The high-rise intake manifold (PN P4582599) from Mopar is the only one available for W-9 heads with a 9.200-inch deck. For some reason, the intake and the heads didn't line up. Mike had to make 1/4-inch spacers to fit under each leg of the intake so the single-plane manifold would mate up to the heads correctly. We are told that little problem has since been corrected. Sitting on top of the manifold is a Barry Grant Gold Claw 850-cfm four-barrel carburetor. All told, the engine has a powerband of 3,600 to 8,500 rpm and idles at 850 rpm, which is incredible.
Mike detailed some of the challenges encountered during the build. "We had to make a custom galley tray underneath the intake manifold because it was not yet available," he said. "The valvetrain became a real chore, as did the intake-manifold fitment. Even the front cover had to be machined to fit. We were a year too early building this motor. Chrysler asked us why things did not fit, and then they remachined it. Because of the feedback we gave them, parts are now becoming available.
"We had to make the thermostat housing and form water-return lines out of steel braided hose to fit under the intake manifold. The valve covers were not milled correctly, so we machined them straight for clearance so the hold-down nuts would fit. The valve covers also had to be milled around the valvesprings for clearance. We also had to cut the valve-cover gasket around the valvesprings so they would not hit. The heads had to be milled in the area of the inner head bolts in order to get them to fit. We also had to machine the balancer to make it fit on the front of the block."
Some parts were readily available from either Chrysler or the aftermarket. The harmonic balancer, Milodon oil pan (PN 30935), and the oil pickup were easily attainable. The timing chain and gears were standard, and the timing-chain cover (PN P4876632) was a racing piece. Headers will have to be custom-made for the car in which the engine will be installed.
We asked Mike if he was surprised at how the engine performed on the dyno considering the glitches he encountered while building the engine.
"Yes," he answered, "we had no problems at all during the two days we spent on the dyno. We put it on the dyno and just tuned it. We jetted the carburetor and played with the timing. It only took 34 degrees of total timing because the combustion- chamber size is very efficient. This combination is maxed out on power. I don't think more or less cam would help at all. We spent a lot of time in cam selection; it was not just a shot in the dark. I was on the phone with Comp Cams about it. They were the only ones in the industry who knew what I wanted in a 48-degree lifter. They were very helpful."
This project was difficult only because Mike was breaking new ground. The new W-9 heads were the issue, but they do make some awesome power. Now that he's done, Mike is going to disassemble the motor, go to 13.5:1 on the compression, and cam it up to see if he can get 700 horses out of 340 inches. There is also an R3 block with a 9.56-inch deck available. That's how you get the big-inch small-blocks like 450 ci with the W-9 heads. Everyone wants to see what he can get with that combination. Can we all say glutton for punishment?
"This thing is stout!" exclaimed Mike. "The amount of torque we found was impressive." He's been building high-performance engines for over 30 years and was surprised at the 496 ft-lb of torque at 5,800 rpm from a 340ci motor. The 602 hp at 7,000 was expected. Sure, maybe the engine fell a little short of the 2 hp per cubic-inch, but making 1.85 horses per cubic inch is still respectable. Mike knows he can reach his goal with vacuum pumps and other racing goodies, but for now he's content with the results.
Although a stock timing-chain...
Although a stock timing-chain cover would have fit, an Arrow racingtiming-chain cover was used.
The harmonic balancer had...
The harmonic balancer had to be honed in order to fit over thecrankshaft. The water pump--also a standard part--was installed.
Because the intake ports were...
Because the intake ports were moved to accommodate pushrod alignment,Mike needed to use offset lifters in some locations. He used acombination of centered, left, and right offset lifters. The offsetdenotes the pushrod sets in either the right, center, or left area ofthe top of the lifter. Note the R, C, and L on the lifter holes.
The Mopar W-9 aluminum heads...
The Mopar W-9 aluminum heads were ready out of the box. The heads have a50cc combustion chamber. There was no extensive porting done on theheads. Mike just knocked off the flashings and shined up the ports.
The valvesprings were Isky...
The valvesprings were Isky (9385) with matching titanium retainers and10-degree locks.
The heads had to be milled...
The heads had to be milled in order to get the inner head bolts to fit.The valve-cover gasket was also notched around the valvesprings forclearance. The head gasket fit without any modification.