Rather than grinding the mains...
Rather than grinding the mains of the 440 crank to the smaller 400 dimension, Schurbon line-bored the block to accommodate the larger 440 bearings.
As a foundation for their engine, Schurbon Engine and Machine started with a factory 400 block, performing all the necessary machine work in-house to accommodate the forged 440 crankshaft and Keith Black hypereutectic pistons. Mo-par City supplied a deep oil pan from an industrial crane, keeping oil away from the crank and eliminating the need for a windage tray, and assisted in the assembly of the bottom end. Factory connecting rods were deemed strong enough for this application, and far cheaper than aftermarket rods, so Schurbon fitted a set of standard 440 rods with ARP bolts and Clevite bearings. A stock, standard volume Melling oil pump was utilized to keep the engine lubricated, and the .600 plus lift Comp flat-tappet camshaft optimized power while costing much less than a roller cam and the associated hardware.
This year's rules required all the competitors to use Edelbrock's popular Performer RPM cylinder heads, and the engine builders were allowed to perform all the port work they liked. We also allowed epoxy modification to the ports, but no welding was allowed. Schurbon ported their heads in-house, raising the port to max wedge size and then filling the bottom of the intake port with epoxy to control port volume. The heads were then fitted with inexpensive stainless steel valves, Comp springs, and used retainers and locks. To actuate the valves, Schurbon used an ancient set of ductile iron 1.5 ratio adjustable rocker arms to save even more money on this inexpensive big-block. Though this engine showed up at the Mopar Nationals wearing an expensive new single-plane aluminum intake and Dominator, the induction was quickly changed to a used Weiand tunnel-ram and dual second-hand Quadrajets during the qualifying dyno session. This change both added power and saved money, resulting in a first place finish for Schurbon Engine and Machine.
All of this year's competitors...
All of this year's competitors used the same Edelbrock Performer RPM cylinder heads. Schurbon ported their cylinder heads in-house, performing a multi-angle valve job as well.
Morton, Illinois
Chenoweth Speed and Machine from Morton, Illinois, also calculated that it would take an inexpensively built low-deck to contend for the top positions in this year's Engine Challenge. The Chenoweth's are no strangers to Mopar engines, as their shop specializes in building Chrysler products of all types, from stock rebuilds to all-out race Hemis. Utilizing an array of second-hand parts combined with inexpensive new parts where necessary, engine builders Dale and Mike Chenoweth made this year's competition very close, coming within decimals of first place.
During their session on Comp's dyno, the Chenoweth's tuned their engine through a series of jet and timing changes, and then pulled the same trick as Schurbon, changing induction to a Weiand tunnel-ram and a pair of Carter AFB carburetors. Hoping for a gain in power, the induction swap was actually a disappointment, dropping power across the board. After a couple of quick tuning changes to the Carters, Mike and Dale determined they wouldn't be able to tune the tunnel-ram to the power of their single Dominator in the allotted time, so they switched back to the more expensive setup.
Ductile iron adjustable rocker...
Ductile iron adjustable rocker arms were chosen to help control the cost of this engine. All the competitors utilized the same Hooker Super-Competition coated headers.
Starting with a factory 400 Chrysler block, the Chenoweth's treated the engine block to their "block in a bag" process, machining the block to precise specifications. Additionally, the mains were line-bored to the larger 440 size to fit a stock forged 440 crankshaft. Various second-hand parts were utilized including the forged I-beam connecting rods, oil pump, oil pan, windage tray, and even the Engle flat-tappet camshaft and Howard Cams oil-thru lifters. New Diamond forged pistons were utilized which added to the cost of the engine, and the rotating assembly was balanced in-house.
Choosing heads for this year's contest was easy as all of the engine builders were required by the rules to utilize the same Edelbrock Performer RPM castings. Chenoweth Speed and Machine ported their Edelbrock heads, performed a multi-angle valve job, then installed stainless-steel valves and new Chet Herbert valve springs. Although the Chenoweth's changed intakes during their dyno session, they changed back to their Edelbrock Victor 383 single-plane intake and Quick Fuel Technology prepped Holley Dominator when their dual-quads didn't make the expected power. Had the tunnel-ram worked, it would have saved enough cost to make this a much closer contest, though it would have been difficult to beat Schurbon's stout power score and low cost. We congratulate Chenoweth Speed and Machine on their very solid second place finish in the 2009 Amsoil/Mopar Muscle Engine Challenge.
