Up front, all the accessories...
Up front, all the accessories need to be cleared to make room for a cam change. Take note of the various bolt positions and bracket locations when tearing down, since a full accessory package such as the one on this Charger can be quite a puzzle to figure out later.
Frankly, with the variety of aftermarket offerings available today, the economics of reworking an old set of iron heads is upside down. Duplicating the port flow would require porting from the best cylinder head experts to the extent that the porting cost alone would likely exceed the price of a new set of aftermarket Edelbrock, Indy, or MP replacements. Besides porting, these 452s were machined for 2.14/1.81-inch valves, fitted with new bronze guides, machined for dual springs, machined for positive PC-type valve stem seals, flat-milled 0.060 inch on both the deck and intake face, cut with a custom Serdi valve job, and machined with a deshrouding cut to within 0.030 inch of the head-gasket line concentric with the valves. The valves were Speed-Pro units in the aforementioned sizes. They were modified with a back-cut on the intake valve and a radiused margin on the exhaust, as well as thermal barrier coating on the valves' heads, and an antirecession moly coating on the exhaust valves' face. We'd hate to calculate the hours of headwork wrapped up in these iron wonders.
We weren't exactly sure of the compression ratio of our subject, but a cranking compression of 165 psi with the current cam indicated that it wasn't likely high. For the sake of low maintenance and driveability, we wanted to go with a hydraulic grind and keep the duration fairly short, which would play well with a moderate-compression short-block. Although the duration would be conservative to meet our driveability goals, we wanted a significant amount of lift to tap into as much of our head's airflow as possible. This dictated that a dedicated, fast-rate 0.904-inch tappet grind would be the best choice. Mopar tappets, at a 0.904-inch diameter, are significantly larger in diameter than those found on most other engine families. With the larger tappet diameter, a faster rate of lift can be designed into a cam-shaft's lobes. We had tested some fast-rate Mopar grinds from Hughes Engines, and we were impressed with the results of maximizing the valve lift at a given level of duration.
When we had performed our initial testing of the Hughes cams, we were surprised by the outstanding output in a 440 with only the small 223/230 at 0.050 inch camshaft. We noticed that this camshaft exhibited good torque lower in the range and carried well into the upper revs despite its short duration. By the same token, the short duration provided the excellent idle quality and good vacuum we were after for our street 440. With a great balance of power output to road manners, the Hughes HL2330BL seemed to be the best choice for our street application. Specifications of this Hughes cam are 272/276 rated duration, 223/230 duration at 0.050 inch lift, 0.504/0.515 inch lift with the stock 1.5:1 rocker ratio, and a lobe separation angle of 110 degrees. When upping the ante to 1.6:1 aftermarket rockers, the valve lift increases to 0.538/0.549 inch.
To top off our modification plans, we chose the old standby Holley Street Dominator single-plane intake. Though an older design, the Street Dominator has always proven to be an excellent intake on the 440, and it is well-finished right out of the box. The Street Dominator has good low-end response for a single-plane, yet dyno testing has shown it retains excellent output at higher rpm. For carburetion, an 850-cfm mechanical secondary Speed Demon carb was chosen to provide the required airflow for our large-displacement engine. Although many favor smaller carburetors for street applications, we have found that a well-set-up 440 consistently responds to the 850 configuration.
Use a puller to remove the...
Use a puller to remove the damper to get to the timing case.
Cylinder-head removal was...
Cylinder-head removal was the most difficult part of our buildup. To gain access to the outer head bolts, the headers needed to be dropped. Good, free-breathing heads are the key to making power, particularly if the camshaft choice is limited by driveability constraints.