Dyno Time: We Assemble and Test Our 390 Ford Dyno Time: We Assemble and Test Our 390 Ford
When we last looked in on Jim Reid Jr., of Reid’s Automotive, he had completed the teardown, inspection, machinework, and short-block assembly of our Ford 390. This time around he’s finishing our FE and collecting data for the world to see on his dyno.
Arguably, the biggest improvement that can be made to most engines is a good set of cylinder heads, which is certainly true for the 390. To that end Chuck Vranas chose an Edelbrock Power Package kit that included a pair of aluminum Performer RPM heads. Equipped with Cobra Jet–sized, 2.090-inch intake valves and 1.660-inch exhausts, the combustion chamber volumes are 72.0 cc and the intake runners are 170 cc—all of which add up to excellent flowing heads for solid, streetable performance. Our heads came equipped with valvesprings for use with the hydraulic, flat-tappet cam that was also part of the Power Package. The camshaft specs are 0.572-/0.572-inch intake and exhaust lift, with duration at 0.050-inch lift of 236/236 degrees (advertised duration is 296/296 degrees).
One of the unique features of FEs is the path oil has to take in order to feed the rocker arms. Passages from cam bearings (number two on the left side, number four on the right) deliver oil around a head bolt on each side to one of the rocker arm supports where oil is fed to the rocker arm shafts that have feed holes to lubricate the rocker arms. During assembly it’s critical that the rocker shafts are installed with the oil holes toward the heads, otherwise the rockers will be starved for oil.
Most hot rodders agree, when it comes to cool carburetion nothing beats two four-barrels. Another part of the Power Package we used was a dual-quad kit that included an Edelbrock 2036 RPM Dual-Quad Air-Gap manifold and carburetors designed for 390-428 big-block Ford FE applications. Included in the kit is a pair of 500-cfm Thunder Series AVS carburetors calibrated specifically for dual-quad applications (one manual choke, one electric choke). To make the installation simple, the kit included Edelbrock’s high-tech progressive throttle linkage, Russell fuel inlet kit, high-quality intake gaskets, and carburetor stud kit. The manifold and Thunder Series carbs are available with a standard satin finish or Edelbrock’s bright EnduraShine chrome-like finish.
One of the reasons Edelbrock’s carburetors work so well is the dual-quad configuration can be traced to the heir annular flow booster technology. Basically, fuel is delivered from eight equally spaced orifices in the booster rings rather than down-leg boosters, which simply dump raw fuel into the venturi. The result is superior fuel distribution with what Edelbrock describes as EFI-like driveability. They add that flat spots are completely eliminated, and throttle response in the low- to mid-rpm range is improved tremendously with no sacrificing of that top-end power. Additional advantages are Thunder Series AVS carburetors are unaffected by engine backfires as there are no power valves to blow out and for fast, simple, part-throttle tuning, metering rods and springs can be changed in seconds without carburetor removal or fuel draining. Completing the fuel system is an Edelbrock mechanical fuel pump that will support up to 600 hp.
To make sure there is a steady supply of spark, we selected MSD’s most popular distributor, the Pro-Billet. This series of distributors requires an ignition controller such as an MSD 6A, 6Al, or 7AL-2. There are a number of advantages to using an ignition controller, chief among them are the high-output capacitive discharge spark with multiple sparks occurring below 3,000 rpm that helps provide a clean idle with improved starting and throttle response. For ease of installation Pro-Billet distributors have a two-pin connector that plugs directly into the control box.
The finishing touch for our FE was an ARP engine and accessory bolt kit (PN 555-9602). The polished stainless steel fasteners look great and they are considerably stronger that standard fasteners.
Once completed, the 390 was run on the dyno to break in the cam and then it was time to see just what our vintage FE was capable of. While we were impressed with the peak numbers, the truth is for a street engine impressing your friends is their real value. What we believe is more important for a driver are the torque averages from the beginning of the dyno pull to the end and specifically those in the rpm range the engine will normally be operating in. Torque is what moves the car, and by the looks of the numbers this FE will move the T-bird it’s going in just fine.
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