Adding Auxiliary Oil Volume, or, How to Expose One’s Fluid Mechanics Ignorance

[Dirk_S]

NOTE THAT THIS OIL TOPIC IS WITH SIDECAR USE SPECIFICALLY IN MIND.

The consensus is that my bike burned through much of its oil on a multi-hour ride a few months back due to the added load of a sidecar and good friend who likes to eat a lot of cheeseburgers. Low oil light -> Pbbt spun bearing.

The stock sump on these air-cooled bikes don’t hold much, leading to the necessity to monitor levels a little more closely. Some folks have added the well-known sump extension/spacer that allows the oil reservoir to deepen.  I’m hesitant to do this, because I take the V7 II off-road, and the sump’s exposed enough as it is. I don’t want to be banging into any more rocks, ruts, and roots.

BUT…

What about adding auxiliary volume next to the stock sump? For the 2016 V7 II, Guzzi bumped the evap canister on top of the bell housing/crankcase. This leaves space down below the bell housing where it used to be. That’s enough space to put something like a fuel friend or some other aftermarket container for oil, and connect it to the rear drain plug. Pics attached:










Now, I know enough about fluid dynamics that the oil in the sump and container will want to level off as best it can because of gravity. If the container exists above the top fill line, the oil will drain into the sump and raise the fill line, but if the container remains at or below the fill line…?

What am I not considering?

[bigbikerrick]

Go deep sump,and put a skid plate on it.  That way you have a little more "cushion", and its protected as well.
Rick D.

[moto-uno]

  Plastic external oil tank with lines and fittings and hot engine parts " what could possibly go wrong ?"     Peter

[Kev m]

BUT…

What about adding auxiliary volume next to the stock sump? For the 2016 V7 II, Guzzi bumped the evap canister on top of the bell housing/crankcase. This leaves space down below the bell housing where it used to be. That’s enough space to put something like a fuel friend or some other aftermarket container for oil, and connect it to the rear drain plug. Pics attached:

Now, I know enough about fluid dynamics that the oil in the sump and container will want to level off as best it can because of gravity. If the container exists above the top fill line, the oil will drain into the sump and raise the fill line, but if the container remains at or below the fill line…?

What am I not considering?

* Crankcase pressure
* Momentum (acceleration, braking, maybe even leaning forces)

If the level was high enough in the auxiliary wouldn't it just overfill the crankcase just sitting there.

I have an extended sump on my V7I - it makes me feel warm and fuzzy. I have run it long and hard and it HAS dropped the level somewhat (burned a little and transferred a little to the airbox). But no where near enough to just run out and burn up.

I forget the details of your incident, but did you not get an oil pressure warning at some point?

I dunno --- I kinda think a certain amount of mechanical sympathy is needed with these. If you're going to run it long and hard with a heavy load, friggin check the oil at each fuel fill. If that's not sufficient, there's another problem (possibly including that it's the wrong tool for the job).

[n3303j]

My ratty ass Ural hauling a sidecar with 90K kilometers on the clock uses less than a pint in between oil changes (2,500 miles). A properly broken in motor should not use a lot.
Check your oil every fuel stop. You've got a sidecar to carry the extra. Once you've established a consumption rate, plan accordingly.

FWIW The old BMWs (60s) specified extra piston clearance when hauling a chair.

[bigbikerrick]

A smallblock is probably not the best choice as a sidecar tug. If its a heavy sidecar, with a 250 lb passenger, thats quite the load. It would require spinning the engine up pretty good, especially for highway speeds.  I would think oil level,and quality would be very important in this application.
Rick.

[Huzo]

Kev mentioned “leaning forces”.
They do not exist in a turn, because the force tipping you over is equal to the force standing you up…
If you were to hang a pendulum of sorts in front of your eyes and then tip your bike into a turn during a ride, you’d find that the pendulum would still point directly at the fuel cap, no matter how far you leaned over.

[Kev m]

Kev mentioned “leaning forces”.
They do not exist in a turn, because the force tipping you over is equal to the force standing you up…
If you were to hang a pendulum of sorts in front of your eyes and then tip your bike into a turn during a ride, you’d find that the pendulum would still point directly at the fuel cap, no matter how far you leaned over.

Though I do have a basic understanding of this - it's not true on the side stand, and I wonder how much it is true with regards to counter-leaning in slow riding or even sudden pitching the bike to one side or another. Granted, this all might be RCHs with regards to fluid transfer between two sumps.

[Huzo]

Though I do have a basic understanding of this - it's not true on the side stand, and I wonder how much it is true with regards to counter-leaning in slow riding or even sudden pitching the bike to one side or another. Granted, this all might be RCHs with regards to fluid transfer between two sumps.

