Re: my "twin bee"

chris74100 Tue Oct 22, 2013 1:34 pm

No, it is the only one whom I built.The fuel is standard with 5% nitromethane, and this engine use a stock "reed".
Now I builds one 4 cylinders boxer of 16 cm3, 2 stroke

roddie Tue Oct 22, 2013 9:09 pm

chris74100 wrote:No, it is the only one whom I built.The fuel is standard with 5% nitromethane, and this engine use a stock "reed".
Now I builds one 4 cylinders boxer of 16 cm3, 2 stroke

I am assuming a 4 cyl. will have a proportionately sized "rotary-valve" induction?

Did you increase the fuel/air-flow in the 1st 2 cylinder engine? (asked in my previous post) I am aware of the fuel restrictions/availability in your region... but your Cox engine components were designed to run on fuel with a nitro content of 3-times (minimum) of what your stated test-fuel has.

I would "personally" pay the shipping... "to and from" the U.S. to have one of our "engine people" here; run your 2 cylinder model, on "cox" fuel. You already have several people interested in your engine... and there's quite a large Cox community here in the U.S. You "may" be able to profit from a production-run, if the engine's performance is adequate.

We are all very envious of your skills!

Roddie

chris74100 Wed Oct 23, 2013 12:01 am

Hi, Roddie, the fuel/air-flow is similar at the standard babee be. I'm not modified.
Maybe would be it better to put a carburetor

roddie Thu Oct 24, 2013 10:37 am

chris74100 wrote:Hi, Roddie, the fuel/air-flow is similar at the standard babee be. I'm not modified.
Maybe would be it better to put a carburetor

Chris, in my opinion... a 4 cylinder should have a venturi size of a .15 to .20 engine (if using the Cox .049 cylinders) and large enough to bore-out, if there's still not enough air-flow.

Maybe design a crankcase with the venturi in the "center"; equally feeding the 2 front and rear cylinders with a rotary-valve crankshaft supported with bearings?

There's always the consideration of the "mounting" provisions too. A "radial" mount would probably be better than "beam mounts". I've seen multi's with a "rear" intake... and this makes it difficult to mount the engine to a firewall.

I am sure that if "anyone" can build it... "you" can!

Roddie

chris74100 Thu Oct 24, 2013 10:42 am

Lol, the 4 cylinders is 4x .20ci, (16cm3 in metric).

roddie Thu Oct 24, 2013 3:17 pm

chris74100 wrote:Lol, the 4 cylinders is 4x .20ci, (16cm3 in metric).

Sorry Chris... I should have caught that in your previous post... Embarassed

chris74100 Sat Oct 26, 2013 4:49 am

This morning, I made a tap to fix cylinders

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chris74100 Sat Oct 26, 2013 4:51 am

OVERLORD Sat Oct 26, 2013 9:25 am

I've never seen somebody make a tap himself - And of such a fine thread. Very nice job!

lieven

roddie Sat Oct 26, 2013 10:50 am

Nice shop you have there! I ran a "Blake" grinder years ago, for a small local tap company. The machine was for grinding the "flutes" in the tap. The abrasive wheel was "diamond-dressed" down each side, to the proper thickness, and then a "radius" was dressed on; which was frequently "re-dressed" as needed. There was a "rhythm/technique" that had to be mastered while "feeding" into the wheel and then "retracting"... that produced a finish; free of chatter/burn. When completing a piece, the "lands" had to measure within .003" of each other in thickness. It could be a bear to set up... especially with small stuff such as 000-120 pitch. You could almost "see through" the wheel, after dressing it into thickness for these.

Keep us posted on the 4 cylinder's development!

Roddie

pkrankow Sat Oct 26, 2013 11:01 am

Very cool.
Phil

chris74100 Sat Oct 26, 2013 11:03 am

Thanks, but this tap can only aluminium tapping.

chris74100 Tue Nov 05, 2013 12:40 pm

Here is the beginning of the construction of my second " twin bee ".I wait for the parts of Canada to continue.

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chris74100 Wed Nov 06, 2013 2:09 pm

**RknRusty** Wed Nov 06, 2013 2:36 pm

Watching with fascination.

pkrankow Wed Nov 06, 2013 3:17 pm

RknRusty wrote:Watching with fascination.

yes. same here.
Phil

chris74100 Thu Nov 07, 2013 5:16 am

The Crankshaft is almost ended.

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chris74100 Sat Nov 09, 2013 9:20 am

That's my new stand of the new "twin bee"

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And with the engine

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chris74100 Mon Nov 11, 2013 11:13 am

With "paint" and name, N° 0000 for the prototype, CBY.98 for the name and "capacity", and my name (Christian BaillY), the commercial engine will have n°0001

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