Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[DavidB]

Im running the SE backing plate on the bike that routs the crankcase vapor into the throttle body on my twin cam. Does anyone have a good alternative that vents these oil vapors to some place other than back into the intake where it eventualy builds up on the pistons.
Thanks Dave.

[Midnight Rider]

Im running the SE backing plate on the bike that routs the crankcase vapor into the throttle body on my twin cam. Does anyone have a good alternative that vents these oil vapors to some place other than back into the intake where it eventualy builds up on the pistons.
Thanks Dave.

Dave...take a look at the Doherty PowerPacc with the Powervents...it gives you the option of plumbing the crankcase vents to the backplate via a couple of 90 degree fittings, or if you want to, it can be vented to the atmosphere.  I posted a thread on the system here somewhere (twin cam section) that shows pics of what I'm talking about.  You might also find that it causes less pressure in the crankcase as well.  It's a very well made system, with nicely machined parts, and a slightly bigger air cleaner to flow more air.

[RJ749]

Im running the SE backing plate on the bike that routs the crankcase vapor into the throttle body on my twin cam. Does anyone have a good alternative that vents these oil vapors to some place other than back into the intake where it eventualy builds up on the pistons.
Thanks Dave.

Dave here's the thread Terry speaks of.  http://www.cvoharley.com/smf/index.php/topic,10033.30.html

[Midnight Rider]

Thanks Rog...I was just looking for it...lots of discussion there.  The pics/install starts with post 39

[DavidB]

Thanks Guys,
 I pulled the heads thinking I had a valve seal leaking but the crud on top of the pistons is coming from the breather system pumping oil into the intake. Thanks to the EPA

[Midnight Rider]

Thanks Guys,
 I pulled the heads thinking I had a valve seal leaking but the crud on top of the pistons is coming from the breather system pumping oil into the intake. Thanks to the EPA

Dave...if you've got things apart and want to solve this issue permanently, take a look at the Doherty Mystfree system.  IT WORKS!!  99% elimination of the issue with just that system, and if you put the PowerPacc on too, venting oil would be nonexistant.  Twolane (Don) has the Mystfree on his scoot and swears by it.

[BalDeagle]

Thanks Rog...I was just looking for it...lots of discussion there.  The pics/install starts with post 39

Thanks for pointing us back to that thread TC - a real interesting read. I am going to go for the Doherty PP with Powervents and that thread answered a lot of questions.



Nige

P.S. Really well made looking piece of kit too.

[Midnight Rider]

Thanks for pointing us back to that thread TC - a real interesting read. I am going to go for the Doherty PP with Powervents and that thread answered a lot of questions.



Nige

P.S. Really well made looking piece of kit too.

Nige...I know the SERK's have a A/C cover that already sticks out a bit further.  One thing you might want to consider to help alleviate that problem is the Kuryakyn floorboard extenders...they are basically a set of spacers for each side (including an oddball for the jiffy stand side of the bike) that move the floorboards outward 3/4"...I have installed these on my bike and enjoy the foot position much more, and braking is not an issue.  Just something to consider in order to give your knee a bit more room on the right side of the bike and put your foot on the board a bit more.

[BalDeagle]

Nige...I know the SERK's have a A/C cover that already sticks out a bit further.  One thing you might want to consider to help alleviate that problem is the Kuryakyn floorboard extenders...they are basically a set of spacers for each side (including an oddball for the jiffy stand side of the bike) that move the floorboards outward 3/4"...I have installed these on my bike and enjoy the foot position much more, and braking is not an issue.  Just something to consider in order to give your knee a bit more room on the right side of the bike and put your foot on the board a bit more.

Thanks for the tip TC. I am going to buy a pair of Kuryakyn Iso Wings anyway so I'll just add the floorboard extenders to the wish list.



Nige

[DavidB]

Dave...if you've got things apart and want to solve this issue permanently, take a look at the Doherty Mystfree system.  IT WORKS!!  99% elimination of the issue with just that system, and if you put the PowerPacc on too, venting oil would be nonexistant.  Twolane (Don) has the Mystfree on his scoot and swears by it.

