differences between .020 cylinder pistons?

Thank's
I'm happy to be here

Bob

I am assuming that is a photo of Fürstenfeldbruck? Where do you fly the planes?

https://www.google.com/maps/place/82256+F%C3%BCrstenfeldbruck,+Germany/@48.1765193,11.2374031,6237m/data=!3m1!1e3!4m5!3m4!1s0x479e7fe3d5348edb:0x444dc1e316c94068!8m2!3d48.1739373!4d11.2430079
Mind you, Emanuel is probably sleeping.
Bob

emanuel wrote:I want to build a TeeDee from scratch. My existing cylinders are different. at the bottom right is an original TeeDee. Are the performance of the cylinders and pistons the same? Or is the last generation better with the rim on the exhaust?]

All my older Tee Dee020-s with the thin wall and stepped wall cylinder have tapered cylinder bore, while the 2 Pee Wee-s I have with thick wall cylinder do not have that...I have some later, thick wall OEM 020 cylinder/piston sets too, that do not have tapered bore either.

My Roaring 20 R/C bird has an old-stock TeeDee020 with thin wall cylinder on it..I already flew the heck out of it, (its smaller radial mount is near molten through by the hot exhaust gas behind the cylinder) still it has as new compression, and swings the 3-bladed COX 3.125 x 2.5 prop at 24.5k with only 20% nitro in the fuel...amazing lil gem. I am not sure how a non-taper 020 Tee Dee would compare, probably only a slight difference to the advantage of the old stock tapered one.

I usually ride my bike and look for an open meadow. There are also a couple of model airfields where I've been a guest. But unfortunately 2 months ago I pinched the nerve of my left hand on my spine. I can't even tinker with the Cox right now. In spring it will work again.

The original TeeDee cylinder (bottom right) is still very good and I felt that the cylinder bore was conical. The Tribble Drome PeeWee (top right) and the housing (middle right) also have the thin-walled cylinder. I was hoping they have a tapered cylinder bore too. At the moment I cannot safely disassemble the two because of the left hand and spine. It's torture, total lockdown, a bunch of model projects started here, but I can't do anything right now.

balogh wrote:
All my older Tee Dee020-s with the thin wall and stepped wall cylinder have tapered cylinder bore, while the 2 Pee Wees I have with thick wall cylinder do not have that...I have some later, thick wall OEM 020 cylinder/piston sets too, that do not have tapered bore either.

Balogh, thanks for the education. I thought there was a little pinch at the top of some .020 cylinders, but
I always attributed it to castor oil accumulation.
Nothing makes me happier than learning something new.

Emanuel, sorry to hear about your injury, and
I hope you recover soon.
Bob

Thank's I hope so too.

dckrsn wrote:

balogh wrote:
All my older Tee Dee020-s with the thin wall and stepped wall cylinder have tapered cylinder bore, while the 2 Pee Wees I have with thick wall cylinder do not have that...I have some later, thick wall OEM 020 cylinder/piston sets too, that do not have tapered bore either.

Balogh, thanks for the education. I thought there was a little pinch at the top of some .020 cylinders, but
I always attributed it to castor oil accumulation.
Nothing makes me happier than learning something new.

Emanuel, sorry to hear about your injury, and
I hope you recover soon.
Bob

Thanks Bob, you are welcome.. the best way to check taper bore is by slowly pushing the piston into the degreased cylinder when the engine is disassembled.