Double slotted exhaust port on Baby Bee or similar reed engine

RudderOnlyPlot Mon Apr 18, 2022 11:54 am

I picked up a box of Cox engines at an auction and one of them, a Babe Bee sized reed engine with a hex thrust washer, has two thin exhaust slots on the cylinder rather than single wider one, which I've never seen before. Does anyone know what this is about? Like, what is the purpose? Is it confined to a particular model or models? I tried to attach a picture but I didn't succeed. I'm pretty new to this forum. Thanks!
Jim C

balogh Mon Apr 18, 2022 12:32 pm

In March 1976 COX started the production of cylinders with slit exhaust, a design that was less prone to throw flames from an excessively primed cylinder to the hand of a young pilot and thus avoided burnt fingers. Refer to the left of this page where the cylinder identification link will introduce you to all COX cylinders..

RudderOnlyPlot Mon Apr 18, 2022 4:39 pm

Thanks! You are a fountain of information! I don't see the link you mentioned about Cox cylinder ID, though. Could I find it in an Internet search? If so, what search words would get me right to it?
Jim C

Marleysky Mon Apr 18, 2022 4:59 pm

If you are using the "Classic Web Browser" you'll see it on the left hand side of the page: please excuse my poor arrow drawing.

Double slotted exhaust port on Baby Bee or similar reed engine Scree163

LostServoScrew Mon Apr 18, 2022 8:33 pm

https://www.coxengineforum.com/h23-cylinder-identification

LostServoScrew Mon Apr 18, 2022 8:37 pm

You tend to see, I think, the double thin exhaust slots on engines from roughly the 80's on?

balogh Tue Apr 19, 2022 12:26 am

LostServoScrew wrote:You tend to see, I think, the double thin exhaust slots on engines from roughly the 80's on?

The March 1976 starting date was quoted incorrectly, sorry. The date is February 27th 1978 as it was mentioned in Dan Sitter's COX Model Engine Handbook on page 11.