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| Joined: | 03-14-2005 |
| Location: | Atlanta, Georgia USA |
| Posts: | 406 |
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What you've got there is what we tend to refer to as the 'big-valve' conversion, which was pioneered by Richard R. at West Coast Racing Cylinder Heads. The Intake valve measurement is stock. However, the exhaust valves puportedly are modified motorcycle valves which are ~.06" larger than stock. I'm pretty sure the JHPS store now stocks these valves.
Richard is the guy who is the most famous for producing 907 heads/engines that flow enough to produce 220-240hp. The only problem is that if you are interested in competition, the big valves are illegal to use (but who's gonna know? lol).
Generally speaking, big power gains on the top-end come at the expense of low-end torque and drivability. However, this is generally not true about modifications made to the exhaust portion of the engine 'equation'. In practice, anything you can do to 'un-cork' the exhaust will produce power gains all through the rev-range.
Take advantage of the bigger valves and install a free-flowing exhaust system.
For additional perfomance gains, the #1 thing you can do is install pistons with a realistic c/r. The new head gasket nets about 8.0:1 on stock pistons. With stock cam duration, I'm running close to 11:1 on pump gas, and the car has tremendous torque from 2500-6000rpm.
Use the bigger valves, free-flowing exhaust, and higher c/r pistons as a basis for your performance upgrades. Later you can try different cams and carb configurations to fit your driving style.
Let me know if you need someone to build you an engine!
Judson Manning
DLC Motorsports
Atlanta, GA