Throughout this book, we’ve T focused on using simple parts and straightforward buildups, but this chapter will show what it takes to build a highly custom, special-use engine. With this engine buildup, you’ll learn many processes to get the multiple systems of a one-off engine working in concert. An engine like this requires considerable time, skills, and money to put together, so not everyone should attempt it, but learning what these steps look like will help you understand more about Gen III V-8 engine buildups.
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With that said, let’s assume for a minute that you want the only 427-ci (7.0-liter) C5 Corvette on your block, or maybe your Camaro/Firebird just doesn’t have the scary power that you just must have. If this is true, and if you have plenty of money to spend, then the engine being built in this chapter is for you. It is a 1,200-hp, hard-core street/strip Gen IIIbased V-8 engine that will propel a car with 10.5-inch-wide tires to mid-8-second 1/4-mile passes at over 160 mph. If that doesn’t mean much to you, how about mid-3-second 0-60 mph times and mid-5-second 0-100 mph times! Just imagine being shot out of a cannon.
While you might not be building a supercharged C5R engine, if you want a big cube and/or 700+ hp engine, the long block being built here is what you are looking for. Now, for more single usage vehicles, you could have a machine shop bore out the stock cast-in cylinder liners on a stock Gen III V-8 block and glue cylinder liners into the remaining holes (like those from Darton). But, if you want something that has been engineered by GM to reliably operate while making obscene power, the engine being built here is for you.
This specialized power does come at a price, though. The aluminum GM Performance Parts C5R engine block alone costs $6,500 and still needs machine work before it is useable (we are told by machine shops that to have your stock block sleeved with Darton sleeves will run you at least $2,400). The aluminum C5R cylinder heads are CNC-ported and cost $4,000 a pair. The Lunati forged crankshaft will run you about $2,500, the custom billet steel Oliver rods about $1,100, and the specially machined and coated forged-aluminum JE pistons are about $1,000 a set. The F1 ProCharger centrifugal blower will set you back about $3,000. And this is just the basics.
The machine work and general massaging to get these one-off components to work in concert to make the 1,200 hp will probably cost you at least as much as the parts. The machine work includes modifying the engine block to accept massive, custom 1/2-inch head studs, cutting off the stock oil pump mounting bosses, clearancing the bottom of the cylinders so the heavy-duty rods can swing through, and more. You’ll need to get all the bearing diameters set up with the proper tolerances, set the minimum valve-to-piston clearance without sacrificing any performance, tune up the oiling system, build a custom ignition system, and more.
The one advantage you have in front of you is that every little detail it takes to build this engine is thoroughly photographed and explained here. The exact component set and process, down to tips like tolerances and assembly lube, is shown for anyone to duplicate, improve on, and enjoy.
The head engine builder at Wheel to Wheel Powertrain (W2W), Kurt Urban, personally assembled this engine. Up until this point, 1,200 hp is the most power W2W has made with the Gen III V-8 architecture. The engine is being built to power an F-body street/strip car. Previously, this car has completed the 1/4-mile in just under 9.55 seconds @ 145 mph with a stock-block Gen III V-8, making it the fastest supercharged Gen III-powered vehicle known at the moment.
There are a few ways to build 1,000+ hp street/strip engines. W2W has built both supercharged and turbocharged stock-block Gen III V-8s that have made over 700 hp, so they had an idea what it would take to make 1,000 hp. While a turbo engine would be easier on parts, the previous engine in this car was a supercharged engine, so it was decided a more powerful supercharged engine would be easier to integrate into the existing set-up of the car.
The one impressive thing about a supercharged engine is the monstrously deep powerband they provide. Now, a supercharger does consume a fair amount of crankshaft power to spin it, but the immediate power production is the payoff versus a turbo. For example, based on W2W’s testing, the F1 supercharger boosting this engine requires about 200 horsepower to make about 1,200 hp at the flywheel. So really, the engine is producing 1,400 hp at the crank, but who’s counting, right?
As you’ll see, the ignition system, intake manifold, front accessory drive system, blower drive, and fuel system on this engine are completely custom built and required some dyno time and engineering to get right. The ignition fires off an MSD 7AL called to action by a belt-driven mallory distributor that runs off the camshaft. The offset-beltdrive distributor mount is a custom piece machined up by W2W (and now available from W2W). It is offset to allow room for the massive 90-mm throttle body that is bolted to the inlet of the fully fabricated W2W intake manifold. The drive pulley on the camshaft is available from Jesel.
