Finally finished my DIY write-up. Thanks to everyone who blazed the trail and helped me online and offline. Let me know if I need to revise anything. - Jimmy
Boss 302R/302S Racing-style Breather Can
The factory Boss Mustang PCV system increases engine pressure and forces oil into the engine intake, especially during hard track driving. This results in a slight loss of horsepower and a reduction in engine oil at a time when they are needed the most.
One solution is to use an oil separator. This fits in-line with the PCV system and separates oil and oil vapor into a catch can and returns only "clean" air back into the engine. This is a good system, but no oil separator is perfect and some amount of oil or oil vapor will continue to be injested through the intake via the PCV system.
Ford Racing Boss 302S with factory racing breather system.
The 302R and 302S factory race cars use a simple breather system that bypasses the PCV system altogether. This system ensures that no oil is ingested through the intake and should free a couple of ponies. The downsides of this system are that it is more expensive than an oil separator and it almost certainly violates any emission system
do-not-tamper laws that many states have, which might cause some trouble when trying to get your safety or emissions inspection sticker.
Ford Racing does not sell this system as a kit. Rehagan Racing does sell this system as a kit, but it is spendy at $425. I put together my own kit for about $235 using OEM parts and high grade hoses and fittings. My version is overkill and a budget-minded person could do this (assuming the use of the core Peterson breather can), for about $150.
Parts:
[list type=decimal]
[*](1) - Peterson Fluid Systems 08-0400 Breather Can with AN -12 Ports (about $90), Link: http://amzn.to/WOzGUC
[*](2) - Summit 220244B - AN -10 to AN -12 Adapter Black (about $10.25/ea.)
[*](2) - Earl's AT800110ERL - AN -10 ST Ano-Tuff Swivel-Seal Hose Ends (about $13.25/ea.)
[*](2) - Fragola E-Z Clamp Hose End, -10 AN - Black (about $6.95/ea.)
[*](1) - Earl's 350610ERL - AN -10 PRO-LITE 350 HOSE 6 FOOT (about $57.95)
[*](1) - Dorman 02253 - Bypass Cap Assortment (about $5.00) + (2) hose clamps to secure the caps.
OEM Parts:
[*](1) - CR3Z-6A664-A - HOSE VENT ($9.44)
[*](1) - 4L2Z-6762-AA - ELBOW, CRANKCASE VENT ($11.31)
[/list]
Instructions:
1. Mount the catch can.
Find a suitable location on the firewall in the same area as the factory race cars. Be sure to leave enough room to remove the top of the catch can for servicing. Measure and mark the location of the band clamp. Drill holes and mount band clamp with your choice of fastener. Since I don't see the need to ever remove the band clamp, I chose to use rivets. Secure the catch can with the band clamp. Orient the ports as shown in the photo.
Notes: I found that removing the upper strut brace made access easier. I also removed the sound deadening material that was against the firewall. Honestly, I just don't like the idea of 'moving blankets' stapled around the engine bay. If you don't remove it, you will have to cut or drill through it to mount the catch can. Finally, I had to remove one of the plastic pins that secures the cowl trim piece to the firewall to prevent interference with the catch can.
2. Make the hoses.
I would recommend first installing the hose ends that mate to the catch can. Connect the hose (using the AN -10 to AN -12 adapter) and tighten everything down (illustration 1). Then measure hose (twice) and cut (once) to proper length. Attach the two (2) plastic quick connectors from the driver's side vent tube that is no longer needed. Attach the plastic connectors to the hose using the clamp-style hose ends.
Notes: Removing the plastic OEM quick connectors from the vent tube is somewhat difficult, because the tube is hard plastic. I don't recommend trying to cut against the nipple, because any gouge could be a leak point. This is the technique I used. Cut the hose about 1" from the tip of the nipple. Then make two cuts into the hose. Grab the tab you have just formed with a pair of needle nose pliers. Then, holding the tip of the tab firmly, roll the pliers so that you are tearing a ribbon out of the hose. If you can get the ribbon all the way to the end of the hose, the pressure fit of the hose will be released and the connector will be free. I took the photo before I had perfected my technique and I was just trying to pull downward, but the ribbon would break before getting to the end. Thin needle nose pliers work better and the rolling technique is the way to go.
3. Replace PCV valve.
On the passenger side of the engine, remove the PCV valve from the head and replace with the same style crankcase vent elbow that is found on the driver's side. Alternately, you could remove the PCV valve assembly and discard the internal valve.
Notes: I don't think this matters in any way, but the PCV valve (blue) and the crankcase vent elbow (black) are not
exactly the same length.
4. Connect the hoses to the crankcase vents.
5. Cap the intake/vacuum nipples.
Finished!
Notes and revisions:
Sharp eyes will notice that I used small rivets and washers to secure the band clamp. I had properly sized rivets set aside for the project, but once I got started, I realized that my rivet gun did not accommodate the shank of the large rivets. I will replace those soon, so that the can is properly secured.
As you can see, it is a very tight fit for the catch can. Another possible revision is to cut the top of the firewall for easier access for servicing the catch can. This can be seen in the photo of the factory setup at the top of the page. In truth, it's not that hard to service the catch can. It is only held in place by a band clamp. It can easily be released from that and tilted forward to clear the top of the firewall. A better revision that I am considering is getting the racing oil pan, tapping it, and running a drain from the catch can back into the oil pan. Then the catch can becomes service free.