1972 Dodge Dart Custom Best Machine 900hp Engine
Best Machine Builds The Mother Of All Wedge Engines
From the September, 2005 issue of Mopar Muscle
By Randy Bolig
Photography by Chuck Millen
When it comes to building an engine, when is enough really enough? Well, if you ask Wes Hudgins of Goodyear, Arizona, he'll probably tell you that you can never have enough when it comes to horsepower. Wes has this car that he likes to make go really quick, and when it came time for motorvation, he contacted Best Machine in Shelby Township, Michigan. While speaking with the guys there, they came up with a game plan for a really stout combination. Now, this wasn't going to be a run-of-the-mill stock-blocked engine that could kick it on the local boulevard; this was going to be nothing but pure adrenaline for close to 8 seconds.
Building an engine that displaces horsepower of over 915 or so, and a torque reading of 731 lb-ft, means you better know what you're doing when it comes to choosing parts. Let's face it, stock rods and pistons ain't gonna cut it. The list of parts chosen was definitely top-shelf, which left the durability issues up to the assembly process. I think we can all agree, simply throwing all the parts in a pile and hoping it all goes together isn't going to happen. paying close attention to the small details is what makes a good engine great.
The base of this build is...
The base of this build is a Keith Black aluminum wedge block featuring a 9.980-inch deck height. The block comes fully machined with main caps, studs, and cam bearings installed from KB, as well as all relevant hardware. Best Machine O-ringed the block, and honed the cylinder bores with a torque plate, and clearance was added in the location of the pushrods.
Since this engine isn't going to be making many trips to the local Piggly Wiggly, a more race-oriented race block could be used. The Keith Black aluminum 400 Wedge low-deck block is a strong, lightweight block featuring full water jackets, removable cylinder sleeves, stronger mains, and a larger bore/stroke capability. The block comes fully machined with main caps, studs, and cam bearings installed, plus all relevant hardware. Our version came with a deck height of 9.980 inches. Building the rotating assembly began with a Callies 4.250-inch Magnum Plus crankshaft that had been gun drilled to reduce weight, and is designed with Chevy rod journals. Say what you will, connecting rods for this application are readily available in this journal size, and the smaller journal size makes the crank a little lighter. From the crankshaft, GRP connecting rods, measuring 6.58 inches, are then connected to the CP custom piston that brings the final squeeze ratio to 15.0:1-definitely not pump-gas territory. The camshaft is another custom piece by Straightline Performance. The seriously big bulges measure a healthy 280/295 degrees of duration at .050-inch valve lift, and .818/.819-inches of valve lift. The 113-inch lobe separation would help with the idle quality, as well. Idle quality, who are we kidding? Connecting the cam to the crankshaft would be a Jesel beltdrive keeping it all under control.
Making the bottom end live...
Making the bottom end live under harsh conditions is the job of quality parts like this Callies crankshaft with 4.250-inches of stroke. Best machine modified the crankshaft by removing some metal from the counterweights to lighten it and aid in the balancing process.
Once the rings were gapped,...
Once the rings were gapped, and the rods checked for tolerance, the piston assembly was put in the block. Dart Coatings coated the CP pistons with the top receiving a Pro Stock Gold treatment for a little extra protection during passes using the nitrous, and the sides got a Moly coating.
There is a serious portion...
There is a serious portion of the piston poking out the cylinder hole, and this means we better have our act together when it comes time for a camshaft install. Use the wrong cam specs, and the valves will hit the pistons.
For this build, a custom cam...
For this build, a custom cam from Straightline Performance was chosen. With .818/.819-inches of lift, and 280/290-degrees of duration at .050-inch lift, a serious idle is the result.
The B-1 heads were given the...
The B-1 heads were given the once over to make a few modifications. When the Best Machine custom cutters had finished whittling away the unnecessary aluminum, the flow bench rewarded us with some really good numbers. (See Chart 1)
Enlargement of the pushrod...
Enlargement of the pushrod holes was one modification made to the heads. With this large a camshaft and the T&D rocker arms, the stock holes had interference issues.
T&D rocker arms feature a...
T&D rocker arms feature a 1.7 ratio.
Another modification was to...
Another modification was to the oil drain back holes. Return oil flow is greatly improved with this simple modification.
The valves are titanium and...
The valves are titanium and measure a healthy 2.300/1.780-inch diameter, but have .100-inch longer stems.
It's The Tops
Heads make power! No one can argue with that, and to make sure there was enough power made, a set of Brodix B-1 heads was chosen. Now, Brodix makes a really good head right out of the box, but these were given to Dwayne Porter, who cleaned up the bowls, gasket matched the intake ports, and polished the chambers. Afterwards, Best Machine touched them with a Serdi valve job, using custom cutters designed by Best Machine. Special provisions were also made to the heads to accommodate additional cooling lines added under the center exhaust ports to help cooling. This extra cooling was deemed necessary for when the 350hp NX Pro Shark Fogger is applied. To finish the heads, Stealth titanium valves, measuring 2.300/1.780 inches, are actuated by the T&D rocker arms and Manton 71/416-inch pushrods. Feeding the monster a metered dose of juice is a Pro Systems 1250 Dominator perched on an unported Brodix intake.
There are several good aftermarket...
There are several good aftermarket distributors available; the problem is that with our heads, a stock-style distributor will not fit. Best Machine chose to use a NRC (Newman Racing Components) offset distributor.
We can blow a lot of hot air, and tell you the what, where, and how of what we did, but unless we show you the what, where, and how of what we did, it's just that-hot air. So follow along, as we show you just what it took to build enough horsepower to make a '72 Dodge Dart travel the quarter-mile in 8 seconds.
B-1 Head Flow
Super Flow 600 measured at 28 inches of water
With the engine together,...
With the engine together, it was time to see if it really was as good as we hoped. The engine was loaded on the Superflow 901 dyno at Impastato Racing in Chesterfield Township, Michigan.
Making this engine live requires...
Making this engine live requires some serious oiling concerns be addressed. The custom Striaghtline oil pan was fitted with several location-specific oil lines. A Milodon Pro Stock oil pump with an Indy Maxx Remote filter cover ensures oil reaches every place it's needed.
The single-plane Brodix intake...
The single-plane Brodix intake was not ported. These intakes possess an impressive flow capability without needing any touching. We're sure there are one or two more horsepower to be had by grabbing a cutter, but opted to not do it yet. Besides, we will be trying another intake plumbed for nitrous at a later date.
Before the engine was run,...
Before the engine was run, valve lash was set at .023/.029-inch. After a brief warm-up and break-in run, lash was reset at .014/.017-inch warm.
Once everything was connected,...
Once everything was connected, the Pro Systems 1250 Dominator carburetor was primed, and the engine roared to life with no hassles. Running an engine on the dyno is a harsh environment, so before any testing was done, the engine was allowed to run with no load applied at various rpm.
After the warm-up period,...
After the warm-up period, a couple pulls were made to get the carburetor jetting where it needed to be (84 front jets with a 5.5 power valve, and 92 rear jets with no power valve), then a final power pull was made.
And there you have it, 915.2...
And there you have it, 915.2 hp at 7,300 rpm and 731.8 lb-ft of torque at 5,500 rpm. If that ain't enough to curl your toes, give the guys at Best Machine a call, we're sure they can accommodate you.