Inside A 440-Cubed 400 Part II

4. Here is a bird's-eye view of the Holly Street Dominator in modified (left) and unmodified form. Note the work that was done in the plenum area to facilitate flow. What you can't see is that the runner entrances were massaged to work with the square-bore carb and the exits were port-matched to the heads.

5. Mounted on the engine and measured from the sides, this split-image clearly illustrates that the tops of the intakes are equal in height at 1 inch from the top of the valve cover to the carb mounting flange on each intake. The Holley is to the left and a stock cast-iron Pontiac intake is to the right.

6. Casting #16 1968 cylinder heads were ported to flow 250 cfm at .550 lift on the intake side at 28 inches of water, which produced 240 cfm at the net lift of .520 with a 160cc intake runner volume. The exhaust side is even more interesting in that no porting is needed for this combination--the stock 170 cfm at .500 lift will get the job done according to Taylor.

7. Combustion chambers are Pontiac's open design. For this application, the heads were milled .030 to reduce the chamber size from 72ccs to 66ccs. Taylor related that no other work is needed in the chamber. Nunzi one-piece stainless steel 2.11/1.77 valves are installed. The intake valve job features no top cut, a 30° seat, and 65° bottom cut. Exhaust is stock at 45°.

8. A TFX solid roller cam is employed in this combination because Jim says; "To get the desired power at this RPM level, a solid roller is needed. The same hp could be obtained with solid flat-tappet cam but the motor would need more lift, which would negate the option to retain the stock valve covers because of the needed valvetrain changes. Also the engine would be thrashing with the flat tappet cam and there would be very low vacuum at idle. With this solid roller cam, there is 10 inches of vacuum at 1000 rpm and there is virtually no tapping sound despite the use of solid roller lifters. Crower recommends no lifter bore oil restrictors because their lifters flow oil at a rate that is a little more than the stock Pontiac lifter--about 3 gallons per hour. However, Taylor still restricts the lifter bores on the intake side and has experienced excellent reliability.

9. Here the SRP pistons exhibit a good burn pattern across the tops. The burn pattern will give clues as to how efficient the combustion process is in a particular engine. A uniform pattern across the piston top is desirable. Combustion chamber type, i.e., wedge or hemispherical, chamber shape, and piston type, i.e., dished, flat top or domed, will also contribute to the burn pattern. Jim likes the pattern but notes that much of the residue is from the initial oiling on the bench to lube the valves and guides.

10. A full-length 1968 400 windage tray is employed for this buildup, as is a Sealed Power oil pump with a Nunzi pump driveshaft. The pump is prepared by disassembling it, checking the ball seat and spring pressure, gears and base plate for any potential problems. A crank scraper of Taylor's own making removes the oil from the spinning crank, which increases power. The pads on main caps (discussed in Dressed For The Nines in the October 2001 HPP) are thick enough to shim the tray away from the crank, thereby avoiding contact (F.Y.I., 455s had their own windage tray to clear the crank throws).

11. Here is the unassuming block/crank combination that provides 440.58 cubes of rip-your-head-off Pontiac power. This block is a 1968 2-bolt 400 in this case, which would require mount adaptors for a Second-Gen. T/A installation. However, any 400 block can be used to build this engine, so you can begin with a later block that will bolt right in. Our block was hot tanked and Magnafluxed, the decks and main alignment were checked, the lifter bores were checked for excessive wear, and then the block was bored and honed to 4.188-in. with a torque plate. It was also clearanced for the crank throws. Crank preparation includes hot tanking, Magnafluxing, checking the index and stroke, cutting -.010 on rod journals and cutting the mains to 3 inches.

12. The SRP forged aluminum pistons feature a flat top with two valve reliefs that have 5ccs volume. A great benefit of these special JE 4032 high-silicon alloy pistons is that Jim can run each tighter (.0025 piston to wall) than any other piston that he knows of. It doesn't expand, it doesn't slap and it's fairly light at 520 grams. Crower Sportsman (part No. SP93419B or PF) (this engine has bushed rods) forged steel connecting rods were employed in the stock 6.625 length. Each is made in the USA from forged 4340 steel and Rockwell at 34 +/- 2 points. The rods in this set weigh 808 grams and takes a .980 Pontiac pin. The cap screws are from Crower and the full-floating SRP pins are held in place with double spiral locks.