Engine Bay Black Dust

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DIW

DIW

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Can anybody throw any light on the source of a fine black dust covering the surfaces of the engine bay after a trip ? I think the drive belts might be the culprits but all tensions etc seem ok and only done 10 hrs since changed. Engines KAD 32P/DP, Boat Sealine F33.
Thanks
Ian
 
Yes it's the V belts, rust will develop on the pulley surfaces then do a nice job of abrading your belts thereafter.
Something to watch out for is that if your air intake is in the engine bay, the air filter can get clogged up with the dust.
Anyone know how to prevent rust on those surfaces and don't suggest grease or oil!
 
measure the length between centre of the two pulleys, add about 6", then get a straight bar of this length and no bigger diameter than the widest part of the belt, bend a right angle starting the bend 6" from one end.
Lay the bar(90 degree end) on the large pully "v" and gently lay the other end into the other groove, should be an exact fit, if not the pulley on the alt is out of alignment. Pack out the Alt, or remove packing to obtain this fittment. Problem solved.
harder to explain than do. good luck
 
One possible cause is the wrong size of V belt. Belts should drive through the sides, but if the belt is too narrow (typically this happens with UK car spares type belts on jap engines - half inch instead of 13mm) then it sits at the bottom of the pulley groove, slips, ribs off black powder and the prob gets worse.

Once belts are slipping, its usually best to replace with new.
 
Machinery which has stood for a time and developed a rust covering on the polished pulley face will rapidly wear its first set of belts. I have worked with up to 'E' section belts which are 1.5" wide and as they were sometimes over twenty feet long and therefore rather expensive we polished the grooves with sand paper to remove the worst of it sometimes. This was quite time consuming on pulleys up to 6 feet in diameter but access was not too difficult generally. On smaller pulleys we found it more economical to let a belt do the polishing and monitor it more often than usual, whilst accepting the shorter belt life.

Grass cutters, combine harvesters et al which are used seasonally also have the problem as a matter of course. I seem to recall Waxoil being recommended to protect pulleys in these circumstances but I don't have any experience of the success or otherwise and it would no doubt be important to remove it which would be time consuming also.

Some years ago there were designs of belt in which the softer rubber and cords of the belt were obviously wrapped with a rubberised cloth which would protect the internals however they would not last well in my experience. If you avoid that design most industrial belts perform in a similar manner in my experience.

To enhance the performance of the original Vee belt the depth of the belt was increased and a given width of belt on given pulley diameters could handle more horsepower. Some were cut with notches to permit them to flex more easily so that they could better tolerate a smaller pulley diameter on vehicles and other equipment with shorter life expectancies than industrial equipment where belt lives of twenty years or more could be obtained on plant running 24 hours a day year round.

Black dust can be removed with a vacuum cleaner. We did that quite a bit. It is an indication of belt wear. To extend belt life check tension, temperature and that the belt is the correct one for the application in terms of width, depth and, on a small diameter alternator pulley, the need for a notched belt to increase flexibility (at the expense of contact area).
 
erm, altho others say it's the belts, i wd expect belt dust to concentrate around where the belts actually are - it's more obvious innit? If the whole of the surfaces are covered black, it might be an exhaust leak. Hope it isn't, but run the engines in neutral and there shd be not the slightest leak from them.
 
as previously posted suggest that you check that the water pump multi v belt is properly alinged especially if it has just been changed if it is one groove out it can end up braking loss of cooling etc
 
Best solution in terms of finding the right belt is to go along to Fenner power transmissions - supplying things like drive belts to the engineering industry is their full time business and they are very helpful. They will make sure you have the right size and type.

gates belts are fine, but to suggest using them to cure a problem is a bit like saying use Goodyear tyres to stop your tyre wear. It will work if you are using really cheap and nasty, but Gates no more have a strangle hold on good quality belts than Goddyear have on tyres. Brand name tyranny!
 
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