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|G|et |T|urned |O|n
1,594 Posts
Discussion Starter #1
I've been asked by a few people for some help on making the catch-can that I have, and I cannot find the original thread by Owe5Goat, so I figured I'd post my own DIY thread...

Parts List:
- IronForce (by Campbell Hausfeld) air-oil seperator from Lowes (I dont have model #, but it is the one that's 7.5" long)
- Chrome Chevy alternator bracket from Autozone
- 3/8" SAE (oil and gas safe) hose from Autozone or HW store - 2 feet should do, I think
- Right-angle nylon plumbing fittings from HW store. One side screws into the air-oil seperator, the other is a "barbed" side to slide into the SAE hose. Also need black rubber washers to seal between aluminum and nylon fitting.
- Nylon thread tape
- 1.5" wide straight aluminum stock ... need some 1/8th inch thick and 1/16th inch thick
- Stainless Steel nuts (with the nylon locking inside), bolts, washers and lock washers (I forget what sizes I used)

First, remove the stock hose that routes the PCV oil to the throttle body. Pic:

Second, I would loosen the positive battery terminal and twist the cables counter-clockwise, and retighten. This will get the positive terminal further away from the engine block. This is not a required step, but I HIGHLY recommend doing this.

The side of the engine block has 2 holes threaded in it, near the freeze plug. One of them has a bolt in it already, holding a ground point to the block. Remove that bolt. The chevy alternator bracket's mounting slot will run between those 2 holes. I recommend you take that bolt to the HW store and match it's threads up to 2 slightly longer stainless bolts. Get matching washers and lock washers for them. Essentially, these 2 bolts are going thru the washers and lock washers, the ground point, and the alternator bracket itself, so they need to be a bit longer than the stock bolt you removed... but not too long!

Note that 3 modifications need to be made to the Chevy alternator bracket: It need to be cut, bent and the mounting slot drilled out/widened slightly at the point where the mounting bolts fit through it. You need to be VERY CAREFUL about 2 things with regards to bending the alternator bracket: /1/ That the bend in the bracket doesn’t allow the catch-can or mounting HW to come too close to the + battery terminal. Keep in mind: as the engine torques, the catch-can will move towards the battery! /2/ That the HEIGHT of the bracket will hold the catch-can away from the hoses below it. Engine torque will not affect this location. Mine sits about half an inch from those hoses. It does NOT touch them. That half-inch also allows you to remove the can to empty it.

With a vise and a torch, bend the alternator bracket to the desired angle, cut it to length, and widen the mounting slot at the points where the 2 bolts need to pass through. If you don’t use the torch, you might crack the chrome. The bend you make in the alternator bracket will determine where the catch-can sits relative to the engine, hoses (above and below), the FRC’s, and relative to the + battery.

The thinner (1/16”) aluminum stock, is used to form the “collar” around the catch-can’s mounting top. You will need to drill the holes in this piece for the nylon fittings to screw through. Be sure to use a torch to heat the aluminum, as it WILL crack or snap if you don’t. Keep in mind, aluminum is hard to heat up, and to bend without it breaking. The thicker (1/8”) aluminum stock makes the straight piece that connects the collar to the alternator bracket. You will need to customize the length of this piece to make sure the catch-can sits at the proper height (away from the hoses below it, and not too high). See pix for how the 3 different parts bolt together. (bracket & aluminum) Don’t forget the nylon tape on the threads of the fittings, and to use the rubber sealing washers.

Essentially, that’s all there is to fabricating it. Once you’ve made all the pieces, assemble them, making adjustments as need be to make sure the catch-can sits safely in the open space. There is a FLOW direction on the catch-can… make sure the FLOW is towards the throttle body. (see the arrow on top of the catch-can in one of the pix) Cut the SAE hose to length, and route it how you want from the catch-can to the 2 openings.

Any questions, let me know. Enjoy.

Thanks again to Bill (Owe5Goat) for the original concept.


Member: Black Sheep Squadron
4,065 Posts
WOW, thanks for the time, and the good looking write up. This will be one of the next mods I do to my car, and your thread will definately help me.


ChimChim is in the HD's trunk
4,966 Posts
Very nice write up. This is one of the nicer DIY mods just about anyone can do and it is well worth it in the end when you see how much crude this thing catches.

I gotta say yours is identical to mine. They look factory!

Cabra Rapida
388 Posts
Will be doing this soon, thanks for the write-up.
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