White & Poppe engine breathing

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huw.parsons
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White & Poppe engine breathing

Postby huw.parsons » Sun Jun 05, 2011 3:52 pm

Hello all

Does anyone know if there were any changes to the crankcase breather on W&P engines between 1911 and 1925?
Looking at all the available pictures I have and those on the website, there appears to be just the tiny tube and ball between
the crankcase and timing chest. It regularly bungs up and the ball jams very easily resulting in air coming out of every other gap usually
accompanied by large quantities of oil. Not good on a belt drive single speeder!
Was there an improved system in later years?
I notice Tony Peglar's 1913 bike has an added breather from the back of the timing chest.(ref. club bike pictures done by Marcus on the website)
Do later bikes have a drive side breather onto the drive chain?

Any help appreciated as I'm doing a strip inspection on the engine and now is the time to add a breather so the bike is ready for it's
100 year old celebrations next year!

Cheers

Huw

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Postby tony.barnett » Sun Jun 05, 2011 7:31 pm

Huw,

My 1920 W&P engine does indeed have a breather onto the primary drive chain. I'd guess that this would be detrimental on a belt driver tho. My own TT Ariel seems to externally lubricate as well, including liberal coating of any drive friction surfaces, so I'd be interested in the outcome of your investigation. I was always under the impression that it breathed through the mainshaft but maybe I'm getting confused. It don't take much..

Cheers,

TB
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Re: White & Poppe engine breathing

Postby adrie.degraaff » Sun Jun 05, 2011 8:18 pm

A belt driver has a blind hole where the chaindriver has the breather-dripfeed.

Pre 1910 breating was mainly trough the crankshafts, I have never seen a 1910 model.

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Postby huw.parsons » Sun Jun 05, 2011 10:31 pm

Adrie, you mean the hole ,with ball bearing in, that exits the timing side crankcase to drip on the Magneto timing chain?
I'm pleased to hear that they fitted a more substantial breather later on . My 1912 bike is much more sensitive to having too much oil than it used to be
before fitting a less worn piston, rings, new tappet rods and bushes. She likes to vent oil at the slightest excuse, particularly through the main shaft drive
bearing despite having a lip seal fitted.
I pretty much go with 1 drop of oil every three to five seconds and half a cylinder before tackling a steep hill. She still occasionally decides to vent copious
amounts of oil onto the back of the drive pulley which of course sprays it onto the rear pulley and belt. This seems to be completely at random though!

Any other W&P riders have any opinions on this? I'll make some non e-group telephone enquiries too and let you know the results TB


HP

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Postby adrie.degraaff » Mon Jun 06, 2011 8:15 am

No, the drive side.

I think you are over lubricating, your sparkplug won't like this.

If you have a black oily sparkplug on route, break some ceramic material away from the inside of the sparkplug, thus making it hotter and burning the oil better.

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Re: White & Poppe engine breathing

Postby huw.parsons » Mon Jun 06, 2011 11:37 am

I thought so as well Adrie but the plug couldn't look healthier or work better. No signs of excess oil past the piston at all. Its a Champion N6.

There are no vents of any sort on the drive side of either of my pairs of crankcases. Both have the small hole and ball which vents to the timing chest.
As I say the ball is tiny and frequently jams. I think this is the problem or at least part of it. The thing is did W&P improve on this in later engines?
They obviously thought a vent to the chain on the drive side was a good Idea.

Thanks again

Huw

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Postby huw.parsons » Sun Jun 12, 2011 9:27 pm

just looked over this thread; please forgive my daft mistakes. For magneto chain please read cam gear and the n6 plug should of course be A6...

Still trying to fathom out the mysteries of W&P breathing and why my engine isnt quite right, more soon.

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Re: White & Poppe engine breathing

Postby huw.parsons » Mon Jul 04, 2011 5:54 pm

Well so far, all I've discovered is that neither of the crankcase pairs I have feature in any of the parts books drawings from 1911 to 1925.
The breathing on the 1912 pair is by tiny breather and ball bearing in a brass plug above the inlet cam and has a pipe that vents to atmosphere. I have also seen this plug removed altogether on another running engine, presumably to cure the same problem.
the other (battered) cases have a breather and ball but this is cast into the bottom of the timing chest with a hole underneath to atmosphere

the 1911 cases just breathed through the main drive bearing as far as I can tell.
Chain cum belt engines have the drive side breather that Tony mentioned previously.

If anyone has any more opinion or experience, especially of the single speed belt drive bikes, please help!

I'm about to put the engine back together and am in two minds as to fitting a larger breather in the timing chest as
on Tony Peglars bike. I hate the thought of drilling a hole in a 100 year old case but would love to stop spraying
liberal amounts of oil over the belt!

Cheers

HuwP

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Re: White & Poppe engine breathing

Postby patrick.robotham » Mon Jul 04, 2011 6:16 pm

I have a 1923, and had a 1924, they both had breathers from the top of the crankcase above the drive side main bearing and then via a small tube onto the top of the drive sprocket. Also have a small tube coming out of the timing chest. Oil also breathes through the drive side mainbearing and the valve tappet blocks. My problem is oil on the belt from the moss gearbox so am going to fit a sealed bearing this winter, this has been a problem on all three belt drive bikes I have ownwed with this gearbox. If you are taking your engine to bits I would rally be interested to know your valve timing.Pat

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huw.parsons
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Re: White & Poppe engine breathing

Postby huw.parsons » Mon Jul 04, 2011 10:11 pm

Thanks for that Pat

It seems to me the breathing was steadily improved over the years. I'll post some photo's of my early cases when I get back home in a weeks time.
Interesting what you say about the tappet bushes; the bike has been far more prone to throwing out oil since the rebuild and these were replaced at the time,
with a sloppy cast iron piston and rings it's probable that the tiny 1912 patterb breather just cant cope.

I got my cams built up and re-ground three years ago; they should be at the standard profiles giving timings as in the 1913 manual/catalogue in the
Document library. I plan on taking my actual timings with a degree wheel when the engine is back together next month. I'll let you know the results..

Still bemused by the recommended 1/64th " tappet clearance; seems really huge to me. I rather like the way the catalogue suggests it's about "the
thickness of a calling card" and to use one to set the correct clearance.

Cheers

Huw


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