RE: The thread on cams.
Call Izcy and ask them your questions. Presumably they have developed the
cam priofile by experimentation with different engine specs. They should
be able to tell you if the cam was developed for use in a stock engine.
When TR built the TR6 engine, they developed a cam profile to go with it.
that is NOT to say that this is only profile that will work with it,
nor that it is the best profile. Cam grinders who develop their
own profile SHOULD do so using a dyno and measure engine performence
until the desired grind is found, whether that be full race or street
use. I know Kent does this. I expect Izcy does too.
After saying that, you will almost certainly have to change the carb setting.
If you are using ZS carbs, I don't even think there are a good selection
of needle profiles avalable as these carbs were used for emissions
improvement, although, I am not sure about this. Then to set up
correctly, you will need a dyno set up.
Izcy may be able to tell you what changes you will need to make.
You might look into Triumph Tune, who use Kent cams, to see if they have
a "package" you can use. Or Oselli do alot of dyno work, and may able to
offer a package.
In general, the longer the duration of the cam, the higher up the rev range
the power band will be. You can attempt to offset this by increasing CR.
In fact even a radial cam can be tamed with high CRs. The more radical
the cam the worse idle you will have, in general.
Higher lift will help with torque, but increase the wear on your valve
train components like followers and the cam lobes themselves. Also if
your head flows badly, higher lift will not improve air flow into the
cylinders.
To do this right, take your head to a flow bench, have them find out the
air flow dynamics then get a cam to match the characteristics of the head.
Obviously this is alittle more involved than this. I think that David
Anton at APT does this.
Hope this helps.
Cheers Dennis Wilson
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