TD 020 and Pee Wee cylinder interchangeability

balogh Sat Dec 28, 2013 2:42 pm

For my 4 TD 020-s (one in active use, the 3 others just waiting for their time to come) I have built up a small spare parts inventory and this includes a PeeWee (also 020) cylinder-piston combo in the original plastic bag, still unopened. The plastic bag shows an item number different than the item number for the TD 020 cylinder-piston combo thus I think the cylinder porting, SPI design etc may be different between TD 020 and PeeWee.

Anybody has any information/idea whether the TD020 and PeeWee cyílinders are interchangeable?

I also came across a 020 muffler on ebay that I instantly bought, and the mere existence of this part suggests the Pee Wee may be non-SPI design because mufflers and SPI design are inherently incompatible (the crankcase of an SPI engine like TeeDee-s would suck in exhaust gases from the muffler when the piston skirt opens the crankcase towards the outside world, and compromise the engine peak speed).

**Cribbs74** Sat Dec 28, 2013 3:00 pm

They are fully interchangeable.

balogh Sat Dec 28, 2013 3:04 pm

Cribbs74 wrote:They are fully interchangeable.

Thanks...then I keep wondering why COX has come out with the 020 muffler that, while I have not tried it on the TD 020 yet, is most likely to cause erratic run on the TD020 which has SPI design...I would have guessed the muffler was supposed to come for the PeeWee providing this is non-SPI (which it is not, if its cylinder is interchangeable with the TD 020, which is SPi...).

Thanks, anyway.

balogh Sat Dec 28, 2013 3:42 pm

balogh wrote:
Cribbs74 wrote:They are fully interchangeable.

Thanks...then I keep wondering why COX has come out with the 020 muffler that, while I have not tried it on the TD 020 yet, is most likely to cause erratic run on the TD020 which has SPI design...I would have guessed the muffler was supposed to come for the PeeWee providing this is non-SPI (which it is not, if its cylinder is interchangeable with the TD 020, which is SPi...).

Thanks, anyway.

To answer my own question, here is what I found: http://www.mh-aerotools.de/airfoils/documents/cox_test_peewee_020_aeromodeller_march_1976.pdf

Yes, the Pee Wee also has SPI design... (But, then, which engine if not the TeeDee020 and Pee Wee, will use the muffler....???)