Correct about the side stand argument.
Counter steering provides a brief lateral acceleration to displace the bike from vertical to leaned, but the steady state turn occurs half a second later and balance is restored.
Do the pendulum exercise Kev…
The sidecar boys are in a different world, they have the same forces as in a car.
If you sit in a car with a glass of water going around a sharp turn, it’ll spill out the side.
Sit on the back of a bike with the same glass and it’ll stay level with the rim of the glass.
If you do the glass of water experiment in the car, lean the glass into the corner like the bike and it’ll become clear, that way you can leave Isaac Newton out of it…

[Dirk_S]

Responses to the responses:

Yes, I get there are bigger, better, faster, smarter, stronger, lighter tools. There’s always something that’s available on the market that does something better than what we currently have at our disposal. But why does stock car racing exist? Why do we put auxiliary gas tanks and panniers on our motorcycles? People still attempt to cross Asia on rickshaws, and climb mountains they’re not biologically meant to climb, etc. A Subaru can’t do everything a Jeep can, but it can do some, and with a little modification, it can do some MORE. And so on.

The V7 is a mid-weight standard. Jack-of-all trades, master of none. It can be pushed and altered toward multiple directions. If someone can prove that a V7 cannot do “some more”, then I’ll give up, sell the machine and spend more money than I want to have the perfect tool for the moment. But so far, I think I’m proving to myself that it can do “some more”, but it just needs modification, and I need to continue learning and understanding the limits. I know—it’s not a Ural. It’s not a UTV or ATV or dirt bike. Doesn’t mean I can’t read, learn, try, learn, play, learn, fail, and learn some more, and ultimately tweak, adjust the bike or my awareness of the bike’s capabilities. All to make it do “a little more”.

I know that even Urals get taxed with high throttle for long periods of time. With slightly higher hp, I thought the V7 would do a little better. Maybe it can, but I still pushed it. Again, I understand that I need to continue adjusting my own expectations while also visiting potential workarounds or mods.

Yes, I’ll check the oil more often as I should have from the beginning. Getting smarter, I swear to gawd. Believe me.

I’m hesitant to deepen the sump even with a bash plate attached because the ground clearance goes away. Less clearance = more bangs & bumps = potentially more damage, regardless of sump protector. You know that famous analogy—give a man a suit of armor, and it’ll still hurt if he’s run over by an elephant.

Sorry to write so much there, but I don’t think it’s appreciated by some that there are others who like to tinker and tweak what they already have and push some boundaries.

So, anyway, about the original post 

If the level was high enough in the auxiliary wouldn't it just overfill the crankcase just sitting there.

This is my analogy: I have two gallon jugs, each half-filled with water. I connect them with hoses at the bottom of each jug.
A) if one jug sits higher than the other, the higher jug will dump its water into the lower one until their levels on the same elevation, right?
B) but if the jugs are beside each other, with Rich’s fill level beside the other’s, one’s not going to fill the other.

B is what I’m envisioning. In fact, maybe option C, where I make sure the container sits a little lower than the top fill line. Really, it’s the minutia within this particular idea that I’m extra curious about.

* Crankcase pressure

How does the pressure differ from having the extra volume to the side instead of below? I mean, I know fluids are put under more pressure the deeper they are, but I’m guessing that’s not where you’re going with that?

* Momentum (acceleration, braking, maybe even leaning forces)

I might know where you’re going with this, but I also might not.

Plastic external oil tank with lines and fittings and hot engine parts " what could possibly go wrong ?"     Peter

I was thinking IF a plastic container were used, the skid plate would absolutely be necessary. Can also consider a metal container. Let’s keep that theoretical alive.

Re: Kev and Huzo—Interesting thoughts on the sump level in turns and lean. Off-road/trail riding certainly comes with it some amount of climbs at low speed—with an extra liter of oil volume next to the existing, will this cause too much or too little oil to exist in the crankcase for a given amount of time?

[n3303j]

Kev mentioned “leaning forces”.
They do not exist in a turn, because the force tipping you over is equal to the force standing you up…
*SNIP*

Dirk is talking 3 wheel sidecar rig. That pulls horizontal Gs in every corner.

[Dr. Enzo Toma]

Sit on the back of a bike with the same glass and it’ll stay level with the rim of the glass.

The empirical data I have from regularly riding with drinks on a motorcycle show otherwise! This would only be true when the force matches the tilt angle, which isn't consistently the case when cornering with a motorcycle same as it isn't when banking a plane. You can drag pegs at parking lot speed without the force to match that tilt angle in a cup of water. The motorcycle doesn't fall over the same as water would spill out because of its steering geometry, counter balance of weight, and tire traction.

[Dirk_S]

Dirk is talking 3 wheel sidecar rig. That pulls horizontal Gs in every corner.

Crud, thanks—I should’ve mentioned this is with sidecar use specifically in mind.

[fotoguzzi]

Rwill this cause too much or too little oil to exist in the crankcase for a given amount of time?

both

[n3303j]

  Could always convert the engine to dry sump with a big reservoir.

[rtbickel]

IMO, and from a non-engineer perspective, you should use a metal tank with the bottom of it level with the bottom of the sump and the connector between the sump (drain plug fitting?) and tank should also be level with or only very slightly above the bottoms and large enough to allow the oil to flow freely between them.  Top of the tank should not be above the current full level of the sump and only add additional oil to the fill the additional capacity of the tank to avoid overfilling.  Hope I didn't forget anything.

