Clearly the bike revs higher in 4th & 5th gear.  Prior to disconnecting the breather hose from the airbox, it would sign off at 7000 in 4th and actually start slowing down.  With the breather hose vented to atmospheric, I ran it up to about 7250 in 4th before I had to shut down.  I have gone for three rides since I did the catch can (one was to the dyno), and not one-drop of oil has accumulated in the can.  On the dyno, we did several runs in 4th up around 7500 with no indication of the mixture going rich.  I have a vid of one of those pulls if you want to see how the A/F ratio holds.

The bike also seems to run cleaner each time I ride it.  I attribute that to airflow cleaning the excess oil out of the air filter.  It was a mess after several LSR attempts with the breather connected to the airbox.  I'm too lazy to clean the filter, figure fresh air can do it for me.  What the heck, its clean oil.  

I'm likin the catch can.  I should have a check valve on it in a week or two.  I do have some concern over pulling a vacuum in the crankcase.  I think it's unlikely, but there is a slim chance that the vacuum could cause suction lift problems with the oil pump.  Plenty of other engines use the check valves/reed valves so, as I said, I think its unlikely.  I think it will depend on how much suction head the pump runs at sustained WOT conditions.  The oil pressure gage will come in handy to monitor for any suction lift problems.  Any interruption in oil flow should show up on the gage.  Will it respond fast enough???

Man this is fun.  

So I go out and get a check valve assembly, Hayden KrankVent Plus, do a few mods to it, and stick it in the vent hose between the head cover and catch can.  It runs great. Seems to have a bit more mid range torque. The WOT times from 4K to 7K are still right at 2.9 seconds or so, but it feels significantly better at part throttle.  The catch can is absolutely bone dry.  I'm lovin it.

So I decide that its time to see what sort of crankcase vacuum it's pullin.  I make a little fitting to allow installation of a vacuum gage.

I fire it up and it pulls like a dismal 0.5" Hg.  I certainly expected a bit more than that.  OK, so maybe without the KrankVent the case was pressurized significantly, so if its now a little below atmospheric that's cool, right?

I take out the KrankVent and try again.  I figure I should see some pressure.  Now I push about 0.5" Hg.  Hmmmm!

After pinpointing the source I do the old feeler gage check.  That's a .003" feeler shoved into the joint.

I'm not givin up on this.  It felt really good with the KrankVent installed.  To be fair to Hayden, I did modify their product, and the mods I did were intended to make it more efficient.  I spoke with their tech guy, Tony, before I did these tests.  They are a standup outfit.  He spent a long time with me.  I think their product may be a good fit for the Savage.  It might work just fine right out of the package, and my mods might be the culprit here.

Seat-o-da-pants it felt crisp and frisky at cruise.  I think it was runnin significantly better.  I suspect the gasket was blown long before I discovered it because the case was always under vacuum so no oil would come out, only dirt would go in.  The leak didn't show up until I took the KrankVent out.

I need to come up with a fix for the weak link and try again.  Then I can see what sort of vacuum it pulls.  I can put in a bleed orifice to limit vacuum.  If I get it sorted out it will also help to keep the engine absolutely oil-dry.  That would be a bonus.

I just love messin with this thing.  Now I have an excuse to yank the engine.  Nirvana.

Knowledge is power.

Mike

DBM
Thanks!
So good to hear that the crankcase vent valves worked. Every serious racer uses them. Made me crazy to read all the reports of high RPM oil use and no-one had bothered to do this.
When Nortons become 850cc and pulverized their base gaskets, Loctite developed a goop to use for the cylinder base instead of a gasket.
Maybe try that stuff?

DBM

I am a little bit confused.....your vacuum gauge only reads a vacuum and not pressure.  Are you saying that with the valve installed it pulls a vacuum - but without the gauge it makes a "positive" pressure in the crankcase?  How did you read a positive on that vacuum gauge?

Sorry that you got a leak.....that location requires a bunch of work to get to that gasket!  I would not think that the gasket would fail just from changing 0.5" of pressure to 0.5" of vacuum....the net result is a change from pushing on the gasket to pulling on it, as your numbers show the same value but in a different direction.

In your pursuit of a tighter squish - have you considered leaving the gasket out and using the same Suzukibond that you use on the head cap to seal the cylinder base?