It’s pretty rare to come across a new way to do a common thing. Years ago, billet hood hinges were introduced and since then other makers have turned out mostly cosmetic variations of the same idea. It’s been the same with pulley kits. Sure, every company has its own way of making it happen, but in the end they all share the same basic idea of brackets and bolts to hold the needed accessories in place on the front of the engine.
Well, Holley is fairly new to the complete drive system world so maybe that’s why they didn’t have any preconceived notions about how it’s “supposed” to be done. They tossed aside how everyone else does it and decided that brackets were an unnecessary part of the accessory drive system equation. Yep, the new Mid-Mount Complete Accessory System from Holley has zero brackets to support all the needed accessories to the front of LS and LT engines.
Now, when we first heard of this new bracketless kit we immediately thought there was a catch. But there wasn’t. What Holley did was design a water pump housing that could serve double (triple? quadruple?) duty by acting as host to the power steering pump, A/C compressor, and alternator in addition to pumping water through the engine. No brackets, no spacers, no shims, no problem!
Of course, that makes for a very non-traditional water pump housing shape. But it also eliminates a ton of parts and makes for a very easy-to-install system that has a clean and compact look. Given that the water pump is the key to everything, Holley made sure it was easy to rebuild using common OE parts. Holley offers the kits in various forms to fit different budgets and there are three finishes to choose from: polished, black, and natural. So let’s check out Holley’s new take on a front drive system.
1. This whole kit revolves around one of the craziest water pumps we’ve ever laid eyes upon. We can only imagine how much caffeine the engineers had to consume to figure it all out. In addition to being the water pump, this also serves as all of the “brackets” for the Holley drive system. The version for GM’s LT engine series is nearly identical, differing only in the how the water pump housing attaches to the engine.
2. Obviously, this isn’t a water pump you can go buy at the local auto parts store, so Holley did the smart thing and made the water pump rebuildable using parts you can buy at the local store. Also, on the back of the pump there’s a 1/8th-inch pipe thread hole to run the LS steam line to, which shows they really thought this kit out in terms of making LS swaps easier. Before dropping in the pump’s impeller section we installed this ACDelco gasket (PN 12619770).
3. The pump is easily rebuilt using an OE pump assembly. In fact, you wouldn’t even need to remove the pump from the engine to replace the impeller unit. If you want a spare pump cartridge, the Holley part number is 97-200. This cartridge-style water pump is common with LT1-equipped C7 Corvettes.
4. To bolt the pump to the housing we simply lined up the holes in the pulley and installed the six M6x1.0x20 button head bolts.
5. We picked up the premium kit (PN 20-180), which is upgraded with an SFI-certified ATI Super Damper (PN 97-190). The base kit uses a GM-style one-piece damper with an integrated pulley (PN 97-205) and includes a GM crank bolt.
6. To our ATI damper, we attached the supplied crank pulley using three 12-point fasteners.
7. The assembled Holley water pump bolted to the LS engine just like any other, with two gaskets and six bolts. However, five of the bolts are M8x115 and one is a shorter M8x50 flange head bolt (the farthest bolt to the right when looking at the pump). The six bolts were tightened in a sequential pattern.
8. We then installed the thermostat/housing and the heater hose barbs. The system is very flexible since the hose barbs can face either to the side or the bottom. Plugs were included to seal up the two unused holes and Loctite brand 567 pipe sealant was used on all of the fittings. Holley also offers a swivel thermostat housing (PN 2670NA) and swivel hose barbs (PN SS988412ERL & SS988409ERL) for those with fitment issues.
9. Not sure it could get any easier than this. The Holley 150-amp alternator is designed to handle high-rpm abuse and is about as compact as possible. This unit utilizes the same architecture and six-phase technology as found in the C7 Corvette. It attached to the pump housing with one M10x75 socket head bolt and one M10x80 button head fastener. A pigtail for wiring this into the car was included (PN 197-400). These pulley kits are also available in polished and black finishes.
10. Moving on to the power steering pump we needed to install the -6 AN adapter assembly as shown. The banjo bolt was snugged to 25 ft-lb. The Saginaw Type II pump has a cast-iron body and an integral, baffled reservoir.
11. After grabbing our handy installation tool we drove the pulley onto the shaft of the power steering pump. Per the instructions, we stopped when the pulley was perfectly flush with the end of the shaft.
12. It was then time for the Sanden SD7 A/C compressor to go on. This compact, high-performance compressor is designed to handle bursts of high-rpm duty and is compatible with most aftermarket A/C systems, such as Vintage Air. This was installed using two M8x95 socket head bolts per the instructions.
13. The OE-style tensioner was bolted in place using an M8x70 button head bolt and an M8 flat washer.
14. This small “winged” piece gave us a place to attach the tensioner’s cover. The center fits into the square hole on the tensioner (from the back).
15. The square hole in the tensioner is there for a 1/2-inch drive wrench so that the tensioner can be forced down for belt installation. The part number for the six-rib serpentine belt is 6PK1715.
16. With the belt in place, we could install the cosmetic cover using the supplied hardware. This cover must come off to remove or install the six-rib serpentine belt.
17. The A/C cover attached with three fasteners. For this one we dabbed each bolt with a bit of blue thread locker.
18. Finally, we popped on the cosmetic cover for the alternator. This is simply a small billet cap with an O-ring.
19. And just like that, our drive system was complete. Since we didn’t have any brackets to line up, install, or otherwise mess with, this was quite possibly the fastest drive system install we’ve ever done.
Photography by Steven Rupp