CNW '72 Breather Mod

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L.A.B. said:
http://www.accessnorton.com/restoration-adding-modifications-butchery-t12077-60.html#p140739
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Ummm - thanks for the forum link. Now my head is spinning faster than my oil pump. :mrgreen:
 
tomspro said:
L.A.B. said:
http://www.accessnorton.com/restoration-adding-modifications-butchery-t12077-60.html#p140739
Click to expand...

Ummm - thanks for the forum link. Now my head is spinning faster than my oil pump. :mrgreen:
Click to expand...

No case modifications are needed to bolt the breather to the rear of the 72 cases.
It is a tight fit with the engine in place but very do-able. I use hex head bolts to fit it when the engine is in place instead of socket head capscrews. That makes it easier. Jim
 
comnoz said:
tomspro said:
L.A.B. said:
http://www.accessnorton.com/restoration-adding-modifications-butchery-t12077-60.html#p140739
Click to expand...

Ummm - thanks for the forum link. Now my head is spinning faster than my oil pump. :mrgreen:
Click to expand...

No case modifications are needed to bolt the breather to the rear of the 72 cases.
It is a tight fit with the engine in place but very do-able. I use hex head bolts to fit it when the engine is in place instead of socket head capscrews. That makes it easier. Jim
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Thanks Jim - would still be nice to hear from someone who did this and what their experience was.
I have no reason to do the 'fully monty' case mod with my engine at this time.
Yet I have persistent leaks and would like to something that improves things without spending major buck and time.
Of course, cleaning out my original breather and hose is the simplest step - as suggested by 1up3down.
 
Just curious, what's the status of your layshaft bearing?
 
I put mine in while I had the inner and outer covers off the gearbox (still in frame) for my layshaft bearing job and it was fairly easy. It can be done without doing all that but you will be working from more under the bike rather than the side. If you can hang the bike up you'd be all set.
 
FWIW - been researching this as I thought it would work on my 68 cases but found out that mod doesn't work there. In talking with CNW they appear to be putting a new product on the market that replaces the 1.5" sump plug and gives similar breathing. They told me about 60 days out.

Just my .02 and probably not worth that.

have a good one,
Dave
 
The sump breather you are talking about is made by Jim Comstock and there has already been a few threads about how well this is working

I am sure some will chime in about how efficient it is

I am hoping to have some stock when he finishes his next batch

Matt / Colorado Norton Works

www.coloradonortonworks.com
 
CNW said:
The sump breather you are talking about is made by Jim Comstock and there has already been a few threads about how well this is working

I am sure some will chime in about how efficient it is

I am hoping to have some stock when he finishes his next batch

Matt / Colorado Norton Works

http://www.coloradonortonworks.com
Click to expand...

It is indeed a very efficient device.

It is very well made, and fits easily.

I also think it is a great aid to engines that wet sump as this will simply allow gas pressure to push excessive oil back through the breather pipe and into the oil tank.

Can't fault it!
 
I'm not sure what happened with the original poster, but if he has a breather off the back of the case, he probably doesn't have the large sump plug.

Tomspro, I wasn't trying to be obtuse when I asked about your layshaft bearing. It just comes natural I guess. The point of the question is that if these kinds of things have not been addressed, then I would recommend making a plan to tear a little deeper into the bike and make the job of doing the breather a little easier. I suspect Comnoz could do the job with his eyes closed. I need a little more room to work because I am a good mechanic but not a great one. To me this means I want to check those threads, clean the area properly, get a good seal and properly torque my fasteners. I know I don't have the skills to do that well in a cramped space. The frustration level is too high for me as well seeing as how I am supposed to enjoy working on my bike, I prefer to make it a job that doesn't cause me to swear every few moments. Sometimes by avoiding work we just make the job that much harder. And I don't forgive myself easily for screwing up threads in my aluminum cases when I could have avoided it with a little more effort.
My two and a half cents.

