Anti wet sump valve sieze (2015)

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Works same way in Cream of the Crop Combats IF turning over slow enough decending pistons can push some oil out before accending to suck oil back again. Those with breather ports above oil level in cases will not function to return oil to tank on slow turn overs. Still this assumes that its better to slowly grind friction surfaces rather than moving em fast enough they slide with less friction till oil pressure-flow hits. hobot proven way > Just start em to rev above 2000 till accepts good throttle then ride off in low gears so rpms up and engine loads low-ish till full warmed to take lugging short shifting hi torque and late shifting lower gear WOT tire wearing delights.

A missing teeth Gravel rider here came to same conclusion I did, if going fast enough ya tend to skip over some bumps and just encounter the tops of others.
 
Thanks Fast Eddie, what you've explained does make sense but it all sounds a bit "hit & miss" to me.
 
daveparry said:
Thanks Fast Eddie, what you've explained does make sense but it all sounds a bit "hit & miss" to me.
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The 'hit & miss' of it is probably due to my explanation!

I found the video link from Comnoz, a picture paints a thousand words 'an all that:

wet-sump-start-t20950.html
 
Fast Eddie said:
No dire warnings from me Glen... But I am not keen on adding something that I don't need. And with the breather set up and oil pump on mine, I don't need owt else.

I actually think that yours, with the built in ignition key holder thingy, is the best one of the lot. If I needed one, I'd copy that. But then I'd have to fit an key operated ignition switch as well!

I like to keep my bikes as simple as possible... To match my intellect...!
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Nigel, I agree, simple is almost always best. My MK111 takes a similar amount of time to wet sump, so it will not get a shutoff valve. I intend to deal with wet sumping of that bike by riding it more frequently. The other thing with the MK 3 is that it doesn't leak oil out of the cases as the sump fills.
My 650 ss on the other hand likes to fill it's sump in about two weeks then starts oiling the floor. It also smokes profusely for at least two minutes when started with a wet sump. One oily , smokey startup must coke up the head more than 5,000 miles of normal running.
So due to it's particular set of problems and my laziness (don't want to tear the engine down to reseal the cases) it got a valve. It seems to have eliminated all of the annoying problems described above. Now I can just get on it and ride without worrying "has it sat too long, should I drain it, does it need oil adding " etc.

Glen
 
If the engine wetsumps and you can get it started, then at least the oil is where you need it initially, flying around the crankcase, won't take long to get enough back to the tank to feed the pump. Might blow some out of the primary chain case oil seal while you get there.
 
gripper said:
If the engine wetsumps and you can get it started, then at least the oil is where you need it initially, flying around the crankcase, won't take long to get enough back to the tank to feed the pump. Might blow some out of the primary chain case oil seal while you get there.
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And in addition to that, a good portion of this oil resides in the timing chest which seeks the same level as the crank cavity. So it's not ALL that oil sloshing about the crank and therefore isn't as bad as one would think. One could even realistically say no real issue at all, right Jim? But then again, there would 50% less to talk about around here.
 
Hi hobot.
A Combat engine returns oil to the oiltank via the standard breather circuit at idle (a fact personally observed since 1981)
Adding a reedvalve at the crankcases or inline to the breather circuit does not change the breather oilflow at idle (observed fact). A reedvalve on the crankcase will ensure a oneway oilflow at slow kick over ala comnoz video - other than that, it is another pressure blowoff valve.
Ta.
 
Hey no doubt about it a light low inertia reed valve closest to the source of pressure pulses with the TS case blocked off so remove its volume dampening of flapper moving air waves is proven one the best routes to take - if not bored with just good enough and like snickering inside on success of their own one in a row solution, wet sump to breathing ease. All in good guy fun fussing with obsolete cycles - punctuated now and then by a engine catastrophe or permanent to deadly injury out to blue no fault of your own but addicted to cycles. To me two things Norton really screwed up on Combats, a. the forward oil drain that windage piles up for breather to remove when on 2S cam power rpms into elastic seam weep zone, and b. low down dirt breather oil baffle fouls removing the gear box w/o 1st having to do all it takes to tip engine forward out of cradle, ugh. If a slim jim reeve valve fit a Combat and ease gearbox removal then that's only reason I'd want one on Trixie but want it yesterday so ready to pay today if does exist as bolt on install.

