/o/k 2 questions: So this thing makes roughly 190hp and 73lb-ft.

>>16761719
They have lower torque but much much higher RPM.

HP is calculated from both torque and RPM, so an engine with low torque can still have high HP by having high RPM.

>>16761749
OK, I didn't factor in RPM. So regarding my second question, how would these differences be felt on the road?
I could never get my head around the relationship between the two values. I mean, people say that a high torque value means the car will accelerate better. I guess that loosely translates into more "pull".
What then does the HP value influence?

>>16761719
Power is just torque * RPM. Higher torque with the same power means an engine is running at lower RPM, that's all. If you're using lb-ft and HP, you'll need a unit conversion, so the equation is this:
>HP = (lb-ft * RPM) / 5252

It doesn't actually matter what the torque or RPM at the engine is, because you have gearing to turn it into whatever you want. In an ideal scenario (no friction losses), your power at the flywheel is the same as your power at the tires. This means that as you increase the RPM of the wheels relative to the engine they receive less torque, and vice versa.

Now, we throw a bit of a wrench into the works when we consider that engines don't have linear power output. So you can't just run at a lower engine speed and a higher gear to get the same effect as a higher engine speed and a lower RPM; your power is going to be different between the two engine speeds.

Ideally, you'd want to keep the engine running at peak power the entire time for the best acceleration, which means a specific RPM. Then you'd use gearing to match that to your road speed so you're accelerating rather than doing a burnout. However, this would require a special race-designed CVT that doesn't exist.

So instead, we add more gears to our gearboxes to keep the engine as close to peak power as possible. You don't actually want to shift when you reach your peak power RPM, because power curves are bell shaped. Shifting at the peak means your average level is lower than if you put the peak in the middle of your shift and benefit from the highest parts of the rising and falling slopes.

In a very peaky engine that has an aggressive slope to the power curve, it can be difficult to shift at exactly the right point to benefit from the maximum amount of power between shifts.

>>16761859
Since I'm bored of my novel, I'll just say it this way: peak power doesn't matter a whole lot, and peak torque is absolutely irrelevant in every possible way. What matters is the average amount of power between shift points, which requires a gearing map overlaid on a dyno chart. No one ever does that for any car or any reason, so the differences between engines and drivetrains just comes down to guesswork and subjective experience.

>>16761845
Torque is the amount of potential energy the engine can output. Horsepower is the amount of work the engine does. This is a made up engine: at 1000 cycles per minute the engine could output 1hp in one minute. At 3000 cycles per minute the engine outputs 3hp in one minute because its able to fit more cycles in the same amount of time so it can do more time.

So civic- big engine (high torque)spins few times per minute (low rpm)=100hp
Bike-small engine(low torque) spins many times per minjte(high rpm)=100hp

>>16761859
Thanks for spelling it out man.
Slightly off point, but with regards to those facts and figures, does bore/stroke play a factor as well?
I'm guessing in the case of the bike it has a much shorter stroke to facilitate higher RPM?

>>16761719
As far as your identical car different engine question, a car geared for the Civic engine with the bike engine in it would feel very sluggish more
so at low rpm. The car geared for the bike engine with the Civic engine would feel very quick and if manual you would have to shift very often and you would have a very limited top speed and terrible gas mileage. Like pedaling in 1st gear on a bike, you'll excelerate quickly but would t go fast. The Civic geared bike engine car would be like riding a bike in the highest gear only, accelerate slowly but you can get a high top speed

>>16761921
It does, basically how much surface are the expanding burning gasses of combustion can push against(bore) and how it actually expands and pushes the piston down(stroke)

>>16761921
Bore is the primary determining factor in the maximum amount of power you can make. Stroke increases your displacement and therefore how much air you can bring in, but it also lowers your max RPM and cancels itself out. However, if your valvetrain is optimized for a lower RPM or your bottom end is massively oversquare (short stroke) you may be able to increase your stroke and increase the displacement of your engine without affecting your RPM limit, meaning more torque at the same RPM, meaning more power. Econobox type engines can generally benefit from this, while Honda and most motorcycle engines tend to be very optimized. Most big V8s are generally capable of more peak horsepower by reducing the stroke, although the low revving burble and broad power band are part of the charm of a V8 as much as the power is.

>>16761935
Downshift, brah. The reason you don't use a motorcycle engine in a car isn't that you need "muh torkz," it's that car transmissions don't like to shift at high RPM. You'll shred your synchros and send little bits of brass all over the gearbox to bind up your gears.

>>16761719
Smaller engines, way higher revs, different tuning, different amount of cylinders.

>>16764405
They're both four cylinder engines though.

R1 sounds different because it has a different firing order.