Russ
 
FWIW - been researching this as I thought it would work on my 68 cases but found out that mod doesn't work there. In talking with CNW they appear to be putting a new product on the market that replaces the 1.5" sump plug and gives similar breathing. They told me about 60 days out.

Just my .02 and probably not worth that.

have a good one,
Dave

The rear crankcase breather will fit 1968 cases with some simple machining. The sump plug type might not fit however, due to the bottom frame cross brace. I'm sure Jim would know.

Martyn.
 
Matchless said:
FWIW - been researching this as I thought it would work on my 68 cases but found out that mod doesn't work there. In talking with CNW they appear to be putting a new product on the market that replaces the 1.5" sump plug and gives similar breathing. They told me about 60 days out.

Just my .02 and probably not worth that.

have a good one,
Dave

The rear crankcase breather will fit 1968 cases with some simple machining. The sump plug type might not fit however, due to the bottom frame cross brace. I'm sure Jim would know.

Martyn.
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Martyn is correct. The early frames have a crosstube under the front edge of the sump plug. My breather will not clear. So far the only way I have found to fit an effective reed breather with this frame design requires machining the rear of the engine case. Jim
 
I'm using the XS650 reed valve (as are others on this site) with the stock breather hose going to this unit under the seat then normal hose from the reed valve box to the top of the oil tank on my '72 combat engine. I have no experience Jim's breather. Are there value benefits at a much higher cost of $220/per?
 
I did mine without taking any thing off the engine. It takes some care getting the gasket surface clean and bolting up the first half of the breather. from there you just have to use the hex head bolts so that you can get onto them with an open end or box end wrench. I would be careful to hook the hose onto the breather first to avoid having to do it after the breather is in place.
I did mine on the side stand so that the bike was leaned over far enough to actually get my head under there and see what I was doing. Put the tires up on some 2x4s so it leans a bit more.
It is just like Kenny says, "Put on Jim's breather! They work great and you wont have any more oil leaks."
Cheers, Dan.
 
illf8ed said:
I'm using the XS650 reed valve (as are others on this site) with the stock breather hose going to this unit under the seat then normal hose from the reed valve box to the top of the oil tank on my '72 combat engine. I have no experience Jim's breather. Are there value benefits at a much higher cost of $220/per?
Click to expand...

1.First my breather does not plug up with oil water mix from condensation. It is attached to the engine so it runs at engine temperature and gathers no condensation.

2.My breather is closely coupled to the crankcase so the reeds resonate with the crankcase pulses. That means it will still create a vacuum even at highway speed.

3.My breather picks up low in the engine case so it removes excess oil that has gathered in the cases when parked. It will clear a wet sump condition in only a few slow kicks or a few seconds after the engine is started.

4.It's out of sight and out of mind. Jim
 
I had a XS breather long before Jim Comstock produced his breather reed valve. If I were to install one today it would definitely be the Comstock/CNW reed valve. The benefits Jim mentioned, plus the fact that both Jim Comstock and Colorado Norton Works have contributed greatly to improving our beloved Nortons is well worth the additional cost.
 
comnoz said:
Matchless said:
FWIW - been researching this as I thought it would work on my 68 cases but found out that mod doesn't work there. In talking with CNW they appear to be putting a new product on the market that replaces the 1.5" sump plug and gives similar breathing. They told me about 60 days out.

Just my .02 and probably not worth that.

have a good one,
Dave

The rear crankcase breather will fit 1968 cases with some simple machining. The sump plug type might not fit however, due to the bottom frame cross brace. I'm sure Jim would know.

Martyn.
Click to expand...

Is that the case with a 70 frame? I've replaced my widowmaker with a 70 frame.

Martyn is correct. The early frames have a crosstube under the front edge of the sump plug. My breather will not clear. So far the only way I have found to fit an effective reed breather with this frame design requires machining the rear of the engine case. Jim
Click to expand...
 
+1
I have Jim's breather on my 72.
Zero oil seepage, including around the unmodified tach housing.
Just a few light kicks to clear a wet sump.
Easy to install in situ.
 
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