What happens if you start an engine that wet sumped?
- Thread starter dennisgb
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Well, If the case is very full the pistons can lock, but normally this is rare, the oil soon gets pumped back to the tank...Bonus is the internals are well lubed!
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Yes as the oil returns to the tank things will stabilize. I'm seeing a different concern in that all the oil has entered the crankcase and emptying the oiltank to the point where only air will be offered to the motor (as the tank is empty now) until the oil is pumping back. That would be an air-lock or big bubble at critical startup time , no ?
DogT
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I used to start mine all the time when I didn't even know the words wet sumped and I would let it sit for months. Never had a problem. It did leak a lot because it blew a lot of oil out of the tank breather into the air filter and I probably had more engine oil in the primary from leaky bolts into the crank case, but other than that I never had a problem. Now I worry about it all the time, installed a feed line ball valve, studs and nuts in the primary to crankcase and it doesn't leak. I wouldn't worry about it too much, except if you let it sit over winter, you may want to drain the sump and put it back in the oil tank. Give you a chance to clean out that filter anyhow.
Dave
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Dave
69S
Since the oil is in the crankcase, the con-rod big ends will be splashing around in it. You can keep the ignition off and kick it over a few times to get some oil back to the tank.
My company hack 650-SS used to completely drain the oil tank just when parked overnight, so I used to kick it over with the magneto kill switch down before letting it fire up. The only time I had real problems wasn't with wet-sumping, but with a failure of the gasket on that fitting on the bottom of the crankcase that feeds th oil back to the tank. I'd ridden the bike from Wolverhampton to my home town of Leyland, just prior to leaving N-v to emigrate. On the way back to the office, I was cruising down the M6 motorway at about 90 mph in the fast lane when the engine started to seize up.. I managed to get into the slow lane and off into a rest area, just as it breathed its last.
It was a rather ignominious return for my last week at N-V with a seriously damaged bike in the moto-cross team van! I think the bike was still in the Competition Department garage area when N-V moved to Andover, along with that P-11 we'd been working on.
My company hack 650-SS used to completely drain the oil tank just when parked overnight, so I used to kick it over with the magneto kill switch down before letting it fire up. The only time I had real problems wasn't with wet-sumping, but with a failure of the gasket on that fitting on the bottom of the crankcase that feeds th oil back to the tank. I'd ridden the bike from Wolverhampton to my home town of Leyland, just prior to leaving N-v to emigrate. On the way back to the office, I was cruising down the M6 motorway at about 90 mph in the fast lane when the engine started to seize up.. I managed to get into the slow lane and off into a rest area, just as it breathed its last.
It was a rather ignominious return for my last week at N-V with a seriously damaged bike in the moto-cross team van! I think the bike was still in the Competition Department garage area when N-V moved to Andover, along with that P-11 we'd been working on.
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Really love your Norton tales Frank, pulled over to watch its last breath after a 90 mph routine commute, yeah man, with my head shaking on how well I'd take it.
First off a Commando can not oil lock d/t too much in crankcase, it might stifle a good kick through with 3 quarts in there but would push a good bit back to pump of up into head and TS volume. Read <Ludwig cam oil bath> with both his and Comstock's very short new cam life events due mainly to lack of lube on first lifter rubbing on first startings, so to me the real question is What extra good does wet sump start have... Cam splash lube on first kick over would be the list topper for me. Some have said it blew out their seals but with so so so many of us over so so many decades starting with wet sump and how rare crank seal failure is I will take my easy cheap to fix seal failure over you know what.
I would like me or some one to test how much wet sump actually might splash
on lobes, but putting more and more oil in on open top cases with just rods sticking up to rotate fast as could and watch the mess made or not. Definiely protect rod but hold em even with a dowel through em?
My special has shut off valve but only if set up over many days or more.
First off a Commando can not oil lock d/t too much in crankcase, it might stifle a good kick through with 3 quarts in there but would push a good bit back to pump of up into head and TS volume. Read <Ludwig cam oil bath> with both his and Comstock's very short new cam life events due mainly to lack of lube on first lifter rubbing on first startings, so to me the real question is What extra good does wet sump start have... Cam splash lube on first kick over would be the list topper for me. Some have said it blew out their seals but with so so so many of us over so so many decades starting with wet sump and how rare crank seal failure is I will take my easy cheap to fix seal failure over you know what.
I would like me or some one to test how much wet sump actually might splash
on lobes, but putting more and more oil in on open top cases with just rods sticking up to rotate fast as could and watch the mess made or not. Definiely protect rod but hold em even with a dowel through em?
My special has shut off valve but only if set up over many days or more.
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Just kick it through a few times, which we all ought to do anyway to prime the oil pump/passages and carbs anyway.
From looking at the breather return, with a reed valve on the sump breather of my '73 750, the crank case seems to be pumped clear in two or three easy kick throughs.
From looking at the breather return, with a reed valve on the sump breather of my '73 750, the crank case seems to be pumped clear in two or three easy kick throughs.
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Mine will drain the oil tank if it sits for more than a few weeks. As long as I can see oil up over the level of the pickup screen I don't worry about it too much. The Comstock breather I installed in the sump plug helps return oil to the tank much quicker than the oil pump alone also.
