Is this excessive wet sumping?

Richard Tool said:

It has been mentioned in this thread about parallel twins having a significant design flaw that unavoidably creates excessive crankcase pressure. Not trying to be pedantic here but important to note that it is the 360 degree crank along with the parallel twin design that compounds the problem.

Click to expand...

I thought the fact that I was referring to a 360 degree crank was obvious.... I know some japanese parallel twins have 180 degree cranks and clearly if one piston is going up when the other is coming down there's no real change in crankcase pressure.......

10drum said:

The old-timer has been in business since 1962. He's been a franchise dealer of Triumph, BSA, Norton, Yamaha, Honda, and Ducati. He sells an anti-sump check valve for Nortons and BSAs. I asked him if there is anything I can do to the oil pump to help reduce wet sumping. He said no, and he didn't mention anything about a reed valve crankcase vent. However long he's been selling the check valve I would think if there were any issues he would not promote it, since most likely he would've been forced to repair the results of those issues.

That being said, I'm am still against installing any restriction in the suction line to the oil pump, plus I think they look tacky.

Click to expand...

Most Velocettes were fitted with a ball check valve at the bottom of the oil tank by the factory. I have never even heard a discussion of Velocettes check valve causing an engine failure. The spring is very weak and is basically there to control the ball. Because of this, the ball will not seat if the oil is not hot. Thus, most velos do not wet sump unless they are kicked over when cold without heating the oil. This unseats the check ball and causes the ball to be ineffective. I don't have any idea if the anti-sump valves offered for nortons have the same problem but this may explain the inconsistent effectiveness of them. While some of the check valves may be problematic, I know many norton owners that use them without problem and I am using one now.

Totally agree that the oil pump needs attention after high mileage. The side plates wear where they contact the gears. This can usually be corrected by lapping them until flat. The hardest part of this job is removing the four screws that hold the pump together. I rarely succeed in removing all four screws without destroying them and would replace the screws because the heads are always torn up. The price of dealing with a staked fastener. Personally, I like the type of gear displacement pump used by Norton, and Velocette and in many automotive engines. preferring it to a Triumph style pump.

ilikevelos said:

Most Velocettes were fitted with a ball check valve at the bottom of the oil tank by the factory. I have never even heard a discussion of Velocettes check valve causing an engine failure. The spring is very weak and is basically there to control the ball. Because of this, the ball will not seat if the oil is not hot. Thus, most velos do not wet sump unless they are kicked over when cold without heating the oil. This unseats the check ball and causes the ball to be ineffective. I don't have any idea if the anti-sump valves offered for nortons have the same problem but this may explain the inconsistent effectiveness of them. While some of the check valves may be problematic, I know many norton owners that use them without problem and I am using one now.

Totally agree that the oil pump needs attention after high mileage. The side plates wear where they contact the gears. This can usually be corrected by lapping them until flat. The hardest part of this job is removing the four screws that hold the pump together. I rarely succeed in removing all four screws without destroying them and would replace the screws because the heads are always torn up. The price of dealing with a staked fastener. Personally, I like the type of gear displacement pump used by Norton, and Velocette and in many automotive engines. preferring it to a Triumph style pump.

Click to expand...

Interesting, I've never been into the oil pump on my Norton. I have had an oil pump from a BSA A10 apart. It was similar to the gear type pumps I maintained in the pipeline industry, just smaller. I do not agree with my old friend that there is nothing you can do to a gear pump to "reduce" wet sumping, however I do not think there is anything that can be done to gear oil pump to "stop" wet sumping without adding some sort of check valve "internal" to the pump. That being said, I think is why he recommends adding an "external" check valve. Years of maintaining pipelines, I know not to restrict gravity fed suction to a pump.

10drum said:

Interesting, I've never been into the oil pump on my Norton. I have had an oil pump from a BSA A10 apart. It was similar to the gear type pumps I maintained in the pipeline industry, just smaller. I do not agree with my old friend that there is nothing you can do to a gear pump to "reduce" wet sumping, however I do not think there is anything that can be done to gear oil pump to "stop" wet sumping without adding some sort of check valve "internal" to the pump. That being said, I think is why he recommends adding an "external" check valve. Years of maintaining pipelines, I know not to restrict gravity fed suction to a pump.

Click to expand...

That's why a lot of people like the AMR modification. It's downstream of the pump, so it maintains the pump prime while also restricting the wet sumping when the bike isn't running. The claim is that as long as the pump stays primed then it blows open the AMR seal easily. Since there's no check valve between the tank and the pump, then the pump is always going to be primed by gravity.

When I worked on a race car pit crew, I asked a lot of questions and made a lot of suggestions, and was schooled daily on what has already been tried and discarded versus what modifications and ideas actually work. When my crew chief would bring me up to speed on something he would say, "Now you are seeing the whole picture". I think at this point regarding wet sumping, you are seeing the whole picture...

o0norton0o said:

That's why a lot of people like the AMR modification. It's downstream of the pump, so it maintains the pump prime while also restricting the wet sumping when the bike isn't running. The claim is that as long as the pump stays primed then it blows open the AMR seal easily. Since there's no check valve between the tank and the pump, then the pump is always going to be primed by gravity.

When I worked on a race car pit crew, I asked a lot of questions and made a lot of suggestions, and was schooled daily on what has already been tried and discarded versus what modifications and ideas actually work. When my crew chief would bring me up to speed on something he would say, "Now you are seeing the whole picture". I think at this point regarding wet sumping, you are seeing the whole picture...

Click to expand...

Thanks for the insight into the AMR modification. Might be something I have done over the winter.

