different piston design for IC engine

[jack620]

Fastest steamboat I ever saw!

 

[Goldflash]

Wow I am impressed with your Hydroplane. Can you supply more details on the uniflow engine and the flash steam system
Goldflash

 

[windy]

I decided to alter an old piston to reduce weight and friction to find any problems that might arise on the uniflow flash steam engine.
One of my local club members pointed out that when the piston is a few degrees past BDC the uniflow ports are now open to the crankcase and that oil could be lost to the atmosphere via the silencer.
After a run the boat sinks if not retrieved quickly so water could enter the crankcase by the silencer.
So I have an old barrel and piston and will alter it to the new shape and run the engine up on the lathe and see what happens to the lubrication.
Modifying the piston reduced the weight by at least 1/8oz maybe more but will have to check the crankshaft balance if the test is successful.

Windy

 

[trumpy81]

How does the crank bore get off center from the cylinder bore?? and how does this increase the compression.
Alec Ryals

Alec if you draw a circle that represents the crank, normally the cylinder center line would follow the vertical center line from the center of that circle.

If you then draw another line parallel to the vertical center line but some distance away from it, the second line would then be the center line of the cylinder.

I hope that makes sense?

As for compression, I didn't mention that at all?

 

[trumpy81]

It doesn't increase compression. It increases contact pressure per surface area because of bigger side forces.
The piston skirt is pressed against the wall of the cylinder liner. It's sidewards.

Sorry Till, I didn't see your post until after I replied. Yours is a much better explanation than mine ... lol ... Thanks.

 

[Alec Ryals]

No one makes a engine with off-set cylinders except for models.
Alec Ryals

 

[Alec Ryals]

Hello, Are you running a westinghouse (Stuart Sirus or Sun) type engine.
Thank You
Alec Ryals

 

[canadianhorsepower]

No one makes a engine with off-set cylinders except for models.
Alec Ryals

Not quite, it's a common practice on hot saws,
and some scooter

 

[Lakc]

No one makes a engine with off-set cylinders except for models.
Alec Ryals

http://en.wikipedia.org/wiki/Desaxe

Appears a few production ones do.

 

[jixxerbill]

http://en.wikipedia.org/wiki/Desaxe

Appears a few production ones do.

Must be more than can be seen in that video.. that engine will not rotate the way it looks there ?

 

[Lakc]

Dont believe everything you read on the internet, even Wikipedia.
While the cylinders do show desaxe, the video is not really appropriate to that page. The beauty, and downfall, of some wiki pages is that anyone can edit them.

The text citations for Toyota and VW both using desaxe engines is believable, however, and the ASE paper cited makes it rather credible.

 

[aonemarine]

I remember seeing an old piston design that did not have a wrist pin, instead it had a ball and socket...
That hydroplane is awsome!! Love to see some more about it. There is nothing like it in the US that I know of.....

 

[Till]

No one makes a engine with off-set cylinders except for models.
Alec Ryals

You are wrong.

A good example is the very successful Volkswagen VR6 engine family.
If you are bored and willing to pass free time, please have a look at: http://en.wikipedia.org/wiki/VR6

 

[windy]

Hi aonemarine.
If you look at the following there is a lot about my side of model engineering. http://www.onthewire.co.uk/

It used to be done in the States years ago but radio control has taken over.

We have classes for shop bought engined powered hydro's and British classes for home built engines of IC and steam.

The home built ic class is over 130mph so Bob the previous steam record holder and myself are trying to beat that speed in 2013.

Tuning ideas are freely exchanged which is very good for developement.

If you contact Hugh and Lynn on the above web site they are always interested in the history of tethered cars and hydroplanes so if there are any members that know of the States tethered cars or boats they would be interested.

Paul

 

[petertha]

I have not seen any model competition engine with a short piston and wondered why. Windy

I was trying to remember what RC engine piston I had come across that struck me as being severley hogged out. It was the OS-FS-120 4-stroke (circa mid 80's? but dont hold me to that date). Ive pasted in some google pics of it & other 'reduced' pistons for visual reference. Some are not necessarily shortened but lets say put on a severe diet in other dimensions

Here is a link to OS parts manuals. Hopefully you can scan accross the exploded views as a means to examine pistons & judge relative dimensions.
http://www.osengines.com/parts/exploded-views.html

 

[windy]

Another type of piston to think about.

 

[RonSkingley]

Hi Paul,

Please excuse a quick 'off topic' remark, but I'm very glad to hear there is still interest in flash steam hydroplanes.
My step father was Arthur Cockman, so I have an interest there, and I well remember Sundays at Victoria Park with my father, Jack Skingley.
I now live in Southern Ireland so unfortunately have little opportunity of visiting there.

All the best, and keep up the good work

Ron

 

[trumpy81]

Hi aonemarine.
If you look at the following there is a lot about my side of model engineering. http://www.onthewire.co.uk/

It used to be done in the States years ago but radio control has taken over.

We have classes for shop bought engined powered hydro's and British classes for home built engines of IC and steam.

The home built ic class is over 130mph so Bob the previous steam record holder and myself are trying to beat that speed in 2013.

Tuning ideas are freely exchanged which is very good for developement.

If you contact Hugh and Lynn on the above web site they are always interested in the history of tethered cars and hydroplanes so if there are any members that know of the States tethered cars or boats they would be interested.

Paul

Paul, I'd love to see what your hydroplane would do if allowed to free run (untethered) The tethering must introduce drag and other speed restricting effects?

As far as I know, the SSME (Sydney Society of Model Engineers) in Sydney still have tethered events for cars and boats, have you heard of them?

 

[Lauri]

Hi.

How about this? This is the piston/cylinder group of our control line engine.

L

 

[trumpy81]

Hi.

How about this? This is the piston/cylinder group of our control line engine.

L

That's an impressive looking piece of gear Lauri. I bet it performs well?