Oil (and water) cooling revisited

[RussMcB]

My apologies for bringing back a topic that has been discussed often, but it's on my mind again. I'm sure others', too.

In my brief recent outing, my oil temps were too high (273 degrees), so I need to make improvements. I've identified areas where I can improve air flow to and from the coolers (and sealing them better), but I'm not sure that will be enough. I'm also considering changing from a single tube transmission type cooler to a "full flow" racing oil cooler.

I've gone back and reread a lot of posts. One thing that caught my attention was that many people think oil cooling is the big challenge with our cars, and that water cooling is usually not a problem.

Therefore, I'm once again considering using one VD radiator for water cooling, and the other VD radiator for oil cooling.

I know Sean O. tried a single water rad and it did not work for him, but I'm wondering if it is still a viable option. I think it would be a great way to cool the oil, but wonder if a single water rad will be enough.

As a reminder, my oil cooling is done after the dry sump's scavenge pump, so I don't need to worry about the VD radiator's pressure limits. The pressure should be pretty low since the oil would be routed from the radiator to the vented (no pressure) dry sump oil tank.

So, do you think a single, stock VD radiator will be enough for the water cooling system? The core is 20"x8"x1.5".

BTW, the intake for my VD sidepods is only 8" x 5" on each side. I may need to increase them.

Oh, another question: Does volume affect cooling effectiveness? In other words, if there is less water in the cooling system (after removing one rad and some pipe length), will the lessor volume hurt the cooling ability?

Thanks for your thoughts.

[Fred Michael]

One radiator that size is probably not enough in my opinion. Put in a proper oil cooler and mount it in front of the radiator if you can but right behind if you cannot.
Lesser volume will hurt cooling but probably not as much as less radiator surface area.

Fred

[Art Smith]

Russ-

keeping in mind the loose relationship normally associated with quality and price paid, here's my two cents:

1.) I wouldn't give a single 20" x 8" x 1 1/2" core any hope or a prayer to cool a 1000cc FB engine. it's on the order of 50% of what I'm using to cool my FF engines and you have an extra 50hp......................

2.) an 8" x 5" (40 square inches) opening for 20" x 8" x 1 1/2" (160 square inches) core sounds very SMALL. all other things equal, most of the "rules of thumb" I'm familiar with suggest starting in the 40-50% region paying particular attention to distributed pressure recovery across the entire core face (sealing the inlet duct is only part of what's required). there is NO cooling without air flow through the core and there is NO air flow without differential pressure between the front face and the rear face of the core. dynamic pressure recovery takes attention to detail; approaching zero back pressure takes work assuming minimum drag is of interest to you. you might be surprised at how much can be learned with a simple water manometer in the cockpit or a differential pressure transducer. read Carroll Smith's Tune to Win, it's a place to start where the basics are explained correctly without most of the math.

3.) less water and tubing/hose means a lighter car and that's normally assumed to be a good thing. total mass of water in the system doesn't appear anywhere in the basic heat exchanger performance equation so I wouldn't worry about that part of your concerns. the cooling system performance would only suffer to the extent heat was being rejected from the extra surface area provided by the tubing/hose (extremely inefficient in relative terms).

4.) the transmission cooler has to go; you need a much better heat exchanger to help minimize the risk associated with the installation.

it's my advise to leave both of the water radiators alone, fix the inlet ducts, and spend all of your time working to minimize the risk of installing an oil cooler assuming you're still using the stock pump. the stock pump wasn't sized to support propelling a 1000lbs vehicle around a race track and that's the basic problem in my view. given a stock pump, I'd recommend minimum length AN-10 or -12 HS-79 hoses with highflow fittings from XRP to minimize additional pressure drop in the system. give some serious thought to providing cooling air to the oil cooler with an electric fan that has it's own unique fresh air inlet. there's any number of high pressure areas a clever fellow could suck/ingest cold air from and feed a fan with a 4" flex hose (or two)............................. when sizing things, remember the fan provides cooling 100% of every lap and not just when the car is at speed!!! a real oil pump solves the pressure drop flow problem AND enables using lighter oil in the 200-225F range. the viscosity (oil's weight) needed to maintain pressure at temperature with a stock pump adversely impacts flow below 200F AND costs serious horsepower!!! how many of the recent 1000cc engine failures occured on engines with dry sump/aftermarket racing pumps??

Art
artesmith@earthlink.net

[ghickman]

Russ
In my opinion the inlet size on your side pods is marginal but should still work. We designed our car to run 2 radiators and the largest oil cooler we could squezze into the side pod behind one of the radiators. Proper ducting I feel is just as important. Try to duct the air so it has nowhere to go but thru the radiator and oil cooler. Spend additional time with ducting so that it straightens the flow before entering the coolers.

The oil cooling on these liter bike motors is super critical. The GSXR1000 factory manual calls for a normal oil temp of 140 degrees F. With the motor sharing the oil with the gearbox keeping the oil temp in check is key. If you're seeing oil temps as high as 270 that in my opinion will lead to a connecting rod failure.

