is how noisy the engine is in the cab when driving, even though the engine is in the back. However all the gear noises from the front end matches the engine noise - is much worse when cold but as the oil and grease in the front end warms up it gets a lot better.

At least you will be able to drive around with the wind in your hair - I dont have any hair for the wind to get into making me more aerodynamic

Garry

[AustHaflinger]

Last year I replaced the oil filter housing to a screw on type (the best thing I have done ) and as part of that I had to remove the crank pulley. Doing that I also replaced the drive belts so had to pull the top dynastart pulley apart to suit the new belts - it was annoying where I would adjust up but when the engine start they loosen off but after about 6 goes I managed to get the belts to the right tension.

After the initial tension was right the belts have loosened off so that on a humid day the belts will not turn the engine immediately until the moisture on the pulleys has evaporated.

So I dont have to sit there for ages adjusting this again over and over is there a "rule of thumb" that each shim adjusts the tension of the belts - eg 1 shim on each pulley equates to 1/4" tension on the belts?

Thanks

Garry

[heinkeljb]

Hi Gary,

I don't know of any quick way to get the tension right on the v belts. I tend to just put them on with an equal number of shims on both sides of the outside pulley. If that turns out to be too slack, then move one shim from the middle to the outside. If too tight, then move one shim to the middle from the out side.
Biggest issue is finding a suitable rod to put in the hole to lock the pulley. A rod big enough to go in the hole is too big to go down past the boss on the dynastart. I found a nice size rod that went in and tuned out to be too soft - it just bent when I was tightening the nut! Think I will have to buy a specific screwdriver just for that task...

John

[AustHaflinger]

Yes thanks John - as I thought but I thought I would ask any way - the last time I did this job I used a philips head screw driver and it worked ok.

When I had my old belts on they slipped all the time on start, particularly if it had been raining a bit. So I used to carry roll of toilet paper in the engine compartment and if I had a problem with slippage, a sheet rolled up into a ball and put in the gap between the belts and the crank pulley provided enough additional friction to start and would be just spat out after the first 3/4 of a revolution.

Garry

[ogdenenterprise]

I could never get my belts to tension correctly, they were either too tight so when I removed a shim they were loose.
I ended up getting some steel shimming sheets and made up a few spacers to make up the inbetween slack.

Dave

[AustHaflinger]

Yes like a few things in the Haflinger not a great design - when the engine was being designed - castings for a tensioner mount could have been included.