ED Competition Special 2cc

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Sunbird
Posts: 16
Joined: 22 Feb 2018, 08:24

ED Competition Special 2cc

Post by Sunbird » 26 Sep 2019, 18:03

I recently acquired an ED Comp Special as shown in the photo. From the outside it looks in a reasonable mechanical condition apart from the missing fuel tank. I'm yet to strip it down for cleaning as it is still gummed up and unable to turn. The shut off valve is working fine.

Is there anyone on this forum who could tell me how the aluminum head is removed. I'm assuming it would screw off but there are no flats on the head for a spanner.

Also if anyone has a similar engine, I'm looking for the outside diameter of the tank. My intention is to machine up a tank from aluminum bar stock and I would like to make it as close to the original as possible. A photo of the tank would be a bonus.

Thanks
Ian
Attachments
Comp Special.JPG
ED Comp Special

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PaulJ
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Joined: 16 Feb 2018, 19:01
Location: Ipswich, UK

Re: ED Competition Special 2cc

Post by PaulJ » 26 Sep 2019, 23:00

The head does screw off, there is a good cutaway drawing here......

http://www.controlline.org.uk/phpBB2/vi ... rel=-10000

My Comp Special has a plastic repro tank but I have a "Penny Slot" which has an ali tank which I think is the same and the OD is 28.5mm..... or more likely 1 1/8" !
Penny Slot.jpg
If you need any more pictures or dimensions, pm me.

Paul

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tiptipflyer
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Joined: 16 Feb 2018, 22:49
Location: Germany

Re: ED Competition Special 2cc

Post by tiptipflyer » 27 Sep 2019, 05:56

There is an easy way to free up a gummed engine. I usually heat them with a heat gun and carefully turn them. When heated up, they will normally free. Then oil them with fine machine oil and you do not need to disassemble the engine.

Frank

Colonel Blink
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Joined: 21 Mar 2018, 12:43
Location: Ilkley, UK

Re: ED Competition Special 2cc

Post by Colonel Blink » 27 Sep 2019, 07:53

I know nothing about the design of model engines (or disassembly), but that design of having that length of thread on a thin sleeve, where the upper end of the thread is open to combustion looks like a recipe for disaster!!!

Assuming the sleeve is steel and the head is aluminium, heat would definitely be the answer here as the coefficient of thermal expansion of steel is just over half that of aluminium. In an ideal world because of the construction it would be great if you could get it to unscrew just with hand effort - but I have a feeling that is unlikely. Maybe gentle use of something like a strap wrench (as used on oil filters) may be the key?

The above are simply ramblings of a tired mind inexperienced in the ways of model engines of which you speak :). I shall now stand aside and let those who know say it should be done.....

jackdaw
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Joined: 16 Feb 2018, 20:30
Location: Wet and Windy North Wales

Re: ED Competition Special 2cc

Post by jackdaw » 27 Sep 2019, 11:46

Head is screwed on liner. It is not exposed to combustion - there is a contra-piston in the top of the liner, it's a diesel. To remove: place engine in plastic bag and put in freezer overnight. Remove from freezer and bag and just heat head with small gas torch or hot air gun(this gives maximum differential expansion between aluminium head and steel liner with the heat from the head softening any old gummy oil in the threads). Wearing leather/suede gardening gloves twist head off engine.

If this fails then you need to repeat the above process but use a 'strap wrench' on the head. Cheap plastic, with rubber strap, 'strap wrenches' are available from Ebay.

You may also find the contra-piston is seized, DO NOT KNOCK OUT/REMOVE FROM LINER. To free up clean well, warm and use thin oil(3 in 1) liberally. Use suitably sized wooden dowel and knock contra-piston back up bore slightly to free.

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Sunbird
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Joined: 22 Feb 2018, 08:24

Re: ED Competition Special 2cc

Post by Sunbird » 27 Sep 2019, 18:19

Thanks to all who contributed to my query. Your advice has been most useful and the engine is now free to turn without the need to dismantle. Wonderful tool the heat gun. The head screwed off easily using the heat and leather glove method. I will need to remove the cylinder however to free up the contra-piston which needs some persuasion from the underside.

To Paul thanks for posting the photo of your engine and the tank diameter measurement. The link to the cutaway of the engine is useful.

With a bit of luck I should get this little gem running in the next week or so.

Regards
Ian

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Wayne_H
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Location: Temora, NSW. Australia
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Re: ED Competition Special 2cc

Post by Wayne_H » 28 Sep 2019, 11:16

Sunbird wrote:
27 Sep 2019, 18:19
....With a bit of luck I should get this little gem running in the next week or so.

Regards
Ian
ah Ian, I can almost smell the ether from here :lol:

The very first model aircraft engine I ever attempted to start was my Dad's ED 1.46, which I still have. He bought it new in the mid-50's.
Cheers,

Wayne
Once a Retrobate, always a Retrobate............ :roll:

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PaulJ
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Joined: 16 Feb 2018, 19:01
Location: Ipswich, UK

Re: ED Competition Special 2cc

Post by PaulJ » 29 Sep 2019, 09:44

Ian, this for sale for spares on Facebook for £30....
71571727_10221434597918139_1934121612743802880_n.jpg
I've sent you a pm.

Paul

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F2B
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Joined: 16 Feb 2018, 11:23
Location: 20 m NE of Amsterdam

Re: ED Competition Special 2cc

Post by F2B » 15 Oct 2019, 18:36

Sunbird wrote:
27 Sep 2019, 18:19
I will need to remove the cylinder however to free up the contra-piston which needs some persuasion from the underside.
As it is probably in the position where it has been while running the last time, I would think that priming with one drop of fuel would produce enough 'bang' at the first flick to knock the contra piston all the way up against the comp screw, where you'd want it.
Sunbird wrote:
27 Sep 2019, 18:19
With a bit of luck I should get this little gem running in the next week or so.
Please... I am running out of popcorn... :lol:
All of us old diesel heads are keeping fingers crossed for you! :mrgreen:
F2B or not to be....

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Sunbird
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Joined: 22 Feb 2018, 08:24

Re: ED Competition Special 2cc

Post by Sunbird » 22 Oct 2019, 09:46

I'm please to report that the engine is now complete with a new tank and is running well.
The contra piston was leaking at first but I managed to "grow" its diameter sufficiently by heating it up to cherry red and quenching it in oil. Thanks to Paul for this suggestion.

Starting is easy using a home brew of Castor Oil, Paraffin and Ether mixed in equal proportions. On a 10x4 nylon propeller I was reading 6600 RPM which might improve as the contra-piston and cylinder develops a shellac buildup. I'm not sure which single channel old timer I will build for this engine but was thinking something in the region of a 50" wing span.
Thanks to all for your comments and suggestion in getting this old engine back up and running.

Regards
Ian
Attachments
new tank.JPG
Engine with the new tank
Last edited by Sunbird on 22 Oct 2019, 16:46, edited 1 time in total.

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