Everyone’s got an accessory system on the front of their engine, whether it’s factory, aftermarket, or custom fabricated. It’s just one of those basic necessities if you want an engine to work and your car to move. For us, most of our time is spent thinking about the engine itself—intake manifolds, camshafts, carb versus EFI—you know, the exciting stuff that you can brag about on the Internet. But when it comes to fit and finish and, ultimately, the functionality of your ride, the accessories become quite important.
Now let’s move that thought train along and apply it to the LS-based engines we’re seeing swapped into more and more hot rods and muscle cars these days. Clearance and cohesion can be a couple of the biggest issues to conquer when fitting a modern engine in a not-so modern body. That’s where Holley’s new mid-mounted complete accessory systems for LS engines comes in. Not only is it compact, bringing everything in nice and snug to the width of the LS, but it’s also as complete as it gets, taking the headache out of lining everything up. Instead of using a bunch of brackets and spacers to bring all your accessories into unison, their all-new water pump housing does all of that in one. The casting incorporates everything from the cartridge-style water pump to the alternator to the power steering to the A/C compressor.
We thought we’d give the new system a try but not because we just felt like it. In fact, our 5.3L LS-powered 1947 Chevy pickup was having some issues—namely that it kept throwing belts. We’d fiddled with different bracketry and spacers but nothing seemed to do the trick so when Holley told us about their new LS accessory system it was a no-brainer.
As far as the install goes, it is about as simple as unbolting the old stuff and bolting on the new stuff. Since this is a kit designed for LS swaps, Holley did their best to make this kit go in as easily as possible, but depending on your application you might need to get a little creative when it comes to routing hoses and other lines. But if you’ve already committed to the challenge of an engine swap this should be the least of your worries. So follow along as we journey through the process of installing Holley’s new accessory system on the LS in our 1947 Chevy truck!
Step one: identifying the parts. This kit comes with all the goods you’ll likely need to make this upgrade happen, including hardware, gaskets, wiring, pulley, tensioner, damper, alternator, A/C compressor, power steering pump, water pump, thermostat, and belt.
Now for the literal step one: disassemble all of the old stuff, starting by removing the serpentine belt.
Next you are going to want to drain and remove the radiator to give you more room to work because, at least in our case, we are doing this install with the engine still in the car. If you have the choice to install everything before dropping the engine in, do it!
Continue disassembly of the old serpentine system by removing the old accessories and brackets accumulating in the removal of the old water pump.
Now it’s time to begin assembly of the new goodies, beginning with the water pump housing on which the rest of the accessories are attached. Holley’s housing design removes the necessity of clunky brackets and spacers. Yay! First place the provided water pump gasket on the housing (there is only one way to do it thanks to a little locator pin on the housing face).
Then you can install the cartridge-style water pump using the six M6X20 Alan bolts through the holes in the water pump pulley and torque to the specs provided in the instruction sheet. There are eight very similar Alan bolts provided in the kit so make sure you are using the six longer ones for this part.
Remove the water pump steam port from the old pump and reinstall on the new Holley water pump housing. If there is any significant damage to the old one you’ll need to purchase up a new one.
You might have noticed by now that there are four heater hose ports. Luckily this wasn’t an accident and Holley did this to give you an option, depending on where you want to route you heater hoses. With the supplied plugs, we blocked off the lower two ports then installed the two hose barbs in the other two ports. Make sure to use Teflon tape on the threads to ensure a watertight seal.
At this point you should probably use a balancer puller to remove the old harmonic balancer. We say “should” because we did this much later in the installation process, which made it a little more difficult.
With the old balancer removed, you can then install the new one provided in Holley’s kit.
Now you should be ready to install the water pump housing if you want (you could actually install all the accessories on the housing before installing on your LS but we decided it was easier to do it in pieces). Before throwing it on, make sure you have a clean mounting surface on your LS block and then put the provided gaskets on each side of the water pump housing, as shown.
Install the water pump housing using the provided bolts and torque to spec as specified by the instruction sheet.
Next up it’s time to start prepping the power steering pump, beginning by installing the -6 AN adapter assembly. We placed the assembly in a vise to make this task a lot easier.
Then press on the power steering pump pulley using an LS power steering pulley installer.
It is crucial that the pump shaft and pulley hub faces are perfectly flush, otherwise the belt won’t line up. So take it slow when pressing on the pulley, checking depth frequently.
Now that you have the power steering pump assembled, don’t install it! Well at least not yet. First you’ll need to install the alternator because the power steering pump will block one of the alternator mounting bolts.
OK, now that the alternator is in place you can install the assembled power steering pump using the bolts provided.
Time to focus on the opposite side and attach the A/C compressor, which is as easy as screwing in two Allen-head bolts.
Just below the A/C compressor, bolt on the new tensioner pulley.
Next up install the provided thermostat and thermostat housing using the provided gasket and those shorter two M6 Allen bolts.
And just like that you can now install the new serpentine belt by releasing pressure on the tensioner. Refer to the provided directions for proper routing of the belt around the accessories.
From here on out it’s a matter of reinstalling everything else from the power steering hoses to the radiator. In our case it took some creativity to successfully connect the upper and lower radiator hoses, which is something we won’t go into detail regarding because it differs from application to application.
The end result is a simple and cohesive solution to a normally complex issue, and for that, Holley, we thank you.