Harbor freight engine swap
 

Not intended to be eco specifically, but I bet it would get great mileage. Of course it doesn't have a clutch or throttle, so they have to push start it. I'm really surprised they didn't rig up a throttle, wouldn't be too hard!

Pretty cool! :)

https://www.youtube.com/watch?v=52pL2-NozN4

Unless it's fuel injected, I doubt it would get very good gas mileage. Maybe not even then. The BSFC on these engines is about 350 g/kwh; That's in the poor range of a car engine, which will hit about 250 g/kwh in it's sweet spot. No timing advance, no OHC, nada to help it.

There's a similar video with a Geo Metro with a 10hp diesel and a CVT. That might have been limited in speed, but would have been a bit more efficient at least.

A car engine spends very little time in its sweet spot, and it wouldn't be unreasonable to say that it spends a lot of time around the 500g range due to it being so overpowered. This thing, well...Good luck with hills! :eek: Also, about the bsfc thing, it may not produce power all that efficiently, but it doesn't produce much power to begin with, so you don't have to worry about wind losses if you can't go fast to begin with!

It does have overhead valves(pushrod), so at least its got that going for it. These engines are also built for a much narrower engine RPM range than car engines, so they should run fairly well at those speeds. Lawn engines come with uber soft valve springs, so the valve train friction should be pretty low. I couldn't even check the valve clearances in my honda GCV 160 without the feeler pushing the valve down and giving a false reading..

My 20 year old car engine peaks around 210 and is under 250 for a majority of realistic operating conditions.

:turtle:

Should have had the clutch and throttle hooked up and they could actually drive the thing.

I have already considered to fit a car with a recoil starter similar to that stationary engine, even though I was willing to try it in a conventional car engine. That was an early Pontiac Trans Sport with the 3.1 engine and a TBI, which had a malfunctioning starter and some other electrical failures...

But anyway, back to topic: with a clutch and a properly linked throttle, I wouldn't mind taking a test-drive on that.

Just found out Honda is finally introducing new small engines, a new gcv series with 145, 170, and 200cc engines.They included some fuel consumption at "continuous rated output at 3600 RPM" figures with only two significant digits, but here were the results.

Assuming gas weighs 6.2 lbs per gallon, also assuming their "continuous rated output at 3600 RPM" means maximum power output at 3600 RPM, which was listed.

GCV 145 (7.7:1 CR) 263 g/kw/h
GCV 170 (8.0:1 CR) 247 g/kw/h
GCV 200 (8.0:1 CR) 247 g/kw/h

Its too bad the 145 was dumbed down with a lower compression ratio, it is the only undersquare engine of the three. These new engines however are much more undersquare than the engines they are replacing. The engines these are replacing also had higher compression ratios as well: 8.5:1

No promise a chinese clone of older Honda pushrod technology is that efficient, but don't underestimate small engine efficiency.

https://global.honda/newsroom/news/2...13eng-gcv.html

Specifications

MODEL UP190
Engine Type Single-cylinder,4-Stroke,Air-cooled,OHV Gasoline Engine
Bore X Strorke/(mm) 90X66
Displacement Capacity/(cc) 420
Max.Output/(HP)/rpm 14/3600
Fuel Consumption/(g/kWh) ≤374

Less than is a start, though not a great one...

Brand Honda
Power Source Petrol
Power Details Air cooled 4-stroke OHV petrol engine, 25° inclined cylinder, horizontal shaft
Cylinder Sleeve Type Cast iron cylinder sleeve type
Bore x Stroke 82 x 64 mm
Compression 8.0 : 1
Max Power Output 8.1 Kw (11 HP) / 3600 rpm
Max Torque 23.5 Nm / 2.4 Kgm / 2500 rpm
Ignition System Transistorised
Starting Method Key Start
Fuel tank Capacity 6.5 litres
Specific Fuel Cons. 313 g/kW.hr

313 isn't so bad...but none of these compare to what's in your post.

Go Kart
 

Have watched youtube…..A couple of thoughts ….

2cycle go cart horizontal shaft harbor freight Chinese knock gas engine will be underpower ...will wait to see how accel and hwy speed workout

gkart
 

Oh yeah just because you can do something does not mean you should go ahead and act on that mindset. Common sense is not as common as one would think