Very rare old school 5-hunny

[Leftcoast leftkicker]

http://www.vintageworksbikes.com/1972Husqvarnatwin.html

 

[Motosportz]

It's a twin****************************************

 

[Colo moto]

I'm probably wrong on this, but I think that is the only 500 twin in existence. I vaguely remember reading an article saying that Edison Dye had requested a 500 twin for baja. I think it won the 1000 that year, but husky never produced them.

 

[robertaccio]

Wow that thing is amazing, makes me think of the "Yankee Z" twin.

 

[Stapleking]

In fact, they did make a few of them. One resides in a Seely-framed roadracing bike that had factory support for a brief foray into 500 cc. GP racing in the 70's. The bike is in the HVA company museum. rofessor:

 

[Colo moto]

Yeah, that's what it was, they made a few 500 twins for road racing, and the GP's, and then made that 1 for Edison and the baja race.

 

[Leftcoast leftkicker]

I think the only other is in Tom White's museum in SoCal

 

[dfeckel]

I've never seen a multiple-cylinder 2 stroke merge the exhausts into a single expansion chamber. I wonder if the opposite cylinder interfered with the scavenging exhaust pulses. Did the cylinders fire in tandem? If so, I bet it were a bit vibey...

 

[Stapleking]

I think the off-road bike was a "twingle".* The roadracers were not and used two expansion chamber exhausts.

*I'll check

 

[Norman Foley]

I've never seen a multiple-cylinder 2 stroke merge the exhausts into a single expansion chamber. I wonder if the opposite cylinder interfered with the scavenging exhaust pulses. Did the cylinders fire in tandem? If so, I bet it were a bit vibey...

Pretty standard on 2 stroke snowmobile engines to have "Y" pipe to one spany.

 

[Joe Chod]

I'm probably wrong on this, but I think that is the only 500 twin in existence.

One must never forget the twin "Yankee" made of 2 Ossa motor made right here in Schenectady,NY. Some of my older club members rode them and boy.........look out where you pointed it because thats where it was going! A bike made in USA from foreign parts long before ATK.
Theres one around me but I have never seen it and it is bad in need of a resto.

Joe

 

[Dirtdame]

Wow, thanks for linking to item and sharing. That is amazing looking.

 

[Stapleking]

From the Horse's mouth:

"...there were at least 2 or 3 versions of the twin. On the first version there were 2 independant cranks, linked with a splined sleeve. You could set the firing sequence anyway you wanted. If both cylinders fired at the same time the vibration was so bad the bike was unrideable; close to 180 degrees apart was best. A single exhaust pipe was used because space was limited and there was plenty of power anyway."

And there you have it.

 

[Colo moto]

From the Horse's mouth:

"...there were at least 2 or 3 versions of the twin. On the first version there were 2 independant cranks, linked with a splined sleeve. You could set the firing sequence anyway you wanted. If both cylinders fired at the same time the vibration was so bad the bike was unrideable; close to 180 degrees apart was best. A single exhaust pipe was used because space was limited and there was plenty of power anyway."

And there you have it.

Awesome info stapleking. Thanks for digging for the details.

 

[Stapleking]

Bin digging...more info: There were perhaps 10 of the 500 c.c. twins built by HVA. It was designed by Urban Larsson, who now works for us [yes, he is old]. The design was then sold/tranferred to Folan, a small Swedish engineering co. who modified it to water-cooled. They built 100 or so of them, in various displacements, using Husky barrels, pistons, etc. on a custom-order basis. Most if not all went into sidecar racers. See attached pic.

View attachment 593

 

[robertaccio]

Wow that thing is amazing, makes me think of the "Yankee Z" twin.

One must never forget the twin "Yankee" made of 2 Ossa motor made right here in Schenectady,NY. Some of my older club members rode them and boy.........look out where you pointed it because thats where it was going! A bike made in USA from foreign parts long before ATK.
Theres one around me but I have never seen it and it is bad in need of a resto.

Joe
http://www.yankeetwin.com/

 

[Stapleking]

There was a Yankee on E-bay a 'couple years ago. I was tempted.....

Also, apparently the water-cooled Husky twin was slated for production, but then the company was bought by Electrolux and the bike operation sold to Cagiva. Cagiva did nothing with the design, probably due to a chronic lack of $$$. So, it died at Folan.