Please, folks, correct any errors in this. John is ready to rebuild his
'66 and is looking for a "fast road" configuration. I have concentrated
on the engine and overlooked such niceties as free-flow exhaust, headers,
bigger carbs, port-n-polish, and breakerless ignition (the last of which I
recommend >highly<).:
John...
1) The cam. You could put in a "3/4 cam" and get some benefit. I used a
Kent Cam with a 286 degree duration ("fast road"). It helped (but I was
going from a car with badly broken rings). The kit contained dual
springs (which I think you already have), new lifters, and cam lube as
well as a timing disk and the cam. This is supposed to be >the< mod for
"waking up" the engine. Much over "fast road" and you'll lose torque on
the low end vs. raising horsepower on the high end.
2) Overbore. You'll pick up some torque here. Going over 0.040" might
involve non-standard head gaskets, as the opening in the piston bore becomes
smaller than the piston bore. Of course you want to go to oversized
pistons, not just oversized rings. A normal overbore might add 1-2% in
torque and power.
3) Compression. Us 'murricans got the low-compression engines so we have
a lot of latitude to play with (starting at 8:0:1 on my engine). You
could go up to about 9.5:1 to 10.0:1 on modern pump gas (premium). The
thumb rule is about 4% more power for every unit rise in compression.
4) "Unshroud" the intake valves. The 18V block already has some
crescents ground into it to enance flow from the intake valves.
5) New rockers. You can get a different ratio for the rockers, which
opens the valves more and for a longer duration. Note that this might
cause interference with the piston. In addition, "roller rockers" reduce
the friction in this assembly. Not sure about the effectiveness of the
last part.
7) Bigger intake valves.
You might find the original "Special Tuning" book invaluable. They do
concentrate on compression, and talk about cams which are no longer
available. The advice would be especially appropriate for your '66, though.
John M. Trindle | jtrindle@tsquare.com | Tidewater Sports Car Club
'73 MGB DSP | '69 Spitfire E Stock | '88 RX-7 C Stock
Home Page: http://www.widomaker.com/~trindle
"The Unapplicable Law:
Washing your car to make it rain doesn't work."
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