West Bend (aka Chrysler Power Bee) 580

[jgflawn]

Just about to begin work on restoring my West Bend 580 - parts are en-route. Have a 58037. 5.8 cu. in.; 4.0 HP @5500 rpm, but Karting guys spin up to 11000 rpm at some expense to piston and rings. Assuming the rebuild works, I'll be replacing a B&S 5.25 ft. lb. torque at 3060 rpm; only 3.5 ft. lbs at 3600 rpm (90000 series) on a single stage snowblower. Will use the OEM adjustable throttle and should be able to really throw some snow.

Karting forums are generally extremely close to the chest with info - and no wonder given the sport.

The best info I've found for the 580 I'm using is from the following open public documents - supplied by the US gov't of all things, which are specific to the 58037 use (jumping jack), but are step by step instructions on overall engine work including detailed specs, line drawings and step by step tear-down and rebuild instructions. Differences are in the crankshaft and mounts only so pretty universal to all West Bend 580's.
TM 5-3895-360-14
TM 5-3895-360-13
TM5-3895-360-24P
The following are the 'theoretical' maximum rpm for the engine based on bmep, bhp, piston speed and piston acceleration (which is what wears rings)
max rpm 3500ft/min piston speed 12048
max rpm 80000ft/sec^2 piston accel. 8842
Based on these I'm safe at spinning to 8000 rpm without ring failure, and 12000 rpm without rod/block - which is close to observable reality of 11000 rpm