Hello,

I am looking for tools to select a camshaft. Something that I can input the engine spec, camshaft spec and the output provides at least the RPM range, and it would be great if it could estimate the torque and horse power as well...

thank you

 

I would just call Fuelmoto.
http://www.fuelmotousa.com/

 

Fuelmoto are OK, they have dyno charts but no tools to calculate. I am looking for something that I can calculate using a calculator tool. Here is something from Mikuni

************ From Mikuni *************
The most important cam timing event is the intake valve closing angle. The intake closing point determines the minimum rpm at which the engine begins to do its best work. The later the intake valves close, the higher the rpm must be before the engine gets "on the cam."

Long duration, late closing cam designs are necessary to drag the last bit of power out of an engine. Unfortunately, these same cams can perform poorly under more normal riding conditions. In the quest for maximum power output, many-too-many Harley owners choose a late closing, high-rpm cam for their engine. The problem with such choices is that the engine seldom spends time in the rpm range favored by such cams.

The majority of virtually any Harley motor's life is spent in the mid-portion of its rpm limits, between 2000 and 4000 rpm. At open-road cruising speeds, that range is more like 2500 to 3500 rpm. With current Big Twin gearing, top gear at 2500 rpm returns a road speed of 55 mph and 3500 delivers 84 mph. Riders sometimes "putt" around at 2000 or less. Even when accelerating to cruising speed, few of us use more than 4000 - 4500 rpm as a shift point. Very seldom, in day-to-day use, do our engines get near 5000 rpm, let alone 6000.

Even the mildest of Harley-Davidson's aftermarket cams (Evo or Twin Cam) do their best work above 3000 rpm. At 2000, the majority of these cams seldom perform significantly better than stock cam(s).

The rpm at which a Big Twin gets "happy" can be predicted by the closing point (angle) of the intake valves. The angle is expressed as the number of degrees After Bottom Dead Center (ABDC) that the valves reach .053" from being fully seated.

The following list predicts the rpm at which the engine gets "on the cam" based on the closing angle of the intake valves. These relationships are approximate but should hold true to within 200 rpm or so. They also assume that all other tuning factors, exhaust, ignition, etc., are operating correctly.


30 degrees = 2400 rpm
35 degrees = 3000 rpm
40 degrees = 3600 rpm
45 degrees = 4000 rpm
50+ degrees = 4500 rpm

 

I'm not sure why you want to "calculate", but my .02 says to just pick where you want the power and select a cam for that range. I disagree with the specs at the bottom of your post Nick. I think it's all how you have things set up and how well they work together. I'm running a Woods TW777 cam and have 100 torque at 2250 rpm's and it pulls to redline.

 

I will be installing a set of Andrews 48H cams in couple weeks. This cam closes at 29 and is known for its low end to mid range torque. This is where I ride 99% of the time.

 

What you really need to calculate is your riding style, how you want the bike to perform, and mods you have or plan to have; then choose your cam.

 

Too many variables to run a simple calculation. Heads, deck height, pistons, exhaust, throttle body and tune. To compare actual cams you can use big boyz cam comparison tool.
http://www.bigboyzheadporting.com/tccams.htm
You can use their compression/displacement calculator to see what you need to do to get to that 195-200CCP
http://www.bigboyzheadporting.com/TwinCamComp.htm

I would say analyze how you ride and what you want to gain from the swap and talk to a builder. There are several on this board in the engine section.

 

Years ago I purchased Craig Walter's Accelerator Pro software which was a pretty cool tool. But it hasn't been updated in years.
Maybe look at the Dynomation-5 software.

http://www.motionsoftware.com/index.html

 

Cams come in two types, the ones that make Horsepower, and the ones that make Torque.
If you ride in the RPM range from 2000 RPM to 3400 RPM, get a Torque cams.
If you ride in the RPM range From 3000 RPM to 6000 RPM, get a Power Cams.

I have seen people get the wrong cams befor, make a wise choice. Less Is more sometimes.

 

I figure to leave it to the experts who make cams - Isky never disappointed me in selection of small block cams.. But a plug in would be bitchen...