Jim Hand's Performance Changes in 2001

Engine specs of Jim's 473 from 2000

After a successful season in 2000 with the new 473 engine and finding out what it's performance capability was with after market parts, Jim decided to revert back to a stock style cam and induction system. This would give Jim and Tom Hand the opportunity to find out just how good the stock intake, and 041 cam, really were. Jim surmised that some performance would be lost, but as the wagon was comfortably running in the mid 11's, he believed that it would still be competitive with other similar weight cars. With that in mind, off came the the Edelbrock RPM intake, the Holley carb, and out came the Wolverine 234/244/112 LS camshaft.

Jim reinstalled his trusty 1969 Q-jet and modified the intake. Specifically, the intake runners were cleaned, straightened, and enlarged to standard gasket size for better airflow. A pair of carb spacers were made of phenolic material with the top one completely open, and the lower partially open and contoured to follow the shape of the divider in the stock intake. The open spacer allows both sides of the carb to furnish air/fuel to each cylinder even though the stock intake is a dual plane design. The complete exhaust crossover was removed from the intake years earlier, as had the front/rear dividers in each side of the intake. Jim believed the improved flow would come closer to equaling the RPM flow, and the two spacers would mimic the height of the RPM. Here's what the spacers look like.

A Mellings SPC-8 cam, which is an exact copy of the original 041 cam, 230 intake degrees @ .050, 240 exhaust degrees @ .050, .313 lobe lift on both, and with a 113.5 lobe separation was installed replacing the Wolverine grind. It was set with the intake at 111 and the exhaust at 116. (Advanced one degree from the suggested Pontiac position of 112/115, and advanced overall by 2.5 degrees.)

As part of Jim's ongoing testing, he obtained a 800 cfm Q-jet from fellow Pontiac enthusiast Cliff Ruggles to try. The carb was originally from a '77 350 CI engine. A direct A-B test was made between it and his originally modified 750 Q-jet at the track and no significant performance differences were noted. However, the 800 was subjectively smoother on the street.

No other changes were made. All internal engine parts including Rhoads lifters and Harland Sharp 1.65 rockers, drive train parts, exhaust, and cooling systems remained the same. As Jim expected the wagon lost about .25-.3 seconds as a result of the cam, intake, and carb changes. At Arkansas City at the all Pontiac event in October, 2001, the car ran consistent high 11.70 and low 11.80. The 60' times ranged from 1.61 to 1.63, and the speed was around 112.5 to 113. Consistency was the key as the car made 9 runs with the 60' either 1.61 or 1.62! This performance level compared favorably to the events in 2000 with similar weather where the car ran in the 11.53 @ 115.5 range with 1.59 60' times.

The wagon is Car # 208. Note the combination of good reaction time of .515 with an ET of only .0082 over the dial-in. (.500 is a perfect light!) That is the way to win close races! (Jim has a good driver - Kevin Kirk!) Kevin won the Second Chance race of five rounds driving the wagon. Although hard to believe, the engine smoother than ever with idle vacuum at 15+ at 730 rpm in Drive. And when shifted from Neutral to Drive, less then 25 rpm drop occured!

What prompted Jim to slow the car down? For bracket racing several tenths makes little or no difference, unless close to a class break. Since 12 seconds is the break point between street cars and all out race cars running electronics, Jim decided he had a better chance to be competitive by staying closer to that 12.00 point. He could slow the car some by installing a throttle stop, taking out timing, or by restricting the air valve opening on the Q Jet, or some combination of all.

With the changes Jim again got to see how well the Pontiac intake and cam work on a correctly set up vehicle! At the Ark City race, the event manager decided on the morning of the race to add an additional class for non electronic cars running quicker then 11.99, so Jim didn't have to slow the car for the class at that event!

Jim also swapped gears late in the season installing a 3.31 ring & pinion. However, he didn't get to run the car with that gearing as the strip closed for the season. Jim expects similar performance with the 3.31 gears.

Engine specs of Jim's 473 from 2000

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