The Bucket Foundry

[Flettner]

No, a 700 twin is what it will be, been negotiating with my build partner, he wants reed, I don't. So after a ride on the F9, it's going to be variable rotary valve, EFI. Maybe a V, maybe a parallel twin?
No, a V is what has been decided.

[ken seeber]

Let me call it sub-piston pumping. And then I'd say it is the simplest starting provision you can have on a two-stroke engine. Once it's running, well......

I like it. It's been a while, but we now have another acronym....SPP

Yes please...
I've got two complete 1KT engines screaming to be joined together....

Bert, when you say 1KT, do you mean Yamaha KT100S kart engines? Depending on the application, one could run them side by side, fin tips almost touching. Then couple them in the middle with a chain drive take off. Would mean reversing the crankcase on one of the engines and you can get reverse direction ignition rotors. Would be wide, smokey and noisy and 40 hp. Could also give Frits the opportunity to demo a compact 2 into 1 exhaust to keep Willy happy.

[F5 Dave]

1KT= first model TZR250
Followed by same 2MA, reverse 3MA, v twin. 3XV

[husaberg]

I like it. It's been a while, but we now have another acronym....SPP

Bert, when you say 1KT, do you mean Yamaha KT100S kart engines? Depending on the application, one could run them side by side, fin tips almost touching. Then couple them in the middle with a chain drive take off. Would mean reversing the crankcase on one of the engines and you can get reverse direction ignition rotors. Would be wide, smokey and noisy and 40 hp. Could also give Frits the opportunity to demo a compact 2 into 1 exhaust to keep Willy happy.

1KT= first model TZR250
Followed by same 2MA, reverse 3MA, v twin. 3XV

I think only us and the Japanase called the origional model the 1KT.
To the rest of the world from what i understand they started out as 2MA's.
There is a 2XT as well.
http://www.nostalgicsportsbikes.com/...1kt2ma2xt.html

[Niels Abildgaard]

No, a 700 twin is what it will be.A V is what has been decided.

Hello Flettner

Wise choice.
Am dreaming of a single crank 90 degree V2.
Have tried to scheme a standard 2 conrod side by side on a single pin arrangement.
Problem is that the two needle cages go up and down in angular velocity and make renewal nessecary very often.
A solution can be to have a sligthly bigger common needle cage running inside a ring and the let each conrod ride on this ring or cylinder with uncaged needles like some pistonpins.

[Frits Overmars]

Am dreaming of a single crank 90 degree V2. Have tried to scheme a standard 2 conrod side by side on a single pin arrangement. Problem is that the two needle cages go up and down in angular velocity and make renewal nessecary very often.
A solution can be to have a sligthly bigger common needle cage running inside a ring and the let each conrod ride on this ring or cylinder with uncaged needles like some pistonpins.

Niels, the total angular movement of a small end bearing over one crankshaft revolution is about 6 x less than the total angular movement of the big end bearing.
What works in a small end (and even that is doubtful) may not work in a big end.

[Niels Abildgaard]

Frits

My hope is that the single inside /outside bearing ring will rotate with the crankshaft mean velocity and the two rows of uncaged needles only even the angle difference between the two conrods out.
I will try to make an animation.And show it here if it works.

[Flettner]

Frits

My hope is that the single inside /outside bearing ring will rotate with the crankshaft mean velocity and the two rows of uncaged needles only even the angle difference between the two conrods out.
I will try to make an animation.And show it here if it works.

Am I missing something? Wouldn't you just use two complete big ends (singular) and fit thrust washer between them? Ie three thrust washers in all.

I'm going to just make it a single crank with the center section one piece, EN39B case hardened, including crank pins. The center bearing will be a split roller with a split labyrinth seal. This is to try to keep the engine as narrow as practical. Being EFI there will be no carburetor stuck out each side, just a bellmouth into an air box. Also having a V will free up space around the cylinder for injectors where a parallel twin would be more difficult.

[TZ350]

I'm going to just make it a single crank with the center section one piece, EN39B case hardened, including crank pins. The center bearing will be a split roller with a split labyrinth seal. This is to try to keep the engine as narrow as practical. Being EFI there will be no carburetor stuck out each side, just a bellmouth into an air box. Also having a V will free up space around the cylinder for injectors where a parallel twin would be more difficult.

I like this very much ....

[WilDun]

Am I missing something? Wouldn't you just use two complete big ends (singular) and fit thrust washer between them? Ie three thrust washers in all.

I'm going to just make it a single crank with the center section one piece, EN39B case hardened, including crank pins. The center bearing will be a split roller with a split labyrinth seal. This is to try to keep the engine as narrow as practical. Being EFI there will be no carburetor stuck out each side, just a bellmouth into an air box. Also having a V will free up space around the cylinder for injectors where a parallel twin would be more difficult.

Will it be 1 labryrinth seal with 1 needle roller bearing on each side or 1 needle roller with a labrynth seal on each side or ........ am I'm just thick??

Just dragging my furnace out from under a tarp outside (where it's been for about 6 weeks) - might need to go careful with the warm up and make sure it's dry before I light the burner! - guess a lightbulb overnight and half an hour with a heat gun, then it'll be all on - a race against time before winter starts to set in, also before your new project sets in!

[husaberg]

Am I missing something? Wouldn't you just use two complete big ends (singular) and fit thrust washer between them? Ie three thrust washers in all.

I'm going to just make it a single crank with the center section one piece, EN39B case hardened, including crank pins. The center bearing will be a split roller with a split labyrinth seal. This is to try to keep the engine as narrow as practical. Being EFI there will be no carburetor stuck out each side, just a bellmouth into an air box. Also having a V will free up space around the cylinder for injectors where a parallel twin would be more difficult.

Neil you don't need the lab seal just a piston ring
Then you can share the one crankpin just like a Ducati.
The Jbb Engine
Also both inlets on one side so even narrower.

[Grumph]

I look at that JBB crank and think...I've got enough Villiers bits here to do that.......Even the simple case halves could be used.....

[husaberg]

I look at that JBB crank and think...I've got enough Villiers bits here to do that.......Even the simple case halves could be used.....

You might want to use a real big end bearing though.
If you ever run short of villiers engines the old has a shed full (literally)
Remember that doubled up 2t V4 with a supercharger.

http://www.thecampervanchronicles.de/villiers_v4.htm

[Niels Abildgaard]

Frits

My hope is that the single inside /outside bearing ring will rotate with the crankshaft mean velocity and the two rows of uncaged needles only even the angle difference between the two conrods out.
I will try to make an animation.And show it here if it works.

Not an animation but three pictures showing my revolutionary V2 crank system for two strokes.
I have something to do the next couple of days trying to understand if it works.
Between crankpin and floating bearing ring there is a normal caged needle bearing,but this turns at a constant angular velocityand lasts forever.
Each conrod rides the floating ring on uncaged needles but the angular displacement is very small during one revolution.

[Grumph]

But is the extra layer (no pun) of complexity really neccessary ?

The whole bearing looks too much IMO like the floating bush bigends originated by Henri in the 1920's and perpetuated by Royal Enfield.
These proved to be too heavy and suffered from a lack of lubrication to the inner bearing.

KISS - and proven technology should be satisfactory IMO.