What’s next?

[Jasonb]

I don't think they fire in unison, if you look at the eccentrics that drive the ignitors they are at 180degrees on the cam shaft so one cylinder fires each rotation of the crankshaft. That will put a lot of uneven load into the top cross head.

[vtsteam]

Wow, then forget about my "uneven firing". They do every stroke.

[vtsteam]

It would be great to see a model running. Very interesting.

[Alyn Foundry]

FB to the rescue….

Group member Nick Rowland ( of RMC fame ) from the USA has a considerable wealth of information.

They also made a single cylinder version.

   Graham.

[Jasonb]

It's the single cylinder that was show in the link Dave posted along with the photos. also image sof the single in his last photo

If you missed it https://patents.google.com/patent/US607580A/en

[Alyn Foundry]

It would appear that other manufacturers were doing similar configurations at that time also.

A Russ.

Photo courtesy of Nick Rowland.

   Graham.

[Admiral_dk]

Wow, then forget about my "uneven firing". They do every stroke.

It should be once every revolution - the 180 degrees are on the Camshaft running @ half speed => Firing every 360 degrees.
If not - it wouldn't make sense with the pistons running in parallel 

Per

[vtsteam]

Sorry, meant revolution, not stroke.