Oddball engines and prototypes

[T.W.R]

Is the 4cyl a 2 stroke or a flathead like a vintage Plymouth 4?

cheers, Daryl.

Just a 2 stroke roughly 15-18cc
The guy that made it just made engines as part of his hobby for model aircraft but actually worked on the team that made the high speed cameras for the U2 spy plane A good mate of the oldman...they were in S.A.M
I'd have to locate some of the other photos of the other engines but there were numerous layouts....4cyl boxer style etc

[Lightbulb]

Seeing that spark ignition with the advance retard lever, reminded me of a French made model diesel engine, that used an eccentric bushing to raise and lower the centre line of the crankshaft, to alter the engines compression ratio. It also altered the port timing as well. There was another engine that rotated the barrel on a very fine thread, and lifted the whole barrel up and down to add or subtract compression. There are so many variations of model engine made it will be a website on it's own. I don't think you could create any really new engine much these days that has not been tried before but mainly due to machine tools or material choice were not really practical to make as working examples. There are numerous variations of rotary valve engines out there as well. Then there are super charged V12 2stroke engines made by a guy in Cambridge recently for something to do and so on. Even been rotary cam model engines made by a Russian modeller in the 1970's to create a stream lined engine for a scale turbo prop model plane. Not sure if it was a 4 stroke, but thought it was a 2 stroke as well.
Neil

[T.W.R]

Have a close look at the lever on the smaller of the two motors 4" nail
They're both kiwi made motors from the 30s

[lohring]

On model engines again; I race RC model boats. While I have run the glow ignition open fuel classes, my expertise is in the 26 to 36 cc spark ignition, "gasoline" fueled engines. (Gasoline is in quotes because there isn't a standard gasoline, unlike with the fuel classes.) We've tested a wide variety of gasolines as well as nitro/gasoline and nitro/methanol mixtures with mostly spark ignitions. We ran a brief series of tests on a 26 cc engine with glow ignition and nitro/methanol fuel, but the glow plugs we had weren't durable enough. The spark plugs failed with 40% nitro fuel, but ran fine at lower levels. We typically run 60% or more nitro in the glow ignition engines.

These small engines have a lot of piston circumference and clearance for their displacement compared to larger engines. We found a long time ago that more oil meant more power, probably due to better piston sealing. Also the engines are very sensitive to friction. The older engines had two rings so removing one gave an instant power boost.

I should also note that modern radios are very resistant to ignition noise and other forms of interference. However, mechanical control system failures are still common. Moisture damage in receivers and servos, as well as plug disconnects and control system battery failure still happen.

Lohring Miller

[Frits Overmars]

Is the 4cyl a 2 stroke or a flathead?

Just a 2 stroke roughly 15-18cc

Sure. Hence the valve springs, right?

[guyhockley]

Neil,
So really the model engines don't bear a lot of resemblance to competition engines used in bikes, karts etc. mainly because of the use of ringless pistons and plain bearings (where lubrication is concerned) and where pollution is really of no consequence (at present) and the use of "excess" oil which either comes out raw or as smoke!

Apart from the ringless pistons, sounds a bit like my British Seagull outboard!

[guyhockley]

Kind of sleeve valve and model engines, these were heavily featured in british magazines a few years back.
http://www.rcvengines.com/

[T.W.R]

Sure. Hence the valve springs, right?

Wrong.....have to blow your theory out there fella try mock valve springs

[Pursang]

Kind of sleeve valve and model engines, these were heavily featured in british magazines a few years back.
http://www.rcvengines.com/

Probably the best rotary valve concept I've seen..so far!
She'd rev Ok, and the rapid exhaust bleed-down opening would lend itself to a 'tuned' pipe. (4T long expansion chamber).





Would make an 'interesting' 2 Stroke too, with the piston completely separated from the valve function.

Big bore, Short stroke, lots of squish, asymmetric timing.

Exhaust & transfer flows would be upside down.

Think like the piston is the effective head and the RV head is the piston at BDC.

Where to put the spark plug??

Cheers, Daryl.

[Frits Overmars]

Just a 2 stroke roughly 15-18cc

Sure. Hence the valve springs, right?

Wrong.....have to blow your theory out there fella try mock valve springs

Would love to. And the inlet ports at the same height as the exhaust ports would be a mock-up as well?

[T.W.R]

Would love to. And the inlet ports at the same height as the exhaust ports would be a mock-up as well?

Your only looking at a picture making assumptions...... so stick to what you think you know
I've seen the motor in the flesh, held it and heard it running

[Pursang]

Would make an 'interesting' 2 Stroke too, with the piston completely separated from the valve function.

Big bore, Short stroke, lots of squish, asymmetric timing.

Cheers, Daryl.

AND Whatever timing profile you might wish for.



and this one...
https://s3.amazonaws.com/WEBPOSTS/KI...ilus+drive.gif

cheers, Daryl

[WilDun]

Your only looking at a picture making assumptions...... so stick to what you think you know :clap

We sometimes look at things and the signal might suddenly take a wrong turn on the way to the brain! - that's the only conclusion I can come to here!
Although, maybe it could it just be something simple like posting the wrong picture? - or how about not understanding engines - the person to whom I am referring?? - that I refuse to disclose!

Or is it the start of yet another troll session?

[guyhockley]

Quick, a distraction!
Rotary valves and oil splash bottom ends for 2 smokes, plus a few other interesting bits...
http://www.motorsportmagazine.com/ar...ke-car-engines

[T.W.R]

We sometimes look at things and the signal might suddenly take a wrong turn on the way to the brain! - that's the only conclusion I can come to here!
Although, maybe it could it just be something simple like posting the wrong picture? - or how about not understanding engines - the person to whom I am referring?? - that I refuse to disclose!

Or is it the start of yet another troll session?

Cute
I'd bet the majority of model aircraft engines you've ever had anything to do with would stupid wee cox engines, maybe if you were lucky 1 or 2 OS engines & possibly a couple DC engines most likely nothing bigger than a Merlin or Sabre
Bet you wouldn't even know how many different model aircraft engines were built by kiwis prior to the 1970s

To see how clued up you are on these do tell what the difference is between an O&R 60 & Purple Head O&R 60 you probably haven't even got a clue what O & R stands for
Or an easy one what a Mills .75 was copied off
Or what a Taipan is & what it's capacity was
Or what S.A.M stands for