Hi Wayne,
IMO, the intake valve closing point has by far the most effect on engine
power characteristics. The other timing events have relatively less
effect on power characteristics. Early closing of the intake valve
should increase low & mid rpm torque. Simply by allowing more mixture to
be compressed. Six to ten degrees of advance is not completely out of
reason, & short - track engines sometimes have the cam timing purposely
advanced to increase low rpm torque. Retarded cam timing can often be
used to advantage on long tracks to move the power band to a higher rpm.
As you say, ignition timing is in the reasonable range.
I think you are on the right track by looking at the carb setup.
Dave Russell
WAS wrote:
> Hello,
> The engine is not producing anywhere near the power
> it should. It idles well, runs smooth, but is way down on power. It has
> none of the low end torque or high end power that it should. Another
> variable is the car has twin Weber DGV carbs on a modified BJ-8 manifold
> done by Pierce injection. The setup is similar to the goose neck setup
> for TR-6's. Measured the total ignition advance at 3000 rpm and got 35
> degrees which seemed close enough.
> Measured the opening of the intake and closing of the exhaust and
> with .012" clearance at the rockers the intake opens at 26 degrees (10
> degrees early) and the exhaust closes at 11 degrees (10 degrees early).
>
my test agrees with the cam being advanced about 10 degrees.
> My guess is the cam being advanced while not good does not explain
> the lack of power.
>
> When I pulled the spark plugs they look very lean even at idle so I
> suspect the problem is a very lean mixture across the whole rpm range.
> Is anyone else out there running two Weber DGV carburetors?
> I told my friend if it were my car I would remove the Webers and put
> on a pair of HD-8's.
> Regards
> Wayne
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