Topic: Irradicating the oil tank.

[Retro Rocket]

I have been looking at loads of pictures of the 750/4, K and F models and i love doing things differently, therefore my question is......Does anyone think it possible to eliminate the oil tank completely. I have been toying with the idea of using a bigger sump and also using an early GSXR1100 oil cooler { fairly large} to increase the oil capacity of the bike to what it would be in standard form with the oil tank.
In this thread,reply number 195 Rob shows  a picture of a bigger capacity sump.  

http://forums.sohc4.net/index.php?topic=70333.175

What do you guys think.....?  I have more idea's but i would like to see what you guy's think first.


Mick

[lordmember1969]

Very interested  in what will come out off this..

[CBJoe]

Wasn't the CB750A a wet sump?  Maybe parts are interchangeable with regards to the pan.

[mick7504]

Mick
I think if you were to go down this path, I would be making absoutely certain that the resevoir of clean filterd oil is maintained if not exceeded.
Especially so in a modified engine where this is "more" than imperative.
Aside the modification, what are the benefits?
The thing that is a number 1 priority is the oil pump which is the heart of the engine, and a good supply of clean filtered oil is essential.
It certainly would be doable but I would be seriously weighing up he pros and cons.
Just my thoughts mate.
Mick

[lordmember1969]

Wasn't the CB750A a wet sump?  Maybe parts are interchangeable with regards to the pan.

They are not the same:( not the same parts number on the oil pan gasket.

[Retro Rocket]

Mick
I think if you were to go down this path, I would be making absoutely certain that the resevoir of clean filterd oil is maintained if not exceeded.
Especially so in a modified engine where this is "more" than imperative.
Aside the modification, what are the benefits?
The thing that is a number 1 priority is the oil pump which is the heart of the engine, and a good supply of clean filtered oil is essential.
It certainly would be doable but I would be seriously weighing up he pros and cons.
Just my thoughts mate.
Mick

Thanks Mick. I was just looking at a couple of pics and i have a second bike that i was just thinking about what to do with it.
There was no particular reason for the mod other than to clean up the area behind the covers and because i can, i mean ...why else....   I was also thinking of running a bigger filter to increase volume as well. Was just wondering if it would be possible, and if not then why.....Wouldn't it be easier maybe, for the oil pump because it wouldn't have to push the oil up into the oil tank, or would the larger oil cooler cancel that effect out......Just thinking out loud.....humour me guys..

Mick

[Frankencake]

I have been looking at loads of pictures of the 750/4, K and F models and i love doing things differently, therefore my question is......Does anyone think it possible to eliminate the oil tank completely. I have been toying with the idea of using a bigger sump and also using an early GSXR1100 oil cooler { fairly large} to increase the oil capacity of the bike to what it would be in standard form with the oil tank.
In this thread,reply number 195 Rob shows  a picture of a bigger capacity sump.  

http://forums.sohc4.net/index.php?topic=70333.175

What do you guys think.....?  I have more idea's but i would like to see what you guy's think first.


Mick

Now I'm no engineer but it seems feasible to get rid of that pesky oil can so long as you have a large oilcooler.  Let slook at the purpose of the oil tank.
1. reservoir
2. cooler
3. Sediment catch?  I don't think so by design but it certainly does catch a bit.
4. Mucking up that rear triangle.

I say go for it.  Bypass the tank and feed the out to the in or run lines up to a big oil cooler up front.
Next you have to figure out how to fill the bike with oil without turning it upside down.  You also have to figure out how to determine a safe oil level.  Oil pressure does not tell you it's empty until it's empty.

That's my two cents from a complete idiot.

[Retro Rocket]

Hi Cupcake....Well there is a bigger sump but they are pretty rare {70's drag accessory}, i also thought that some sort of dipstick tucked in between the clutch housing and the points area,there's a small gap there above the clutch cable, If not then I'm sure i can work something out there. What about a sight glass?

Mick

[lrutt]

Gonna be hard to fab oil lines, cooler, and upgrade a filter that will hold 4 qrts of oil. Fabing a bigger or extened oil pan as well. If the goal is to clean up the area under the seat then:

- Build an oil tank that will mount under the swingarm behind the engine. Plenty of room there and well protected.
- Build an extended gas tank cafe style then section of a front area to act as your oil tank. Keep the heat from your legs but still provide plenty of capacity, just like the old bikes did.
- Build up and box in a section of the frame triangle running across the top of the motor to act as an oil tank.

Lots of options it seems like.

I'd go with the tank under the swing arm. Run a rear hugger like the new bikes, then mount the oil cooler (large one) under the seat on those 2 frame rails that hold the rear inner fender. I've seen that done on some bikes as well. Looks very trick. That is a high vacuum area and plenty of air will be pulled through.

