It's always exciting to work with some piece of new machinery. You get to simultaneously learn about a collection of hardware that few people have ever seen, and you also get to be one of the first people to experiment with making that mechanical marvel even better. That's why we were so hot to tinker with GM's Gen III engine since they first came out in the '99 Silverado. Naturally we always want to play with the biggest and baddest version of everything. So when we got together with the guys at Turnkey Engine Supply (who specialize in late-model GM engines) to talk about Gen III engines, we asked about putting a 6.0L truck engine in our '82 K5 Blazer.
If you read last month's issue ("6.0L Engine Swap"), you know the new 4.8-, 5.3-, 5.7- (LS1), and 6.0L small-blocks are of an all-new design with features and performance bred from more than 50 years of small-block development by hot rodders around the world. We showed you that while not a direct bolt-in for your old 350, these engines are easily adapted to any chassis that can fit a traditional Chevy V-8. In fact, the Gen III engine is shorter and lighter than the old small-block, but the bellhousing pattern has gone almost unchanged so these engines will work with most of the popular transmissions.
This month we show you how we wrapped up our installation and fill you in on the Magna Charger supercharger with the Radix intercooler that we teased you with last time. We've put just about 7,000 miles on the engine with and without the supercharger. Though we've had a few development snags, we couldn't be happier with our engine swap. If we've piqued your interest about slinging one of these engines into your 4x4, give Advance Adapters a call. Advance has already done a lot of these engine swaps (including emissions-legal versions) and can help you sort out the particulars for your Jeep, Toyota, or even Ford!
To ensure we never, ever have a cooling problem, we went all-out and specified a Be Cool aluminum two-core radiator (PN 60013) for our project. Why use a Be Cool two-core instead of a four-core brass-and-copper unit from the local parts store? Because of aluminum's superior strength, each core can be built larger to provide more heat-radiating surface area (31 percent more, according to Be Cool) without restricting airflow like a four-core radiator can. Be Cool's two-core bolts in with the stock mounts and will actually out-cool a conventional four-core radiator. And unlike other aluminum radiators on the market, Be Cool's units are TIG-welded instead of being glued together with epoxy. We plumbed the Be Cool with the upper and lower hoses for a '99 Silverado (5.3L engine) and filled the system with a 60/40 mix of Dex-Cool antifreeze and distilled water. Be Cool recommended its dual 11-inch puller fans (PN 75007) for our supercharged application, and the combination has proved flawless from Las Vegas summer traffic to Mississippi mud running.
Turnkey Engine Supply uses state-of-the-art Delphi MEFI 4 ECMs to run its nonemissions crate engines like ours. This controller (A) was developed for boat engines so it's waterproof and can tolerate the high temperatures and vibrations common in a 4x4's engine compartment. We bolted ours to the passenger-side fender with the Turnkey-supplied relay pack (B), fuse block (C), and Be Cool fan relays (D). The Turnkey harness is a first-class piece and will control electric fans, an electric fuel pump, and an O2 sensor as well as provide a tachometer lead and a check-engine light output.
Supplemental Fuel Supply
Last month we modified the stock fuel tank and sending unit to run an in-tank pump from a '95 LT1-powered Caprice. That's enough fuel for a naturally aspirated 6.0L, but to feed our Magna Charger supercharged engine, Summit Racing supplied this Aeromotive pump and fuel filter combo. On our K5 the in-tank pump feeds the Aeromotive pump (Summit PN AEI-11101) through -8 AN hose from Orme Brothers. To protect the pump we added a 100-micron filter (Summit PN AEI-12304) before the pump and a finer 10-micron filter (Summit PN AEI-12301) after to protect the high-flow Magna Charger injectors. Unused fuel is returned to the gas tank through a -6 AN line that runs in the framerail above the fuel pump.
If you're working with an '80-and-newer GM power-steering box, your original hoses will work with the Gen III engine's power-steering pump. At the very least you should flush the old fluid out of the lines, but we replaced our hoses with new ones from the parts store to remove any contamination from the system. If your truck has Hydro boost brakes like ours, Turnkey can easily accommodate your vehicle needs too.
