The 2001 truck line includes a new 8.1 liter 496 cubic inch "8100" big block. The bore will remain at 4.250", but the stroke will be increased to 4.370". The firing order is also new 1-8-7-2-6-5-4-3 and features individual ignition coils mounted near the spark plugs, similar to the LS1 Gen. III smallblocks. CR is 9.1-1 and it uses Sequential Fuel Injection (SFI). All 8.1 liter BBC production motors come with an internally balanced crank, four bolt main caps and redesigned heads with equal length port runners. The 2001 model 8.1 liter BBC uses a roller hydraulic cam and makes 340HP @ 4200 rpm and 455 ft./lbs. @ 3200 rpm. You'll be able to get either an Allison 1000 5-speed auto trannie or a new ZF S6-650 six speed manual gearbox with this new big block. Both trannies are built for a maximum of 520 ft./lbs. of torque.
The Marine versions of the 8.1 liter big block comes in two power levels, a 375hp/490 ft./lb. model or a 415hp/490 ft./lb model.
GM/Performance Parts introduced a "short deck" smallblock block (PN-24502650) in 1997 for racers wanting to build a short stroke motor. The block deck height is 8.200". The siamesed cylinder bores are 3.894" and this CNC prepared block can be bored to 4.190". It has splayed steel main caps on #2-4 and the crank journal diameters are 2.300" to fit the early style small journal cranks. It uses the two piece rear main seals, but can use the late model one-piece oil pan gasket. A big block style water pump is used. The cam bore has been raised .391" compared to a production smallblock and the cam journals are 2.25" in diameter to fit roller cam bearings. The "short deck" Bowtie smallblock uses the Oldsmobile Aurora bellhousing pattern. Gen.I style heads will bolt to the block, but you'll need an aftermarket custom intake.
GM/Performance Parts has introduced a "medium deck" smallblock bare block (PN-12480050) in the 2001 model year for racers wanting to build a NHRA Pro Stock Truck smallblock motor. The deck height is 8.700" and can be decked to 8.500". Bores are 3.900" and max bore is 4.190". The "medium" deck height block uses the standard Chevy bellhousing pattern and has 2.300" main bearing diameters and uses a 2.25" cam bearing. The crank centerline to cam centerline is 4.953" and GMPPP recommends a Jesel timing belt for this application. The block is delivered without the head bolt holes or the lifter bores drilled.
Looking for a used late model Gen.II LT1 or LT4? How about a Gen.III LS1? Try BILLY GRAHAM'S CAMARO/FIREBIRD SALVAGE, in Calera, Alabama, 1-205-668-1169. They stock a number of late model engines from wrecks and you can get complete setups including, 6-speed trannies, exhaust manifolds, wiring harness, computers and all the engine accessories.
Thinking about pulling the alternator off of your drag race engine in order to gain a few horsepower? If you do, make sure the battery on it's own can provide enough electrical power to run your ignition box, fuel pump and any other electrical devices like delay boxes, etc. The few horsepower you gain by removing the alternator and charging the battery between rounds, may also cause the race car to be inconsistant and/or lose power. Hi-power ignition boxes and other race electronics, can quickly drain a battery charge causing lower voltages and a reduction of ignition power and slower electric fuel pump operation. You may not be fully charging the battery between rounds, especially in the later rounds when there isn't much time. With more and more electrical devices putting a strain on the battery, you can trade a few HP for the consistancy an alternator provides by keeping the battery charged. Buy yourself some deep groove pulleys to keep the belts on at high rpm. You can also reduce the diameter of the crank pulley. This will have the effect of slowing down the pulley driving the alternator. The same effect can be had by using the stock diameter crank pulley, but increasing the diameter of the alternator pulley. Moroso and others sell deep groove pulleys of various diameters for drag racers.
When using an MSD ignition box, make sure you ground the box to the engine block itself. Placing the ground wire, (usually a heavy gauge black wire), somewhere else, like on the body panels, can lead to a high rpm miss in the engine. A miss can sometimes be hard to track down, but on a number of occasions the miss was due to a poor grounding of the ignition box. Placing the ground wire on the engine gives the shortest, most direct path for the circuit and the high rpm miss will disappear. And speaking of good grounds, take a short piece of battery cable and make a ground strap that runs from the engine block to the frame rail of your vehicle. If you have moved your battery to the rear of the vehicle, connect your battery's ground cable directly to the frame.
A new 23 degree SBC aluminum head has been released by GM/Performance Parts for '99 (PN-12464298, Casting number - 12367713). The new 350 cubic inch "ZZ430" crate engines were the first motors to get the new heads. (Only 430 "ZZ430" limited edition crate motors were initially produced.) The heads have redesigned "fast burn" 62cc chambers and 2.00"/1.56" valves, with hollow stem intakes and the exhaust valves are sodium filled. The chambers can take a 2.02"/1.60" if you are so inclined. Intake port volume is 210cc and have raised runners .024" higher than stock. The D-shaped exhaust is 78cc. Screw in rocker studs and angle plugs are also used. The intake port entry is raised higher and has intake manifold bolt holes to fit either Vortec or raised runner 23' intakes. You can use a new GM split plenum intake PN-12366573. The deck surface is .400" thick. Recommendations are that a flattop piston works best with these heads.
A "ZZ430" crate motor using the "ZZ4" "HOT"
hydraulic roller cam, 9.8-1 CR, 750 Holley, headers and an Edelbrock Performer RPM dual plane intake made 430 hp at
5600 rpm and 431 ft/lbs. of torque at 4000 rpm. Very impressive for an over the counter street
motor on 92 octane pump fuels. Another magazine ran a flow test and the "Fast Burn" 23' heads flowed 275cfm intake and 193cfm exhaust at .600" lift out of the box. Right now the heads can be found on the limited edition "ZZ430" crate motor, or you can buy them over the counter under PN-12464298 complete with valves, lightweight retainers and springs for $1,000.00 for a complete pair. They will fit any Gen.I block and the heads are drilled and tapped for use with both Vortec style intakes or with a Chevy raised runner 23' style intake.
HOLLEY CARB INFORMATION
HOLLEY TUNING TIPS
CHEVY V-8 CASTING NUMBERS
CHEVY V-8 CASTING NUMBER LOCATIONS
CHEVY V-8 CRANKSHAFT JOURNAL SIZES
CHEVY V-8 BORE AND STROKE LIST