For the advancement of Commando innovation why don't you put your clever mind on an exhaust extractor i can mimic and save me trial and failures like Texas oil geyser out head vent : (
 
Hi hobot.
Forget about exhaust vacuum.
You have 3-5+ inHg vacuum available via crankcase airflow (with large reed valve).
Ta.
 
Ok3-5 psi is significant and over kill good for average Commando blow by so good on all those so set up. I'm not changing much on plain ole Trixie even if causes some hi rpm leaks but Peel is another animal I'm grasping at straws to do what I want her to. hehe sometimes more is better.
 
needing said:
Hi hobot.
A Combat engine returns oil to the oiltank via the standard breather circuit at idle (a fact personally observed since 1981).
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Most curtainly not by design. A misfortunate design flaw of which us 72 owners must make due with.

needing said:
Adding a reedvalve at the crankcases or inline to the breather circuit does not change the breather oilflow at idle (observed fact).
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No, but it sure screws up the airflow of which it was intended. Duh!

needing said:
A reedvalve on the crankcase will ensure a oneway oilflow at slow kick over ala comnoz video - other than that, it is another pressure blowoff valve.
Ta.
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Wrong! I think your observation/assumption is uderstandably misunderstood by the mountainous multitude of ramblings within the passages of this forum, but quite frankly, I think you're just High.
 
Hi pete v.
1. Flaw, you say. I consider Combat breather circuit a boon.
2. Airflow is unrestricted once the wetsump is cleared in 1st mins if startup.
3. Oh, that is low - your choice.
 
Here's one of Trixies rebuild initial start ups with a view of the Combat bigger secondary back up oil return from blowby only even after most a minute of cam break in rpm. Its always a pensive and semi-violent process to tolerate. I always start up like this unless out in public then often just step on it w/o any throttle so it sounds like just turn on at dead slow idle because it did. I'd semi wet sumped it pumping oil into crank till poured out sump plug then plugged and pumped a bit more and closed TS cover then let er rip until a show stopper spreading on floor

[video]https://www.youtube.com/watch?v=HmiZ0QI18ks[/video]
 
Hi hobot.
There you go, from 1:40 minutes on your video - the 'froth' generator, the stuff that floats on top of the oiltank oil.
 
gripper said:
Just to share my tale of woe, I fitted an anti wet sump valve to my 1970 fastback after rebuilding it 3000 miles ago. The bike has stood for 12 weeks over winter while the roads here are covered in salt. Started it last weekend, checked for a return of oil, tick, off we go. Ten miles later the bottom end locks up. Luckily I got the clutch in pretty quick but it was solid. The reason was that the AWSV should have the pipe connecting it to the timing chest primed. For 3000 miles of regular use that wasn't a problem, but over the 12 weeks of rest, that slug of oil had piddled away into the sump. The poor little pump was sucking on nothing. The oil that had initially been seen returning to the tank was the residual from the crank, feed pipe etc. I've yet to split the cases but the initial inspection shows a splattering of white metal flakes in the LH side of the crank cases and there seems to be some smearing of the edge of the conrod big end eye, on the alloy side at least. The bottom of the LH piston skirt has a witness mark where the stroke has increased to allow the crank to give it the good news. I'm hoping the smearing to the big end of the conrod is just superficial. So just in case you think the return of oil to your tank is an indicator that all is well, make sure that this return continues as a flow of frothy oil once the pump has dealt with the initial drain down. If that flow stops completely you must check the priming of the pipe below the valve. I'll let you all know what else I find :cry:
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Bad news, sorry to hear. I was lucky enough to have my valve "fail" on the bench whilst changing oil lines. Never again. Shipped my timing cover off to AMR for the proper fix. She's sat for 6 weeks now with a full tank of straight 50, and no appreciable drop in level at all.

Best of luck on the rebuild.
 
pete.v said:
And in addition to that, a good portion of this oil resides in the timing chest which seeks the same level as the crank cavity. So it's not ALL that oil sloshing about the crank and therefore isn't as bad as one would think. One could even realistically say no real issue at all, right Jim? But then again, there would 50% less to talk about around here.
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I would say that the OP with his destroyed engine probably considers this to be a topic worthy of discussion. Since these poppet type inline valves are still being sold and seem to have been installed in fairly great numbers, this might even be a more important topic that what kind of Carb someone thinks is best or where to get an original looking brakelight switch?

Both of which are OK topics for me, it's all good, read what interests you, ignore the rest, but why complain that a discussion which is of interest to others doesn't interest you?

Glen
 
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