Wilsons Sandbox

Devon wrote:

> Has anyone ever tried a PCV valve on the KLR's crankcase > breather hose? >

Interesting thought. Wonder if this would improve some of the light surging the KLR seems prone to at mid RPM's. Could there be a cavitation effect going on changing the air intake characteristics? Would a PCV valve help? Keep me posted if you try it. Todd

--- In DSN_klr650@yahoogroups.com, Devon Jarvis wrote:

> Has anyone ever tried a PCV valve on the KLR's crankcase > breather hose?

Have you tried this link? Quote.. Large displacement, singles and twins really come alive with the Krank Vent!! WWW.et-performance.com/krank_vents.html Tom A15

In a message dated 2003-06-10 5:44:43 PM Pacific Daylight Time, tcgrigg@... writes:

> > Have you tried this link? Quote.. > Large displacement, singles and twins really come alive with the > Krank Vent!! > > WWW.et-performance.com/krank_vents.html > > Tom > A15 > >

I just did a google search on Krank Vent and found a couple of web sites that flatly claim they were unable to show any improvement on their HDs. An MCN article had similar results and after talking with the vendor (In this case the part was made by Tom Hayden Enterprises so wonder how ET-Performance fits in as the Hayden Krank Vent name was also trademarked?) and based on that conversation MCN determined the device was useless on anything but an early Evo engine. Here's my take on such devices. When I see one on a factory YZ/CR/DR/KTM racing 4-stroke I might give one some thought. If these things where such a shoe in for a performance boost why are the factories wasting time on esoteric head work? Pat G'ville, Nv [Non-text portions of this message have been removed]

> Here's my take on such devices. When I see one on a factory

YZ/CR/DR/KTM

> racing 4-stroke I might give one some thought. If these things

where such a shoe

> in for a performance boost why are the factories wasting time on

esoteric head

> work?

Pat, my post wasn't intended as an endorsement, just trying to provide some info to a couple of Devon's questions, i.e. these guys claimed no success with automotive pcvs and waddup with large displacement singles. Tom

In a message dated 2003-06-10 7:21:49 PM Pacific Daylight Time, tcgrigg@... writes:

> > Pat, my post wasn't intended as an endorsement, just trying to > provide some info to a couple of Devon's questions, i.e. these guys > claimed no success with automotive pcvs and waddup with large > displacement singles. > > Tom > >

Tom, And my post wasn't pointed towards you, it was an answer to the original question. It really was more an addition, but you have my apology. I'm always looking for anything that could improve performance so when You came up with the Krank Vent link I started doing some research at the speed of the web. Pat G'ville, Nv [Non-text portions of this message have been removed]

I guess a PCV valve is not exactly the right thing. I'm thinking more like a check valve. People have made good points about the large change in crankcase volume with a single, so I'm thinking the simplest thing would be a check valve on the large crank breather hose, and a 1/4" ID hose bypassing the valve- the valve would be open to vent pressure as the piston drops, and then it would close as the piston rose, so the crankcase would suck in air through a small hose- leaving the mean crankcase pressure a bit lower, but not creating an extreme amount of vacuum. Devon A15 kdxkawboy@... wrote:

>In a message dated 2003-06-10 5:44:43 PM Pacific Daylight Time, >tcgrigg@... writes: > > > >>Have you tried this link? Quote.. >>Large displacement, singles and twins really come alive with the >>Krank Vent!! >> >>WWW.et-performance.com/krank_vents.html >> >>Tom >>A15 >> >> >> >> > >I just did a google search on Krank Vent and found a couple of web sites that >flatly claim they were unable to show any improvement on their HDs. An MCN >article had similar results and after talking with the vendor (In this case the >part was made by Tom Hayden Enterprises so wonder how ET-Performance fits in >as the Hayden Krank Vent name was also trademarked?) and based on that >conversation MCN determined the device was useless on anything but an early Evo >engine. > >Here's my take on such devices. When I see one on a factory YZ/CR/DR/KTM >racing 4-stroke I might give one some thought. If these things where such a shoe >in for a performance boost why are the factories wasting time on esoteric head >work? > >Pat >G'ville, Nv > > >[Non-text portions of this message have been removed] > > >List sponsored by Dual Sport News at www.dualsportnews.com. List FAQ courtesy of Chris Krok at: www.bigcee.com/klr650faq.html >Unsubscribe by sending a blank message to: >DSN_klr650-unsubscribe@yahoogroups.com . > > > >Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ > > > > >

Devon Jarvis wrote:

> Has anyone ever tried a PCV valve on the KLR's crankcase > breather hose?

I doubt it.

> I read somewhere in an interview with a guy who builds drag > bikes, one of the tricks is auxiliary crankcase air > scavenging pumps- Having a vacuum in the crankcase actually > adds a few % of power.

Sorta, kinda. I would have thought that the power to run a scavenge pump big enough to give sufficient vacuum would negate the advantage.

> Would this work on a single? The crankcase breather vents > into the airbox, on the inside of the filter. The pressure > would go up and down with the stock setup, but I don't know > to what extent that would affect carburetion.

The breather feeds toward the atmostpheric side of the carby so it should not bother the carb. The breather pushes into the airbox twice as often as the carb sucks. So, when the piston is on the intake stroke the breather is helping a bit to feed the airbox (on the filtered) side. When the engine is on the exhaust stroke, the breather is pulling air into the airbox, and potentially pulling air back from the carby as well. It would be interesting to see what would happen to the jetting if the breather is vented to atmosphere and not the airbox. You certainly would not want to plumb the PCV into the carby-to-head adapter. During the intake stroke, the breather would tend to reduce or eliminate the vacuum signal at the carby. I can imagine that a simple one-way valve in the breather system could create some vacuum of its own, but you would mainly get vacuum when the piston is on the way up from BDC. You may see some power gain from such a set up because the carby would see more cooler airbox intake air and less of the heated crankcase gases and air. At least this system is less likely to throw oil vapour into the airbox which may or may not be a good thing. PCV works nice on a multicylinder engine where the total crankcase volume does not change much and the low-pressure (aka "vacuum") in the manifold is fairly constant, or at least not as pulsy as a single. Mister_T Melbourne Australia -- /_/_/_/_/_)_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/ | RC17 KLR600 KHGZ31JAMG SA22C Solaris FreeBSD 4.7-R | ) Team RC17 Australia http://www.teamrc17.net | |_________________________________________________________________|/

Go to the Yahoo groups website and do a search for "Repo4Sale" --- In DSN_klr650@yahoogroups.com, "Pat Schmid" wrote:

> Today, my inbox has several emails from a repo4sale. While I don't > read all the post, my addled memory (unlike Bill Clinton I freely

own

> up to inhaling in the 60s) wants to say that repo4sale is held in

low

> opinion in these parts, something about bogus performance parts. I > expect y'allcan refresh my memory before I make any replies. > > Pat > G'ville, Nv