A remote control panel displays...
A remote control panel displays data and controls the dyno's function from inside the car. In preparation for a power pull, the car is run through the gears, and then brought to full throttle in top gear, and run through the test rpm range.
My Corvette
We had a chance to talk to Rick Stoner about this particular machine to gain some insight into this car and Rick's enthusiasm for the marquee. As Rick says, "It's a ground-up restoration that's been done for a little while; we went through every nut and bolt. I wanted to bring it up to a high-quality Corvette; I'm not into the national Corvette show-car stuff, but wanted a nice car and an all-numbers matching car. I wanted it to use all stock stuff, to make it the way it was when it was brand-new."
We inquired about where Rick's interest in these midyear Corvettes originated. Rick says, "I've always liked the Corvettes. I bought my first one in 1969 from a friend of mine that was going into the service. I bought it for $3,000, and I still have that car. If you can find good buys on these cars, you won't lose with these cars. I have nine of them now. It may be a big investment in these things, but I can go out and touch them, feel them, and drive them."
With the new plugs, air filter,...
With the new plugs, air filter, and basic tune-up parts in place, the first full power tests were run. Grunting against the rollers, we found a baseline of 290 hp at 5,000 rpm, and a torque peak of 331 lb-ft at 3,900 rpm.
We inquired about the engine, and Rick informed us, "The engine is absolutely rebuilt from the ground up with all stock components. I didn't put [hardened] seats [in the heads] in this one, so it will have to run leaded gas or additives if you were to drive it very much. The latest one I did, I installed the hardened valve seats so I could run unleaded pump gas with no additives. I did knock some compression out of it when I rebuilt it, but I didn't change anything else."
Rick conveyed that these cars provide a unique driving experience, "For a guy who grew up with those cars, driving them just makes you feel like you are 18 years old again. I've always loved those old cars, and the value has always been good. I like the earlier cars the best, the midyears, and the old straight axle cars. I didn't particularly care for the Corvettes after 1967. It's surprising how well these cars still perform on the road. My little '64 roadster gets 21-22 mpg on the highway with a 300hp, single four-barrel engine. The 427 car has a lot of punch to it, but I'm not drag racing them anymore, so I'm not out flat-footing, seeing how fast it will go. I'm a little too old, and if I wanted to do that I would get a race car. This is just a cruiser, something to have fun with on a Sunday afternoon, or go to a car show in, or just go for a nice evening ride if I want to. It's relaxing, it's fun, it's enjoyable, and people, when they see it, appreciate the car as well."
Power tuning on the dyno comes...
Power tuning on the dyno comes down to the air/fuel ratio and ignition timing at full load and wide-open throttle. The numbers showed a lean mixture, which indicated a jetting change is required. The carb was opened for a step-up of two jet sizes.
These four-barrel 427 engines...
These four-barrel 427 engines used a vacuum mechanism to control the secondary barrel opening rate and timing. Additional test pulls revealed that a quicker opening rate could provide a benefit, an adjustment made by removing the vacuum pod and replacing the spring inside.
The most important aspect...
The most important aspect of dyno testing is crunching the numbers to analyze the results and determine the course of improvements. Here, the dyno tuner's skill and knowledge is key. The crew at Westech was thorough.
With the jetting dialed in,...
With the jetting dialed in, the next step is the ignition timing. Here, a trial and error process of adjustments, called a timing loop, zeros in on the precise ignition timing required for best output.
With some fine-tuning and...
With some fine-tuning and no major component changes, the dyno tune brought this big-block's peak output to just over 300 hp at the rear wheels with 345 lb-ft of peak torque for a nice power gain of 11 hp and 14 lb-ft.