COX TeeDee 049, new Q

But my point is why won`t a newer/ish #4 tapered set piston fit into my older tapered cylinder at all, matched set,no not a match, but should go up the cylinder part way at least;this won`t even let 1 start,tried 3 from the mid cox era, with the thicker but relief cut #4cylinders,
It should at least start to fit in the bore from the bottom of the cylinder I would think.

Maby the cylinder is out of round.

Mike 1484

If its a #4 could be like Mike said out of round. Maybe get set of claipers and measure.
Dan

And of course, you checked the cylinder for a varnish layer?

George

I devarnished/cleaned with strongest bore solvent I could find, this is bad stuff,will totally disolve the copper head gaskets,etc. So it is a fast devarnisher,nice shiny bore.

I did check it for being misshapen, its not out of round as far as I can tell.

I devarnished/cleaned with strongest bore solvent I could find, this is bad stuff,will totally disolve the copper head gaskets,etc. So it is a fast devarnisher,nice shiny bore.

I did check it for being misshapen, its not out of round as far as I can tell.

The older cylinders were snugged down by a cox wrench in the cylinder port. I have several cylinders like this that are scrap because of a wrench being over applied or the wrench bending the cylinder in the port area.Some times they can be salvaged with a light cleaning with a small hone or a lap made from a steel rod and a very fine abrasive lapping compound if it is only a small imperfection at the exhaust area.I would just pitch it and buy a new piston and cylinder unless you have the time and tools to fool with it.The old cylinders were very easy to damage because of the thin wall bypass area so close to the exaust ports.

Mike1484

That damage to the txhauat port area is not the culprit either.

Scrap it for replacement sounds like a waste, especially due to this cylinder having the outside diameter I need for a project AND the fact that since it is a smaller bore diameter than my other pistons fit in, its a simple matter of honing it out to fit a "standard" piston to fit if I wish to.

I was hoping that someone else heard of or had noticed this bore mismatch as well.

Now I am tempted to search out an old teedee for sale somewhere just to see if it matches mine, out of sheer curiosity alone.

I have a couple newer design NIP marked TeeDee 049 cylinders, and it sure feels like they have a good taper. Very, very tight as the piston is moved up to about 1/2- 3/4 cylinder with a liberal dose of after run oil. One actually stuck on me as I nudged it a bit to far. Thick walled with no #4 stamp's.

PV Pilot wrote:I have a couple newer design NIP marked TeeDee 049 cylinders, and it sure feels like they have a good taper. Very, very tight as the piston is moved up to about 1/2- 3/4 cylinder with a liberal dose of after run oil. One actually stuck on me as I nudged it a bit to far. Thick walled with no #4 stamp's.

You lucky dog not all of us are so fortunate.

So I will be waiting for Bernies new teedee cylinnders to be available.

The cylinder I mentioned earlier is a prime candidate to be bored out for a worn out tapered piston to fit.

Meanwhile I just recieved my used ebay engine; it was listed as a "teedee or medallion", here is what it really is:
teedee 051 red carb body=cracked
Medalion crank
old ,thin walled #2 piston/cylinder
Standard low comp glowhead
big old spinner on it with a topflite 5.25x4 prop, lots of evidence of starter motor use,no thrust washer of course