Building a race bike

martymoose said:
Suzuki bandit gsxr 1200 motor has a huge oil cooler on it, plummed from the bottom.

Agree Chris check valve a bad idea
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Based on the slab side motor, I started my slabside without the crankcase vacuum connected. After about two minutes of running, oil started pissing/bubbling out of the cam cover gasket.

I?ve always questioned if the two minutes of running was a dry run..... until the cooler filled and pumped the air through. Just saying
 
Rob I wouldn?t worry, just been playing around with the new cooler, no way it can fit with the hoses at the top. Just means you change all the oil when you drain it. If Laverda and Suzuki are not worried about air pockets, neither am I.
 
Maybe mounting them upsidedown would leave a great place for sludge to settle and collect as well eventually blocking flow through the cooler?
 
julian said:
Another idea in my head is to run the oil cooler on the blow-off side of the pressure regulator. 
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I'm not convinced that's a good idea. The blow-off only opens when the pressure exceeds your set value of 80psi, and only bleeds off enough oil to bring the pressure down. That means you'll only get some of the oil going through the cooler. If the pressure is below the blow-off set point, you won't get any flow through the cooler at all.

You mentioned the possibility of a separate pump for the cooler circuit so I've been thinking about that ?

I reckon the problem with the oil cooler ballooning in your race car was because you were using a positive displacement pump (eg. gear pump or your gerotor type). Any blockage or high resistance point downstream of the cooler would send the pressure sky-high. If you use a separate pump just to circulate oil through the cooler, you may be better off with a centrifugal pump, just like a normal coolant pump. They will only deliver up to a limited pressure. Actually, you could re-purpose a coolant pump for the job if you wanted to. A disadvantage of a centrifugal oil cooling pump is that it would need to be mounted below the sump oil level because it's not self priming (priming isn't an issue with a coolant pump in liquid cooling systems because the whole system is always flooded with coolant).

I was thinking about an electric pump to circulate low pressure oil from the sump to the cooler and back to the sump. The advantage being that you can control it with a thermostat. But I think I recall something about not running a battery on your bike (or am I thinking of someone else?). If that's the case you'll need a mechanically driven pump. Incidentally, you don't need any kind of filtration in the oil pick-up pipe if its just going through the cooler and back to the sump. A centrifugal pump won't be bothered by any particles suspended in the liquid. Just hang the open end of the pick-up pipe below the oil level in the sump.

I wouldn't be concerned about a separate pump for the cooler circuit sucking up all the oil and starving the lubrication pressure pump. The cooler circuit will return the same amount of oil to the sump as it sucks out, so won't affect the oil level as long as you allow for the volume of oil contained in the cooling system. It does mean that when the cooling pump stops, oil will drain back into the sump and the level will rise a bit.

Sorry if I'm rambling on about stuff you already know. Just trying to help.

 
Dellortoman said:
I'm not convinced that's a good idea. The blow-off only opens when the pressure exceeds your set value of 80psi, and only bleeds off enough oil to bring the pressure down. That means you'll only get some of the oil going through the cooler. If the pressure is below the blow-off set point, you won't get any flow through the cooler at all..
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Yes, the relief valve opens when the set pressure is exceeded. But watching a pressure gauge on a late plain bearing jap four will show that the max pressure is reached at quite low rpm. From this point upwards in the revs, the valve is open and oil would be available for a cooler circuit.
Julian has the opportunity making his own pump to size it so that his required max pressure is reached at low rpm - pushing quite a lot of oil out the relief valve.

Trying to site two pickups in what is a quite small volume sump can have consequences. Surge can starve one and submerge the other. I've been involved in baffling sumps for roadracing sidecars. It's not easy predicting where oil will go - and just how it gets back to the sump too. Better to have one large pickup well sited and if necessary run two pumps off that one pickup. That's how the air/oil cooled GSXR's do it.
 
Hi All,

I think Greg summed it up.

There are several ways of doing it and I don't know which is best.  only KISS.  Which is the overriding push for a single big pump and the cooler on the blow off.  I do agree that it could possible do nothing, but then it would be my fault for not fitting a big enough pump.  I am, it will be a good size so hopefully we will be ok there.

(The prob we had with the ballooning scavenge cooler was a wet sumped engine on a long down hill section completely off throttle behind a safety car,  when it pulled off and all hell was opened up, the neat oil went through the very big scavenge pump rotors and oil pressure must have been in the multi 100s)  never happened again but wow was it a lesson.

