http://www.is-it-a-lemon.com/muscle_car ... sembly.htm
That website has some other 426 Race Hemi information, too.Machining and Assembly
The raw cylinder blocks and heads were shipped from their respective foundries to the Trenton, Michigan, engine plant for machining. Changes were made to the 426 Wedge-block line to allow for the Hemi's requirements.
"Trenton could put the blocks down their main machining line," Weertman says, "and then they had offline operations for the block, for example, to put in [the main-bearing cap] side bolt holes. Trenton was giving us virtually hour-by-hour service on the blocks. I was in touch with the factory manager, and he understood our desire. Of course, he had his own production schedules to meet. We challenged them to do this whole job quickly because the corporation had almost no time to get the job done."
Although the production 426 street and race Hemis were to be assembled at Chrysler's Marysville, Michigan, engine plant, the test and early racing engines were assembled at the engine labs in Highland Park. The Hemi parts shipped there from the Trenton plant underwent minute inspection and checking before being approved for final assembly.
"Prior to building each engine," Troy Simonsen relates, "we did a lot of dimensional checks. We Zyglowed the pistons to look for cracks, and we Magnaglowed the blocks, the cranks, the rods and the heads. Steve Baker and I had the responsibility of the day-to-day, nuts and bolts—was the engine holding together?—and analyzing and testing anything that required mechanical development. We supervised and wrote the orders for building up all of the engines, which included all of the ones that went to the Daytona race."
Steve Baker joined Chrysler in 1960 and entered the Chrysler Institute. He had the good fortune to be assigned to the engine lab that would eventually oversee assembly and testing of the 426 race Hemi. With so much riding on the success of the Hemi, it was essential each engine was assembled with great care.
"Our only secret here," Baker says, "was that we took extreme care in cleanliness and making sure the parts were good. It took about eighty man-hours to assemble a race Hemi, not counting the machining time. Most of that time was in inspection, checking all the parts to make sure they were within tolerance. Things like taking a white cloth through each cylinder bore, not just to make sure they were clean, but to make sure the assembly guys understood this was the way it was done."
Chrysler had no previous experience testing an engine designed purely for circle-track racing. Weertman called in Larry Adams, in charge of the race Hemi engine testing program.
"I said to Larry, 'How do we find out if our engine's going to be durable enough for Daytona?' We had durability schedules for testing passenger-car production engines—long 800 hour tests. We didn't have any durability schedules for our racing engines."
Weertman and Adams came up with the idea of running the engine testing in the lab identical to the demands made on the engine during an actual 500 mile race, including straightaways, banked turns and pit stops.
The first 426 race Hemi build-up started the last week in November 1963 and was ready for lab testing the first week in December. The Daytona race was only two months away. Before putting the new engine through its race-profile testing, the engineers thought it prudent to bring it up to speed slowly to establish power readings in the dyno room.
"At the time," Baker remembers, "that room had a 400 horsepower Amplidyne dynamometer. Well, we knew we had a hell of a lot more horsepower. There were several of us there—the operator, myself, and the department manager, Ev Moeller. So we slide-ruled the observed power. We got 400 horse-power around 4800 rpm. There was a possibility we were going to break the dyno. Moeller was in charge and said to go ahead. He would take responsibility so the operator wouldn't get into trouble for damaging equipment. As I remember, we got up to more than 425 horsepower the very first run we made with the engine—and the dyno didn't break. Everyone was pretty pleased with that."
