Where Is All That
Power Coming From?
Today’s high performance aftermarket has made it relatively easy to build a high horsepower or high winding engine combination. You can order an aftermarket block, crank, heads, pistons or whatever you desire from companies such as Summit Racing or Jeg’s. The days of hunting through junkyards or visiting swap meets for specific parts are over. Or are they?
Bracket racing continues to get faster and faster each year. Many racers have the mindset that the less time you are on the track, the more consistent your car will be. Other racers view ‘chasing’ of their opponent to be a key factor in winning rounds and eventually races. So faster has become better.
When you are class racing, going fast can be an ego related venture. Some drivers simply want to own/ operate the fastest combination in the country. Drivers that are serious about winning know that they need to be relatively fast in order to get beyond a heads-up run during competition.
All of a sudden, we are back to the days of hunting for those hard to find part numbers. Certain components permit for a more suitable combination in Super Stock. Those parts need to have factory part numbers and can be hard to find since they are no longer in production. For example, the project S-10 truck will work well with a small block Chevrolet combo.
The options when building a SBC are numerous in Super Stock. The determining factor is the horsepower rating. A 350 cubic inch motor can be rated anywhere from 250 through 385 horsepower. The amount of ‘factored horsepower’ determines the final weight of the race entry. So selection of an engine combination and the body style in which it will fit becomes scientific.
Team Duck Tape's Super Stocker will be a ’95 S-10 pick-up truck. A 255 horsepower 350-inch small block Chevy is our engine selection.
In the GT/Truck classes, classification is determined by dividing the shipping weight by the factored horsepower for the selected engine combination. (found in NHRA's Classification Guide). The stock '95 S-10 has a weight factor of 15.87 x 180 horsepower for the original 4.3L V6, equals 2857lbs shipping weight. If we use a 1969 era 250hp 350cid, the Guide shows it defactored to 230hp. 2857 divided by 230 equals 12.42, which puts us on the high side of GT/TC's 11.50 to 12.49 weight break. We're allowed to move to the top of the class (11.50lbs per factored horsepower) which means out minimum race weight in GT/TC would be 11.5x230, + 170lbs for the driver = 2815lbs. If we chose to run the 255hp 350 (factored at 290hp), our class would be (2857/290=9.85) GT/TA in the 9.50 to 10.49 lb break, or we could add weight to move down one class to GT/TB at 10.50 lbs. The minimum weight in GT/TA would be 9.50x290+170 = 2925lbs, or in GT/TB, it would be 10.5x290+170 = 3215lbs. Confused? Yes, we have our moments, too.
So, you can see that selecting a different variation of an engine, or a different year engine may give you a different horsepower factor, and thus change the class or race weight of the vehicle. You can use a higher horsepower engine, but you will either have to carry more weight, or run against a quicker class index. You must also then cross reference NHRA's Engine Blueprint Specifications to see what part numbers you must use for the heads, carb, etc. (Note: IHRA primarily uses the same classification guide and blueprint specs. To be certain on a particular combination, check with your IHRA tech official, but generally speaking, NHRA's online Guides will get you what you need to know!)
Our entire combination revolves around the 23-degree Chevrolet head with a casting sequence ending in 441. The 441 head was available in from ’67 through ’69. So the amount of product in salvageable condition is limited.
Luckily, Team Duck Tape has friends, who have friends, who know people that somewhere down the line met a guy that has a set of heads. The story isn’t quite that complex, but it did take nearly two to three weeks to find a virgin set of 441 castings.
Now that the heads have been located, the remaining engine components will be gathered based upon this selection. A standard 350 crank will be used. A regular 5.7 inch rod will also be needed. The roller cam will be a specific grind that will allow the 76 cc head to actually breathe.
According to the IHRA rulebook, the heads can be improved. The limiting factor is that the spark plug hole itself cannot be relocated. With this information in mind, Mike Hupertz and the staff at Hupertz Engineering in Painesville, Ohio have begun working their magic.
Hupertz’s primary customer base hails from the world of circle track. In this arena, Mike is also limited by the rulebook and is restricted to a steal Chevrolet casting. Yet he makes unreal power and his customers consistently finish well.
Mike is not just an engine builder; he is also a drag racer. Hupertz runs a small block 355 in his ’71 Chevelle. A car that weighs over 3,000 pounds still clicks off times as quick as 10.34 at 128 mph in the quarter. In ’98 Hupertz even netted a Super Pro (box class) championship at Thompson Drag Raceway during his rookie season. His on track experience simply compliments his small block product knowledge. So Hupertz got the call to transform our stock 441 head into a Super Stock gem.
Our index of 11.40 should be obtainable. Larger valves, a shaft rocker system and countless hours of bowl work will net our team the increased power to put the SS pickup truck into the low 11-second zone with limited funds.
The short-block will be a standard 4-bolt 010 unit. The steel crank and good H-beam rods will be capped off with an accepted class legal piston. Our piston of choice will come from local manufacturer, WISECO Pistons of Mentor, Ohio.
Final assembly of the 255 horsepower 350 will occur at Hupertz Engineering. A stylish, yet effective quadra-jet carb will deliver the air/fuel mixture to make our little engine hum. Dyno numbers will help in the initial set-up of the truck.
As for now, we have completed the rolling chassis. The gathering of engine parts is over and the remainder of work will be done this winter. So the next question quickly arose… what transmission will be best in this application?
For top-notch transmission advice, we turned to Marco Abruzzi at Abruzzi Racing Transmissions. Abruzzi is the defending IHRA Top Sportsman World Champion and longtime bracket racer. His expertise led us to select a power glide.
Abruzzi crafted an extremely quick glide using an aftermarket 1.98 gear set. He also installed a faster operating Transbrake and a custom Abruzzi valve body. Other tricks of the trade were utilized to provide the quickest transfer of power with the least amount lost.
A standard power glide, intended for bracket racing, will use a stock style 1.76 gear set and cost roughly $900 to $1,200. A properly equipped Super Stock style glide runs closer to $2,220 or more. Again the term ‘budget’ is stretched to include a transmission nearly twice the normal cost.
More specific transmission related information can be gained at www.abruzziracing.com or by calling 330-369-1707. To reach Hupertz Engineering please call Mike directly at 440-392-2138.
Since we are out of dollars and out of
space, this concludes article two of the not so easy ‘Budget Super Stock’
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