Unorthodox Pulley Installation
By Leo Atienza
Thanks to Buzz and Mike for helping me out.
The purpose of this modification is to slow down the belt driven accessories such as your AC compressor and your alternator. Slowing down the rate at which the belt turns these accessories in turn gives the horsepower required to run these things back to the engine. There are several aftermarket pulleys available for the the Twincam LD9 engine, such as Rksport, Unorthodox, and GM even has a part number for a smaller pulley (this is the same pulley Mantapart sells) . On my car I chose to go with the Unorthodox piece.
A nice bonus you get from buying the Unorthodox pulley is weight. The stock pulley weighs over 4lbs, 7 oz. The smaller GM pulley weighs 4.0 lbs. The UR Pulley weighs only 14 oz !! This reduced weight is the same as reducing weight from your flywheel or crankshaft. You are reducing rotational mass. Only its much easier to install this pulley than it is to install a lightweight flywheel or a knife edged crank.
Once installed this pulley had a definite effect on seat of the pants feel. It seems as if though the car was jumpier off the line and is much happier through every gear. You can definitely fell the difference in this mod when your done.
Jack up the car and support it on jackstands (or something). Remove the passenger side wheel so you can access the wheelwell cover. Remove the screws holding it in, There are a lot of them, as well as a couple of plastic push screws (these are a pain to remove). You may want to buy a few replacement push in screws because you will either destroy or mangle the ones you have when you take them out. It will take you a while to find all the screws but keep at it and eventually you will be able to remove the covers and expose the pulley.
Take this piece off first. Then you will have to lower the panel directly covering the pulley (next picture). This panel has some electrical wiring attached to it so be careful and unsnap the wire bundle from it loom before you start tugging like crazy. You’ll figure it out.
Now you can remove the belt. (picture above was with the belt already off). You will need a belt tensioner tool to make this easier. Otherwise you can use a long open end wrench. Basically the tensioner is a pulley that presses against the belt to tighten it. You need to move this tensioner pulley to relax the belt so you can remove it. See next pics.
Here Buzz (Blue sweater) removes the belt with his finger. Im holding the tensioner pulley back by pullin it towards the car. Be very careful here. If you have a buddy with his finger under the belt and somehow you accidentally let go of the tensioner (or it slips), the tensioner will spring back into place and possibly hurt (crush the crap out of) your buddies finger.
Move this tensioner pulley backwards (towards the car) to loosen the belt.
**Make sure you take note of how the belt is installed so you know how to put it back **
Once the belt is off you can finally remove the pulley itself. I think the socket size is 27mm. You will need a long extension (to clear the wheelwell, as well as a large screwdriver to jam into the pulley to keep it from turning. I long breaker bar will help, or if you have a large piece of pipe to slip over the handle of your socket wrench, you will need the extra leverage since the pulley nut is on their so tight.
Notice the long extension to clear the wheelwell. Also, here Buzz jams a decent size screwdriver between the pulley and the engine to keep the pulley from rotating as you try and loosen the nut.
A piece of wood under your extension helps keep it from “bending”. Otherwise when you start cranking on it, the extension will flex downward and you will loose some of your twist. The wood should be tall enough to keep the extension sticking out straight.
Here we slipped a long steel pipe over the handle of the wrench. The added leverage made this very easy. Notice again the extension sitting on the wood block at the bottom.
Once your all set just start turning the pulley bolt counter clockwise. A good twist from will be enough to crack it loose. After you feel it give, remove the pipe from your wrench handle and you can loosen it normally. Take off the bolt. There will be a washer underneath it. Remove the screwdriver and your ready to remove the stock pulley.
Install a pulley removal tool onto the pulley. Its pretty obvious how it goes on but you can look at our picture to see exactly. Basically the way it works is
There are a couple of problems here though.
1- The side of the wheelwell is low enough to block the pulley removal tool. I guess it depends on the size/shape of your pulley remover. Ours had a problem. You will get the pulley out 80% only to realize it cant move out any further because it is hitting the inside of the wheelwell.
So what do you have to do? Well, all we did was mess around with the positioning of our pulley remover until it was in an “optimum” position. Basically you want it so that the shorter “fingers” of it are facing up like a V. Your’s maybe different. Check with your hand to see if the fuel line is pinched between the tool and the wheelwell. If it is, reposition the tool, you can also push the fuel line up and out of the way a bit, but not much. We fiddled with ours for about 20 minutes and eventually got the pulley out.
The new pulley slides on surprisingly easy. Installation is the reverse of removal.
- The Unorthodox Pulley is a lightweight aluminum, which is also soft. When you jam the screwdriver in it (to keep it from turning as your tighten the crank pulley bolt) wrap the screwdriver with a good amount of cloth. This will help prevent it from denting the pulley as the screwdriver gets pinched between the pulley and the engine.
- The book recommends you torque the pulley bolt to 160 lb-ft. I ended up just tightening it as much as I could, then putting the pipe over the wrench again for added leverage and giving it another ½ turn.
- Even with the tensioner pulley completely pulled toward the front of the vehicle, it may be hard to get the belt back on. Guide it through as much as you can, when its mostly on except for the part that refuses to cooperate, use the socket wrench again to turn the pulley and “roll” the belt back on.