A closer look at Heiden Tuning engine breather

[kwhy3000]

Quality looks decent. Will prob polish out the tooling marks of the exterior. Over $100 shipped and took almost two weeks to get to me here in Montana but that’s kind of expected these days. A pricey purchase but I was more curious than anything which brings me to some questions for you guys. This is advertised as a reed valve system which I assume is the ‘screen’ mounted over the slot with a small screw. Air can escape from the engine but can’t go back in. That’s until you notice the drilled hole below the slot which would allow air both ways. Am I missing something here? Is the tiny drilled hole so small that it slowly equalizes the pressure? Is it a misdrilled hole? As you can tell I am not educated enough to know how exactly this is supposed to function. Thoughts are much appreciated.

Link- https://www.heidentuning.com/xs650-...eather-system-reed-valve-complete-detail.html

https://imgur.com/a/2fo48iy

 

[gggGary]

Small hole is to allow oil that accumulates behind the reed back into the crankcase.
Yes the Carbon fiber? is the reed. I've been running an external reed valve on Madness but didn't put enough miles on her last summer to reach any firm conclusions. She had been using a bit so bodged one up. The Norton guys are often big believers in reed valves.

 

[kwhy3000]

Small hole is to allow oil that accumulates behind the reed back into the crankcase.
Yes the Carbon fiber? is the reed. I've been running an external reed valve on Madness but didn't put enough miles on her last summer to reach any firm conclusions. She had been using a bit so bodged one up. The Norton guys are often big believers in reed valves.

That makes more sense. Yea, I realize the carbon fiber is the reed, I was trying to explain it in a simple way and failed haha Thanks for the explanation. Do you think there will be enough oil running back through the hole at all times that the engine is running that it won’t suck air through it? Wouldn’t it kind of defeat the purpose of the reed valve if that happens? I’ve read quite a bit about these but am curious how it will actually function. Time will tell I suppose

 

[gggGary]

I think the hole is small enough that there will still be a substantial net gain from the reed valve action, keeping crank pressure lower.

 

[kwhy3000]

Here packing my cylinder head/cam/rocker box that’s being sent out for a valve job/clearances/etc and this is staring me in the face. Top and bottom holes aren’t directly connected here where breather is mounted. It all makes sense now and I believe this unit from Heiden will work like a charm. I’ll be sure to let you know. Curious how yours works out as well. Really appreciate the info!

https://imgur.com/a/MOPsWXQ

 

[Universal J moto]

Great pics. What’s interesting is that really… all you need is the reed plate section sandwiched between the (gutted) stock breather outlet and head shell. But the whole Heiden package looks very nice.

 

[gggGary]

Link to a couple different ways to skin this cat.
https://www.xs650.com/threads/crankcase-vent-using-a-reed-valve.61188/

 

[Cleaner802]

Here packing my cylinder head/cam/rocker box that’s being sent out for a valve job/clearances/etc and this is staring me in the face. Top and bottom holes aren’t directly connected here where breather is mounted. It all makes sense now and I believe this unit from Heiden will work like a charm. I’ll be sure to let you know. Curious how yours works out as well. Really appreciate the info

How did this solution work out for you? No more oil loss? Worth the price? Thanx!