Ditch the battery and go kicker only, elecrics either under the tank or in the tail section, pods, and you have a totally clean under seat area. you could even go remote oil filter under there and ditch the one upfront if you wanted to design some trick headers.

[Retro Rocket]

Gonna be hard to fab oil lines, cooler, and upgrade a filter that will hold 4 qrts of oil. Fabing a bigger or extened oil pan as well. If the goal is to clean up the area under the seat then:

- Build an oil tank that will mount under the swingarm behind the engine. Plenty of room there and well protected.
- Build an extended gas tank cafe style then section of a front area to act as your oil tank. Keep the heat from your legs but still provide plenty of capacity, just like the old bikes did.
- Build up and box in a section of the frame triangle running across the top of the motor to act as an oil tank.

Lots of options it seems like.

I'd go with the tank under the swing arm. Run a rear hugger like the new bikes, then mount the oil cooler (large one) under the seat on those 2 frame rails that hold the rear inner fender. I've seen that done on some bikes as well. Looks very trick. That is a high vacuum area and plenty of air will be pulled through.

Ditch the battery and go kicker only, electrics either under the tank or in the tail section, pods, and you have a totally clean under seat area. you could even go remote oil filter under there and ditch the one upfront if you wanted to design some trick headers.

Thanks for the input. Those have all been done and i was going for something different, i am keeping the look of the bike sort of modified standard. Doesn't the auto 750 have a wet sump?  4 quarts is only 3.785 litres. I would have to find out internal oil volume but i think with a bigger sump and a big oil cooler it would be very close.

Mick

[lordmember1969]

 
[/quote]

Thanks for the input. Those have all been done and i was going for something different, i am keeping the look of the bike sort of modified standard. Doesn't the auto 750 have a wet sump?  4 quarts is only 3.785 litres. I would have to find out internal oil volume but i think with a bigger sump and a big oil cooler it would be very close.

Mick
[/quote]

You could also ad an extra oilfilter on the return line, like many British bikes did. Could give you up to 1 litres extra:) Depending on size spin on filter you choose..

[754]

Mick the aftermarket sump is more of Deeper and Cooler than bigger..at most 10% increase.

 I can run thru some ideas that may help but it will be later tonite..

 750A sump is not even close..to CB series.

[KingCustomCycles.com]

The stock oil tank is "not pressure in pressure out" as you are proposing.  It is suction feed to the pressure pump and then scavenge pressure back to the tank with the tank equalizing that and vented to atmosphere.  I am not sure of the significance of that but it a system that is a closed loop with varying pressure within could cause problems. I know it is a concern in other hydraulic systems such as aircraft and dynamometer water installations.

[Duke McDukiedook]

Get rid of it. Oil is overrated.

[IHWillys]

...
- Build an extended gas tank cafe style then section of a front area to act as your oil tank. Keep the heat from your legs but still provide plenty of capacity, just like the old bikes did.
- Build up and box in a section of the frame triangle running across the top of the motor to act as an oil tank.
...

Is seems to me that these two are straightforward options as they are simply moving the tank to an alternate, less obvious location.  As I know very little about the 750, the other proposed location of below the swingarm makes we wonder about providing head pressure to the pump. 

Ken

[Kong]

If I were looking for a place to hide an oil tank on a 750 I'd be looking at all that grand space being used up by the gas tank and wondering to myself just how much gas I really needed to carry - as well as how much space there already is under the tank.  I can't see where it would be at all difficult to fabricate a tank of a couple of quart, let's say two or three, capacity that could be either integrated with the existing tank or hidden under it.  My next choice would be to use the frame, but not the swing arm but recalling the problems Triumph had when they tried it on the original 750-Tripple production bikes (blown engines caused by contaminated oil) I'd be hesitant there too

[ev0lve]

Not answering your question but I was thinking of making or, more likely, having made a tank that would replace the mud guard in between the two tubes at the rear of the machine. Flat on one side curved to the same radius as the tire on the back.

This was where that idea came from



Plenty of room and capacity and pretty unobtrusive if nestled in there nicely.

Although, if an oil cooler and larger capacity filter would do it that's far easier, cheaper, and cleaner.

[Frankencake]

So, let's see.  We've got an engine.  On one end is a tank with a feed to the oil pump and the "used"oil return.  On the other end we have the potential for an oil cooler.  What is the pressure of the oil as it enters the filter housing/oil cooler?  Scavenge pressure?  Bearing pressure?  Never minding all of that, you could use just an oil cooler as a reservoir.  Plumb it to the inlet/outlet at the clutch housing.  Modify your oil cooler to have positive ventilation (routed to the crankcase at the valve cover) and a dipstick. (use a small radiator with a cap)  Using a veined cooler would have much more cooling capacity than the stock tank, thus eliminating that facet.  You would just have to work on adequate size of the cooler.  In my opinion, the 750 design holds too much oil to begin with and the tank is too big. Use steel lines to do the plumbing so you can hide them behind the frame rails.  3/8" should do.  In this case, you will use the oil filter housing as just an oil filter housing and not plumb an oil cooler into it.  There's no need to add a cooler to that mix up there with the main reservoir being a cooler already.
I think you are on to something Mick. 

