General Topics/Tech TipsDiscussion on break in periods, rider comfort, seats and pad suggestions. Tech tips as they become available will be posted here.
What, if anything, would happen if I used solid breather bolts that did not have any holes for venting?
Both pistons travel down at same time since they share same crank pin. (They fire opposed to help balance) They are a tad off getting there at same time but won't discuss that little bit here.
Since as they go down, they compress crank case under bottom of piston. That needs to go somewhere.
Hence the breathers. They pass air and a little blow by from ring gaps thru a 180 turn and a small oil catcher foam and one way popit valves out. (Popit valves prevent pull back and fluttering.)
It dumps into breather box. Note that atmosphere press is only going in throttle body. So only vent gas is pulled in. A little tramp oil will fall out on filter but it hurts nothing.
Last edited by Jackie Paper; 12-03-2022 at 10:43 AM.
If you're looking to get rid of the oily crankcase fumes being sucked back into the engine, and don't want plumbing and a catch can, check out DK Custom Outlaw Breather Bolts. They vent to the atmosphere. I have a pair of the black ones installed on Reaper, and they work, and look, great.
that is a good one mr. max
a very important point is missed. normally the hd engine will create c/c vacuum but drops off to near nothing around 5k. without this vacuum, you will burn oil and lose power.
i hope clammy does not live in cali.
the biggest issue with hd venting is where they dump the vapor, need to take a lesson from rice, hummmm, hd going there anyways. when you dump to a low flow area, particulate will drop out especially when you go from a higher pressure. Attachment 611098
nary an issue and this machine gets pushed hard.
12-03-2022, 09:38 AM