| 2009 participants |
| Chenoweth Speed and Machine | JD Engine and Machine |
| Mike Chenoweth | Jeff Dickey |
| Morton, IL, 61550 | Columbia, MO, 65203 |
| 309/266-8084 | 573/445-4550 |
| chenowethspeedandmachine.com | |
| LaRoy Engines | Mid America Racing Engines |
| Jim LaRoy | David Bruns |
| Challis, ID 83226 | Washington, IA 52353 |
| 208/ 879-2969 | 319/653-6282 |
| jglaroy@custertel.net | midamericadb@iowatelecom.net |
| Promax Performance | R.M. Competition |
| Ben Gorman | Randy Malik |
| Indianapolis, IN | Roseville, MI, 48066 |
| 317/484-1451 | 586/909-1591 |
| sales@promaxcarbs.com | rmcomprandy@yahoo.com |
| Schurbon Engine and Machine |
| Scott Schurbon |
| Maquoketa, IA, 52060 |
| 563/652-3100 |
| Schurbo@msn.com |
The heads were ported to max-wedge...
The heads were ported to max-wedge dimensions, and then the bottom of the intake port was filled with epoxy to reduce volume.
To optimize power and save...
To optimize power and save costs, Schurbon utilized a second-hand Weiand tunnel-ram with a pair of antique Quadrajet carburetors. This was good for some 30 additional horsepower and the used induction parts were priced at a fraction of a new Holley Dominator and aluminum intake.
Though the Rochester carbs...
Though the Rochester carbs are inexpensive, they're also difficult to tune given time restrictions of our contest. Fortunately, Scott persuaded the secondary's to open a little quicker, netting enough power for a first place finish in the 2009 Amsoil/Mopar Muscle Engine Challenge. We congratulate Schurbon Engine and Machine/Mo-par City on their win.
Chenoweth Speed and Machine...
Chenoweth Speed and Machine finished a close second this year as their 452 cubic inch big-block made 589.6 horsepower and 518.9 lb/ft of torque.
The dual-quad induction that...
The dual-quad induction that the Chenoweth's bolted on dropped power significantly, causing concern that the engine was hurt. After determining the engine was alright, Mike and Dale Chenoweth gained power by tuning the carbs, but were still significantly shy of the power the single four-barrel made.
Like all of this year's competitors,...
Like all of this year's competitors, the Chenoweth's started with a factory Chrysler 400 block and then fitted it with a factory Chrysler 440 crankshaft, performing all of the necessary machine work in-house.
We're not sure how necessary...
We're not sure how necessary they are, but the added gussets in the valley of this engine sure make it look stronger.
By modifying a factory oil...
By modifying a factory oil pan and pickup, Chenoweth Speed and Machine saved money and also reduced crankcase windage by getting the oil further from the crankshaft.
New Diamond forged pistons...
New Diamond forged pistons were matched to a set of reconditioned forged I-beam connecting rods, and the rotating assembly was then balanced.
All of the competitors were...
All of the competitors were required to use the same Edelbrock Performer RPM aluminum cylinder heads. Chenoweth Speed and Machine ported their heads in-house, installing stainless steel valves and Chet Herbert valve springs.
During their dyno sessions,...
During their dyno sessions, the Chenoweth's swapped to a tunnel-ram intake but lost significant power. With tuning they gained some of the power back,....
....but eventually reinstalled...
....but eventually reinstalled the Edelbrock single-plane intake and Quick Fuel Dominator for their best power numbers.
The Chenoweth's noted that...
The Chenoweth's noted that this engine wasn't making as much power as they thought it should, and we found out why during the teardown. Seems the piston-to-valve clearance was a little close in this motor, resulting in a couple of bent exhaust valves.
To actuate the valves, the...
To actuate the valves, the Chenoweth's used a second-hand set of Harland Sharp aluminum roller rocker arms.
Running Rockett Brand 93 octane...
Running Rockett Brand 93 octane pump gas, Dale and Mike Chenoweth tuned their economically built 452 inch big-block to a best pull of 589.6 horsepower and 518.9 lb/ft of torque on Comp's dyno. We congratulate Chenoweth Speed and Machine on their second place finish in this year's Amsoil/Mopar Muscle Engine Challenge.