Oil valve solution to oil falling to crankcase

Sorry to hear you're having trouble kicking your Commando MichaelD. Maybe someone here in the forum could help?

I'm no spring chicken myself, so I put e-start at the top of my list when looking for a Norton of my own. It took 6 months to find a decent one close enough to see it in person and bring it home. I happened to get a small price break too, so that helped!

Interesting about the JS instruction. I am seeing that the Reed valves do a lot of good resolving breathing issues with the 828 Commando engine, helping it to run better and leak less oil, also that it is a valid approach to wet sumping.

In my case, I did not trust having a spring loaded in-line valve controlling my oil flow, and was looking for an alternate solution to the wet sumping problem which the PO was clearly trying to solve.

The fact that the valve was there gave me a pretty good indication that my new bike was prone to wet sumping, even though it is a Mk III. There is also a nipple looking drain plug / oil filter bolt on the bike, again indicating a history of wet sumping and subsequent oil draining and refilling.

I am looking forward to installing my Reed Valve asap.

Presently, I am being distracted by my Royal Enfield, which lost a hydraulic lifter keeper clip causing catastrophic oil pressure loss to the cams. Piston and barrel were deeply scored as well. This occurred just as I was buying my Commando.

All new parts are now installed, and I should be able to become increasingly intimate with Kali-Commando soon!

Ed

Edfury828 said:

Sorry to hear you're having trouble kicking your Commando MichaelD. Maybe someone here in the forum could help?


Ed

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Thanks Ed, I really need help with ParcelForce's customs people who have been admiring my new CNW starter for the last two weeks, but are showing no signs of delivering it to me. I've owned this bike for 48 years so am upgrading the bike rather than changing it

MichaelD said:

Thanks Ed, I really need help with ParcelForce's customs people who have been admiring my new CNW starter for the last two weeks, but are showing no signs of delivering it to me. I've owned this bike for 48 years so am upgrading the bike rather than changing it

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You’ll have NO trouble once you get that cNw kit fitted Michael !

Enjoy.

MichaelD said:

Last week, without anyone suggesting it, I tried kicking the bike over 10 times before trying to start it. The bike had sat for three weeks and would definitely have wet-sumped. After those 10 kicks, the bike just didn't want to start, after a break it usually takes maybe 5 kicks to get it moving, but it took over 20 minutes to get it moving this time. I took out a plug and it didn't look flooded, so I just carried on kicking until it got going. Not going to try that again, my knee can't take the strain.

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If your engine wet-sumps in less than 3 weeks I suggest that you have a knackered oil pump.

hybridracer said:

If your engine wet-sumps in less than 3 weeks I suggest that you have a knackered oil pump.

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Yes, I'm sure you're right. Its on the list, after I've fitted the CNW starter, and replaced the 40-year old isolastics for new vernier versions, and installed the HNW X-ring chain kit, and improved the back brake, and updated some of the electrics. There are just so many upgrades we can do to these bikes, it wasn't like this back in the 70s and 80s when I rode the bike regularly.

The oil pump would be further up the list if the oil pressure gauge indicated a problem, but despite the wet sumping, the oil pressure seems to be fine when the engine is running.

Fast Eddie said:

You’ll have NO trouble once you get that cNw kit fitted Michael !

Enjoy.

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I've been reading your build posts, and seeing how delighted you were with the CNW kit helped me make that particularly expensive decision.

Unfortunately I kept reading your posts and have now started buying parts for a new 920 engine, I think it will take me longer than it took you to complete your build ...

MichaelD said:

I've been reading your build posts, and seeing how delighted you were with the CNW kit helped me make that particularly expensive decision.

Unfortunately I kept reading your posts and have now started buying parts for a new 920 engine, I think it will take me longer than it took you to complete your build ...

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Sorry about that mate

You’ll be pleased to know I don’t do build threads anymore, so at least you won’t be tempted to follow me and build a 1007 !!

Fast Eddie said:

Sorry about that mate

You’ll be pleased to know I don’t do build threads anymore, so at least you won’t be tempted to follow me and build a 1007 !!

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I am pleased, I'm too easily influenced

This upgrading is all much more expensive than I expected, this year I've spent 20x the cost of the bike when I bought it in 1975. But having read lcrken's posts on his 1007 build, that is definitely a step too far for me, it seems to be much more bespoke engineering rather than assembly

Kip said:

Geez - sorry I ruffled feathers on this topic. I was trying to get an authoritative answer to the "standpipe" question where sump reed valves are concerned...and instead, I got remarks on the extremes. So, let me try again by putting the question differently: Has anyone measured the distance from the base (gasket surface) of these reed sump plugs to the top of the standpipe? It seems very likely that measurement would be optimal for proper function.

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The measurement is irrelevant because the dam in the 850 sets the clash (height) which by default gives clearance to the crankshaft on the 750 having no dam. That would be on the 1968 to 1971 engines that have the large oil scavenge plug pick up but the Comstock unit will only work with the 1971 frame as the bottom cross tube was moved so does not clash with it and all 850's)

Stock.


Some the 850 cases will stop the unit seating so the internal dam needs machining for clearance, I used a 12 mm ball nose cutter in the mill to cut a channel (After discussing it with Jim Comstock)







The riser tube is obviously there to minimise the unit robbing the scavenge and it should be noted the unit will only pick up static wet sump levels by default based on its location.
It is firstly a crankcase evacuation unit to lower case atmospheric pressure.
Is it the best location, perhaps not but it works and has saved plenty of folk from looking at the actual culprit of wet sumping so has become a band aid of sorts it seems with its main purpose forgotten to some.

You need to plug the 850 timing side wall to get the maximum benefit. (I put bleed holes in them)

I had forgotten until this post of drilling between the oil inlet and return galleries in the case to lower the timing side oil level to a level I guessimated would be correct for the Altas engine if it was tilted forward as in the Commando.

Better to just get rid of the dam. Its useless.

FWIW - I chose the NYC reed breather and was spooked when I first unwrapped it because the standpipe was movable! Reading the instructions made it clear that it was intentional - to ensure it would work with variations in dam heights. If the standpipe was rigid and not slightly flexible it could "foul" the dam and not screw into the case straight and seat properly.