[lrutt]

BTW. you also have to be concerned with getting your oil to an optimum operating temp. Too big of cooler will mean too cool of oil. Not burning off the condensation and being to viscous for proper lubrication. You can keep oil too cool as well you know. Have to find that happy medium of betwen 200 - 250 or so.

[Frankencake]

BTW. you also have to be concerned with getting your oil to an optimum operating temp. Too big of cooler will mean too cool of oil. Not burning off the condensation and being to viscous for proper lubrication. You can keep oil too cool as well you know. Have to find that happy medium of betwen 200 - 250 or so.

That would be the riders responsibility now, Wouldn't it?

[Retro Rocket]

BTW. you also have to be concerned with getting your oil to an optimum operating temp. Too big of cooler will mean too cool of oil. Not burning off the condensation and being to viscous for proper lubrication. You can keep oil too cool as well you know. Have to find that happy medium of betwen 200 - 250 or so.

Yes, the oil temp had occurred to me. Just throwing this out there at the moment to see what the general consensus was. I was a bit tired late last night when i posted this but there are other reasons i would like to try and work this out. I am looking for somewhere to hide a fuel pump and maybe some ballast for hid lights and resistors for led winkers. Not trying to be a pioneer just trying to see if this can be done.....I am not interested in discussing other methods like in the fuel tank or frame, i want to find out the pro's and cons of this tankless system....Can someone tell me if the auto's have the oil tank.?

Mick

[Kong]

Dry sump autos certainly have an oil tank.  You can't just run it in a loop through a filter and think that is enough for the engine.  Remember, all you've got to return the oil to the pickup is gravity and so there has to be some reserve in the system just so transitions from low RPM (and oil flow rate) to high RPM don't leave the engine starved for oil simply because its all puddled up in the top of the head and hasn't had time to drip down to the bottom just yet..  I believe if you look into your oil tank and rapidly take the RPM from idle to something fast the level should dip - well, what happens if there is no tank to dip from?  My guess is the pump runs dry, and the bearings run dry, and the cylinder walls run dry; everything else, I believe, is splash lubricated so it wouldn't matter so much.  But at any the point is some reserve is necessary just to makeup for the variation of the speed of return through the engine... wouldn't ya think?   

[Frankencake]

Dry sump autos certainly have an oil tank.  You can't just run it in a loop through a filter and think that is enough for the engine.  Remember, all you've got to return the oil to the pickup is gravity and so there has to be some reserve in the system just so transitions from low RPM (and oil flow rate) to high RPM don't leave the engine starved for oil simply because its all puddled up in the top of the head and hasn't had time to drip down to the bottom just yet..  I believe if you look into your oil tank and rapidly take the RPM from idle to something fast the level should dip - well, what happens if there is no tank to dip from?  My guess is the pump runs dry, and the bearings run dry, and the cylinder walls run dry; everything else, I believe, is splash lubricated so it wouldn't matter so much.  But at any the point is some reserve is necessary just to makeup for the variation of the speed of return through the engine... wouldn't ya think?   

  Yes.  That's why I suggest that the "oil cooler/reservoir" be large enough to hold the amount of oil needed to prevent a dry bearing condition or any other nasty situation.  Also keeping the cooler vented to the crankcase/atmosphere would allow drainage into the oil pickup at the side of the engine.  It would be high enough to establish head pressure and avoid catastrophe as well.

[Cuts Crooked]

I believe if you look into your oil tank and rapidly take the RPM from idle to something fast the level should dip - well, what happens if there is no tank to dip from?  My guess is the pump runs dry, and the bearings run dry, and the cylinder walls run dry;

Absolutely correctomundo!!!!!!!!!! I've done just that and watched the level rise and fall in the tank with the RPMs. Try it yerself, it'll surprize ya how much oil levels change in there with demand.  Honda engineers knew what they were doing when they devised the oiling system for the 750. Why screw with something that works, in exchange for something that might/could end up siezing yer mill?

If you really want a wet sump, find a 750A....totally different critter. Otherwise I'd listen to those who recommend hiding the tank or replacing it with an oversized filter.

[KingCustomCycles.com]

CB750A models do not have oil tanks.  The DOHC doesn't either, and may be an option.