Mid America Racing Engines
Washington, Iowa
Engine builder David Bruns of Mid America Racing Engines has brought competitive engines to all our competitions to date. The Hemi he brought to the first Challenge was a solid street engine with very broad torque and power curves, and last year's big-block impressed us with awesome power and torque, winning the '06 Engine Challenge. This year David brought yet another good engine to the contest, impressing everyone in attendance by making nearly 570 hp and 490 lb-ft of torque for a contest-leading combined score. While the expense of aluminum cylinder heads and a roller cam kept him from another win, we were still impressed with the power and reliability of this engine, earning Mid America Racing Engines a Fourth Place finish.
David Bruns of Mid America...
David Bruns of Mid America Racing Engines won last year's contest and though placing Fourth overall this year, earned the honor of making the most horsepower in this year's Challenge.
In 2006, engine builder David...
In 2006, engine builder David Bruns won our competition. This year his small-block made more power than any of the competitors.
Indy aluminum cylinder heads,...
Indy aluminum cylinder heads, a high-volume single-plane intake, and a stack of carb spacers helped engine builder David Bruns attain contest-leading power in this year's Engine Challenge.
Like most competitors this year, David used a stock 360 core block as the foundation for his build. The block was machined in-house for Probe forged pistons with PBM piston rings and an Eagle 4-inch stroke crankshaft. Scat connecting rods were utilized for their durability; the compression ratio of this 410ci small-block was 11.7:1. To handle oiling, David chose a Moroso oil pan, which he modified by adding oil control baffles, combined with a Milodon windage tray and Clevite oil pump. Oil from the top end was routed to the pan via the back of the block and away from the rotating assembly by metal plates under the camshaft tunnel. King rod and main bearings kept everything spinning freely, and Clevite cam bearings held the Cam Motion solid roller camshaft in place. A PBM timing set was used to spin the cam and enclosed by a stock timing cover.
Going for big power numbers meant utilizing aftermarket cylinder heads, and engine builder David Bruns chose Indy 360 H1-1 units to top his engine. These heads were machined in-house for stainless steel 2.125-inch intake and 1.65-inch exhaust valves and PBM roller valvesprings. David also ported the cylinder heads himself, reshaping the exhaust ports to mimic the proven profile and volume of Mopar W-2 cylinder heads. To actuate the valves, 1.6-ratio Indy roller rocker arms were used along with 3/8 -inch-diameter hardened pushrods. Knowing this combination would like an intake with big runners and a high plenum volume, David chose the Indy 360-14-3R aluminum single plane intake for induction duties. Double carb spacers beneath the Holley 1,000-cfm 4150 series carb provided additional intake volume, and additional power for this combination. Ignition was handled by an MSD distributor.
Inside his 360 block, engine...
Inside his 360 block, engine builder David Bruns utilized an Eagle crank, Scat rods, Probe pistons, and a Cam Motion solid roller camshaft.
A Milodon windage tray along...
A Milodon windage tray along with a Moroso pan with added baffles helped keep power-robbing crankcase windage to a minimum.
Looking closely, you can see...
Looking closely, you can see one of the metal plates epoxied in place under the camshaft tunnel in the block. These plates direct returning oil to the back of the block and into the pan without soaking the rotating assembly, also helping reduce crankcase windage.
Scat I-beam connecting rods...
Scat I-beam connecting rods are hard to beat for the price, and Probe flat-top pistons helped this engine achieve contest-leading power.
Using Indy heads with modified...
Using Indy heads with modified ports necessitated the use of header adapters on the Mid America entry. Schoenfeld headers expelled the spent gasses.
The Indy heads used on this...
The Indy heads used on this engine were ported in-house, and the exhaust ports were modified to the tried and true W-2 port dimensions.
Since Indy heads require a...
Since Indy heads require a different rocker arm offset, David utilized Indy's 1.6-ratio aluminum roller rocker arms.
Though placing Fourth overall,...
Though placing Fourth overall, making the most power in the contest is certainly a win of sorts for Mid America Racing Engines. We congratulate David Bruns on his strong performance in this year's Engine Challenge.
With an excellent combustion...
With an excellent combustion chamber design, big valves, and big ports, aluminum Indy cylinder heads were one of the keys to Mid America's contest-leading power numbers.