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Old 02-20-2019, 02:04 AM   #3 (permalink)
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Join Date: May 2012
Location: Georgia
Posts: 724

Cibbie - '88 Honda CBR 250R
90 day: 51.09 mpg (US)

Rarity - '06 Honda Accord EX V6
Team Honda
90 day: 35.74 mpg (US)

Baby viff - '86 Honda VFR 400R
90 day: 42.15 mpg (US)

Latios - '08 Suzuki SV650SF
90 day: 70.6 mpg (US)
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Originally Posted by Stubby79 View Post
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! 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..
-Kaze o tatakaimasen-

Best trip in V6: 52.0
Best tank in V6: 46.0
Best tank in CBR: 61.3
Best tank in VFR: 62.5
Best tank in SV: 83.9

Originally Posted by MetroMPG View Post
You can lead a fashion-conscious horse to unusual-looking water...

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