Controversial topics?

[Dodge Freak]

Air Bags, save lives or do more harm then good ?

Did you know now we are not to hold the steering wheel at 10 and 2 o clock ? Drivers have had their hands-arms torn off by the air bag deploying. And how come its unsafe for kids to be in the front seat of air bag cars but all the adults are OK

Best thing about air bags is they disable the car and driver after the first good impact. No more Blues Brothers movie mall scenes, ha ha. Why I believe we really have mandatory air bags--so jerks can't ram stuff and keep on going

[rb0804]

How about exhaust valve opening, open early to help scavenge cylinder or open late to get more 'push' on the piston?

[machine shop tom]

It's probably too late, but the issue of gun control certainly gets academic types' panties in a bunch. Especially when evidence points out that more gun control = more violent crime. A good example is how the crime rates changed in the England when hand guns were banned.

tom

[Workshop]

It's probably too late, but the issue of gun control certainly gets academic types' panties in a bunch. Especially when evidence points out that more gun control = more violent crime. A good example is how the crime rates changed in the England when hand guns were banned.

tom

Yeah, another good example is how easy crackheads can get guns. Nothing wrong with gun control as long as it's applied to the right people.
I thought England always had high crime rates, after all they used to ship their criminals all over the place.

[justahoby]

What about rod stroke ratio???

[Circlotron]

What about those people who state that for two engines of the same capacity, the one with the longer stroke will have more torque because the longer crank throw has more leverage? They so totally don't get the point that even though it does in fact have greater leverage, it is exactly countered by the smaller bore pistons having less surface area so the same pounds-per-square-inch of combustion pressure has less square inches to work on so the torque is basically the same.

The only real difference is that the long stroke narrow bore motor can only be fitted with tiny valves so it would work best at lower rpms.

[John Wallace]

What about those people who state that for two engines of the same capacity, the one with the longer stroke will have more torque because the longer crank throw has more leverage? They so totally don't get the point that even though it does in fact have greater leverage, it is exactly countered by the smaller bore pistons having less surface area so the same pounds-per-square-inch of combustion pressure has less square inches to work on so the torque is basically the same.

Could you explain your theory a little more?

I think the peak torque would be at a lower rpm compared to the 'non-stroked' combo?

If an engine had the same piston/bore and the crank was stroked 1/4" would the HP/Torque be the same then?

[justahoby]

What about those people who state that for two engines of the same capacity, the one with the longer stroke will have more torque because the longer crank throw has more leverage? They so totally don't get the point that even though it does in fact have greater leverage, it is exactly countered by the smaller bore pistons having less surface area so the same pounds-per-square-inch of combustion pressure has less square inches to work on so the torque is basically the same.

Could you explain your theory a little more?

I think the peak torque would be at a lower rpm compared to the 'non-stroked' combo?

If an engine had the same piston/bore and the crank was stroked 1/4" would the HP/Torque be the same then?

Then big bore always wins It goes on and on.. but I agree, stroke helps down low.
Billy Joel Song "STroke me!!"

[mbrooks]

torque vs. horsepower

[Olefud]

Holy crap Dan.

I think thats 8x longer than what I would ever need. Great topic but- what are the major opposing arguments? Turbulent flow does XYZ vs pressure separation does XYZ?

There’s a bit of room here for discussion. Turbulent flow inherently involves more parasitic energy loss than laminar flow. So why does, as Dan IMO correctly states, turbulence in the boundary layer lower drag? A Hint as where to start is the Kamm effect and attached vs. detached flow over a car’s surface -I'm not up to a Dan level discourse-.

[twl]

Holy crap Dan.

I think thats 8x longer than what I would ever need. Great topic but- what are the major opposing arguments? Turbulent flow does XYZ vs pressure separation does XYZ?

There’s a bit of room here for discussion. Turbulent flow inherently involves more parasitic energy loss than laminar flow. So why does, as Dan IMO correctly states, turbulence in the boundary layer lower drag? A Hint as where to start is the Kamm effect and attached vs. detached flow over a car’s surface -I'm not up to a Dan level discourse-.

I'd say it's because a little bit of controlled turbulence in the right place can avoid getting a lot of turbulence in the major portion of the flow.