6.0L v8 or 6.0L v12?
12-25-2006, 09:31 PM
#41
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Location: Dayton OH
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Number of cylinders Interesting thoughts
It was explained to me several years ago when the Offie engine used by most of the Indy cars went from 4 cylinder to 8 cylinder of the same displacement and valve design. What the engineer told me was there were two reasons. (1) improved cooling on a per cylinder basis to provide additional detonation control. (2) and this requires a bit of thought. He explained that the peak combustion chamber pressure lasts a very sort percentage of the power stroke and that the piston, as soon as it gets past 30degrees accelerates away from the expanding gas (fire). So having more cylinders provides more piston surface area exposed to peak combustion pressure at any point in time.
I have not modeled this, so I’m not sure if I agree but I've remembered it for 50 years.
Also there was a Honda Racing Motorcycle of 600cc that's 36cubic inches that made in excess of 300HP. That's 8.33HP per cu inch or 333.3HP per liter. It had 6 pistons that were oval shape in order to fit the 6 valves per cylinder. And it turned close to 20.000 RPM Keep in mind that was at least 30years ago maybe more. So go figure.
Carry on
Great discussion
Pete
It was explained to me several years ago when the Offie engine used by most of the Indy cars went from 4 cylinder to 8 cylinder of the same displacement and valve design. What the engineer told me was there were two reasons. (1) improved cooling on a per cylinder basis to provide additional detonation control. (2) and this requires a bit of thought. He explained that the peak combustion chamber pressure lasts a very sort percentage of the power stroke and that the piston, as soon as it gets past 30degrees accelerates away from the expanding gas (fire). So having more cylinders provides more piston surface area exposed to peak combustion pressure at any point in time.
I have not modeled this, so I’m not sure if I agree but I've remembered it for 50 years.
Also there was a Honda Racing Motorcycle of 600cc that's 36cubic inches that made in excess of 300HP. That's 8.33HP per cu inch or 333.3HP per liter. It had 6 pistons that were oval shape in order to fit the 6 valves per cylinder. And it turned close to 20.000 RPM Keep in mind that was at least 30years ago maybe more. So go figure.
Carry on
Great discussion
Pete
60l, assemble, billet, blocks, cnc, comparison, crankshaft, difference, displacent, engine, friction, ls1, v12, v8, vibration
