Oddball engines and prototypes

[Hemi Makutu]

Commercially available 2T design software... what would poor old Kaaden have given for this?

www.buildandclick.com/html/tuned_pipe.html

[Frits Overmars]

Commercially available 2T design software... what would poor old Kaaden have given for this? www.buildandclick.com/html/tuned_pipe.html

Not a whole lot, I suppose.
Kaaden once discussed two-stroke design by computer with Gordon Blair who had just realised the QUB 250-twin with rotary inlet drum, which produced about 40 hp.
Kaaden responded that at MZ the computer was only used for bookkeeping and that his 250 cc disc-valve twin produced 60 hp .

[Hemi Makutu]

Not a whole lot, I suppose.
Kaaden once discussed two-stroke design by computer with Gordon Blair who had just realised the QUB 250-twin with rotary inlet drum, which produced about 40 hp.
Kaaden responded that at MZ the computer was only used for bookkeeping and that his 250 cc disc-valve twin produced 60 hp .

Quite right Frits,

Poor old Walter Kaaden had done real research with hi-tech resources under Nazi Adolf's regime,
& achieved much under the sparse/spartan DDR regime too.

Without such brilliant ideas-men/engineers the IT-software guys of today would have nothing to input..

I recently read a NACA 2T test from 3/4's of a century ago which evaluated aspects
of a radially ( around crank-end) arranged petal reed-valve crankcase set-up..

[Frits Overmars]

Commercially available 2T design software... what would poor old Kaaden have given for this?

I must add that today there are some pretty good engine simulation programs available.
EngMod2T comes to mind, developed by Neels van Niekerk who is as much a hands-on two-stroke specialist as he is a physics professor.

[Hemi Makutu]

Here: http://naca.central.cranfield.ac.uk/...ca-tm-1131.pdf

This is a NACA translation of German pulse jet development which Kaaden's MZ 2T applied for racing power.

As such, the harnessing of these resonant flows to shaft output made the 2T a natural for G.P. racing ( 'til banned!),
even after the FIM severely limited the number of cylinders & gears to be used, work to broaden 2T powerband
was showing such good results that N/A 4Ts - even using very expensive construction to enable high rpm
- have not been able to match, on a specific output basis.

[Frits Overmars]

Here: http://naca.central.cranfield.ac.uk/...ca-tm-1131.pdf This is a NACA translation of German pulse jet development which Kaaden's MZ 2T applied for racing power.

That paper gives a good impression of typical german thoroughness. I'm glad the nazis didn't win the war but I can't help admiring a number of german achievements.
The research described in the above paper lead to this, the world's first cruise missile:


Walter Kaaden was only indirectly involved in pulse jet research, and I think we should put his merits into perspective here.
These days Kaaden is regarded by many as the father of two-strokes. But he invented neither the two-stroke nor the expansion exhaust or the disc valve. Neither did the german Daniel Zimmermann who equipped a 125 cc engine with a flat disc and made it faster than the piston-ported works MZ's. The east-german communist party then 'suggested' that he donate his engine to MZ... Disc valves were patented in 1918 by the british Sun company who actually raced their 250 cc disc-valver in the 1921 TT on the Isle of Man.

Kaaden didn't invent the expansion pipe either. In 1951 DKW-engineer Erich Wolf equipped the 125 cc bike of works rider Ewald Kluge with such a device. At the time MZ was using megaphones and it took another 5 years before Kaaden saw the light. The light was rather dim too, because the 158° exhaust timing of the MZ was far too short for a real expansion pipe. Kaaden switched back to megaphones and only in 1960 did he understand that he had to raise his exhaust timing by at least 30°.

Having said this, Kaaden was the man who kept two-stroke spirits alive after DKW withdrew from racing, and he achieved a lot under harsh conditions in the former Deutsche Demokratische Republik.

[Hemi Makutu]

Quite correct Frits, I have a copy of the 1957 'Automobile Year' book which notes as such - advances in 2T
power development - & also as 'athodyd' based!

Credit due Kaaden though for getting the 'stinkwheel' riders back on 'the top of the box' in G.P.s - & even getting
the likes of Mike Hailwood to throw his leg over one of 'em...

[Niels Abildgaard]

From memory , his biography states that Kaaden worked on the tailfins of a rocket powered Henschel glide bomb during WW2.
No pulsejet .

[Hemi Makutu]

Swedish academic technical appraisal of E-TEC 2T DI marine engine.

http://publications.lib.chalmers.se/...ext/149154.pdf

[Hemi Makutu]

Has he spent too much.. on the white powder?

http://www.bikebound.com/2016/10/17/gatto-nero/

[tjbw]

Has he spent too much.. on the white powder?

http://www.bikebound.com/2016/10/17/gatto-nero/

I was watching a snowmobile video just yesterday, and thinking what if ..

Didn't expect to see it realised the next day, and it looks good to me.

[Hemi Makutu]

www.hirth-engines.de/index.php/en/

[tjbw]

In 1956 Triumph decided to try a 200cc two stroke twin, to compete against the rumoured Ariel Leader.

The engine had reed valve induction, with a single carb and LONG inlet pipe. The carb is hiding in the chamber just in front of rear mudguard. It has a single alloy casting for the twin cylinder block, with liners. Initially they used a belt for the primary drive, but it was replaced with a chain. The alternator cover for this prototype was made from a saucepan!

It seems they didn't achieve the expected performance, and the project was abandoned.

They did try different inlet lengths, but I wonder if better performance would have been achieved with 2 carbs on short inlets.

The bike is now on display at the Sammy Miller museum in England.

More photos (showing the saucepan) and text here:
https://books.google.co.uk/books?id=...totype&f=false

https://www.flickr.com/photos/motosa...n/photostream/

[tjbw]

Well it's the weekend, so some might like to contemplate this drawing.

To be fair the author commented on a revision to this shortly after it was posted, perhaps he should have corrected the drawing too.

[Hemi Makutu]

http://www.pattakon.com/pattakonPatATeco.htm