Wednesday, May 01, 2013

Uraling in Alaska - Day 26: Improving the Crankcase Venting

So, the bad news is that I heard from URAL today, their shipping clerk sent my parts via GROUND instead of Overnight.  Dammit.  Oh well, it is what it is.  I feel sorry for RichardM and family as they're stuck with me an extra day or two, the part is not slotted to arrive till Friday now.

On the positive side, based on some brainstorming on the part of RichardM and I (mostly RichardM as he's the smart one), we came up with a mod to the crankcase vent mode done to Valencia by Raceway Services.  It's a mod which many Uralisti have done, to avoid having oil and water mix spit out by the crankcase from ending up in the air box and air filter.

What Raceway did was to route the hose coming out of the crankcase fitting, down to a small air filter which was inserted into the 5/8 inch rubber tubing.  So the oil is collected at the filter and the system vents to the atmosphere.

Not a bad system per se, but in really cold/wet weather as I'd been riding in, it tends to freeze and clog up and cause breathing issues for the crankcase, which lead to rough-running and worst case, cause oil leaks as the engine tries to vent and can't via the usual path.  This usually means leaky seals, etc.

So for now, I've got the following setup on Valencia:

 The red lines indicate the path the rubber tubing connected to the 
crankcase fitting takes, looping down and below the left side jug
(The bottom arc is where the small air filter put in by Raceway used to be)

 You can clearly see the white plastic Y junction adapter
Check the text in the pictures for the flow.  Basically,
Air will flow to the top branch going to the air box and
the oil/water will continue down the tube towards the
back of the transmission where the small air filter has been relocated.

 Coming up from the Y Junction, the hose then terminates in the 
stock air box's input tube.  This is where the crankcase breather tube
normally terminates out of the factory.  It's also the cause of oil and water mix
getting inside the air box and contaminating things.

A view of the rear underside of the transmission box, the
small air filter is visible and acts as a vent and collection point
for oil/water spit out by the crankcase.  Periodic removal
of the filter for cleaning will also allow for accumulated oil/water
mix to be drained out and disposed of.

So, bad news re parts arrival, but still a good day overall!  A fellow Airhead and his wife have invited me over for dinner so RichardM and his family get a few hours break from having to look at my face.  :)

UPDATE: 16JUN13:  Above design is now believed to be flawed due to two factors.  1.  If you lose the collection bottle which replaced the small air filter above, you're now possibly sucking in unfiltered air.  2.  Routing some of the air into the airbox means your sending in hot air from the crankcase into the left air is of course better.

So, I've gone back to a plugged hole in the airbox itself.  The crankcase hose is now venting to atmosphere for now till I figure out a more secure collection system that's still easy to clean out.


Bob and Sharon said...

Welcome to Alaska where nothing comes overnight 😊
Everything that comes up here comes by barge or plane there is no ground service. But at least it is on the way

RichardM said...

Or where overnight shipping is expensive, especially for something heavy like a motorcycle head. But like Bob says, at least it's on its way north. And "UPS Ground" just means by ground from Anchorage.

Unfortunately, there are no mountains nearby....

GlennandSun said...

Great venting plan, very much appreciate your sharing the info and the detailed photos so I can duplicate it on Stormin' Norman. Please keep the great data coming. Interested in all your modifications and tips.
We are sorry to hear about your parts coming by banana, ground transport, but being surrounded by great friends and a beautiful state, I imagine that should soften the "slow blow" say nothing about the comfort of great pie too..:) I hope any of our future mechanical delays will be blessed by conditions half as great as the folks, shop and food as you have found in Fairbanks, AK. Comforting and delightful the see what you have found there! GlennandSun

SonjaM said...

One thing seems to be certain when you are in a hurry to continue your journey... shippers seem to screw up the delivery.
Valencia will become indestructible after her makeover.

redlegsrides said...


Thanks for your comments, re modifying your rig remember they're all different so don't fix something that ain't broke as they say! ;).

That said, I have high hopes for the modified crankcase vent system,

Heartily agree with your opinion on the friendly and welcoming support I've been fortunate to find in Fairbanks!

redlegsrides said...


Indestructible? I have my doubts about that but sure hope you're proven correct! :)

redlegsrides said...

Hi Bob, thanks for add some salt tithe wound, it's coming here by way of Ontario, California according to UPS. ; (

Le Sigh....

Unknown said...


You're only "STUCK" if you have to be somewhere fast. Enjoy your vacation and your morning coffees with the Airhead Gurus, at least your Head is "on the way".

I'd imagine that it is just a simple thing of bolting the new head on, and perhaps new rings ? so it can mate with the cylinder ?

Hope your crankcase mod fixes the problem

Hmmm, more Marionberry pie . . . Maybe you should buy one "for the road", or is that bear bait too ?

Riding the Wet Coast

ps: Maybe that could be a money maker. Make those "Y" mods and sell them.

Bob and Sharon said...

I've watched that tracking bs from UPS so many times, I just find it depressing at times. The good thing is, your coming towards the mountains

Your trip will be getting better😉

Jack Riepe said...

Dear Charlie6 (Dom):

I am astounded at the mechanical resourcefulness you continually demonstrate in your love affair with these Amish motorcycles. I am still trying to figure out why the engine pukes up oil and water.

Still, the fix you have devised seems to greatly have improved performance for the cold weather. I am now going back to find out what the hell happened to the head. Is this under warranty?

Damn you are having a real time of an adventure.

Fondest regards,
Twisted Roads

redlegsrides said...

Dear Jack

Yep, not a tame adventure so far but far from it being epic either. As the the head, the valve seat came from the factory uncut and somehow I made it to almost 30,000km with it that way. The parts/labor will be covered under warranty. It was the rough-running caused by what appears to have been frozen moisture on the ignition's optical sensor whic led the mechanic to do a compression check, which led to the discovery of the large inequality in compression readings which led to the tear down of the left jug which led to the duiscovert of the uncut valve in a way, am lucky the ice formed and blocked the optical sensor in the first place!

As to why engine puking water and oil, oil is normal, all engines do this, water is from condensation for when you do short rides that don't allow the engine to get hot enough to burn off collected condensation I am told.

Hope you like the previous articles.


Martha said...

I see the title of a best-seller in the makings: If you give a man a URAL (ala the If you give a mouse a cookie stories, but not sure you recall those stories that the boys thrived on back in the day...)

redlegsrides said...

Oh, I recall the stories.....they were good stories.

BeemerGirl said...

Way too technical for my tired mind. :) But I am ecstatic that you think it is good.

And I love that you are making so many friends!

redlegsrides said...

Have modified this crankcase venting due to new info. See update in the posting. No longer routing some of the hot air from crankcase back into the airbox.