ORIGINAL: fc911c
ORIGINAL: proptop
Slightly larger, with less pitch...hmmm...where have we heard that before...D-U? Dar?
FWIW one of my Webra .50's was like your .55, with very little pinch and almost no base compression. I ran the first gal. of Powermaster 10% sport fuel through it (flew it ) with 4 oz. of extra castor added to help put a little varnish build up on the piston. The extra oil also helps seal things a bit.
As you might imagine, 1 gal didn't put much varnish on it, but it helped, and after another gallon, it has great compression, and has excellent throttle response. You can see a nice, golden brown coating on the skirt area of the piston, just below the top edge.
How does the compression feel, and how quickly does it leak down if you put some oil in the cyl.?
Thanks for the reply
compression feels pretty good not great, it leaks down very fast. It will hold is't compression for only a few seconds.
You can see it bubbling like crazy by the EX port.
Frank
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Personally, I've never seen where having tremendous compression at no/low speed was of much benefit. Neither did the inventor and the manufacturers that installed Dykes rings.
The large diameter/low pitch prop is for bench running - not flying.
Ed Cregger