how to cool off a hot belt
Amsnow
A fan-cooled primary clutch. Strange thought indeed. But a thought with merit.
Snowmobiles that are under heavy loads for long periods of time will heat its drive belt as the sled pulls its way through stress and strain.
Current drive belts have a top-side cogmolded into them to create a fan effect, thus aiding in belt cooling. Some primary and driven clutches have windage plates or have cast-in ribs (on the clutches' outer sides) to also create wind turbulence. Other measures include hood intakes that direct air into and near the drive belt. These measures all have merit, but could more be done?
As for the hood vent, if the snowmobile is moving slow under a heavy load, then fast rushing air is not so... fast.
Consider this. Modern mountain muscle sleds churn long 151- to 159-inch tracks with tall two-inch lugs. This, combined with low gear ratios, force a belt to live in a temperature zone. Belts will cook, glaze and separate, known as delaminating.
These factors also are true for the snowmobile pulling heavy loads or working under heavy throttle surges on long trail rides.
Knowing belts are at the heart of snowmobile momentum, Tri-City Polaris, in Centerville, Utah, developed an electric clutch cooling kit that sits on top of the clutch cover and blows cool air onto the drive belt. TCP General Manager, Max Maxedon, and TCP's Service Manager, Tracy Seegmiller, testify the drive clutch runs an average 40 F cooler and the driven clutch 30 F cooler with this clutch cooling fan kit.
Maxedon tracked the temps by using sensitive temperature-indicating tape. Two identical snowmobiles were prepared for field testing; one with the cooling kit, one without. When this tape was installed on both sleds' clutches, several hard runs up deep snow-infested hills were made, to ensure the belt and clutches were at maximum temps. Temps were recorded. After such, Maxedon recorded that the snowmobile with the clutch cooling kit averaged the cooler temps.
To increase the stakes the test sled with the clutch cooling kit had its vents taped off to keep hot air in, and more runs were made. The clutches remained cooled and the belt protected from glazing and heat consumption.