Air pockets,  not really worrying on a road bike but not good on a race bike,  the oil entering the cooler traps the air in the top, air pressure rises to try to equal oil pressure and the oil does not manage to displace the air fully.  We have had a hard time curing this in the past on certain applications and had a car constantly over heating its oil until we fitted a bleed on the top of the cooler and hey presto, problem solved.  Sometimes though it works perfectly but I would rather have the best designed system form the start here hense the fitting position.

Thanks for the comments though, they are all appreciated,  even rambling  :D :LOL:  you never know what sparks off a fantastic idea,

Jules
 
Ha - bleeding fluid systems whether water or oil can throw up some doozies.
Just in bikes, when someone tells me that a certain model has cooling problems, I always ask if there's a bleed screw on top of the water pump...
Surprising how many people think a water pump will work half full of air.

In your line Julian, there was an old guy here whose brain i used to pick - AMIMechE and SAE qualified - who'd been at Coopers in the early days.
He used to quote the first F1 Cooper as an example of bad cooling system design.
Apparently they had to hoist the nose up to about 45 degrees to bleed the coolant.
Made engine changes in the field a little difficult.
 
hi Julian , I would just like to say thank you for your work, enthusiasm, many skills and taking the time to "feed" us with detailed updates.
This thread/story has kept me enthralled, very interested and entertained through a very bleak 2020 here in the uk. Also reading everyone's input and comments.
Well done so far and good luck with all the work still to do.
That front inlet for the rad is just too "cool" , take it off at once !!!
Please have a good Christmas but don't have too long a break from this project because I for one like others, can't wait to hear it run. Please take some extra trouble if you can and make the start up take place in your local sound studio or concert hall. ha ha.
(other ideas for the best location for engine sound recordings requested please)
Happy Christmas to you and yours. Ian
PS. chop chop as they say.
 
ianpm77 said:
hi Julian , I would just like to say thank you for your work, enthusiasm, many skills and taking the time to "feed" us with detailed updates.
This thread/story has kept me enthralled, very interested and entertained through a very bleak 2020 here in the uk. Also reading everyone's input and comments.
Well done so far and good luck with all the work still to do.
That front inlet for the rad is just too "cool" , take it off at once !!!
Please have a good Christmas but don't have too long a break from this project because I for one like others, can't wait to hear it run. Please take some extra trouble if you can and make the start up take place in your local sound studio or concert hall. ha ha.
(other ideas for the best location for engine sound recordings requested please)
Happy Christmas to you and yours. Ian
PS. chop chop as they say.
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+1

I've made it my goal to see the beast in the flesh and to hear it as soon as it roars!
It's just a 2hrs drive to your shop or wherever the outing may take place ...
:)
 
Hi Jo,
Just pop over any time, happy to show you round,
That Goes for anyone else also,  we Can weer Marks and point from a distance  :LOL: :LOL:

Hope to get a full day or so on it over Christmas.
Tried yesterday but had a customer for 6 Horus  >:D
Nice Guy so not bad really but had plannen a full day of Laverda  ::)

J
 
Having a brain storm session with myself last night and trying to calculate the best balance factor for the crank when I had a bolt of lightning up my bum, 
I have a gear drive primary,  that means that I have a jockey wheel right next to my crank and it is turning the apposite way to the engine rotation.

SO.    Reading the above, What have I decided to do just to complicate my life further?

Jules
 
julian said:
Having a brain storm session with myself last night and trying to calculate the best balance factor for the crank when I had a bolt of lightning up my bum, 
I have a gear drive primary,  that means that I have a jockey wheel right next to my crank and it is turning the apposite way to the engine rotation.

SO.    Reading the above, What have I decided to do just to complicate my life further?

Jules
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Run a low pressure oil pump from it that is 'sucking' oil? From the cooler? I'm a bit flummoxed - wasn't sure what 'above' meant - the para 'above' or a few pages 'above'? Is is a riddle?
 
julian said:
Having a brain storm session with myself last night and trying to calculate the best balance factor for the crank when I had a bolt of lightning up my bum, 
I have a gear drive primary,  that means that I have a jockey wheel right next to my crank and it is turning the apposite way to the engine rotation.

SO.    Reading the above, What have I decided to do just to complicate my life further?

Jules
Click to expand...

As for balance factors???  :-\ :-\ :-\. The eternal question - parallel 360 deg twin revving to 12,000 ... I reckon you'll have to experiment on that one, Julian!
 
The question is related to Balance.   


Jules



PS.
Oil,
Cooler will run vie the blowoff circuit,  pump is Big!
Found out the same gears are used in 1500hp 6cyl Nissans.
 
Balance sharft,i rember reading about an engine that allowed external assess to the crank to add and remove weight easily.
 
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