Intro: Xr6 Aircon Delete Pulley
Removing the air conditioning from a car is something usually done to tidy up the engine bay or to remove weight from the front of the car in prefomance situations.
I'm removing it on a Barra 240T motor that I hope to put into a Ford Falcon xr6 Turbo project car. The main goal of the project for me was to improve the look of the engine and have a project to work on that involved welding and using a lathe.
Step 1: Design
on some cars the aircon can be removed by rerouting a shorter accesory belt but because on the location of the compressor i would have make a pulley on a bracket that took its place. the only real mounting points i could use were the 3 bosses the compressor originally mounted to. the bosses in question aren't of an even height and have some lumpy castings infront of them so the bracket had to be spaced out from the block a little in order to clear and give me a flat surface to make work off. the bracket wiould be made of 3 pieces a large flat piece that is on the surface of the 3 spacers, vertical and at a right angle to the pulley direction.
a small piece that the pulley itself would be mounted to. this is at a right angle to the first piece but still vertical.
and a middle piece that joins the other two and gets the pully out where it needs to be (plus maybe a rib to strengthen it all)
Step 2: Leggys (spacers)
To make the 3 "legs" for The bracket to mount on I cut up some 20mm bar stock faced off both ends in a lathe. Center drilled and drilled a 10mm hole through each one.
Step 3: Cutting Shapes
Through a lot of carefull measuring, trigonometry and frustration (taking into account how far the pulley would be spaced off the bracket, how far the bracket would be spaced off the block, the material thickness at the joins and the belt tension becasue i was using a smaller size pulley etc) I figured out the shapes I needed to cut out that would help the pulley end up where i needed it, marked out the three pieces on some 3mm corten plate and cut them out with an angle grinder.
Step 4: Turning Down For...
the pulley i used was a general automotive one with an OD of 112mm (as close to the stock ac one as i could get) A center hole of 17mm and a bearing in pressed into it. To mount the pulley on the bracket I turned a small stepped piece out of 25mm bar stock that was tight enough that i had to tap it into the pulley but not so tight that it slowed its rotation. 17.05mm worked spot on. I then drilled and tapped a M10x1.5 hole in the center.
I also made a piece for the front side of the pulley, this fits slightly looser and can be pushed in by hand. It has a 10mm hole in the middle, a large flange to cover the bearing. i cut an M10 bolt down to length so that it goes through the front piece and bolts into the thread i tapped in the back piece. the center sections of the front and rear piece added up don't quite make up the thickness of the pulley bearing so when tightened up they will squeeze the pulley between them and hopefully prevent any movement.
Step 5: Tacking
Because the motor was at home and all the fabricating was being done at work I wanted to tack the bracket up and check that it worked before I fully welded it. The legs were bolted on tight before I tacked them to ensure they stayed square with the main plate. The threaded piece for the pulley to mount on was clamped hard against the center of the third plate and tacked on and then finally the whole thing was tacked together paying carefull attention that the face of the pulley remained square off the main plate and therefore the engine block.
Step 6: Finnished Product.
I was satisfied that everything was how i wanted it so i made a rib down the middle that would brace all the pieces and fully welded it all together, put the pulley on and bolted it to the engine. I'm pretty happy with how it turned out and will paint it along with other engine bits later on.