Magna Charger Supercharger
To go big-block hunting with our Turnkey Engine Supply 6.0L, we enlisted the help of a Radix intercooled blower from Magna Charger Products. This Roots-style supercharger is made for Magna Charger by Eaton, the same company that makes blowers for Ford, GM, Mercedes, and Jaguar. What sets the Radix package apart is its integrated intake manifold/intercooler that passes the compressed air through a water-cooled heat exchanger in the intake before it enters the cylinders. The Radix intercooler permits higher boost levels with lower air-intake temperatures than other Roots blowers. Strap one of these Radix blowers kits (PN 01-12-60-001-silver, or PN 01-12-60-002- polished) on an H2 or GM pickup and you'll get more than 400 hp and 400 lb-ft of torque at the rear wheels!
Done, for Now
Our first testdrive with the Radix-blown 6.0L engine was the 2003 Ultimate Adventure, where we introduced a lot of people to the Gen III powerplant. The idle, throttle response, and 400-plus horsepower of this engine combo brought our once-diesel K5 to life. Even with a single 3-inch TTS exhaust system, this engine combo has a great sound and revs great. Our fuel delivery system seems to have worked out well as the truck has never stalled or stumbled at angle. And we're extremely pleased with the Be Cool radiator and fan setup, which we'd recommend to anyone with a powerful engine that they just can't keep cool. But don't go thinking this story is over just yet. We're looking to break the 500hp barrier with our 6.0L. We'll plan a cam swap and maybe some head work, plus we'll upgrade the short block with some ARP fasteners to replace the torque-to-yield hardware that GM uses. Look for an update in the coming months, and get ready to see a lot of old 454s up for sale on eBay!
Driving a Supercharged Truck
On our K5's first shakedown run with the Magna Charger supercharger installed on the 6.0L, we lit up the Blazer's 35-inch Baja Claws as we left the parking lot at TTS. Having only driven the truck with a turbocharged 6.2L diesel we were not prepared for the violent power difference. We filled up on 91-octane (that's the best we've got in California) and got giddy every time we leaned into the throttle and heard the Radix blower scream. With 5.13 gears and a 700R4 transmission we had enough power off the line to spin the tires every time.
To put it mildly, the Radix supercharger does an impressive job of building power down low and carrying it through the mid range where you need it in a truck. In a typical application, a Radix supercharger works wonders on a 5.3L and makes it possible to spin the tires in a full-time four-wheel-drive 6.0L H2. We've got some concerns about the calibration of our 6.0L (too lean) and we don't like the fact that there is no keyway holding the lower pulley on the end of the 6.0L's crank. So we'll be addressing both of these things in the future.
Other Odds and Ends
We were happy to find that some things never change on a GM small-block, no matter how much technology GM throws at us. And yet with any new project comes new challenges. Here are some of the minor changes we also made during the swap.
*We used a throttle cable from an '00 Silverado with a 6.0L engine. We had to enlarge the hole on the firewall slightly and bend the arm on the K5's pedal assembly to give us full throttle, but it all works together.
*We used an AEM Brute Force cold air intake with an old mass airflow sensor to adapt to the cone filter when running the engine naturally aspirated.
*All Gen III engines have a steam purge coming off of the passenger side of the intake manifold. We plumbed this line into the heater hose connection on the Be Cool radiator, but we could have also run it to the overflow bottle.
*We ran the heater hose lines coming out of the 6.0L's water pump right into the K5's heater core instead of the way GM does it with a tee into the surge/coolant recovery tank. Our way seems to build too much pressure in the heater core and causes it to leak after high-rpm drives on the highway.
*Fitting a Gen III engine's A/C compressor in our K5 would have required major frame surgery because it is mounted low on the passenger side of the engine.
*Instead of plumbing an oil cooler into the 6.0L like GM does, we run 10W-30 Mobil 1 synthetic oil, which handles heat better than conventional oil.
*Almost every performance piece that is sold for the Corvette/Firebird/Camaro LS1 engine will work on a 6.0L too.
*GM publishes its own 5.7L LS1 swap guide (PN 88959384) that is a great source for swapping Gen III engines into anything.