Nortoniggy
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acotrel said:
A two stroke pushes the contents of the crankcase directly into the combustion chamber. If your Norton can do the same you have a bigger problem than wet sumping.
:roll:
Ian
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Nortoniggy said:
A 2 stroke does it because fuel from the flooded crankcase got on top of the piston.
A Norton will do it because fuel from a leaky petcock can go directly into the cylinder through an open valve.
This normally only happens on Nortons with Amal carbs. They do not have an overflow tube in the bowl so if the inlet needle leaks and the petcock leaks the bowl overflows and goes right down the intake into the cylinder. Jim
xbacksideslider said:
If ALL the oil has wetsumped, 2 or 3 litres going back into the tank in 2 or 3 kicks sounds a bit optimistic ?
When my old dommie once wet-sumped, I tried using the kickstarter to get the oil back into the tank - just using the oilpump.
After about 1000 kicks, I was thinking this was going to take a while.
Thats only about a minute of running time, at idle.
And if its really wetsumped, it can take 3 or 4 minutes at least to get it all back there. ?
And if the oilpump has nothing but air to pump into the motor, an airlock there won't do anything any good...
Owned my Combat since 1978 and moved to Florida in 1984. For the first 7 years I would put it to sleep during the winters in Pennsylvania and start it up in the spring fully "sumped". Back then (before Access) me and my other Nortoneers didn't even know about the wet sumping concept. Never had any problems.
Flash forward to the present, I've had my bike running again since 2008, joined Access and realized OMG, I should be draining & filling if it sat for a few weeks. Well, even though this only takes 10-15 minutes, it was always a PITA and I was always late getting out of the house to meet up with my other Brit Bike comrades...so I stopped doing this in the last couple of years. Now I start up w/o draining the sump and pay close attention to keeping the RPMs below 2500 for a minute or so....then take off and keep the RPMs below 3500 for the first 10 minutes...or when I get to the Interstate. No problems what so ever.
Flash forward to the present, I've had my bike running again since 2008, joined Access and realized OMG, I should be draining & filling if it sat for a few weeks. Well, even though this only takes 10-15 minutes, it was always a PITA and I was always late getting out of the house to meet up with my other Brit Bike comrades...so I stopped doing this in the last couple of years. Now I start up w/o draining the sump and pay close attention to keeping the RPMs below 2500 for a minute or so....then take off and keep the RPMs below 3500 for the first 10 minutes...or when I get to the Interstate. No problems what so ever.
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ohmygosh cmessenk you should not of been allowed to own a Norton back then and not now either nor me too for that matter.
There are a handful of reports from various lists over the decades of ruined engines turned and turned to pump its own oil to head before 1st start up so likely not very good to do to any age engine.
A Norton oil tank does not hold enough oil to lock the works up below pistons, thank goodness. Gas inside jugs has nothing to do with wet sump. Correct my logic here please. My reasoning says to me that if cam break in requires 2000ish rpm for oil surfing then why not break in cam/lifters each and every start up, wet sumped or not, just as quick as it will respond to good throttle. Cold ring/bore blow by would just help push excess oil out via breather and pump. What sump oil is in there may be enough to get thrown on first kick to cam lobes. Oil pressure hits rod shells rather sooner than flow to head begins and then drains to matter, so crank-rod fling oil wets lobes in a few seconds rather than dozens later. I'm surprised how little ferric dust on magnet appears since I stopped treating Norton as a living thing and just went by mechanical and hydraulic principles. Shocked i saw better finish on lifter faces than Jim supplied and only burnished smooth marks w/o indention's on the valve stems on Trixie heartless wake up calls.
There are a handful of reports from various lists over the decades of ruined engines turned and turned to pump its own oil to head before 1st start up so likely not very good to do to any age engine.
A Norton oil tank does not hold enough oil to lock the works up below pistons, thank goodness. Gas inside jugs has nothing to do with wet sump. Correct my logic here please. My reasoning says to me that if cam break in requires 2000ish rpm for oil surfing then why not break in cam/lifters each and every start up, wet sumped or not, just as quick as it will respond to good throttle. Cold ring/bore blow by would just help push excess oil out via breather and pump. What sump oil is in there may be enough to get thrown on first kick to cam lobes. Oil pressure hits rod shells rather sooner than flow to head begins and then drains to matter, so crank-rod fling oil wets lobes in a few seconds rather than dozens later. I'm surprised how little ferric dust on magnet appears since I stopped treating Norton as a living thing and just went by mechanical and hydraulic principles. Shocked i saw better finish on lifter faces than Jim supplied and only burnished smooth marks w/o indention's on the valve stems on Trixie heartless wake up calls.
hobot said:
Methinks you jest, Hobot fellow Nortoneer. After the 7 years of starting whilst well sumped, my cam was perfect upon rebuild. I would put it out to the Forum to post one....just one....single instance where a main seal ruptured upon a wet sump start. I keep reading how "rare" this occurs, but still haven't read about one happening yet. FWIW, I sleep easy at night...if I screw my Combat up (probably not happening) she's going off to Windy for expert TLC.
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