David Stroud IM Roadster D posted:Giday, Mike. I don't know much about my engine other than it was built 55,000 km ago by a fellow in Vancouver, Canada that had a good reputation. Here's a pic of the new CB Performance alt pulley just sitting on the shaft and my hand holding one half of the pulley that had gone bad. Full o.d of the new ( black pulley ) is 4 1/4" and the one I'm holding is 3 3/4"o.d.
I don't know what a crank "power" pulley is, nor do I know the o.d. of a regular sized one. My crank pulley is shown in the second blurry pic. It is 5 3/4" o.d.
Now quick poll to help make a colour decision on a small plane I'm rebuilding. 5th pic is the type of plane....just a small single seat job but it needs to get painted in Military yellow or silver. Which colour do any of you like, please ? Yellow 3rd pic or silver 4th pic ? Thanks.
Hi David, The normal size of the alternator pulley is 4 1/4" so your bad one may have been an undersized pulley. Your crank pulley is a "power pulley." Normal size crank pulleys are around 6 3/4" and folks often switch to a smaller pulley to reduce the speed of the alt/fan to save power at high rpms.
Regarding paint color, I like the look of the silver with yellow trim (4th pic). The silver helps to set off the shape of the cockpit. Very nice looking plane!