Schurbon Engine and Machine/Mo-par...
Schurbon Engine and Machine/Mo-par City won this year's Amsoil/Mopar Muscle Engine Challenge with a powerful big-block, and Chenoweth Speed and Machine placed a close second. This month we'll go inside each of these engines to see how they did it.
If you're a regular reader or subscriber of Mopar Muscle, then there's no doubt you're familiar with our annual dyno competition. Each year we feature a different Mopar engine combination, giving engine builders from throughout the country the opportunity to demonstrate their skills during our contest. After being built, the engines are delivered to the Mopar Nationals where they are on display for the weekend, and then we take them to Comp Cam's dyno facility in Memphis to see how much power they make. This year, the Amsoil/Mopar Muscle Engine Challenge featured the low deck big-block, and all of the engines were required to run the same Edelbrock Performer RPM cylinder head. The price of the parts used to build each engine was factored into the combined peak horsepower and torque achieved on Comp's engine dyno, for a dollar per power factor used to determine the winner.
Because our rules factored used parts at fair market value this year instead of at new prices like past contests, the engine builders had to be creative, choosing economical parts where they could to save cost. All of our competitors used factory 400 blocks, and using a factory 440 crankshaft was an advantage as well, giving upwards of 451 cubic inches at a fraction of the cost of an aftermarket crank. Realizing that our rules favored inexpensively built engines, and that it would take a seemingly unachievable amount of power to cover the cost of an expensive motor, the top finishers in this year's contest utilized a variety of second-hand parts and economical new parts to complete their engines on a budget.
This year, Maquoketa, Iowa's Schurbon Engine and Machine teamed up with Mo-par City, building the least expensive engine in the contest, with sufficient power to capture the win. Placing a close second, and having the second most economically built engine, was Chenoweth Speed and Machine from Morton, Illinois. At nearly 600 horsepower each of these were stout big-blocks, running smoothly and pulling hard all the way to our contest limit of 7,000 rpm while on Comp's dyno. This month we'll go inside each of these engines and show you what parts and techniques were used to capture the top two spots in the 2009 Amsoil/Mopar Muscle Engine Challenge.
Schurbon Engine and Machine
Maquoketa, Iowa
Schurbon Engine and Machine has participated in several of our dyno competitions, always bringing a solid entry and placing second two years ago with their stroker small-block. Located in Iowa, engine builder Scott Schurbon says his shop will build anything, but loves the opportunity to build high performance Mopar engines. Interpreting the rules for this year's Challenge, Scott decided to build the cheapest engine possible that would still make enough power to be competitive, going for the win on cost. Combining efforts with Mo-par City, Schurbon Engine and Machine scored a win as their 451 inch 400 made more than 580 horsepower on Comp's dyno, running on Rockett Brand 93 octane unleaded fuel.
During his dyno session at Comp, engine builder Scott Schurbon had a trick up his sleeve. Since our rules allow parts changes so long as the parts are legal and the changes are accomplished during the timed dyno sessions, Scott made his qualifying pulls, then swapped his relatively expensive single-plane intake and Holley Dominator for a used Weiand tunnel-ram and a pair of second-hand 625 cfm Quadrajet carbs for a 30 plus gain in horsepower. While most people equate the Rochester Quadrajet with GM, Chrysler actually used these carburetors on their 318 4-barrel production vehicles for a short period, so we didn't give Scott too much grief about his choice of carbs.
Teaming up with Mo-par City,...
Teaming up with Mo-par City, Schurbon Engine and Machine built a powerful 451 inch big block for this year's Engine Challenge. Making 582.7 horsepower and 544.6 lb/ft of torque, this economically built engine made a high enough combined power score to land a win this year.
After his qualifying pulls,...
After his qualifying pulls, engine builder Scott Schurbon removed his single four-barrel, opting for less expensive second-hand tunnel-ram induction. This helped both power and cost, for a big gain in the overall score.
Schurbon Engine and Machine...
Schurbon Engine and Machine utilized a variety of second hand parts to keep costs down, including a factory block, stock connecting rods, and this industrial application oil pan and pickup.
Since this is a normally aspirated...
Since this is a normally aspirated street engine with moderate compression, Schurbon resized a set of stock rods and installed ARP rod bolts. Keith Black Silvo-Lite flat-top hypereutectic cast pistons were also cheaper than forged units, yet deemed strong enough for this application.
The 400 block was machined...
The 400 block was machined in-house to accommodate a factory forged 440 crankshaft and balanced rotating assembly. Schurbon refrained from using aftermarket main caps or a main girdle, keeping costs at a bare minimum.
Did we mention that Schurbon...
Did we mention that Schurbon cut costs any way possible? Check out the single chain, stock-style timing set. For added strength, Schurbon drilled and tapped two additional bolt holes to keep the top gear affixed to the camshaft.