July 23rd, 2010

Text And Photos By Dick DeLoach

Clay Smith Cams installs the Dart SS Heads

In a previous issue, we showed you how the performance pros at Clay Smith Cams (Buena Park, California), prepped a set of Dart Iron Eagle S/S cast iron heads (and installed Manley valves and Clay Smith springs), which were going on a 283ci Chevy V-8. This month, we visit the shop again to watch Chad Langdon and Evan Speilman install the new heads in the Nova, with some help and sage advice from the cam doctor himself, George “Honker” Striegel, owner of Clay Smith Cams. Also, not ones to leave well enough alone, Dave Lange of Lange Performance then installed a set of Comp Cams Ultra Pro-Magnum roller rockers and their associated pieces.

The removal and replacement of the heads was straightforward, with no special tools required other than a torque wrench, but to do this job you’ll also need good set of ratchet wrenches and extensions, various screwdrivers, a power drill with a Scotch-Brite pad and a spatula (scraper) to remove the old gaskets. The most difficult part of the operation was dealing with the headers since they couldn’t be removed, only unbolted from the engine and the exhaust collectors and held out of the way during the operation.

When the car was put on the dyno at Westech Performance (Mira Loma, California), to establish the baseline horsepower and torque figures, they found that while the “EnduraShine” Edelbrock carburetor looks great and works well, at 750 cfm it is simply too large for the little engine. This will be handled in the future. There are plans to install a FAST EZ-EFI unit to cure the over-carburetion problem, but that’s for another issue. To make sure that numbers the Westech dyno produced reflected the true numbers of the before and after runs, the carb was left alone with only mild fiddling to make it idle well. Note that the stock Chevy heads had been shaved so that the combustion chamber measured out to 56 cc’s. The new Dart units also measured out to 56 cc’s, which makes this an “apples to apples” comparison of how the new parts worked compared to the stock units. This way, Westech could get a set of numbers that truly reflected what the installation of the Dart heads and Comp Cams rockers actually added to the engine’s power output.

When the crew from Clay Smith and Dave Lange from Lange Performance/Fuel Curve West (Upland, California), were finished, the car was taken back to Westech and run on their chassis dyno. The results were impressive. The small block had gone from about 150 hp (at 4,000 rpm) to over 200, and from 170 lb-ft of torque to nearly 230, just by adding the Dart heads and Comp Cams roller rockers. The increase was even more pronounced at 3,000 rpm as the horsepower went from 100 to 180 and torque from 120 to 205. That’s an impressive gain, to say the least.

Follow the photos as we show you how the head masters at Clay Smith Cams remove the old heads and install the new Comp Cams equipped Iron Eagles. (Editor’s Note: It’s a lot easier if you have a helper for some of the work, as you’ll see in the photos. Anyone who has worked at installing headers to an early Nova knows that at best they barely fit and can’t be removed without virtually pulling the engine).

We’d like to thank the crew at Clay Smith Cams, including George Striegel, Chad Langdon and Evan Speilman, as well as the unseen Dave Lange of Lange Performance for their hard work on this project.


Dart Heads



Clay Smith Cams



Manley Performance



Westech Performance



Lange Performance/Fuel Curve West



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