Everyone loves a nice push-rod V8 but what’s even better is an aluminum push-rod V8 with some boost. GM’s LS series of motors lends itself to all kinds of projects and turbocharging is no exception. Let’s build a monster for pennies.
Choose The Engine
There are a few options when choosing the engine but in our case we are going with the dirt cheap 5.3L that can be found in many GM Trucks and SUV’s. The iron block version can be found as low as $250 and aluminum block versions like the one we will use from the 04 Buick Rainier run around $500. Our $500 motor has 130k miles and comes with harness, PCM, exhaust manifolds with exhaust flanges, intake manifold, and throttle body and we will use all of these parts.
Engine Cost: $500
Upgrade The Engine
The LM4 5.3L can handle some boost in stock form but we will give it a few upgrades to make it last longer. Our first step will be upgrading the rod bolts. These can be found from ARP for about $90. We go back to ARP for some head studs coming in at $290 as well as some head gaskets from Chevy at $35. Next up, we will upgrade the camshaft. Staying budget conscious, we pick up a used LS6 cam for $50. The camshaft will be complemented by a set of $125 PAC springs to help the valve-train hold up. We will add another $100 for misc gaskets and sealants.
Engine Upgrades: $690
Prep The Engine
We need to fuel this monster and in order to do that we are going to upgrade the injectors. Some may call it an abomination but we are going to use Ford injectors from the SVO of the late 80s to early 90s. They are rated for 440cc and can be found on ebay for $175 for a new set of 8. We will also upgrade the spark plugs with NGK one-step colder units. A set of 8 comes in at $24. We will also need another MAP sensor to detect pressure so we pick up one from the turbocharged Pontiac Solstice that detects up to 2.5bar for $40.
Engine Prep: $239
Lubrication
The turbo will need lubrication from engine oil so we need to plumb it. We will start with the oil drain. We will need to drill and tap a hole for 10mm thread. Once the oil pan is cleaned and reinstalled on the car, we will screw in a ($10) 10mm to -10AN adapter fitting. We will need about 3 feet of -10AN line to run from the turbo oil drain to the pan which will run about $20. We will also need a $15 oil drain flange to connect the turbo to the drain line. On the feed side we will pickup a -4AN oil feed kit that includes a distribution block, lines, and fittings for $70. The distribution block mounts to the top of the oil pan where oil cooler lines would go.
Lubrication Cost: $115
Turbocharger And Piping
Our turbocharger of choice is going to be a Holset HX55. They can be found on various commercial diesel engines and can be picked up in good used condition for $250-300. We will need to pickup a T6 Flange and some 2.5in and 3in tubing. In our case we are going to leave the truck manifolds in place but just flip them forward and make a Y-pipe for them. The manifold will be started with cut off sections of exhaust and then made into a Y-pipe. At the end of the Y-pipe we will make a collector and weld the T6 flange. We will use V-band flanges and clamps on the Y-pipe to facilitate easier removal. The mild steel piping, flanges, and clamps come in around $180. To control boost we will pickup a used 46mm Precison wastegate for $230 and use a junkyard DSM BOV for $15. The DSM BOV will be modified by adding a pressure line from the underside that used pressure from the charge side to hold the diaphragm in place to make it safe up to 30 PSI. Since we are on a budget, we will build a manual screw type boost controller for $20. The intercooler will vary by application but a Chinese Bar and Plate unit with pipes and couplers can be picked up for about $250.
Turbocharger and Piping Cost: $945
Final Results
The project total comes in at a thrifty $2489 and with the parts above you can expect to make about 500 horsepower at 7 psi, 550 horsepower at 10 psi and whopping 610 horsepower along with 590 pound-feet of torque at 12 psi. You may be able to push it a little further and make more power but for lognetivty 12 psi is a good limit.
Other Considerations
This guide is focused on a barebones budget build and there are many parts that can be upgraded based on personal preference and goals. There are also additional items that may be needed but will vary based on the vehicle used and these include tools, brackets, clamps, fuel pump, fuel lines, and tuning software. Many people will own some of these items due to previous projects but for others this can bring an additional cost. The remainder of the exhaust coming out of the turbo will also need to be modified or replaced to match up to the new setup.