Cam Timing HOW?

[Anonymous]

From reading previous posts I understand that 106 degs is the best for all round use on a street bike, but how is this measured?
I understand about finding TDC and using a dial gauge etc. But what I'm not sure about is if the 106 is measured at the point the valve just starts to open or after a certain amount of lift has occured - which is it :?:
Also as said 106 seems to be popular for both cams, but some posts have mentioned that the higher the number, up to 110-112, gives better power at the top but you loose some bottom end. Does anyone know if we are talking about gaining just 1 or 2 bhp or is it much more. I'm use to riding more modern race reps - so I do not mind loosing a little bottom end if I will gain alot of top end :twisted:

 

[rosco15]

Install degree wheel and find TDC with a positive stop. Setup dial indicator on valve and zero indicator with valve closed. Rotate engine until valve is .050" off seat and write down reading on degree wheel. Continue to rotate engine until valve is .050" from closing. Note the number.

To figure lobe center for intake cam subtract opening number from closing number, divide difference by two and add that number to 90. For the exhaust subtract the closing number from the opening number and follow the same formula.
http://www.coperacing.com/techtip.html

I think that is what your asking.

 

[Anonymous]

Thanks :lol:
It mentions on the link cam timing of 110 - I guess this is to get more top end on a drag bike.

 

[rosco15]

110 moves the peak hp and torque up the rpm range. The lower numbers would be better for the street.