Although the following numbers do not represent actual piston speeds, they should suffice in understanding what exactly is going on with the 2.2L engine. Explanation of my logic is as follows.

Stroke:
2.0L - 87mm
2.2L - 90.7mm

My assumption is that the maximum possible and ideal velocity, v_ideal, of the piston must be the linear velocity of the crank at the point where the conrods link to the crank. The actual velocity of the piston, v_actual, is X*v_ideal, where X is the cos(phi)^2 and phi is the angle of the conrod off the axis which the piston travels. Without knowing the length of the conrod, we cannot get v_actual, but I believe v_ideal will at least show us the magnitude of the difference between the 2.2L and the 2.0L at equal revs.

Knowing this, the following numbers arise:

2.0L linear crank velocity:
8200RPM....- 5.95 m/s
9000RPM....- 6.53 m/s
10000RPM..- 7.25 m/s

2.2L linear crank velocity:
8200RPM....- 6.20 m/s
9000RPM....- 6.80 m/s
10000RPM..- 7.56 m/s

If I've made a mistake in my assumptions, please feel free to correct me. I'm trying to put calculations behind the guessing that some people have been doing about piston speeds. Although my numbers are the linear velocities at the crank, I can assure you that the 2.2L engine at 8200RPM is under much less stress than the 2.0L at 9000RPM. I almost positive in saying that the actual piston speed of 2.2L @ 8200 RPM is not approximately equal to the actual piston speed of the 2.0L @ 9000+RPM.

Even if we were to think about it from a business standpoint, it wouldn't make sense for them to build an engine that produces the same amount power at the same amount of piston speed (i.e. stresses) while require more material and more testing only to make a couple ft-lbs of torque and a less 'glamourous' redline. The savings for Honda is in the increased factor of safety in the engine.

Anyway, I hope I'm not too far out of line in my calculations. If anyone's interested in how I came about those numbers, PM me and I can scan this scratch paper I used.

 

That's some hot math my man...Appreciated

 

i havn't been to the honda world long, but in my experience, the reason of an engine swap is either gaining engine durability (ie. stronger internals), or higher power output.

in this case, swaping a 2.2 into an 00-03 will result in no gain on both... so what is the point of the motor swap other than having a different motor and bleed your wallet?

 

Pardon my stupid question, but is there an easy way to raise the stock rev limiter on a MY04 to at least 8600RPM?

 

IT'S COMING OUT TO BE CHEAPER. THAT IS WHY HE WANTS TO DO THIS. WHY DONT YOU READ BEFORE YOU POST???????????

 

I'm not real strong in math but you put out some "really" interesting numbers! I hadn't considered the velocity of the crank before. It makes sense that the crankshaft journal would be moving faster at a given rpm because of the increased circumference that the longer throw provides. 90.7mm vs 87mm draws a bigger circle.

If you're just trying to calculate how fast the crankshaft end of the con rod is moving around the circle, which is how I'm interpreting what you're calling the "linear crank velocity," what is the point of the "phi" variable you mention? I can understand "phi" if you're trying to nail down as accurate a calculation for piston speed as possible but that doesn't have anything to do with what "I think" you're calling linear crank velocity. Am I missing something here?

The simple calculations I do to figure piston speed just yields an average number. I converted the 87 and 90.7 mm dimensions to inches simply because I can relate to them better that way. Take the stoke distance * 2 equals the distance the piston travels in one crank revolution. Multiply that by 8000 or 9000 as appropriate and you've got the distance the piston travels in one minute. Multiply that by 60 gives distance in inches that the piston travels in an hour. Divide that by 12 to get piston distance traveled in feet / hour. Divide that number by 5280 to get piston distance traveled in mph. The numbers I got were:

2.0 @ 9000 rpm
Piston speed = 58.384 mph

2.2 @ 8000 rpm
Piston speed = 54.104 mph

As I said, these are just average numbers. The peak speeds would have to be considerable higher and if I'm following you correctly, your calculations involving the angle of the con rod etc., may produce more accurate numbers at a given point in the crankshafts revolution although they're a bit above me at this point!

FWIW,
Drive Safe,
Steve R.

 

Thanks for taking the time to read, and your useless post

 

You really need to get the piston speeds at an instant to do this right if you wanna get completely technical. Piston speed at and nearing BDC and TDC are really not important and skew things with the averages. Even then, im sure it wont be as big of an increase as some people once made claims for it to be. This isn't a increase in displacement by changes in the rotating dynamics which plays a more significant role. This is just an increase of 1000rpm's.

BTW, I think it was determined before that the rod lengths are the same for the MY's so your calculations would be fine.

 

 

he was being sarcastic

but he's serious about the useless post part

Pretty funny how my post before would have explained it...but u didnt bother to read that either