great scott!

The layout was develpoed in 1920, and scott have tried to bypass Schneurle patents, they layout was put to good effect with the use of Walter Kaaden's expansion chamber on a MZ motorcycle.

Snip from Wiki

This method of scavenging uses carefully shaped and positioned transfer ports to direct the flow of fresh mixture toward the combustion chamber as it enters the cylinder. The fuel/air mixture strikes the cylinder head, then follows the curvature of the combustion chamber, and then is deflected downward. This not only prevents the fuel/air mixture from traveling directly out the exhaust port, but also creates a swirling turbulence which improves combustion efficiency, power and economy. Usually, a piston deflector is not required, so this approach has a distinct advantage over the cross-flow scheme (above). Often referred to as "Schnuerle" (or "Schnürl") loop scavenging after the German inventor of an early form in the mid 1920s, it became widely adopted in that country during the 1930s and spread further afield after World War II. Loop scavenging is the most common type of fuel/air mixture transfer used on modern two-stroke engines. Suzuki was one of the first manufacturers outside of Europe to adopt loop-scavenged two-stroke engines. This operational feature was used in conjunction with the expansion chamber exhaust developed by German motorcycle manufacturer, MZ and Walter Kaaden. Loop scavenging, disc valves and expansion chambers worked in a highly coordinated way to significantly increase the power output of two-stroke engines, particularly from the Japanese manufacturers Suzuki, Yamaha and Kawasaki. Suzuki and Yamaha enjoyed success in grand Prix motorcycle racing in the 1960s due in no small way to the increased power afforded by loop scavenging. An additional benefit of loop scavenging was the piston could be made nearly flat or slightly dome shaped, which allowed the piston to be appreciably lighter and stronger, and consequently to tolerate higher engine speeds. The "flat top" piston also has better thermal properties and is less prone to uneven heating, expansion, piston seizures, dimensional changes and compression losses.

Cheers Steve

After a quick strip down.







I dont really want to go much further then this at the mo, the internals are as nicely made as the externals, the timing gear and all is fitted with a lovely duplex timing chain, trust scott to make a simple 2 stroke complicated....

It has now been degreased and wiped down, all the exhaust components have been separated and the base removed, I may try and reuse the base as cash is getting tighter.

I will also try and tidy it up with stuff I have in the shed already.

Thanks for looking

Cheers Steve

Looks like your going to be busy for a while, are you painting it the same purple as the last one or keeping it red?
I have to ask what did you hit with that big wooden mallet

Stu.

Same blue as the Norman SC, Was separating the exhaust system.

Cheers Steve

Done a little more today, before going out for a few drinks I sanded down the paint so had a nice surface and gave it a coat of under coat to make sure.
So today I rubbed that flat and put some top coat on, I went with the Satin finish, being a military engine I dont really like them to shinny.





Exhaust base, and the connecting pipes have been sprayed black



I tried to get a close up of inside the casing





While the paint was drying and put to one side I turned to the wood, now considering im Useless with wood I think its turned out ok.

Here is part way through.



Will see what else I can get done.......

Cheers Steve

that's watt you call reclamation

Waste not want not etc...

Its fairly nice wood under the 2 stroke grime

Cheers Steve

is it a soft wood ?

Wood wood.....I said in a previous post that im useless with wood, seems quite hard to me.

The smaller sections is soft wood and I wont be using them for this, they will be altered for the pump set.

Cheers Steve

Skankin_giant wrote:Wood wood.....I said in a previous post that im useless with wood, seems quite hard to me.

The smaller sections is soft wood and I wont be using them for this, they will be altered for the pump set.

Cheers Steve

spill out on some new wood , reclamation posts and cut them down

I'm trying to do this one with what I have lying around, so far spent a fiver on 2 plugs, had the paint and all lying about for 12 months or more.
Only other thing I might get is some wheels and axles.

Cheers Steve

Finished the wood yesterday.



put back together ready for me to go back work!





Not sure about wheels yet, would make it easier to move about, but would need to be cheap cheap!

Cheers Steve

Looking well Steve, just need to go round with the brassoi for the finishing touch.

What make of mags on the engine? just noticed it.

I have to say everytime I look at these engines I do find them fasinating, so much engineering that's gone into them. In my opinion it looks to be an engine that was built for reliability with a lot of thought gone into it, but could it be over engineered and become un-reliable? This is what I've found over the years in a lot of cases. Steve have you heard if these engines were good at there job?

Stu.

They would only run for 30min burst (just enough time to shoot at a passing luffwaffer formation) at full load any more and they would over heat.
The magneto is a wico a fitted with impulse.
One on ebay at the mo for £250, double what I paid for mine......

cheers Steve

Bring the NOISE!

https://www.youtube.com/watch?v=CNjUMtzibrU



Took the air valve out and it goes, you can see new the end I try putting it back in only for it to chug out.

Caution: some images might offend...I forgot to put my top back on....

Cheers Steve

It does have a destinctive sound about it, well done on sort of finding the problem even if it's a temporary measure to getting it running. So have you any thought's on why it dies away Steve once the valve is refitted? I know nothing about them so can give any suggestions, yet I'd like to know if you manage to sort it for future referance. Any chance of a pic of the air valve, maybe it might show something.

Stu.

A amal carb is a bit like a villiers type with a slide and needle arrangement, the needle varies the about of fuel drawn and the slide acts like a butterfly valve, I think the needle has been set wrong and it is not drawing enough air/fuel in, so will look at raising the needle on the slide.
The air valve is used for a more precise adjustment on the amount of air drawn, its a hand off from scott’s TT racing bikes, where performance is key.

Here is a Air Valve

http://www.amalcarb.co.uk/ProductDetail.aspx?Id=1901

Its more of a plunger that covers a slot, controlled by a cable with a thumb throttle, I didnt have a control lever so the air valve was completely shut.

Picture of a TT carb



Cheers Steve

steve get a throttle of a older lawnmower like a suffolk , atco ransomes etc .... i have got one if you need one mate .

Going to leave it as is at the mo.thanks anyway.

Cheers Steve

Skankin_giant wrote:Going to leave it as is at the mo.thanks anyway.

Cheers Steve

if you decide you need one just give me a shout

Well at least you know what the problem is and know what to do to sort it, must have given you a few sleepless nights thinking about it I would if it was mine

Stu.

Well we are getting there with the Scott, running for up to a hour, but will fowl the plug, so might try a weaker mixture, think is was running between 40 - 36:1 so will try 50 next time, well here it is.

https://www.youtube.com/watch?v=uDY2ddDqrMc




Cheers Steve

Steve have you tried it under load to see if that helps?

Stu.

Bit hard to put it under load, the exhaust raps around the flywheel, so anything connected to it needs to be direct drive, I have that centrifugal pump I could used if I can get a matching spider for the flywheel.

Cheers Steve

It's a shame as I think a load would help, it runs well but running at tick over will oil the plugs up, I've the same problem that I can't get to easily attach a load to the Lister G so every hour I like to rev it up and clear it out, seems to help and blows a bit of crap out.

Stu.