Jgwright

I know that this is full size but you may find it interesting.

All German WW2 turbine engines were started by the very small compact Riedel starter, a 2 stroke air-cooled twin cylinder engine sited in the bullet fairing of the intake of the jet. They made around 8000 of these little engines and they often ended up in museums and go carts.

The small petrol engine was started by either using the pull handle or by the 24v electric starter. This meant that the plane did not need a service vehicle to start the engine. The little engine uses case pressure to case pressure to push a piston backwards sending the dog clutch to engage with the front of the turbine shaft.

This is an amazing little engine and has many rolling surfaces with roller bearings. The electric starter motor for example has a simple ball race at the front but at the back there is small roller bearings and a very small epicyclic gearbox. The starter gear grabs onto the shaft by means of a one way sprag clutch. The flywheel has balls in galleries that are thrown out by centrifugal force and they exert force on the wet clutch to engage the rear gearbox which is also epicyclic.

Over a year ago now I managed to find a Me 262 starter motor from a motor bike dealer in the Netherlands. However it had many parts missing and it became obvious that it had been dropped early in its life and damaged and then robbed of parts. I spent many hours making the missing ignition system , the carburettor and the piston and dog clutch. I now have it all screwed together and have it running for the first time. The one good thing was the engine had hardly been run at all. There was no sign of wear in the bore of the one cylinder I took out. The bad part is that there is very high compression and it is quite a job to turn it over! I know nothing about 2 strokes and have learned a lot. Fortunately there is a Bernd Sobek who is the world expert in them and has several running who has helped me . Roger Emms also helped me with 2 stroke information and assist in getting it started.

http://www.youtube.com/watch?v=BGUqV0dl9gA
John

Dave Wilshere

John

Excellent project involving a real piece of history

Dave

Jgwright

Thanks Dave

I really enjoyed this one.

As finished and as received


The carburettor in pieces as machined and assembled



The pressure piston assemble and dog clutch

Quandry

Fantastic project John, congratulations on getting it running. Very interesting mechanical design.

I went hunting on Youtube and found this video showing the original pull starter had quite the kick too!

https://youtu.be/oBH0ULVmsow?t=6m23s

Kevin_W

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That is extremely cool!
Now you just need a Jumo 004 to bolt it to.

JP-1

Hi John,

Very interesting project, thanks for posting

Alistair

Jgwright

interesting bit of film. The engine shown was much more free than mine. This appears to confirm that mine did very little running. It sure gives you a workout!

John

Jgwright

yes it would be very interesting to see a Jumo running, there was a project to update one with modern materials but it seems to have ground to a halt. The engines are all in museums now and many are sectioned. I guess my wife really would object to having one in the back garden.

John

raron455

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Thanks for posting that, it was cool, and I learned something too,,,,

Dave Wilshere

There is a few tonnes resisting the recoil over your work mate!

ne

DaveHickey

I wonder if the compression is so high because it ran on jet fuel not gasoline...

causeitflies

I've always wondered about these engines. What is the displacement?

Kevin_W

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John,
I was lucky enough to visit the factory in Ft Worth where they were (initially) building the replica ME-262's. They had several fuselages in various stages of completion, and several sets of wings still in the jigs. The engine mounts were the most interesting thing though. The wanted to keep the mounts as close to stock as possible, but the little GE turbofans they were using to power them are probably 1/4 the size of the original Jumo engines. Their solution was to cast large aluminum cases with the outer dimensions (and mounting points) of the Jumo 004, they were cast in two pieces like a clam shell, and bolted together around the GE engine. It had the added benefit of helping keep the CG manageable.
They also built replica cannons in the nose that were similar weight to the originals.
It was a very interesting visit.
Less than I year after my visit the project ran out of money and was shut down for quite a while. It eventually was moved to Washington state, and I think they completed four flyable airplanes.
I think I have some pictures scanned into photobucket. I will look for them later and post if I can find them.

Jgwright

The Ridel starter ran on standard petrol (gasoline). It has a separate fuel tank in the nose of the engine.

John

Jgwright

The engine has a bore of 70mm and a stroke of only 35mm total volume 270cc. The engine runs at 7,000 rpm with a full jet only so it reaches max rpm as quickly as possible. The engine has covers over the finned cylinders and these are used to try and deflect the cooling air from the front mounted fan around the fins to keep them cool. The engine was fully tested in 1945 by RAE Farnborough and that 27 page report is still available They found the engine produced up to 9 BHP. The cooling was not good and the little engine was only to be used for a max of 4 minutes. Power dropped off quickly was it became hot.

John

Jgwright

Kevin

This was a great project, and I followed progress over the years with its ups and downs. One of these days I hope I may have the chance to see the one sold to Germany at a flying display.

John

erbroens

Very cool... in this video at 16:00 shows this engine in the original 262 :

https://www.youtube.com/watch?v=1nNdDkyiANo

David Gladwin

Superb achievement, John, well done, would love to see it sometime !!

Fuel situation :

The 004B-1 produced a thrust of 2,000 lbf (8.90 kN) and ran primarily on diesel fuel. Gasoline was used for the two-stroke starter motor and for starting the turbojet. A combination of gasoline and diesel was used after starting and then to all diesel fuel.[SUP]6[/SUP]

However, Eric Brown records it also ran on 87 Oct petrol with 5 % oil mixed in.

David.

HarryC

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That's an excellent piece of work John, and lots of interesting history. I love the idea of pull-starting a jet engine. Something to look for next time I am at a museum that has a 262, see if it has the ring pull at the front of the cone.

Jgwright

Thanks Harry

The starter was also used for the He162 to start the BMW turbine. The pull starter makes a lot of sense because it was always possible that it would fail to start on the electric starter. Robert Riedel the designer even thought of building in a slip clutch on the Electric motor to avoid it being overloaded, but this has to be correctly set up. The pilot could start the engine from the cockpit using the electric starter. I did read one report when 3 planes were scrambled and only one was able to get the engines started.

John

dw_crash

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Really neat!!! Wonder what model it would fly? Great job John!!!!

Jgwright

Dave

Interesting question. I found a while ago that Ken Wallis, who has only recently died, adapted one to power a Slingsby Petrel glider and it seems that it made 10 flights or so. Here is a photo of it mounted on the glider. Ken Wallis was the guy who was famous for autogyros and made the Little Nellie for the James Bond film. The flights were made in 1949.

http://www.scalesoaring.co.uk/VINTAG.../Powered_2.png

There was also also a glider in Poland powered by a 4 cylinder engine made from 2 Riedel starter engines joined together.

John

John

Kevin_W

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Here are the pics from my visit to the 262 project.
This was in 1997 so didn't have a digital camera. These are all scanned from film prints, and the lighting was very poor, so please forgive the quality.

Kevin_W

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Kevin_W

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