Cox Tee Dee .15 Mark II cylinder shims

crankbndr Sat Oct 17, 2015 10:41 am

I noticed the cylinder shims in the listing before I bought the engine. When I took it apart there were 3 shims of different thickness under the cylinder to bring the exhaust port
to the left side of the engine where it is supposed to be when tightened down. The cylinder and piston are correct for the MarkII. I never knew shims were used on this engine.
You can see the shims in this photo

Cox Tee Dee .15 Mark II cylinder shims Dsc00930

Cox Tee Dee .15 Mark II cylinder shims Dsc00930

Without the shims the exhaust port is to the right rear when tight and the piston is in the proper position at TDC. The shims place the piston lower in the cylinder at TDC and would lower compression.
I could put one shim in and bring the exhaust out the right side and not lose as much compression.

Cox Tee Dee .15 Mark II cylinder shims Dsc00931

Cox Tee Dee .15 Mark II cylinder shims Dsc00931

1/2A Nut Sat Oct 17, 2015 12:13 pm

My Mark II has no shims It is possible you have a TD case replacement for the cylinder. Small Cox Logo

fredvon4 Sat Oct 17, 2015 1:24 pm

Yes that was my thought also...IIRC this is the only engine Cox did with a deliberately indexed machining to make the cyl to case orientation be correct for the single exhaust port

crankbndr Sun Oct 18, 2015 8:26 am

Sure is another eBay head scratcher, I got the engine from eBay seller ajohnclflyr36, I'm going to send a message and see if he knows why the shims are there.
With no shims the exhaust port is oriented to right rear of the engine exposing the wrist pin. One shim would bring the port to the right side.
I see no reason it wouldn't run well that way, just not how its supposed to be.

crankbndr Sun Oct 18, 2015 10:02 am

The one that got away

http://www.ebay.com/itm/COX-15-MODEL-AIRPLANE-ENGINE-USED-/291569376954?hash=item43e2e39eba%3Ag%3AMQgAAOSwQTVV%7E0JN&nma=true&si=UCDtPsDmRw8%252BksC5P33ozAnEhlU%253D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557

Cox Tee Dee .15 Mark II cylinder shims Cox_1510

Cox Tee Dee .15 Mark II cylinder shims Cox_1510

getback Mon Oct 19, 2015 10:25 am

I seen that one pretty rough looking but if your going to run it well worth the money , I just couldn't at the time and really didn't think it would go for so low a price ! Eric Babe Bee