Jim Hand's 473 Earth Mover

Jim Hand's new block is part of his ongoing research into the effects of various engine changes. Some of the changes are not necessary for a strong running street-strip engine according to Jim, but were done to gain knowledge. [Having personally driven the wagon , I can tell you the large displacement 473 cid engine idles smoothly, has excellent low rpm response, and revs like a very efficient small block engine. Cruising requires very little throttle opening to maintain speed.] With the increase in torque, traction was less than satisfactory prompting Jim to relocate the mufflers behind the rear wheels for weight where it was needed. The wagon launches with great authority.

Jim graciously provided Pontiac Street Performance with the following information. ( j.e.hand@sbcglobal.net)

Technical Data
Engine Block: 1973 Pontiac 455 with 1969 428 4 bolt main caps; "Hard Bloc" added to the bottom of the front soft plugs to add strength to the cylinders
Bore and Stroke: 4.21" x 4.25" for 473.3 cubic inches
Heads: #64 heads with TRW stainless steel 2.11" and 1.77" valves (ported by "Hand"); I/E @28"; .050"= 45/32, .3"= 205/149, .55"= 254/202; port volume = 163-164 cc
Deck Height: zero deck height (.000")
Valve Springs: Jim Butler #052B (dual springs)
Rocker Arms: Harland and Sharp 1.65 roller rockers
Retainers: stock
Keepers: stock
Valve Seals: positive Viton seals (without inserts) to fit installed guides. Positive and o-ring seals used on all valves
Lifters: Rhoads variable duration
Push Rods: Straightline Performance 4130 seamless chromemoly
Crankshaft: stock, journal turned .010", rod journals turned/stroked for big block Chevy rods, +.040 stroke. All reciprocating parts balanced
Rods: Eagle 6.8" rods, PN CRS680003D, from Jim Butler Performance. Longer rods used to minimize side thrust on the cylinder walls
Rod Bolts: equipped with ARP 190,000 psi bolts
Pistons: JE Custom flat top with single valve reliefs to provide 10.07 cr
Rings: Speed Pro file fit Plasma-Moly rings
Main Bearings
Rod Bearings
Cam Bearings:
Clevite (Michigan) 77
Timing Gear and Chain: #062B billet timing set from Jim Butler Performance
Gaskets: standard Fel Pro builder's set, except with custom header gaskets made from Mr. Gasket flat gasket material
Camshaft: Wolverine WG 5059--234/244 degrees intake/ exhaust duration @.050; advertised duration, 300/310 intake/exhaust; .536" lift intake/ .561" lift exhaust with 1.65 rockers; 112 lobe separation angle; cam installed with intake at 110 degrees. Smooth idle with Rhoads lifters, 14" vaccum in Drive at 750 rpm, 15" in Park at 770 rpm. (Note: rough idle with standard hydraulic lifters).
Intake Manifold: Performer RPM with full plenum divider
Carburetion: Pro Systems 830 cfm mechanical linkage (based on a Holley HP pro series), 86 Holley jets front and rear, no power valve. 92 octane Amoco gasoline, no additives
Fuel Pump: Mallory 140 with Holley regulator set for 7 pounds fuel pressure; 1/2" fuel line from tank to regulator, 1/2" gas line through 1/2" Fram metal filter to the tee fitting on the carb. "Hand" fabricated cool induction through firewall with air filter over air inlets on plenum
Exhaust: Hooker 1.75" primaries, 3" collector; Dr. Gas 3" X Crossover into 3" Torque Technologies pipes followed by 3" x 2.5" Flowmaster reducers that enter 2.5" Walker # 17288 21" length Ultra Flow mufflers that are located behind the rear axle; exhaust exits Walker madrel 2.5" tailpipes. Headers modified to fit ports, cleaned up pipes into collectors, and 2" added to all left side primary pipes to more equally match right side length 
Ignition: stock HEI with GM 990 module, Delco cap and rotor, "Cobra" spiral wound solid core resistence wires from J. C. Whitney. Champion RJ12C plugs gapped .050". Mechanical advance starts at 1100 rpm, total of 17 degrees advance in by 2900, and inital timing set at 13, for a total mechanical advance of 30 degrees, plus 14 degrees vaccum advance
Oil Pump: Sealed Power 224-113R, 50 pounds @3000 rpm when warm, 15-20 pounds at idle ; 10W-30 Mobil 1 synthetic oil 
Transmission: TH-400 (built by Tom Hand); Trans Go Shift Kit; transmission governor and valve body modified to automatically shift at 5650-5700 rpm at full throttle. Shifts normally under other conditions. High stall torque ratio "Tight 10" Continental converter.
Rear End: 3.55 gearing in 12 bolt limited slip with HD pre-load springs installed (GM PN 3890860). "C" clip Eliminator package installed for safety. Moser axles installed for strength
Vehicle Weight: 4075 pounds with owner/driver (includes NHRA approved roll bar and full exhaust system in race trim)

Performance: (All runs with Mickey Thompson ET Street tires, 28 x 13.5 x 15, 11" tread width mounted on Cragar Superlite 15" x 10" wide wheels. Front tires are standard tread15" x 205 x 75 on 6" Superlite rims.) All runs with full exhaust in place and connected.

At the October 2000 Pontiac Uprising event held at Arkansas City, KS: Best elapsed time of 11.32 @ 117.24 mph with a 1.54 second 60' time. A four run average of: 11.39 @116.84 mph with 1.56 second 60' times. Weather and track conditions were outstanding.

In more typical 60 degree weather with no wind at the KCIR track on November 4, 2000, the wagon averaged 11.53 @ 115.2 mph with 1.59 second 60 times (9 runs consisting of time trials and bracket racing).

[Back to Jim's earlier block]

Jim's 2001 Performance Update



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