Something big and oily is about to join the collection....

http://www.oldengine.org/members/diesel/Junkers/Junkers001.jpg
http://www.oldengine.org/members/diesel/Junkers/Junkers002.jpg

or at:

http://www.stationary-engine.co.uk/Junkers/Junkers001.jpg
http://www.stationary-engine.co.uk/Junkers/Junkers002.jpg

Peter
--
Peter A Forbes
Prepair Ltd, Rushden, UK
peterforbes@prepair.co.uk
http://www.prepair.co.uk
http://www.prepair.eu

Very nice too - I take it it is an opposed piston job in the 'ususal' 
Junkers fashion?

BTW. Thanks for the Neunen pictures - I reckon pretty much any UK rally 
you visit after that is going to be a bit of an anti-climax. Be nice to 
hear a bit about how they do things over there - is it an SE only rally, 
   does it attract 'mum dad and the kids' type visitors, organisation, 
facilities, the dreaded H&S etc etc?

Nick H

On Fri, 23 May 2008 10:43:13 +0100, Nick H  wrote:

>
>Very nice too - I take it it is an opposed piston job in the 'ususal' 
>Junkers fashion?

Yes, 65mm bore, upper one with different stroke to the lower one.

>BTW. Thanks for the Neunen pictures - I reckon pretty much any UK rally 
>you visit after that is going to be a bit of an anti-climax. Be nice to 
>hear a bit about how they do things over there - is it an SE only rally, 
>   does it attract 'mum dad and the kids' type visitors, organisation, 
>facilities, the dreaded H&S etc etc?
>
>Nick H

It was nice, we had great weather, always a prerequisite for a good rally, and
the people were very friendly indeed, even the French who tend to be a bit
withdrawn.

It is more or less engines only, it isn't a true public rally in the sense that
ours are, it is organised by enthusiasts for enthusiasts, although the public
are admitted for a small charge.

Seems that most of the facilities that the organisers get are supplied free of
charge, mainly as they know the suppliers well! so costs are minimal. The local
town council like the publicity that it brings the town, so they are trying to
find an alternative site for next year. A road development is going through the
site soon so it is the last on this site.

Facilities were good in my view, the campers had proper showers and toilets in
two separate mobile units, electricity was available if you wanted it, and all
the camping/showers/electricity was free for exhibitors, I don't think camping
for visitors was provided.

The site had minimal but visible safety ropes, there were very few children.
Unloading was assisted by the big Volvo which is in the pictures if you needed
it, there was a garage just across the road from the site for fuel and fags
etc., Nuenen town centre was about 2 km away with shops and supermarkets, but as
it was a Bank Holiday, most of these were shut for Sunday and Monday.

We are definitely going next year!
Peter
--
Peter A Forbes
Prepair Ltd, Rushden, UK
peterforbes@prepair.co.uk
http://www.prepair.co.uk
http://www.prepair.eu

On Fri, 23 May 2008 10:43:13 +0100, Nick H  wrote:


>BTW. Thanks for the Neunen pictures - I reckon pretty much any UK rally 
>you visit after that is going to be a bit of an anti-climax. 

Not necessarily so, all shows are different in venue and atmosphere, Portland is
the biggest, but Nuenen (note the spelling) was possibly the nicest that we have
been to, compares well with Astle Park in fact.

The biggest thing about it is the sheer variety of engines. You don't see many
in the UK, especially things like the Swedish Beijers and the Renault hot-bulb
engines, and the S-T flat twin and parachutable steam genny for that matter. 

Peter
--
Peter A Forbes
Prepair Ltd, Rushden, UK
peterforbes@prepair.co.uk
http://www.prepair.co.uk
http://www.prepair.eu

On 23 May, 10:43, Nick H  wrote:
> Very nice too - I take it it is an opposed piston job in the 'ususal'
> Junkers fashion?

There's a couple of cross-sectioned examples photographed here.
http://216.239.59.104/search?q=cache:w-7V8PUFbXoJ:www.geocities.com/hjunkers//ju_hk_m1.htm+Junkers+2HK65&hl=en&ct=clnk&cd=3&gl=uk&client=firefox-a

What a neatly packaged design for an opposed piston. I bet the
crankshaft is complicated though?

Peter A Forbes wrote:
(snip)
> 
> The biggest thing about it is the sheer variety of engines. 
> 

The very essence of a good rally in my view - I'd no more want to look 
at unbroken rows of 'classic' open crank engines than I would Lister 
D's or air-cooled Villiers'!

Nick H

On Fri, 23 May 2008 05:35:24 -0700 (PDT), Andy Dingley 
wrote:

>On 23 May, 10:43, Nick H  wrote:
>> Very nice too - I take it it is an opposed piston job in the 'ususal'
>> Junkers fashion?
>
>There's a couple of cross-sectioned examples photographed here.
>http://216.239.59.104/search?q=cache:w-7V8PUFbXoJ:www.geocities.com/hjunkers//ju_hk_m1.htm+Junkers+2HK65&hl=en&ct=clnk&cd=3&gl=uk&client=firefox-a
>
>What a neatly packaged design for an opposed piston. I bet the
>crankshaft is complicated though?

