Oh I know that I used them in all of my race cars in the past. Maybe I should have been more specific:
If I am using a NPT to AN fitting to go into the head, can the adapter fitting replace the breather bolt? I would think that it would, but before screwing something up I wanted to make sure.

 

I have the same setup. It's a little catch can with breather holes on the screw on lid. Works pretty slick so far.

 

Every Twin Cam is different in how much blow-by there is. Some have virtually none, other puke a lot of oil.

My most recent two 103's are opposite sides of the spectrum, one I am running Outlaw Breather Bolts and about every 1000 miles there is a very light mist that takes 30 seconds to wipe down.

The other one will do that much mist in 20 miles of riding, so I use the Premium Discrete Breather System.

Here's a thread with more information about blow-by and how to reduce it.

https://www.hdforums.com/forum/oil-a...f-my-bike.html




I don't really smell anything, not sure if it's my sniffer, or maybe different kinds of oils smell different...or maybe it depends on how hot the engine gets?



It is a catch-can, and it has a filter inside it.


Yes there is a ring of holes around the top of it that vent. There is a filter inside it to hold the oil in the can so oil doesn't come out the vents at the top.

No, the filter does not breathe from the front face. It is not necessary, the filter breathes more air than a Twin Cam can eat. Here's a LINK with more photo's, Dyno Chart and info.



Yeah, we've tested 8 different catch cans over the last 6 months. This has been the only one that I've really liked.

 

When will this be available? I'll need a version with the drill & tap barbs.

 

Thats a good question
But Ill bet the threads are not NPT in the head.
Maybe some one knows for sure
I can look at my old bolts tonight when I get home


Re: Straight Thread Vs. Tapered Thread

I'm not sure if this is the info you are looking for but

a straight thread is the thread you would find on a bolt and nut.
a tapered thread is the thread you would find on water/gas pipe connections.

a tapered thread is a sealing thread.
a straight thread is an axial load bearing thread.
a straight thread does NOT seal by itself but needs a gasket or needs to be part of a tapered surface to seal. an AN/SAE fitting has a straight thread and the sealing surfaces are mating cones.

 

I would like to know as well.

 

Late next week they will be on the website at this LINK

 

I have a FM Pro-Billet a/c, and ran vacuum hose from the breather bolts to the bottom of the a/c, drilled a hole through the bottom of back plate, then used a T fitting to connect from there to a fuel hose running across the front of the engine into a catch can (from Wimmer Custom Cycle) attached to the left down tube, with optional petcockk for easy drainage. You can't see it in the photo, but it's vented on the other side of the catch can. Works well, and with fairing lowers the whole set up is hardly noticeable. And it doesn't interfere with an oil filter change. Unplug the hose, and use an allen wrench to loosen the clamp and slide it to the left. It's a little pricey, but it works for me.

https://www.wimmercustomcycle.com/Puke-Cans-1.php

 

Well, I ran mine to the open air, no can or filter, and not a drop of oil has come out in almost 1000 miles so far. Not sure if these are even necessary, except to add bling. Just my $.02.

 

As Kevin pointed out, all twin cams are different and your twin cam is probably one of those that never needed it to begin with so in your case, yep it's bling.