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Sep 16, 2019, 05:51 PM
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Oh, Brad.....:


https://www.ebay.com/itm/RARE-COX-TE...oAAOSw2ZRdeC1K
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Sep 16, 2019, 07:23 PM
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1/2A Nut's Avatar
Lol Dave yessssahh thank you, saw that on Sat. and the price is crazy!

This is the second time the engine has come up for sale I think.
Someone landed a bid on it and hung onto it for about 1.5yrs. and now it's back.
It is so rare now they most likely was not willing to use it and destroy the top dollar value.
I have some blank cylinders already bored correctly for the piston just no ports.

Saved photos from the first go around to examine the work.
Thankfully we can imitate the knowledge that was put into that engine to some degree.
I have his drawing on how to do up the bypass ports / timing for pipe use.
Think this engine was around 340 bucks the first time around when it sold.

Greg has been kind enough to provide a manifold header for the Nano X
Took some emails to sort the design out, he took it from there and nailed it.
We can all get good use of them if he makes some more I sure hope so.
Single exhaust is just a matter of slipping on one of those babies once you
have the deck height and orientation correct. I have been buying fore and aft
exhaust TD .051's for the more header manifold add on's looking forward to builds.

$419 is the starting bid looking to seeing if anyone bites it should get one or 3
My ploy like others is no bid till the last few seconds, max will need to be around
551. if I was playing the game. It's worth 5 bucks a flight I figure to have the honor
to fly with it.
Last edited by 1/2A Nut; Sep 16, 2019 at 08:00 PM.
Sep 16, 2019, 08:12 PM
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I was sure you bought the last one? https://www.ebay.com/itm/Model-Airpl...l/123886884218
Sep 16, 2019, 08:20 PM
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1/2A Nut's Avatar
That went for a reasonable price. Save some pics for posterity.
Kustom Kraftsmanship Rear Exhaust Tee Dee by naming one the pics
will show up in a search. But Google seems to limit the duration
on their servers perhaps good for 15 yrs. Stamped #114 must be
around 400 made I would imagine over the years he was taking
orders for them.
Last edited by 1/2A Nut; Sep 16, 2019 at 08:34 PM.
Sep 16, 2019, 08:31 PM
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What should I do with these?
Sep 16, 2019, 08:46 PM
Nitro User
1/2A Nut's Avatar
I have some too can ship your way if willing to batch up a run of them.
Here is what Dale Krin recommends can do the same as a single
exhaust. Use a TD case spin it on and mark for rear exhaust.
Not all fits are alike but will be close by either a shim or by file
work on the case to rotate it into the sweet spot. See last pic
Cylinder shims from Kustom Kraftsmanship for Cox .049/.051 engines.
There is one shim retainer and four shims. Three of the shims are .006
thick and one is .003 thick. The shim retainer is .007 thick on the seat.

Could do a shout out for anyone wanting to submit their blank cylinders
for batch run of mods to get them sent by a given date your way.
I would pay whatever you feel suitable no problem for these four.
- Two on the left can be bored for either .049 or .051.
- The other two have been bored for the .049 displacement.

Joe Klause says SPI is 12 thousandths of a inch when the piston
crown is level to the glow plug shoulder for best open exhaust
performance.

If a tuned pipe or header extension or muffler is to be used
then no SPI is needed can just time it to 165 to 170 and
press on with the fun.

Word was mentioned from Kirn or Kause or Nelson back in
the day they liked 172 for their hand made pipes / best all
around. but does not matter no need to get fussy. Anything
over 170 is just going to start hurting the idle and starting.
The effort alone should have the engine singing well with a
APC 4.75 x 4 with just enough load to keep the rod / pin and
crank from being in harms way. Pistons are easy to replace
I would recommend if blanks need to be bored go with the
most easy to replaced piston .049 displacement.

Could take it to the next level and line the cylinder wall to
outlast pistons.

I have saved some articles:
https://www.rcgroups.com/forums/show...&postcount=127

https://www.rcgroups.com/forums/show...&postcount=128
Last edited by 1/2A Nut; Sep 16, 2019 at 10:14 PM.
Sep 17, 2019, 11:45 AM
Registered User
Nice finds. I put them on favourites. I still think it would be more cost effective to just go with a Profi or Fora. My friend had a few blank cylinders. They needed boring and complete machining. The boring being the difficult part. An indexing head with a fixture to hold the cylinder would not be too difficult. Kind of hard to see inside the part. The cylinders did not last very many flights with the pipe. It was very fast for the day. I remember the outlet being brazed onto the cylinder. Forget who made it for him, but recall all the names in the articles from old Dayton and Cleveland events. I was just a scrawny kid with hair then.
Sep 17, 2019, 05:58 PM
Nitro User
1/2A Nut's Avatar
I have been getting plenty of scream out of TD cylinders and it still have not worn out
one yet. Castor saves the day. So far the piped TD has had around 20 ish runs still
great compression before that it was in a small outrigger hydro perhaps another 28 ish
runs between bench and field.
Sep 17, 2019, 08:40 PM
Registered User
Maybe the brazing destroyed the heat treatment if there even was one. I think the pistons are the harder material.
Sep 17, 2019, 08:59 PM
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toad007's Avatar
I read somewhere the cyl's were made with 1218 LL steel, it wont take a heat treat but it will case harden some. so the trick is in the close tolerances, the fit between the piston and bore is in the 1/10,000 range, not the .005 range as I read above. You cant just spit a cly off the lathe and have it work in the loose range like that.. Im not sure if 1218 can even be chromed, so fit is king if you want it to run right.
Sep 17, 2019, 10:09 PM
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1/2A Nut's Avatar
That's good to know thank you Mel,
Many folks have the bored versions just blanks.
I have two already setup for the .049 piston, good fits on both.
Last edited by 1/2A Nut; Sep 18, 2019 at 12:16 AM.
Sep 18, 2019, 12:36 PM
Registered User
I heard the original machinery made the bores at least, to the .0001" tolerances with the taper. The newer ones are not as good, with .0005". They will run but depend more on break in and or hand fitting/selection for proper fit. That cutaway motor looks cool. I wonder how the swedged part of the piston was machined.
Sep 18, 2019, 02:25 PM
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Thread OP
Quote:
Originally Posted by aspeed
I heard the original machinery made the bores at least, to the .0001" tolerances with the taper. The newer ones are not as good, with .0005". They will run but depend more on break in and or hand fitting/selection for proper fit. That cutaway motor looks cool. I wonder how the swedged part of the piston was machined.
This tool and die maker thinks it was swaged closed around the ball on some kind of rotary machine
Sep 18, 2019, 03:38 PM
Pro Hoarder
turbonut's Avatar
Or just machine part way into the rod then spin it 180 deg and your done..
Latest blog entry: In flight
Sep 18, 2019, 06:32 PM
ffkiwi
Quote:
Originally Posted by toad007
I read somewhere the cyl's were made with 1218 LL steel, it wont take a heat treat but it will case harden some. so the trick is in the close tolerances, the fit between the piston and bore is in the 1/10,000 range, not the .005 range as I read above. You cant just spit a cly off the lathe and have it work in the loose range like that.. Im not sure if 1218 can even be chromed, so fit is king if you want it to run right.
As I recall Gene Hempell was offering chromed reworked TD cylinders back in the day-so either 1218 CAN be chromed...or he had a batch made up from a different steel....which seems unlikely....as does machining up his own 'identical to OEM Cox' cylinders....for the price he was charging back then.

ChrisM
'ffkiwi'


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