Okay….time to turn to the forum…..

[RotoPlane]

I’m tired of searching for this information…..

If one engine cylinder produces 15 hp, two cylinders would produce at least 30 hp.
I’m thinking there should be more than twice as much hp produced,
because the second cylinder is somewhat helping out the first one (kind of
a synergistic effect)…..but I don’t know how to prove it.
Does anyone know?

 

[wanafly]

multiple cylinders

multiple cylinders

Interesting thought... Why would two cylinders produce more or less power than the simple sum of each? The only losses that aren't proportional would be bearings and perhaps the 12V generator. I'd think about what losses can be shared (aren't proportional to cylinder #), and go from there. I suppose the flywheel could be smaller as the cyliner # goes up too, so there's maybe many other aspects to consider...

You'll probably find that the limited number of designs available commercially each have their own immutable specs, and short of designing your own engine, it's a moot point.

You designing your own power plant?

 

[RotoPlane]

You'll probably find that the limited number of designs available commercially each have their own immutable specs, and short of designing your own engine, it's a moot point.

You designing your own power plant?

Yeah, I am. Started building it in 1991 but ran out of money for it.....thought I'd reevaluate and try again. Can't find anything I like better and it is a diesel with no valves or chankshaft to mess with.

 

[Skyjinks]

God, what a complex question from such a few lines!
Generally speaking you should get more 1+1 = 2.2!
As you increase number of cylinders from 1 up to around 6 you incease, ballance, efficiency, and reliability without penalty for friction or weight. Efficiency is particularly increased by induced flows from one cylinder to another both in induction and exhaust, rather than the stop and start of a single cylinder. Flywheel mass for ballancing and cancelling vibration (which consumes energy) can be significantly reduced. Components such as con rods can be lightend, auxilliaries are generally not much different from a single to a multiple cylinder unit. etc.

As I said it's very complex with lots of if/but's so there is no simple answer but generallt the above is correct.

 

[Vance]

Hello Ed,

My experience agrees with Charles.

We used to do single cylinder engine development for a twin cylinder engine. We typically found that when we applied what we had learned to the twin we got 2.2 times the output of the single. I don’t know how much this had to do with the engine brake we were using. It is possible there were loses through the drive that accounted for some of the increase.

I have no experience with diesels.

Thank you, Vance

 

[RotoPlane]

Number of cylinders + (Number of cylinders -1 X .2)

Now the added engine cylinders makes more hp sense.....
Thank you guys for you're help!