With the block fresh out of...
With the block fresh out of the hot tank and passing inspection, it was ready for the first machining process, which in this case was line-boring the mains.
Without a doubt, one of the most impressive-looking engines of all time would arguably be the Chrysler Hemi. But, before you get carried away with images of black wrinkle-finish valve covers installed on bright orange blocks and heads, there is something of which we need to remind you. The Hemi was around for 13 years before all these musclecar guys came in and stole the Fire Power's thunder. Most of us are aware of the origins of the early Hemi and the fact that not only did Chrysler use them to power some of its passenger cars, among other things, but so did Chrysler's Mopar sibling companies, DeSoto and Dodge.
By the time those bright orange engines were running NASCAR, the older Hemis had already been proving themselves on the streets, at the drags, and at the lakes for years. Just ask Don Garlits, the Chrisman brothers, or Fred Larson and Don Cummins, all of whom had very successful early Hemi-powered race cars in the 1950s and on. When Chrysler pulled the plug in 1958, the Hemi's reputation had already been firmly established as the motor to beat.
This would be all fine and good if this were 1958 and there were piles of engine in the junkyard or available at the local Mopar dealer. Problem is, it ain't 1958-it's 2008, and 50 years has passed since a first-gen block rolled off the assembly line. But, while the engines themselves are slightly more elusive than they may have been 50 years ago, there exists today a booming aftermarket industry that supports vintage engine builds, such as the early Hemi, perhaps in a more progressive way today than ever before. A number of the weak spots in those old engines have been addressed, like the water pumps, for which companies like Hot Heads offers adapters to run readily available small-block Chevy pumps in their place, as well as adapters for more transmissions than you can shake a stick at. And, internal items, such as pistons, bearings, seals, gaskets, rings, crank and camshafts, and even CNC'd aluminum heads, are all readily available.
Speed-O-Motive uses Rottler...
Speed-O-Motive uses Rottler CNC machines for just about every machining process. This speeds up the machining process incredibly by having all the specs pre-programmed into the machine's computer. Unfortunately, our extended bellhousing Hemi block was not one the company had done before, so a whole new program had to be written.
The point is, it's easier today to build up a reliable vintage engine like the Hemi than it's ever been. And, with every John, Dick, and Harry running small-block Chevy crate engines, dropping a vintage mill in your hot rod ensures your car will stand out from the crowd and separate you from the cookie-cutter street rods. In a hobby where it's nearly impossible for the average guy to build a hot rod in his garage that competes with what the pros are doing, dropping in a vintage engine ups the ante that little bit, which just may set your hot rod head and shoulders above the rest.
That was exactly my mentality when it came time to pick a mill for my '52 F-1 pickup. Sure, I could have ordered up a crate engine from any of the suppliers across the country, and I probably could have had my project on the road months ago, but who wants to take the easy way out? Always up for a challenge, and wanting to do something different (take my Project Potvin roadster as an extreme example), I set out hunting for a good candidate to power my truck. As luck would have it, I found one locally in a barn that looked pretty clean and didn't appear to be too worse for wear. The price was right, a deal was struck, and soon I was heading over to Speed-O-Motive with the engine in the back of my parts hauler to give those guys a thorough headache with my vintage gem.

The line-boring tool machines...

The line-boring tool machines each main separately, jumping from the first to the next, as opposed to the older-style line-boring machines that ran all the way through the mains. This process also allows the main caps to receive the brunt of the machining, which keeps the crank centerline in the stock location, alleviating any timing-chain slop that could result in traditional line honing.

To determine the exact size...

To determine the exact size to bore and hone the cylinders to, Dennis measured the pistons supplied by Egge Machine. The cylinder bore diameter of the Egge pistons is 3.8525 inches, 0.040-inch over the stock 331ci bore of 3.8125 inches.

With the specs in hand, the...

With the specs in hand, the machine was programmed and ready to go.

Once one bank of cylinders...

Once one bank of cylinders was bored, the tool and program were changed, and the deck surface was machined to match the crank centerline.

The next step was to hone...

The next step was to hone the cylinders. This process helps to create a broken-in type effect on the cylinder walls, which helps prolong piston ring life. The process is once again a CNC job with a plateau finish following the diamond hone.

Since the honing process is...

Since the honing process is removing material, it's necessary to check the bore diameter at a few different spots and at regular intervals to ensure the honing process is not enlarging the bore past spec or putting a taper in the cylinder.

The last step for the Hemi...

The last step for the Hemi block was to install new cam bearings, which we got from Egge Machine. Edson Gutierrez tapped in each bearing with the proper installation tool and a hammer. Notice the block has been painted in high-temp Aervoe engine enamel. The early Hemi blocks were silver for the first few years, so that's the color we're gonna go with.

We then balanced the entire...

We then balanced the entire rotating assembly. First, each end of the rod was weighed and the lightest weight of each end was used as the baseline that all others need to meet within a half gram.

To get the rods all within...

To get the rods all within the same weight, material was removed from the big and little ends on a belt sander until the weight of each rod was to the baseline weight.