Howdy Curtis:
"Running 3 1bbl's carbs would upgrading to a beefy cam be a good idea?"
Yes, a more agressive cam would allow the engine to work in a higher rpm range, which will take advantage of the additional cfm of the tri carbs.
"Why change a cam on a 200 at all?"
Cam timing determines many characteristics of an engine; idle quality, power range, peak HP and peak torque. Of course other facters are interrelated and interdependent, such as, carburetion, CR, ignition and exhaust. Changing cam is a way to change the character of an engine. With out 200s, a stock OEM cam makes for a low and slow, smooth idle, high vacuum, economical, low end torque engine. Bu changing cams you can improve on these qualities or go for a completely different set of characteristics.
"Would a daul pattern cam work the best?"
A dual pattern cam typically uses longer duration on the exhaust cycle. They were 1st found to be benificial for engines with a restrictive exhaust port design. NASCAR engine builders found some benefit at restrictor plate tracks. These improvements were at sustained, high rpm situations. That is usually not the case for our small sixes.
For our engines, a dual pattern cam may have some advantage with a shorter intake duration (Milder) and a longer exhaust duration (Wilder) in the same engine. Other factors will also enter into the final out come.
"By changing the fuel system on a six, does it require more duration?"
No, it is not required to change the cam as a result of a change to the fuel system. In the case of the tri-carbs the visual, coolness factor is impressive all by itself. To take performance advantage of the additional CFM capibilities of a Tri set-up, several other upgrades would be needed; increase in cam duration and valve lift, increased compression, specific ignition timing and improved exhaust.
A stock engine will likely show some performance gains with additional carburetion. To fully utilize the potential, a coordinated engine package is the ideal.
Now, a question for you. What is your ultimate goal? What is your plan for your engine?
Adios, David
