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Old 07-03-2020, 11:43 AM   #33 (permalink)
Daschicken
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Join Date: May 2012
Location: Georgia
Posts: 724

Cibbie - '88 Honda CBR 250R
Motorcycle
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
Motorcycle
90 day: 42.15 mpg (US)

Latios - '08 Suzuki SV650SF
Motorcycle
90 day: 70.6 mpg (US)
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Quote:
Originally Posted by serialk11r View Post
Uh wait, how are emissions standards pushing compression ratios down? CBR-1000RR is at 13:1. NOx aftertreatment is mandatory, not an option.

I did forget the earlier bikes were carbed and have no cats, so that's one less handicap to make up for the poor fueling control. Still, if the ZX6R is making 200 hp/L, I was hoping for the same from the ZX25R. I guess it's hard to win against friction.

I would think that gear driven camshafts are actually more likely because the stroke is short. It probably has around 35mm stroke, 75mm of connecting rod, so it's around 115mm to the valves from the crank, which I would think you can span with a single gear.
Well, I suppose they could make it work with high compression, but I would expect a much higher HP number with higher compression. The top dollar bikes can get high compression. The CBR600 is sitting around 12.2:1. So the development goes where the money is.

Gear driven cams sound awesome, and are Uber reliable, but cancels any thought of head milling. So they are good and bad. I wouldn’t really mind either way, slight preference to gear driven cause I really doubt I would be tearing the engine down any time soon.
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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

Quote:
Originally Posted by MetroMPG View Post
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