The twingle is getting close

comnoz · Apr 17, 2011

Got to spend a little time on my new fuelie bike motor. It's gettin close. 91mm stroke and 80 mm bore for a 0 degree 914- suppose I will be able to start it. Jim

Diablouph · Apr 17, 2011

The thing is so gorgeous, why put it together. Leave it open for all to see. Or, put a window in the case.

bpatton · Apr 17, 2011

WOW. Is it going to be for the strip or for hillclimbing. The vertical kind, that is.

comnoz · Apr 17, 2011

This is for my daily rider. I have always loved the cadence of a big single. I am more enthused about getting this thing running than any motor I have built in some time. Just crossing my fingers and hoping it will stay together. Jim

DaveK · Apr 17, 2011

Wow. Thats pretty nice there. Wish mine was 1/100th that good. I see little holes in the cam, thats for oiling? Never seen that before, then again I haven't seen alot. Is that fitting on the end for that perpose?

swooshdave · Apr 17, 2011

Looks like gear drive on the cam. :mrgreen:

comnoz · Apr 17, 2011

DaveK said:
Wow. Thats pretty nice there. Wish mine was 1/100th that good. I see little holes in the cam, thats for oiling? Never seen that before, then again I haven't seen alot. Is that fitting on the end for that perpose?

Yes I have oil feed through that fitting to the rifle drilled cam. Overkill but the present motor has it so the lines are all in place and I have an oversized oil pump so I have extra oil.

Hortons Norton · Apr 17, 2011

That is going to be one BIG Thumper!!!!!!! Please post a video with sound, But are you not stealing he name? LOL LOL. :wink:

Hobot · Apr 17, 2011

Wow, a 55 cid Twingle Thumper! Will out Potato head the big Twins! i can see it now on throttle the tire chirps on each dual spark hit.
This is one of the most interesting engines I've seen in a long time too and you mentioned main reason why I'm so interested. Look forward to discussing marine engine exhaust valve un-seating values with you.

Hortons Norton · Apr 17, 2011

Is this the first time this has been done?

askdoctorday · Apr 17, 2011

That's beautiful, just beautiful. Really nice work.

Hobot · Apr 17, 2011

Might be first Norton Commando Twingle.
I quiver at the crank flex on dual big twin hits at once. But crank sure is robust as they get, but still a unsupported jump rope crank. Prior examples.

Posts: 09-25-2010 10:04 PM
"split piston singles" were one attempt to solve the low power/ high fuel consumption problems plaguing early two strokes.
One piston was generally bigger than the other and there was a port between the two.
Puch, an Austrian company, made many of the bikes that were sold in the Sears catalog.

http://www.fiero.nl/forum/Forum6/HTML/078421.html

I've got a set of the twinkle cams at the shop, our engine builder is a 76 year old flat track team owner named Bob Donabedian that built a couple of those motors, he said when you got the revs up a bit the bike would rip the track apart but none of his riders could stand the vibrations.
He also built a normal Triumph motor last year that dyno'd out at 72 rear wheel horse and 76 ft lbs of torque, it was a fast bike, real lite and fun the ride.
Good luck with your build but I wouldn't recommend a twinkle fire twin.

comnoz · Apr 17, 2011

Hortons Norton said:
Is this the first time this has been done?

A guy told me about someone in Ca. who was working on one but I was never able to find him or anything about it. It will be the first time I have tried it or seen one. Jim

comnoz · Apr 17, 2011

hobot said:
Might be first Norton Commando Twingle.
I quiver at the crank flex on dual big twin hits at once. But crank sure is robust as they get, but still a unsupported jump rope crank. Prior examples.

The forces on the crank from combustion are only a fraction of the forces resulting from imbalance so I doubt it will change the crank stress much and since the balance will not be changed I doubt that it will change the vibration except for the pulsing power delivery at lower speed. I have added considerable weight to the crank to help this. I worry most about the gearbox.
Of course I may be completely wrong about any or all of this so that is why it has a quick change cam installed. Jim

Hortons Norton · Apr 17, 2011

comnoz said:
Of course I may be completely wrong about any or all of this so that is why it has a quick change cam installed. Jim

This would seem to be a good idea on any Commando?? So the plate is removed and it slides out? Awesome idea Jim.

AussieCombat · Apr 17, 2011

Keep up the good work Jim.. I think your arms are about to get longer.
Speaking of starting, will there be a compression lifter on one side ?
AC.

comnoz · Apr 17, 2011

AussieCombat said:
Keep up the good work Jim.. I think your arms are about to get longer.
Speaking of starting, will there be a compression lifter on one side ?
AC.

I have a feeling that may be necessary but I will find out. If so I can add that to a valve cover. Jim

Hobot · Apr 18, 2011

ugh photo was cutaway of what "twingle" first and only meant, 2stroke with shared crank pin, different size pistons to help charge flow through.

BF same, mass fling the same, should vibrate and isolate the same. As big bang as BI gets so far. Tire frequency traction reaction is a hobby of mine. 720' hits plus isolastic thrust dampening should hook leans real mean. Poor old main shaft and sleeves could complain about it but a fuel squirt should romp and sprint from 4th.

Compress releases are a boogaboo to me. Not much to gain venting in bore area and cam intake don't close till a good way up,anyway. Little old chains saws maybe but not Harley scale compressure, they and diesels vent out the head. Tricky to release enough to kick and also start and run. Exhaust valve lifts in marine diesels are on scale of ~.003" zone. Prey tell how to pull this off. I know I'll need it when not in best condition for karate. Ken Canaga and you both found no place to tap release in chamber. Think of all the kick lever splines this feature would save. I've my own idea but ain't paid to have it created yet.

Apparently HD flat trackers liked two fires at ~once. Article contradicts itself in twingle or big bang both hurting and helping traction.
http://en.wikipedia.org/wiki/Big-bang_firing_order

Jeandr · Apr 18, 2011

I'd like to see you start that with your hand :mrgreen:

Jean

comnoz · Apr 18, 2011

Jeandr said:
I'd like to see you start that with your hand :mrgreen:

Jean

I may have to use both hands.

The twingle is getting close

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