Bitchin' 2 Stroke!

Anyone speaking of 2 strokes and earplugs needs to keep an ear out for the 1936 supercharged 3 cylinder DKW Auto Union, as was raced in the Isle of Man in 1936.

It was said that this was the only bike that could be heard on the mainland - 80 miles away.
Sounds can carry across water a bit, but still.

Amazing sound, even in muted form like they still race sometimes today.
http://www.mcnews.com.au/ClassicsCustom ... 2_full.jpg
 
A 500cc GrandPrix Honda or Yamaha or Suzook put out about 250bhp about 10 years ago, so this is not exactly earthshattering. ?
As a roadbike it might be interesting - but won't be legal ?

P.S. Turbocharged Hayabusas are up in the 600hp+ category ?
 
Not really feasible to ride a GP bike on the road, but I would think that a 250bhp road bike, which weighs a lot less than all 4T sportsbikes would be really good fun.
 
Carbonfibre said:
Not really feasible to ride a GP bike on the road, .
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Why not ?
Doesn't sound far different to what they are effectively going to be doing anyway.

And to cope with that power, going to need GP level of upgraded brakes and suspension.
And to get 250bhp out of a big triple, its going to need expansion chambers ??.

P.S. Manx Nortons and TZ Yams have appeared, thinly disguised, as roadbikes after their useful racing life was over - magazine features were full of them. My fav-o-rite was the G50 Matchless engined trail bikes that someone was doing.
(Not that different to what the factories were doing in the 1930s...).
 
Wonder where you are going to buy an ex GP 2T bike with 250bhp at the rear wheel, and the spares required to keep it running reliably on the road?
 
Carbonfibre said:
Wonder where you are going to buy an ex GP 2T bike with 250bhp at the rear wheel, and the spares required to keep it running reliably on the road?
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Where does it say that this 1100cc triple thingy is going to 'reliably' run on the road' ?
That is about triple the specific output of the old Suzook waterbottle, so mildly tuned its not.
And is going to require race type expansion chambers to make those numbers. ?
So road legal its not either. Should be fun while it lasts though...

P.S. Ducatis can make those numbers, new out of the showroom ?
At a cost though, it must be said.
And then there are the turbocharged Hayabusas....
 
Have a look at the web site of the people making the 1100cc triple............they already make 500cc road going 2T twins with almost double the power of a Brit 4T, and only a little over half the weight. Porting looks quite conservative in comparison to a road race 2T, and I would imagine long term reliability of the road isnt going to be a problem.................
 
Porting can't be too 'conservative' for a 2 stroke, thats still about 3 times the specific output for a Suzook waterbottle.
And they are not legal on the road...

Someone had a TZ750 road registered, since old ones were going for a song at one stage.
At least that had the chassis and brakes to match.
 
Rohan said:
Porting can't be too 'conservative' for a 2 stroke, thats still about 3 times the specific output for a Suzook waterbottle.
And they are not legal on the road...

Someone had a TZ750 road registered, since old ones were going for a song at one stage.
At least that had the chassis and brakes to match.
Click to expand...


The fact that these modern 2T motors use 11 port cylinders, mean that in effect the ports themselves are much smaller, which results in less problems with ring wear. Modern road bike chassis are very good indeed, and only let down by cheap suspension parts, so I would imagine that one of the 1100cc 2T triples in the Kawasaki road chassis as pictured, fitted with good suspension is going to be pretty much the fastest bike on the road!
 
The kwackersiki Jet Ski two strokes carrie some of the same p[art no's as the H2 , ands available 2 or 3 cyl , non unit . :?
 
Thats interesting.............the H1-H2 were great bikes, and here in the UK are today very collectable.
 
I can recall looking at a friends V6 outboard motor - and running a tape over it to see if it would fit anything bike ! It was very compact. Then the discussion drifted to carrying a bucket of water around, so the muffler system would have the right watery burble.....
 
I have a friend who used an Iron duke GM inline 4 from a boat in his case skidsteer. He made up a bunch of adapter plates. It sounded boat like.
 
Rohan said:
I can recall looking at a friends V6 outboard motor - and running a tape over it to see if it would fit anything bike ! It was very compact. Then the discussion drifted to carrying a bucket of water around, so the muffler system would have the right watery burble.....
Click to expand...
300horse Evinrude 2stroke has a nice intake sound running breathers :twisted:
 
With direct cylinder injection, such as is now offered in some automobile engines, two strokes can run as clean as four strokes and make similar gas mileage too. They are inherently lighter, being bereft of valve train.

Given the static method by which displacement is computed, a two stroke will always have superior volumetric efficiency, compared to a four stroke.

If science, instead of politics, ruled racing, then the two strokes would still hold 100% of the spots on the FIM/MotoGP grid. We would likely have plain bearing lower ends with top ends fed by piston ports blowing supercharged air into cylinders fed fuel by post exhaust port closing high pressure direct injection. That said, an expansion chamber IS a supercharger, except, simply stated, it sucks instead of blows.
 
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