The intake is built for a big throttle body and massive 160-lb/hr fuel injectors with a chamber volume and ports big enough to flow air for 1,000+ hp. W2W had the aluminum intake polished by ace polisher Gary Lentz to give the engine some sparkle.
The front accessory drive is a packaging masterpiece. Faced with having to package the supercharged engine into the engine bay of a late-model F-body, W2W turned to their fabrication team to figure it all out. W2W designed the blower mount, and machined it out of billet aluminum plate. The blower needed to be mounted low and tucked close to the engine on the driver side to allow enough room for the supercharger air inlet behind the radiator. Also, since the blower will require a lot of power to spin, the mount needed to be extra sturdy. The main mounting plate is whittled from 5/8-inch-thick billet 6061 aluminum.
While it’s not mounted to the engine, part of the reason for the engine’s power production is the W2W fabricated, Sparco-core air-to-water intercooler, which has an advertised flow of up to 1,800 hp of air at 1 psi drop (which is an extremely high efficiency rating). In the car, the intercooler is mounted in the passenger backseat area, and connected to the engine via a loooonnnnggg 4-inch-diameter aluminum tube snaked from the blower back to the intercooler and back up into the engine intake along the trans tunnel. On the dyno, the intercooler was placed next to the engine with special tubing built just for the dyno testing.
How to Build 1,200-Horsepower Engines
W2W pointed out that the crank, rods, pistons, valves, and other moving parts in the engine are overbuilt as compared to a naturally aspirated (NA) or turbo engine. This is because the supercharger puts a lot of strain on all the components. The crank/rod/piston combination is heavy enough that it requires about 160 grams of mallory to balance the crank — much more than what they would have to put in the crank of a NA engine. Mallory is a heavy metal inserted into different parts of the crankshaft to help balance the rotating assembly.
The oil control on an engine like this is critical to it surviving the abuse, so W2W chose to build a dry-sump oiling system with a Dailey Engineering 5-stage belt-driven oil pump to protect it. The dry sump also helps to pull a vacuum on the crankcase, helping to prevent the combustion blowby passing by the piston rings from building up in the crankcase and causing an explosion. While this might sound extreme, with enough fuel and air being pushed in to this engine to make over 1,000 hp, things like this can happen without vacuum in the oil pan.
Also, you’ll see the experience W2W has with this race-inspired block. A good example is them knowing the lifters need to be “clocked,” so the restrictor in one side of the lifter body is located on the main oil galley side — which runs through the lifter bores and routes pressurized oil throughout the engine. The lifters are a good example of the minefield these blocks present. As you’ll see in the photos, the lifter oil feed hole is at different heights on each side of the lifter. Put the lifter in the engine block 180 degrees opposite of the proper way and boom, you’ve got no oil pressure when the engine is fired up because its pouring through the galleys at breakneck speed. And as an added bonus, you’ll drown the top of the engine because oil is going up the pushrod just as fast.
As a final step in oil control, once on the dyno, W2W discovered there was an excess of oil ending up in the top of the engine. The oil was pooling in the valve covers and being pumped past the valvestem seals. To fix this, restrictors were added to one end of the pushrods to reduce the opening by 50 percent. W2W presses a small roll pin into the opening with Loctite on it to hold it in place (A photo shows this being performed on the 500+ hp engine in Chapter 7).
This engine is not meant to drive across the country, but it will survive some Saturday-night cruising. As you’ll see, the front drive was originally built with a chain driving the supercharger. W2W felt that was necessary for this size blower based on their experience and after consulting with some Fastest Street Car competitors using a similar blower. What they found was the chain was too short to dissipate the heat generated in driving the blower and would quickly seize up. A belt system was created to complete the dyno testing and quarter-mile passes and has been very durable.
Prepping A C5R Race Block
Cleaning Parts for Final Install
Piston and Rod Assembly
Installing the Cam
Degreeing the Cam
Building the Heads
Finishing it Off
So How Did it Do?
As you’ll see by the dyno chart, this engine made the power figure W2W was looking for. But nobody races dynos, so the car was stood up on its bumper a few times before the engine EFI calibration got sorted out. It was enough for this killer to lay down a viciously mid-track wheel-standing pass of 8.56 seconds at 156 mph. Anyone doubting the powerband of this engine was in awe at the ability of it to march after the driver had to lift mid track before getting the car straightened out. This performance puts this car on a level with only a few vehicles in the world.
The W2W team feels the car has an 8.50 at 163 mph pass in it if they can get the tune-up in harmony with the chassis. If that is accomplished, it will be, by far, the quickest streetable Gen III-powered vehicle in the world.
Written by Will Handzel and Posted with Permission of CarTechBooks
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