Antonia Engine - Marshall valve gear

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cyberbadger
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Antonia Engine - Marshall valve gear

Post by cyberbadger » Wed Jan 26, 2022 4:02 pm

I found a steamboater in Germany who has posted a few videos of his Steam Launch Antonia.

The engine looks like it was machined and fabricated custom for this launch.

:?: I was wondering if anyone can identify the valve gear, or perhaps describe the operation of this engine.



Engine under steam:
https://www.youtube.com/watch?v=_KAHf_Ukah8

At the 2 minute mark in the following video the throttle and reversing lever are moved and you can see how this engine responds:
https://www.youtube.com/watch?v=AcU7dOx541c

https://www.youtube.com/watch?v=leI1XEuXcZg

List of all videos this youtuber has uploaded:
https://www.youtube.com/channel/UCyRjCT ... qdw/videos

-CB

P.S. I am also posting this because this steamboater's youtube channel has less then 10 subscribers as of this writing, I'm sure he would appreciate a little more attention because he obviously put a lot of effort into putting this launch together.
Last edited by cyberbadger on Thu Jan 27, 2022 1:26 pm, edited 1 time in total.
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barts
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Re: Antonia Engine Valve Gear Identification

Post by barts » Wed Jan 26, 2022 5:22 pm

This looks like a Marshall gear driving rocker arms w/ valves at the ends of the engine, I'd guess to reduce length. The purpose for the two rocker arms/cylinder, slightly out of phase, is perhaps a riding cut-off. Note the integral flat plate heat exchangers as well. A very neat piece of design, very compact.

https://commons.wikimedia.org/wiki/File ... _1904).jpg

- Bart
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Bart Smaalders http://smaalders.net/barts Lopez Island, WA
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PeteThePen1
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Re: Antonia Engine Valve Gear Identification

Post by PeteThePen1 » Thu Jan 27, 2022 12:29 pm

Thanks for posting these links. It looks an interesting vessel. I need to look at the videos with the sound on (I don't do sound on the laptop) and see what we can learn from that.

Regards

Pete
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Re: Antonia Engine - Marshall valve gear

Post by TriangleTom » Tue Mar 29, 2022 12:08 am

Very fascinating, and a neatly built little engine. Curious about the valvegear though.
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Re: Antonia Engine - Marshall valve gear

Post by TriangleTom » Tue Mar 29, 2022 12:32 am

On closer look, I'm not sure this is a marshall geared engine. I don't see the linkages of a marshall valvegear, it looks like the valve motion may ride in a straight slotted link cut into the round bar, in a way similar to a hackworth.
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