HP/Compression calculation?

At the wheel a stock 650 makes closer to 50hp. Probably 47 or 48 for most older bikes. The 68HP is the factory claim at the crank and is a bit high for the "average" bike.

With what your putting in the bike between 70hp and 80hp should be possible. If you break 80 let me know you you'll probably get close but without more cam I don't know if you'll hit those numbers.

My bike is a 700cc with a much more radical cam and only made 78HP. That extra 84cc probably equals the cam difference between my bike and yours but you'll probably have better torque through the rev range. I bet you get similar HP numbers but would drop my bike like a bad habit in a roll-on.

Old-Skul wrote:

At the wheel a stock 650 makes closer to 50hp. Probably 47 or 48 for most older bikes. The 68HP is the factory claim at the crank and is a bit high for the "average" bike.

With what your putting in the bike between 70hp and 80hp should be possible. If you break 80 let me know you you'll probably get close but without more cam I don't know if you'll hit those numbers.

My bike is a 700cc with a much more radical cam and only made 78HP. That extra 84cc probably equals the cam difference between my bike and yours but you'll probably have better torque through the rev range. I bet you get similar HP numbers but would drop my bike like a bad habit in a roll-on.

Here's the secret: compression. lol

Dang, didn't see the 12.5:1. 80 - 85 seems alot more possible now! Good luck with it.

Just so we are all on the same page, in my post earlier I was talking about crankshaft hp, not rear wheel hp.

Damn, I was hoping my CSR would put out 60 at the wheel, maybe with a little tweaking...