Author Topic: Freelance opposed piston engine  (Read 1334 times)

Offline Myrickman

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Freelance opposed piston engine
« on: January 04, 2025, 11:41:20 AM »
Been away for a few years, but with retirement next month, “I’ll be back”. A friend of mine bought a collection of models and asked me to freshen it up and get it running. I remade the 3/4” pistons and installed viton rings. The lower con rod bearings were reamed oversized and bushed to take out slop. Some added cleaning of the valves and seats completed the task.

https://rumble.com/v33edvp-freelance-horizontal-opposed-piston-model-34-bore.html

Offline Admiral_dk

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Re: Freelance opposed piston engine
« Reply #1 on: January 04, 2025, 06:37:01 PM »
Runs well now  :ThumbsUp:

How does the Valving works on this Engine ?

Per   :cheers:

Offline Niels Abildgaard

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Re: Freelance opposed piston engine
« Reply #2 on: January 05, 2025, 12:21:29 PM »
Been away for a few years, but with retirement next month, “I’ll be back”. A friend of mine bought a collection of models and asked me to freshen it up and get it running. I remade the 3/4” pistons and installed viton rings. The lower con rod bearings were reamed oversized and bushed to take out slop. Some added cleaning of the valves and seats completed the task.

https://rumble.com/v33edvp-freelance-horizontal-opposed-piston-model-34-bore.html

It is lovely.
I am obsessed with OPPOSED PISTON schemes for electricity and aircraft populsion .
Mostly two stroke Junkers but here is a chain synchronized  fourstroke OP .
Probably a worlds first.

Some public funded americans are about to revolutionize world and so.

https://enginuitypowersystems.com/

Can we have a better picture of exhaust valve side?
Cross the synchro chain and machinery can be made vibration -free.

Two 850mm props 600 mm apart turning 66 rps from 66mm pistons stroking 90mm is 27 horsepower and very low noise.
Mass except props ca15kg

I am thinking of how to fit a 40mm inlet and 36 mm exhaust into the miracle.

« Last Edit: January 05, 2025, 08:05:15 PM by Niels Abildgaard »

Offline Johnmcc69

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Re: Freelance opposed piston engine
« Reply #3 on: January 05, 2025, 04:40:16 PM »
 That's amazing!  :pinkelephant: Kind of like the Atkinson engine that gives so many folks fits.

 You did a fine job with that.  :ThumbsUp:

 John

Offline gipetto

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Re: Freelance opposed piston engine
« Reply #4 on: January 06, 2025, 12:14:44 AM »
they're a lot like the split single "twingle" also i think. those have no cam or chain so should have a low difficulty curve for modelling.

Offline Niels Abildgaard

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Re: Freelance opposed piston engine
« Reply #5 on: January 06, 2025, 08:47:49 AM »
There is a company in USA dreaming of making 70 million combined heat and power plants according to the scheme.
I personally think two stroke Junkers are better.

https://www.nature.com/articles/s41467-024-48627-0

 

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