[73 sport]

Instead of hanging oil tank and plumbing on the bike, which would make it look like crap and a mechanical afterbirth, install a flat oil tank on the floor of the chair  connected to the sump at the drain plug with a Tee or Cross hydraulic fitting using aircraft or hydraulic hose and fittings . Horst

[n3303j]

Instead of hanging oil tank and plumbing on the bike, which would make it look like crap and a mechanical afterbirth, install a flat oil tank on the floor of the chair  connected to the sump at the drain plug with a Tee or Cross hydraulic fitting using aircraft or hydraulic hose and fittings . Horst

That'll be real interesting in a left hand turn when all the oil heads to the chair.

[73 sport]

  Tank and sump connection are at the rear of the sump, the oil would not transfer to the tank in left turn or a right turn. The hose should be 1/2", at most 3/8". In a fast, sustained turn, there would be very little oil moved through a 1/2" hose. This set-up is a half-ass convenience to preclude checking the oil at proper intervals. In my opinion, this set-up is an unnecessary abortion. Just for oil transfer, a1/4" or 7/16" hose could be used.

[Kev m]

The sidecar boys are in a different world, they have the same forces as in a car.
If you sit in a car with a glass of water going around a sharp turn, it’ll spill out the side.
Sit on the back of a bike with the same glass and it’ll stay level with the rim of the glass.
If you do the glass of water experiment in the car, lean the glass into the corner like the bike and it’ll become clear, that way you can leave Isaac Newton out of it…

This is a side car rig....

[73 sport]

The oil tank is connected to the rear of the sump , in a left turn, there would be no oil transfer to the tank. In a right turn there would be little transfer to the sump. Since the concern is not volume, but slow transfer to sustain oil level in the sump, a 1/4" or 7/16" hose could be used, limiting oil transfer in a right turn for that short period of time. The concept of this discussion is to preclude checking oil level at proper intervals. It would be cheaper in time, materials, and money to carry one or two quarts of oil and check level occasionally, rather than a Rube Goldberg rig prone to leaks.

[n3303j]

Oil will migrate to the outside of either turn unless the inboard side tube is unported during the turn. If you are unporting a tube at the center rear of the oil pan you are probably unporting the oil pump pickup. Then you have a whole bunch of other problems.

But agreed; it makes the most sense just to monitor oil levels and replenish in a timely manner.

[73 sport]

  The rear oil drain on the sump has no connection to oil galleries or oil pump. I have no idea what the "tubes" you speak of are.

[n3303j]

  The rear oil drain on the sump has no connection to oil galleries or oil pump. I have no idea what the "tubes" you speak of are.

You mentioned tube between rear of sump connected to aux tank in sidecar. That's the tube (line) I'm referring to.

[73 sport]

  I think I'm too deep into this to walk away. In my opinion, it would have to be a long, wide, fast turn to the to the right to move a small amount of oil from the tank to sump through the small diameter hose. Unless he lifted the chair in extended right hand circles at high speed, the oil transfer would be minimal. I reiterate, the connecting hose is small diameter, not meant to move volume. If you want further discussion, find someone else.

[John A]

Could always convert the engine to dry sump with a big reservoir.

It almost is a dry sump already. It would make an interesting project if you had a spare block laying under the bench…

[Stretch]

"Yes, I’ll check the oil more often as I should have from the beginning. Getting smarter, I swear to gawd. Believe me."

I think you have to ask why you need more oil. Is it because you don't check it often enough?

If you deepen the sump, you'll have to lower the oil pickup to benefit from
the increased potential capacity if you want to let your oil run low.

Do you want increased cooling and possibly longer oil change intervals by increasing the amount
of oil?

A deep sump is one way to do that, but you could also add an oil cooler.

Don't want a deep sump because of potential ground clearance issues?
Either don't do that, or add a skid plate as others have suggested.

Personally, I'd check the oil more often - but then you've learnt that hard lesson
and will probably be doing that anyway, eh Dirk?     And if you're going to run
it hard - especially in hot weather or where airflow is restricted -  I'd consider an
oil cooler if you don't already have one. And consider changing it more often.

I'm not sure I'd fool with another sump or auxiliary tank. Remember too that if
your level is low in the sump, an auxiliary tank is not going to help - the level will be
low there, too!

Check yer oil - and your tire pressures while yer at it.....   

                                                                               -Stretch

[Dirk_S]

both

Really though? Say I fill the theoretical aux container up with oil and connect it to the drain plug.

If I ascend, the oil in the sump is going nowhere, because there’s already oil in the aux container.

If I descend, the oil from the aux container … flows into the sump…? Does it for sure? Wouldn’t there be a vacuum? How does air replace the oil in the aux container if the air in the sump doesn’t reach the small passage between the reservoirs?

[Stretch]

You'd vent the other tank to the atmosphere or the sump.

Sump is already vented to the atmosphere or these days, the intake tract.

                                                   -Stretch

                                                   

                                         

[Kev m]

If you deepen the sump, you'll have to lower the oil pickup to benefit from
the increased potential capacity if you want to let your oil run low.

It's been a decade since I installed the sump spacer on my smallblock to increase oil capacity, but IIRC it works because the pickup is already on the bottom end the spacer just expands the chamber and any oil passages in the sump.