Something big and oily is about to join the collection....
-- Peter A Forbes Prepair Ltd, Rushden, UK snipped-for-privacy@prepair.co.uk
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
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 snipped-for-privacy@prepair.co.uk
There's a couple of cross-sectioned examples photographed here. http://216.239.59.104/search?q=cache:w-7V8PUFbXoJ:
Peter A Forbes wrote: (snip)
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
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 snipped-for-privacy@prepair.co.uk
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: snipped-for-privacy@easynet.co.uk
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.
In German, but with cross-section
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
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