Oil Blow-by Project...Final writeup & Pics

[trip]

I know that we've talked about this before, but I'm getting ready to re-route my stock crankcase breather to rectify what I feel is a developing blow by problem with my Nomad.

I've never experienced any lose of oil in my crankcase until I went on a 1500 mile trip to Big Bend this past April. I check my oil level all the time. After we traveled down an interstate at 3500-4000 RPM (85MPH) for a sustained period of time is when I noticed I was loosing some oil.

After reading everything I can get on the web, I'm assuming that it is due to blow by. I'm not leaking any oil and I haven't overfilled it. I have checked and I don't see any kinks in the stock line I have now.

The recommended solution is to replace the stock crankcase hose (3/8" id) coming out of the top, middle of the front head, with a thicker hose, run it up through the front fork into the triple tree hollow opening and place a crankcase breather filter on the end. That way if oil goes up the line any, it will drain back into the head. Then cap off the opening for the stock breather going into the bottom of the right side air cleaner system. My plan is to leave the stock hose in place, but plug it at both ends in case I ever want to use it again.

After checking into this and talking with others that have performed this procedure, I've decided to give it a try.

So, I thought I would run this by the KawaNOW mechanical braintrust and get any feedback that you deem necessary to give. Anyone done this before? Any gotchas?

I also thought about taking pics while I do this and possibly documenting for future member reference.

[Scoot]

PLEASE take Pic's

I'm having the same problem on the freeway. Since 90% of my riding is in-town, I've been satisfied to just put some oil in it from time to time. In 1500 miles of the Mesquite rally ride I used a bit more than 8 ounces, but my average speed was more like 70 MPH.

That's not a breather hose coming out of the head though. The breather hose comes out of the front of the crankcase right above the starter. Look at this diagram. It's No. 92191a. It goes out the back of the right backing plate, between the cylinders, completely over the front head, and straight down to a nipple on the case.
diagra m1

[blowndodge]

My crankcase must not be causing as much turbulence at higher RPM's I don't 'burp' any oil out at high speeds. Are you sure nothing is Kinked? besides Nico's JPEG files??

[trip]

Thanks for the info Cadd. I'll get out and trace the line from the back of the air cleaner system to where it ends up before I do anything. Several friends of mine that have done this say the crankcase breather hose connects in the middle of the front head, routes between the two cylinders over to the right air system housing.

[mcdaddy]

Trip, I'll try to take a closeup picture of mine in the morning and post it for you.

[voyager]

Trip,

The problem with venting the breather to atmosphere ( especially at the front near the triple tree) is that you will constantly smell the fumes.

Trip, the only hoses coming out of the head AFAIK are the coolant hose, and the AIS hose, which actually goes to the reed valve. He may have confused the two.

What might help without buying an additional breather is making that hose longer, so it loops as high as possible under the gooseneck, before coming back down between the cylinders. Also, adding an in-line canister filter to that line, rather close to the crankcase end of the hose, would provide a baffling effect that would reduce the expulsion of oil vapors. I thought about doing that because I happen to have one laying around that might work. Haven't tried it yet though.

[rewindgy]

On my little 800 Drifter it vents into a small clear bottle that hangs in the front of the engine. It is kinda ugly but it does let you see how much blow by happens. Since the 800 is a bit of a rever it used to fill up quicker until I change the sprokets and slowed the engine RPM down a bit! Wonder if you could use the same idea but put a bottle up alittle higher? You can't smell anything on mine even after high speed travel.

[trip]

Thanks McDaddy, a pic will help. Since you've done this with your 1600, do you smell any fumes while riding?

BD, I've checked several times.....can't find a kink anywhere.

Cadd, I want to check this out thoroughly before I do anything. I'm just not sure yet. In looking at the diagram you link to, (and I may not be reading the diagram right), I see that "A" is the crankcase breather intake into the air cleaner. In looking at the "A" hose, it shows to me that 52014 goes into the air cleaner. The hose bends upward, forward and down (as if going on top of the front head, which, of course, is not pictured). I'm gathering from this diagram that the crankcase breather hose connects to the front of the head???

[mcdaddy]

Trip, here you go .. the vent hose is on the front of the engine case right close to the fan. Mine routes straight up and tucks up under the triple tree.

Note: the factory hose is thin and pliable, I just disconnected it at the front case side, folded it up and zip tied it to close it off. It is stuffed up under the tank, so it can be reconnected in about 5 minutes if need be.

Re: Voyager's comment, My experience is that I do on rare occasion smell the oil fumes but only at a dead stop on a hot day . The air flow at any speed is enough to disperse the fumes.

[trip]

Thanks for the pics, McDaddy. I rode my Bike in to work today. Took a break a while ago and went out to verify the location based off your pics. There are two hoses running from the front of the head. I was confusing the middle hose as the crankcase breather hose. It's actually the hose to the left. Explains things.

I'm reading that the hose is 3/8" id, is this what you used to replace the hose with? Also, you haven't experienced any oil trying to come out of that filter, have you?

Thanks,
Trip

[macmac]

I guess the location thang is settled...
Something YOU GUYS might try is a "fire trap" The only place I know you can ask/order one if from volvo. and it would have to be modified probably.

I am sure it will have to be ordered too, as I never replaced one, and they are vintage now, so far as I know.

You would claim it was for a 1984 Volvo 240 turbo with a B21 F engine.

So ok what it does and what it looks like because it is a simple thing. What it does is restrict blow by.

What it looks like is a brass flat wire tape with little evenly spaced bumps stamped into it, and then it is rolled up like paper caps for a cap gun toy.

To me it appears as a common car lighter element could be cut apart for the core, but I have never cut a car lighter for the core, so I am not sure how wide the element really is.

The idea is to slow oil vapor in the form of a coil shaped metalic core. The dimple /dents hold the spacing so the rolled metal has a gap. Vapor and crank air can still flow back and forth as it does, but somewhat slower.

I think oil vapor condences on the flame trap, and these were a part of the tune up process on that car. I think it was every 25,000 miles the flame trap was to be removed and washed out with Safety Clean, which you can use carb cleaner, keroscene, or gasoline to do.

The place to install it would be near the port on the front side of the engine, and maybe place clamps above and below it and add a hooked wire so as to be able to pull it out for cleaning.

On the volvo it sits in a collector body which is oval, and set so any oil that collects in the bottom of the body can run back into the engine.

If you find a dead clunker in the boneyard standing facing the engine it will be on the right, and centered under the intake manifold and still not to easy to reach. It just might pop out in the hose if you pukk it.

It has a brass retainer band like a upside down top hat. Over all it is apx 1 inch OD.. so still to big, but damnned easy to trim.

[mcdaddy]

Not sure of the size Trip, but I think it's like 5/8" or 3/4" heater hose that fits it. Notice that the hose attaches to a nipple that comes out of the top of crankcase ...... right in front of where the bottom of the front cyclinder fins are.

I haven't had any oil seep from it. I have heard of others who have when it is routed elswhere and possibly too low ... (like over by the horn mount)

[lomax]

Trip ........Here is what I did to vent the crankcase on "Betty". We are all looking for more bling and these little filters look pretty good. I have no oil using issues, but had this filter laying around and decided to use it. The oem hose is 3/8 ID and fits very nicely on these filters. I have never had any vapour smell from it.