I like the looks of the mist free system and is the way im gonna go. I just cant see how the harley system can work . Guess its ok around town but at high speed for extended periods of time it looks like all harley has is the old horse hair " Synthetic now" filter to seperate the oil from the air.
Thanks,
 Dave

[Twolanerider]

I like the looks of the mist free system and is the way im gonna go. I just cant see how the harley system can work . Guess its ok around town but at high speed for extended periods of time it looks like all harley has is the old horse hair " Synthetic now" filter to seperate the oil from the air.
Thanks,
 Dave

Dave, if someone isn't having a problem, or at least a big problem, to begin with then using the Doherty kit inside the rockers is a tough evaluation for them.  Hard to prove it is fixing or making better something which hadn't really presented to begin with.  And a lot of bikes don't really present with this issue to begin with.

I was sold on the product when I saw a comparison of the stock part and the Doherty part in cross section.  It could not be more illustrative.  I'm not a fluid dynamics guy but even with a layman's understanding someone can really "see" the difference there and understand the increased capability.  It's just a better design.  Without even raising the question of whether or not the stock design is "good enough;" there's no question the Doherty part is an improvement.

If you do it go ahead and do the drilling recommended in the neighboring parts.  They supply the bit and it's simple and obvious to do.  This lets you take a fuller utility of what the Doherty part is doing for your engine.

When the top end of my engine was apart these went in "just because."  It was so obvious an improvement for so little cost relative to what else was being done that there was just little reason not to use it. 

[Midnight Rider]

I like the looks of the mist free system and is the way im gonna go. I just cant see how the harley system can work . Guess its ok around town but at high speed for extended periods of time it looks like all harley has is the old horse hair " Synthetic now" filter to seperate the oil from the air.
Thanks,
 Dave

Dave...there was a great article in either American Iron or V-Twin a month or two ago about all the Doherty systems, and it gave a very good independent description of how the thing works and the principles behind it.  It also went into some detail about the causes of excessive blow-by in the first place.  The PowerPacc is designed to keep a neutral pressure in the crankcase, thus decreasing the likleyhood of the problem showing itself.  It also pointed out that improper assembly/installation of the cam plate/O-rings can be a MAJOR contributor to the problem.  The article (and Doherty, from my conversations with them) pointed to more than a few cases of improper assembly of these parts from the FACTORY.  Since installing the PP, I still have some mysting, but it is minimal from what I have been told...the PP system, because of the clear tubing running from the PP to the backplate lets you SEE what's going on, and if there is an excessive amount of oil escaping the crankcase through the breather holes.

As Don stated above, one only has to look at the two designs, and know just a little bit about how the things operate to see that it is a better design with the Doherty.  They machine some good parts...

[Hoist!]

Nige...I know the SERK's have a A/C cover that already sticks out a bit further.  One thing you might want to consider to help alleviate that problem is the Kuryakyn floorboard extenders...they are basically a set of spacers for each side (including an oddball for the jiffy stand side of the bike) that move the floorboards outward 3/4"...I have installed these on my bike and enjoy the foot position much more, and braking is not an issue.  Just something to consider in order to give your knee a bit more room on the right side of the bike and put your foot on the board a bit more.

Terry, the PP doesn't really stick out any further than the stock SE A/C. Maybe a 1/4-1/2 in tops. It's not in the way for me at all. I'm, 5-9. Try it this way before predicting you'll have issues. I'm extremely happy with mine, especially since I can now run an S&S Teardrop! Hoist!

[Twolanerider]

Terry, the PP doesn't really stick out any further than the stock SE A/C. Maybe a 1/4-1/2 in tops. It's not in the way for me at all. I'm, 5-9. Try it this way before predicting you'll have issues. I'm extremely happy with mine, especially since I can now run an S&S Teardrop! Hoist!

If anyone is vertically challenged enough that the air cleaner seems a bit "out there" the simple solution is a set of floorboard extenders.  A spacer kit that moves the floorboards outboard just under an inch.  You wouldn't think that little bit would make much difference.  It's huge in leg comfort though.

[BalDeagle]

If anyone is vertically challenged enough that the air cleaner seems a bit "out there" the simple solution is a set of floorboard extenders.  A spacer kit that moves the floorboards outboard just under an inch.  You wouldn't think that little bit would make much difference.  It's huge in leg comfort though.

I guess I'm not really vertically challenged at 6' 0", but the comfort factor of slightly wider boards sounds OK. Does it present any problems with the boards being more likely to grind out in the turns though ?

Nige