And How Many Cylinders Do You Actually Need??

[SteveU.]

And How many Cylinders Do You Actually Need and use meaningfully?

For me here PNW, intermountain, Rural on 21 acres usability begins at at least 2 1/2 horsepower. Carburetor went bad on the ten year old Stihl forestry brush-hogger. Wifes 0.9 hp Stilh yard machine wasted too much time/sweat/daylight hours! Rented to try a new Makita 1.5 hp four-stoke machine. Marvelous low fuel use costs. PITA slow and heavy compared to the 2 1/2 hp Stihl FS250. Bought a new carburetor and hogged-on. Got it done. And moved on the the next summer needs-done, NOW.
I annually use 8 different single cylinder, single purpose, specialized machines 2 1/2 horsepower to 10 horsepower for needs-done-NOW's.
15 to 25 horsepower; I use V-twins and 3 cylinders engines. Three of those.
30 to 100 horsepower; it has always been 4 and 6 cylinders for us. Three of those still get used here as power needed.
Needs-musts  . . . keep-up current highway, mountain passes, HD towing it is larger sixes and small V-8's for me. Two of those available/get used.
All naturally aspirated for my/our we-pay-for needs.
My turbo and "Kompressor" engine workings was all done professional, being paid. I do admire much the big inline turbo diesel engines as long as someone else is directly paying.

One-size-hats-fits-all solutions are stooopid-think, paint-yourself-into-a-corner limiting compromises. Express yourself. And insist on appropriate to the situation, fitted cylinders solutions.
Steve Unruh

[mobile_bob]

Steve

i think if i follow your logic correctly you are spot on!

it is something akin to right sizing or using the right tool for the job

yes a cresent (adjustable) wrench can take out a bolt, or loosen a nut. but rarely is it the perfect solution
and most of us would never think of throwing out all our end wrenches and socket sets in favor of a cresent wrench.

as it relates to cylinder count,  it also follows that a 6/1 lister or as bad a 175 changfa make for a damned poor weed whacker power source... save for maybe as a genset powering an electric whacker (even then pretty poor if no insane)

in the early days of my offgrid dreaming and planning, the design called for as many as 3 different power sources for generating power (electricity)  a 175changfa, a 195 changfa and a c201 isuzu/thermoking each fitted with appropriate generator heads, each being adapted for the load anticipated and season appropriate... as time went along the c201 kind of lost favor because the need just wasn't there... as more time went along  the 195 even became something that came questionable.

all these years later?  i am pretty sure that a 175 water cooled or even a 165 water cooled (if i could find the latter) would likely do all i would need if used along with reasonable pv/battery/inverter systems and used to power what many would call a tiny house.  a tiny house as defined by me would be something around 500-600 sq/ft and sited for solar gain, super insulated and using various other renewables for things like heating (wood).

i too would be interested in what some of the current thinking and experiences are when it comes to this topic

bob g

[SteveU.]

Yep. Yep. That is right BobG
I too own a few sized adjustable Cresent wrenches. Used for no-matter-marked plumbing. Machinery/vehicle working anymore a fellow needs at least 3-8 variations of the common wernch sizes.
10, 13 mm; 1/2", etc in common combo, short combo, swivel racheting head, deep box offset, at least 2-3 cheap combo's been hot wrench and grinder "specialized".

You small house system engine could be street natural gas fueled, eh-yeah. Me, for electrical generation the fuel will be home-grown wood.

You and I are cripple-up old now though. My reel push mower days are long since past. Bent-back double spading in a garden plot out the window at least 15 years ago for me,
Battery mower are heavy and hard to turn/handle. My all-wheel drive walk behind 5 hp Honda engined Huskavarna mower can even drag me up the steepest yard slopes on just grams of gasoline.
Once a year the 7.5 hp B&S OHV slant cylinder 19"wide power forward and reverse rototiller gets it done in three passes on less that 1/2 gallon of gasoline. (Some woodgasing theirs now.) Then like ALL specialized real farm equipment like combines and hay balers, "rests" waiting for 49 months. Ha! Used this way 13 years old and good for another 20-30 years.
34 ton hydraulic log splitter w/10.5 B&S OHV gets either early summer, then late fall worked for ~20 hours, 4 gallons of gasoline. (Some now woodgas fueling theirs now.)
Or . . . most years now anymore to save the old joints I just put the firewood in shed as fewer to handle 50-70 pound chunks. Then winter daily start up the woodsplitter for the one-days wheelbarrow of stovewood splits. SAME annual engine fuel needed usage.
I Stihl brush-hogged and chainsaw cleared a grasses/weeds/brush 4 foot strip along 4000 lineal feet of fence line this last Spring/summer. An annual chore. 4 gallons of mix right there.
These needs could be done with an electric battery cart. Or, the newer 36 and 42 volt rechargables. But . . . I'll seasonally time wise out work any electric for these applications. 10-15 years on dino fuel beat the repairs, maintenance's and replacement costs of electrics. Ha! Have a brushes worn out, com arc'ed  Stilh electric learning this.