Been an interesting thread.
Long time Norton owners are aware of it and deal with it one way or another.
The question was asked, what is acceptable? Being a long time owner, I don't know that answer.
I happen to have a freshly lapped pump. new seals etc. installed.
I purposely put oil in ahead of time to prime the pump and wet sump some.
It sat longer than it should due to a Jacked up knee.
After 2 and 1/2 weeks, with it at TDC, sumped about 34oz, or just over a litre.
I was surprised. So, how much in 24hrs, per the OP?
Missed the 24 hr. mark, however @ 36hrs, 7 oz.
As I said earlier, 16oz in 24hrs, to way to much.

Wet sumping can cause all kinds of issues to the Novice Norton owner.
From a false low oil reading on the stick with the oil in the sump, thus overfilling and causing all kinds of messy issues.
Hard kick over due to a full sump and probably blowing out the primary seal and more.

The debate will go on forever about this, I've accepted the fact it will sump and actually prefer it as it goes into self preservation mode,
filling the sump with oil, helping to lube the 'Flat Tappet' cam and keep the lower end lubed.

A lot of talk about reed valves. ANY reed valve is a good thing. From mild to wild will help your Norton.
I'm going to stir it up and suggest the very best are the Sump mounted reed valves.
From NYC, CNW or whoever.
First off, the closer to the sump, the more efficient. Virtually 0 air being sucked back in.
Second is a by product, a couple of primer kicks will clear the sump enough for a safe start.
The primer kicks push the oil past the reed valve, where it is held till start up, and then returns to the tank.
End of issue. No need for any restricitons in the supply line.
Too all the Naysayers, yes they are expensive, around $300.00 +, don't knock them unless you've experienced them.
Add up the costs for the inline reed valve, inline oil feed stuff, AMR mod, whatever, now it's not so bad.
I've done 2, one on my Combat, one on my 850.

I'm so happy with them I will suggest they are the single best, modification one can do.
Admittedly, my Experience is with the Combat forward, the earlier 750's have other issues mounting these.

With all that said, if someone were to drop a bone stock Combat or 850 on me, what would be my non stock mods, if it was in running condition?

1. Sump reed Breather.
2. Clutch Rod seal.
3. 13 mm master cylinder, or more.
4. Electronic ignition.

I would do the first two right off, depending on funds, probably all of them.

You cannot fit a sump mounted reed valve to a 72, it does not have the large sump plug.

I have one fitted to my 1972 crank case.
Don Pender sells them and CNW sell them as well. There only for the 72 style and Manley type cases.

ozcruiser said:

I have one fitted to my 1972 crank case.
Don Pender sells them and CNW sell them as well. There only for the 72 style and Manley type cases.

Click to expand...

These fit in the original breather location at the back of the crankcase, not the sump

Hi Michael

I am most intetested in your list of mods

Next to yours I list mine after 1 1/2 years of owning my 850

1. Sump reed Breather. ALTON ELECTRIC STARTER
2. Clutch Rod seal. ELECTRONIC IGNITION
3. 13 mm master cylinder, or more. MANUAL OIL LINE SHUTOFF TO PUMP WITH IGNITION CUTOFF
4. Electronic ignition. MY 13MM MASTER CYLINDER HAS BEEN ON ORDER FOR 4 MONTHS!

Dennis

I don't know why so many make a big deal about wet sumping, yes they all do it over time, some more than others, my 74 850 I have had since new has only wet sumped 3 x in those 48+ years I have owned and will only do it if I let it sit for 4 months, I have never touched the oil pump only priming it after bottom end rebuild, so when the oil has dropped (easy to see by looking in the oil tank) if its way down I just drain the sump so easy, I run a XS Yammy reed valved but I run the hose into a 1ltr catch bottle.
I have never had a clutch rod seal fitted as I never overfill my gearbox and I put grease on the clutch rod, I use a measure cup and put in the right amount of GB oil, have never had GB oil migrate to the primary, had ran an electronic ignition but had 2 fail (one Lucas and one Boyar) but the replacement Boyar was still working after 32 years when I put the Joe Hunt on, best one so far, I did a complete front brake upgrade and was money well spent, as for an electric starter no need for one as my Norton is a one kick to start always and my kicking leg is still good with the longer T160 folding kicker (I can't afford to spend that much money on a ES).
But back to the wet sumping, if I don't ride my Norton as much as I use too, retired and my other 1200 Thruxton has taken over most of my ride time, my Norton was an everyday rider till 2013 when I retired, but is still ridden regularly just to keep the oil flowing, so a bit extra oil in the sump helps to keep things lubed when it does sit, but ridden all the time they don't wet sump, well mind don't, as well my Norton has always been oil tight, has never left its mark, and if I get any seepages I fix straight away, but that is very rare, it's always been oil tight and I only installed the reed valve about 14 years ago, never really had a problem with oil leaks but having that pressure only going one way is a great idea.
So wet sumping is not a big problem for me only takes a few minutes to drain out if it's sat to long and if it has sat while draining is a good time to check other things like tyre pressure, chain and lube etc. etc. not a big deal at all, but so many worry about it, putting something in the oil line to restrict wet sumping, no thanks, I just keep doing what suites me and my Norton, it has survived this long without to many problems.
Maybe I have a freak of a Norton or just good practice in how I look after my maintenance of my bikes and a good pat on the tank after a great day out on it with a thank you bike.

Ashley

kommando said:

You cannot fit a sump mounted reed valve to a 72, it does not have the large sump plug.

Click to expand...

Yes, you are correct.
I was lumping the sump and rear breather into one category and referring to them as sump.
Both work well.