HarleyTechTalk

Technical Forums => Milwaukee-Eight => Topic started by: conmag on September 19, 2023, 09:21:08 AM

Title: Head Breathers
Post by: conmag on September 19, 2023, 09:21:08 AM
 My first M8,is it ok to run the head breathers to the ground and not into the intake?
Title: Re: Head Breathers
Post by: rigidthumper on September 19, 2023, 10:30:28 AM
I'm sure that's a violation of some EPA rule, but a lot of guys are doin it :)
Title: Re: Head Breathers
Post by: Hossamania on September 19, 2023, 10:38:55 AM
Do you mean like this?
Yep. It is often encouraged.

24899.jpg
Title: Re: Head Breathers
Post by: IronButt70 on September 19, 2023, 12:51:37 PM
Would venting to a catch can violate EPA rules. Asking for a friend.
Title: Re: Head Breathers
Post by: Hossamania on September 19, 2023, 12:59:00 PM
Quote from: IronButt70 on September 19, 2023, 12:51:37 PMWould venting to a catch can violate EPA rules. Asking for a friend.

Technically, yes.
Title: Re: Head Breathers
Post by: Ohio HD on September 19, 2023, 01:01:00 PM
Quote from: Hossamania on September 19, 2023, 12:59:00 PM
Quote from: IronButt70 on September 19, 2023, 12:51:37 PMWould venting to a catch can violate EPA rules. Asking for a friend.

Technically, yes.

Not if the catch can vents back to the motor, or air breather.   
Title: Re: Head Breathers
Post by: Hossamania on September 19, 2023, 01:03:35 PM
Quote from: Ohio HD on September 19, 2023, 01:01:00 PM
Quote from: Hossamania on September 19, 2023, 12:59:00 PM
Quote from: IronButt70 on September 19, 2023, 12:51:37 PMWould venting to a catch can violate EPA rules. Asking for a friend.

Technically, yes.

Not if the catch can vents back to the motor, or air breather.   

Good point.
Title: Re: Head Breathers
Post by: Ohio HD on September 19, 2023, 01:30:11 PM
They're all the rage on high revving four and six cylinder vehicles. They're baffled to keep the earl in the can.


(https://www.sickspeed.com/cdn/shop/products/oil_catch_round_blue_1024x1024.jpg?v=1526056146)
Title: Re: Head Breathers
Post by: Hossamania on September 19, 2023, 03:09:17 PM
Fancy!
Title: Re: Head Breathers
Post by: Deye76 on September 25, 2023, 01:28:17 PM
If I pull the dipstick on my M8 Softail (2020 Lowrider S) start the bike with a balloon over the oil filler spout it blows the balloon up quickly. Do I need to vent the top trans cover, or the air cleaner breather bolts to a catch can, or both?   
Title: Re: Head Breathers
Post by: hrdtail78 on September 25, 2023, 01:50:15 PM
With a seal in between the crank and rest of the cavity. What does the balloon test tell us?  Crank cavity vacuum should not effect pressure in rest of case.  I would also consider that free flowing a oil cap size hole will effect how the check valves work.  How much psi does it take to make a balloon 2 inch in diameter compared to 3 inch?  IMO the balloon test is air volume and the volume of air is always going to be dependent of displacement of engine.

A better test would be hook a gauge up to the many oil caps offered with a hole and hose or make one like it.  With long enough hose.  You could hold on lap and check at different steady state rpm as well.
Title: Re: Head Breathers
Post by: Deye76 on September 25, 2023, 05:44:26 PM
Not looking to measure anything, just want to relieve some crankcase pressure, thanks for the reply.  :up:
 Talked to a few who have bikes like mine, they vented the trans cover only, think I'll try that.
Title: Re: Head Breathers
Post by: roadkingdresser on September 28, 2023, 02:50:48 AM
Are they venting the stock tranny cover? Any pictures?
Title: Re: Head Breathers
Post by: Hossamania on September 28, 2023, 03:58:19 AM
Quote from: roadkingdresser on September 28, 2023, 02:50:48 AMAre they venting the stock tranny cover? Any pictures?

The stock cover is vented.
Link to Ronnie's, go to transmission housing, part #10:
https://partsfinder.onlinemicrofiche.com/ronnies/showmodel/13/harleydavidsonmc/1410#
Title: Re: Head Breathers
Post by: Deye76 on September 28, 2023, 06:43:22 AM
Quote from: roadkingdresser on September 28, 2023, 02:50:48 AMAre they venting the stock tranny cover? Any pictures?

The factory has a separate passage in the trans case to the oil tank for crankcase pressure, but it still causes excess oil to exit via the head breathers (EPA) venting the trans cover to the atmosphere will alleviate. One could modify the OE cover, but it's plastic, so Trask makes a nice set up, albeit pricey, and more for a Softail I think than a bagger that has a different dipstick spout.
Title: Re: Head Breathers
Post by: cheech on September 28, 2023, 07:47:49 AM
Quote from: Hossamania on September 28, 2023, 03:58:19 AM
Quote from: roadkingdresser on September 28, 2023, 02:50:48 AMAre they venting the stock tranny cover? Any pictures?

The stock cover is vented.
Link to Ronnie's, go to transmission housing, part #10:
https://partsfinder.onlinemicrofiche.com/ronnies/showmodel/13/harleydavidsonmc/1410#

I think this Trask vented trans cover or venting the cover oneself has people confused.
The vent Hoss is referring to is the OEM TRANS vent. Vents the trans cavity to atmosphere.

All the other "venting" methods such as the Trask top cover are venting the OIL TANK to alleviate tank and therefore crankcase pressure to atmosphere which is not the way the OEM ENGINE venting works.
The vent in the Trask trans cover leads to the OIL TANK cavity not the trans oil cavity.

Same as the vented dipstick routine, just another method to achieve the means.
Title: Re: Head Breathers
Post by: Hossamania on September 28, 2023, 09:26:04 AM
Vented dipstick (https://www.jpcycles.com/product/feuling-vented-dipstick-for-harley-touring-2017-2020?utm_source=google&utm_medium=cpc&utm_campaign=PLA-Feuling-Products&utm_id=google_10875911902_147491486139_652203156635_aud-1335249335500%3Apla-1987493581856_m__1777087_CjwKCAjwyNSoBhA9EiwA5aYlb6eITsrc4Vun9v0P-taYRciupsRPM-Bdk0uwrF-ioHJcb0OUeJJDJhoCAvAQAvD_BwE&utm_term=1987493581856&gclid=CjwKCAjwyNSoBhA9EiwA5aYlb6eITsrc4Vun9v0P-taYRciupsRPM-Bdk0uwrF-ioHJcb0OUeJJDJhoCAvAQAvD_BwE&sku_id=1777087)
Title: Re: Head Breathers
Post by: Deye76 on September 28, 2023, 12:17:09 PM
The link from Hoss can't be used on Softails.

Title: Re: Head Breathers
Post by: Hossamania on September 28, 2023, 12:44:42 PM
Quote from: Deye76 on September 28, 2023, 12:17:09 PMThe link from Hoss can't be used on Softails.

I didn't know that, thanks for the info.
Can you do something similar with a modification to your dipstick?
Title: Re: Head Breathers
Post by: Hossamania on September 28, 2023, 12:51:55 PM
Try This one (https://www.feulingparts.com/sku/3086).
Title: Re: Head Breathers
Post by: Fat11Lo on September 29, 2023, 10:57:44 AM
Is it an option to vent the filler neck "T-Man style", he has a you tube video on how to install his kit but it's not hard to come up with the pieces yourself.