Belt drive ventilation

Is it ok to run unventilated Maney belt drive?
Don't want to drill my primary and looks a bit ugly with the access plugs out.
Advice anyone?

If you do decide to drill, this is a really low profile way to do it. Two 1/2" holes front and back on the inner primary and one on the bottom backed with wire mesh, CNW style. Some say ventilation isn't necessary but I like the idea of a little air flowing through there.

When I fitted my RGM belt drive I cut some pieces out of large O ring seal so there where a couple of 1/2 inch long gaps at the lowest points of the case. This I reasoned would let any moisture drain out an also any oil that may past the crank or gearbox seal out before it builds up to a level that would bother the belt or clutch an you would notice it an think OH JOY!!

My paths to pavement take me through water crossings, and often enough damp Gravel which throws wet gritty mist everywhere but especially against the front of the inner cover and swirls around the bugles leaving marks of yuk at low pressure areas. So I asked Keeny Dreer, Steve Maney, DynoDave, Baxter's and OldBrits and Sparx about sealed heating of belt and charger to be told its a complete non issue for either of them. Worse way is opening the front of inner cover where tire sling of even dry road grit lands. So primary reason for holes is indiviual art work expression and secondary mass loss off LH if ya make enough big holes, which is a good thing on both accounts but nothing to do with protection logic at all. Being a pensive sort I checked temps on increasing ride intervals to find that most the heat by far is conducted out through the crank pully and case attachment to engine. You ain't gonna ventilate enough to affect that amount of heat flow but by timid throttle fuel burn.

I know my RGM belt drive will swell enough to make a profound difference on belt tension.

From what I have read here, the Maney drive is much less susceptible to heat expansion.

I would adjust your belt a little loose then when the hubs are hot from running, adjust them again and see how it goes. Keep a close eye on it so undue stresses aren't applied to the mainshaft. If it get too tight from haet expansion then go ahead and open the case as you see fit. There are many ways to do this and is an opportunity to personalize your unit.

Yep Sir Pete, on the heat expansion of pulleys and mount spacing on primary drive tension, but this is exactly the same issue as ancient chain gangs deal with and has no solution at all by even running belt fully naked w/o the inner case installed. Face facts, it don't make a whitworth of difference on setting a sealed or wide open primary on pulley and mounts heating, much as I wish it did too. Of course it makes good sense to have nice cool running parts, duh, but no way to cool enough to matter for our primaries, thank goodness I say. If your conditions allow it - have at the cover and case as I love the art deco like styles with hints of crop circle designs.

Was not part of the reason to help keep the alternator from getting too hot?? I remember seeing a picture of a melted one somewhere. And yes check belt when hot, My RGM belt does get a lot tighter when hot. It may seem too loose when cold but this is correct. My Buell's have final drive belts and there is no better way to destroy the bearings in the wheel and engine sprocket than to run the belt too tight. They told me to adjust it scary loose! But after a hard run up the mountains I could see why, It does change quite a bit. :wink:

I repeat its not hobot opinion but most highly respected Nortoneers stating no ventilation needed so any melting of charger has a mechanical or electrical reason, not normal or even race level running sealed oil tight dry as a bone. Its nerve wracking for me too but after assurances and then severe testing I've gotten past my illogical feelings on venting. Btw I had 3 belts on Ms Peel's short life time, to find weak area in belts are the edges not the teeth. So if clutch not stable or not adjusted for self centering w/o pulley side, it can rub its self apart in short order. Last belt on Peel ran 1000's miles are it got ventalated by Crank nut coming off and run through the teeth with one hole I could and did stick a pencil through, but edges intact and stayed aligned. One belt, 890 count IIRC was just too short for comfort on the gearbox amount of adjusting room. That one I ran a short time w/o cover on to see fine dust effects on belt edges and pulley plates loosing the anodizing, so spent for 920 T count. Should be fine running w/o cover in normal paved roads while the cover is getting drilled, water jet cut and scrolled but be careful as some designs might draw in E.T. to pluck ya right off the saddle and no one would believe it. To beat ole Ludwig at his own weight game, get the Clubman's plastic cpver which is very easy to cut into.

No need to run the Maney belt drive with extra ventilation holes in your primary case/cover. Actually your belt will last longer avoiding road dirt. So far I did 80.000 miles on my Maney belt drive sometimes under tropical weather conditions. Changed belts twice (every 30.000 miles although they last longer). Pulley's still look like new. One of the best modifications I did on my Commando :!:

I agree with the comments about ventilation being unnecessary, and perhaps even undesirable, but i couldn't resist the ventilated caps in he link below.
http://www.eurojamb.com/norton-750-850- ... -1551.html

Thanks all, I've run it with and without the caps in but when running totally sealed, always had that niggling thought in the back of my head. I have seen those mesh caps but they are pretty expensive for what you get IMHO
Again, thanks to all for the advice. I shall power forward with full confidence in an unventilated state!!!