I am redesigning the accessory brackets and locations on a LQ4 using the standard truck style brackets to accommodate an additional compressor for on-board air.

For clarification, OEM before modification: A/C compressor-Passenger Side Bottom (4 groove belt with dedicated tensioner applies pressure in counter-clockwise direction, runs on smooth side of belt, and has short armature); Alternator-Driver Side Top; Power Steering-Driver Side Bottom; Tensioner-Passenger Side (runs on groove side, pulls in counter-clockwise direction, has short armature, and is mounted to three M10 tabs on the water pump housing.)

Here is a pic I found of the OEM accessories without the A/C pump.



To fit the new compressor in (York 210 which is a self oiling compressor and is quite large) I will move the Alternator from the original location to where the tensioner was on the passenger side, the York will be mounted where the alternator was. I can mount the new alternator bracket to either the water pump or the passenger side head. The bracket will be larger if mounted to the head but I believe this is the desired location.

Regardless of how/where I choose to mount the alternator, I now need to place a new tensioner and where the majority of this discussion should revolve. It would be very easy to use either the alternator or new compressor as a tensioner, but IMO I do not believe a static tensioner to be a desirable solution.

Sorry about the length so far, but wanted to ensure that I supply all needed information to so everyone can make informed recommendations from the start.

Questions:
#1 - Can the tensioner be mounted anywhere in the configuration or should it be directly after the crank on the passenger side? Since the crank rotates (from the front) in the clock-wise direction, the belt is pulled through the accessories in that direction. The only time the belt is not under load would be directly off the crank, where it is pushed off the crank. Do tensioners have enough force to be located between accessories? I'm worried that when the accessories are under load and RPM is quickly increased the tensioner will not have enough force to counter the force put on the belt, thus allowing the belt to slack directly after the crank and allow slip on the adjacent accessory.

#2 - Does anyone know where I can find a tensioner that runs on the smooth side, is surface mounted, has a short armature, and applies pressure in the counter-clockwise direction (Aftermarket or OEM)? On a routine salvage yard outing I was able to find a couple tensioners, but all apply in the clockwise rotation, have longer than I would like armatures, and therfore could only be mounted on the driver side between the new compressor and power steering pump.

Thanks for any advice that follows!

 

You could do something similar to the Kwik Performance kits and just have a extra idler pulley...

http://www.kwikperf.com/lsx_ac.html

 

Petraszewsky, this is similar to what I'm looking for. However, it pushes everything too far off the side of the motor to allow for my clearance constraints. As far as the second idler, they really don't need it as there is a straight line from the A/C Pump to the idler under the alternator. Look at the PDF for the truck installation.

The location of the tensioner reinforces my thoughts on it's placement though, you can see they have placed it directly after the crank. The counter-clockwise force and short armature on the tensioner is exactly what I'm looking for, however you'll notice that the spring assembly is behind the pulley, which takes up valuable space in the area directly in front of the head. I need a tensioner that has the spring beside the pulley so I can mount it in front of the water pump, the alternator is shallow enough where it can be mounted directly in front of the head, where the old tensioner was. I'll sketch a drawing later to show what I'm after.

 

Just a FYI the truck pic you have posted above is using a idler relocation bracket so that the belt will clear the car style intake that is on it...But I do understand that even without the relocation bracket that the idler would be in a straight line from the A/C compressor...

 

Agreed on the alternator idler. I would like to thank you for pointing me to the Kwik Performance link. Even though their particular brackets aren't able to help, I ran out of other options and decided to go buy the tensioner for the '02 Z28 they require for their kit. I figured at $40 I could always return it if it didn't work. I was able to get everything squeezed in there! I have it temporarily mocked up with some DOM tubing and all-thread until I get some time later today to make the final brackets. Finding a tensioner that would fit within my constraints was the needle in a haystack. Thanks again! When it's presentable, I'll send some pictures.

 

Glad I could help...