And more and more guys in US, Canada, Sweeden, Finland, Netherlands, Slovenia, Poland now road traveling using just a spec of gasoline for starting up/power boosting on wood now.

A-n-y-o-n-e Prius, Leaf driving; mass trasit riding, even daily bicycling who annually Jet airplane, or charter Ocean ship cruises around, or  north/south motorhome sunbirds is using more Dino juice annually than Me annually. Emitting More carbon dioxide annually than me.
Who was that Hollywood celebrity who said that he would (jet) fly anywhere around the world to speak out about the evils of carbons emitting?
Ha! Save the planet . . . stay home and hoe-in a garden. Then Mr Idealist, ONLY eat what you can home-grow produce. Turn you into a need-to-use-a-little hydrocarbon fuel user for a back/sweat/time saving 2 1/2 horsepower in one year of sweat-slaving. Seen it on every starting out idealist CSA "farm" around here. Tillers/tractors and motorized ATV's or carts by the third year.

Human sweat can only make an average of 1/10 horsepower continuous. Young, fit trained bicyclists measure topped out at 1/4 horsepower. And need over 4000 calories to do that.

You know the numbers. A deep well pump one of the hardest to battery bank supply. And that's only 3/4 to 1 1/2 hp. Very light duty welding/aircompressing.
2 1/2 horsepower for any length of time out of a battery bank is expensive if done long term, year after year. Medium duty welding/aircompressing.

So drive less. Fly less. Motorhome less. Put the a small percentage of the dino-juice saved into daily-use 2 1/2 horsepower get-things-done portable applications a while it is still available and cheap.
Do the stationary power systems far cheaper then without portability, and space, and noise as the expensive to design for limitations.
THEN work forward from a working proven stationary power system for the no-gasoline, needs-must day that will come.

How I'm doing it.
Steve Unruh

[SteveU.]

Well I've slept reflecting on what i've said about my engine cylinders-in-use.

Use an engine with only as many cylinders as needed for the power actually going to be used.
Keep that engine loaded to at least 75% of it's capacity to produce it's best torque RPM designed power.
This will give you the best real-in-use fuel consumption.
Give you the best "beginnings" for the longest achievable engine usable longevity.

NEED more power? Set the less cylinder'ed engine aside, and use a more cylinder'ed engine.

And I do Live these life-learned experiences.

I've said owning using two different Briggs and "scrap-'em" engine above. A B&S fan?
No. They were what came with the equipment's. The equipment's practical usability is what it was about. Use/use-up the original installed engines as long as possible - you already paid for it. Then change it out; or rebuild.
These two B&S's reflect Briggs going back to float carburetors from the PITA cast zink junk pumper-sucker fuel mixers. I learned the hard way to refuse to use those. These two B&S's do have cast iron bores, and push rod overhead valves. Used up my last flathead engine back in ~2007. An aluminum bore Tecumseh. Used up my last points ignition engines even earlier. 2003?
We are well into the 21st century now. Move forward.
The prejudice that any one engine manufacturer is always better: or another, is always bad; is a limitation on getting results.
Might as well believe that our engines run on magic pixie dust, prayers, or dragon's breath.

Real world practical use engineering is a selected a choice of available options, balancing the pro's and cons of those choices.
Anything else is Believers Voodoo. Who do-o-o? Idealists and Purist do-o-o. Out of balanced thinking's. And Voodoo does not; never has; and never will, make usable long term shaft power.
Steve Unruh