There are two extra big end journals, one each side of the main one.

I'll be scanning the multi-lingual parts book soon and posting it on the
websites, it covers 1,2 and 3-cylinder HK65's.

Peter
--
Peter A Forbes
Prepair Ltd, Rushden, UK
peterforbes@prepair.co.uk
http://www.prepair.co.uk
http://www.prepair.eu

On Fri, 23 May 2008 05:35:24 -0700 (PDT), Andy Dingley 
wrote:

>On 23 May, 10:43, Nick H  wrote:
>> Very nice too - I take it it is an opposed piston job in the 'ususal'
>> Junkers fashion?
>
>There's a couple of cross-sectioned examples photographed here.
>http://216.239.59.104/search?q=cache:w-7V8PUFbXoJ:www.geocities.com/hjunkers//ju_hk_m1.htm+Junkers+2HK65&hl=en&ct=clnk&cd=3&gl=uk&client=firefox-a
>
>What a neatly packaged design for an opposed piston. I bet the
>crankshaft is complicated though?

I have just noticed that there is a bit of jiggery-pokery in the timing field.

There are different fuel pump drive gears for different engine speeds, and in
the German handbook I have, it explains how the timing varies with the speed of
the engine setup. I guess that the timing is advanced with increased rpm.

Single cylinder engines inject at 18-19 degrees at 1000rpm, 19 degrees at 1200
rpm and 21 degrees at 1500 rpm.

Twin cylinder engine: No1 cylinder 18-19 deg: No2 cylinder 19-20 deg @ 1000rpm

Three cylinder:  No1 18-19, No2 19-20, No3 20-21 degrees @ 1000 rpm.

And so on.

I don't know why they should vary cylinder to cylinder in the same engine,
unless it is to do with either harmonics in the inlet/exhaust or something to do
with the crank.

Peter


--
Peter & Rita Forbes
Email: diesel@easynet.co.uk
http://www.oldengine.org/members/diesel
http://www.stationary-engine.co.uk
http://www.oldengine.co.uk

On 23 May, 16:09, Peter A Forbes  wrote:

> I don't know why they should vary cylinder to cylinder in the same engine,
> unless it is to do with either harmonics in the inlet/exhaust or something to do
> with the crank.

I can't imagine it's deliberate (WHY?), so I can only assume that it's
trying to compensate for something else, such as varying injector pipe
length.

On 23 May, 13:35, Andy Dingley  wrote:

> What a neatly packaged design for an opposed piston. I bet the
> crankshaft is complicated though?

In German, but with cross-section

http://www.junkers.de/motoren/

http://www.junkers.de/medienbibliothek/junkers/juna_motoren/schaubild-arbeitsweise_001.jpg

On Fri, 23 May 2008 16:09:28 +0100, Peter A Forbes
 wrote:

>On Fri, 23 May 2008 05:35:24 -0700 (PDT), Andy Dingley 
>wrote:
>
>>On 23 May, 10:43, Nick H  wrote:
>>> Very nice too - I take it it is an opposed piston job in the 'ususal'
>>> Junkers fashion?
>>
>>There's a couple of cross-sectioned examples photographed here.
>>http://216.239.59.104/search?q=cache:w-7V8PUFbXoJ:www.geocities.com/hjunkers//ju_hk_m1.htm+Junkers+2HK65&hl=en&ct=clnk&cd=3&gl=uk&client=firefox-a
>>
>>What a neatly packaged design for an opposed piston. I bet the
>>crankshaft is complicated though?
>
>I have just noticed that there is a bit of jiggery-pokery in the timing field.
>
>There are different fuel pump drive gears for different engine speeds, and in
>the German handbook I have, it explains how the timing varies with the speed of
>the engine setup. I guess that the timing is advanced with increased rpm.
>
>Single cylinder engines inject at 18-19 degrees at 1000rpm, 19 degrees at 1200
>rpm and 21 degrees at 1500 rpm.
>
>Twin cylinder engine: No1 cylinder 18-19 deg: No2 cylinder 19-20 deg @ 1000rpm
>
>Three cylinder:  No1 18-19, No2 19-20, No3 20-21 degrees @ 1000 rpm.
>
>And so on.
>
>I don't know why they should vary cylinder to cylinder in the same engine,
>unless it is to do with either harmonics in the inlet/exhaust or something to do
>with the crank.
>
>Peter

Some of the big Crossley 2-strokes vary injection timing and
quantities between cylinders, in a graduated manner. I'm sure it's to
do with variation in charge pressures (distance from the scavenge
pump) as well as exhaust manifold pressures. They rely on 'echoes' for
want of a better word in the exhaust to improve scavenging and thereby
efficiency. Timing is ultimately set on the basis of cylinder
pressures rather than measuring injection points.

Tim