Gary Hickman

[jerry freeman]

Are you running a thermostat or open loop? I've been wondering about that for a while but haven't asked the question. If so, what temperature?

Jerry

[RussMcB]

Thanks, all. Good thoughts.

Art, my main oil pump is the stock bike set-up, but my oil cooler is located in the dry sump scavenge section of the system. When I weighed the pros and cons of where to locate the oil cooler, I thought there would be more advantages than disadvantages to put the oil cooler in the scavenge side, right after the oil is hottest, and not between the main oil pump and the engine. One of the disadvantages to my set up is that theoil in the cooler may be mixed with some scavanged air.

Gary, I'd be worried about an oil cooler mounted behind a water radiator. That just seems like it wouldn't give the oil cooler a chance to be as effective as possible.

Jerry, my thermostat is stock, untouched. I did read in another thread that some people are leaving them in place, but drilling one or more small bypass holes. I need to look at the data in my lap top to see my max water temp from last weekend.

Thanks, guys. You are definitely helping shape my plan of attack.

[RobLav]

This thread is great since I'm in the middle of designing the water and oil heat exchanger locations and plumbing.

Thank You.

[ghickman]

Russ
You may have just solved your problem...you say your cooler is on the scavange side of the pump. Are you 100% sure this is the ideal part of the system for it? If your picking up some cavitation this could very well lead to higher than expected temps and lowering the efficiency of the cooler.

Take a look at any current F3 chassis. Where do you see the oil cooler? Almost always they're mounted directly behind a water radiator. There's always a flow straightener directly in front of the radiator to force the air into them.

Gary

[Brian]

Where are you measuring the temp? It sounds like you have an external scavenge pump. then cooler, then drysump tank, then stock bike pump, then filter/engine. Maybe the pumps are reversed, I don't know. If you are measuring in the bike sump, before the cooler and the drysump tank, your temps will read a lot higher than if you are measuring in the dry sump tank. I've always understood that it was considered proper to measure the oil temp in the dry sump tank so that you understood the temps of the oil that was feeding the bearings. The pressure pump will add a bit to the temp, but not that much.

I also concur with not placing the oil cooler behind the rad if you don't have a water temp issue. The temp differential will be much worse than if you had the oil cooler in front of the water rad.

Volume of oil and water in the system will definitely impact the hysteresis of the system, but not so much the steady state temps that will be achieved.

Brian

[S Lathrop]

My 2 bits.

I have had more bad cooling systems than good in the years I have been doing this.

1. As a rough rule, you will need 300 sq. in. of radiator surface area to cool any thing with side mounted radiators.

2. Cooling the scavenge oil is the most inefficient way to cool the oil because most of what goes through the cooler is air. A proper oil cooler/radiator does an excellent job of separating the air and the oil. Your tranny cooler is nearly useless in separating the air and oil.

3. I would use a good screen type oil filter on the scavenge oil. If you put the filter before the cooler then you will make a significant improvement in the cooler efficiency. Save your money and keep the tranny oil cooler.

4. You can add a small but efficient cooler on the pressure oil where the bike originally had an oil cooler. With the original cooler system (even the cooler itself) and your tranny cooler you might get the job done.

5. I have used oil/water inter coolers and over sized water systems. In fact I use hot engine water to cool the oil. This gives me oil temperatures about 30 to 40 degrees above the water temps. My Zetec FC runs way cooler oil than VDs with this system. I also have to run a thermostat in the water system to get the temps up.

I haven't applied any of the to the bikes yet but I plan to to do what I have found to work.

[RussMcB]

Where are you measuring the temp? It sounds like you have an external scavenge pump. then cooler, then drysump tank, then stock bike pump, then filter/engine. Maybe the pumps are reversed, I don't know. If you are measuring in the bike sump, before the cooler and the drysump tank, your temps will read a lot higher than if you are measuring in the dry sump tank. I've always understood that it was considered proper to measure the oil temp in the dry sump tank so that you understood the temps of the oil that was feeding the bearings. The pressure pump will add a bit to the temp, but not that much.

Brian, thanks for the thoughts. Here's a brief description of my current system:

1) The stock motorcycle oil pump gets it's feed from the remote oil tank.
2) From there, the oil goes to the stock oil filter, which is on a housing with water coolant passing through it (This is the way Kawasaki cooled the oil on the 2005 ZX-10R bikes).
3) The oil goes through the engine (bearings, etc.), then drops to the pan. This is the first place I measure oil temp - where it is hottest. This is where I saw 273 degrees.
4) A separate, aftermarket scavange pump sends the oil though my transmission-type oil cooler, which is located in front of one of my water radiators. It is approximately 8" x 18".
5) The oil goes from the cooler to the remote oil tank. This is where my second oil temp sender is. The max temp there was 242 degrees.

My 2 bits.

I have had more bad cooling systems than good in the years I have been doing this.

1. As a rough rule, you will need 300 sq. in. of radiator surface area to cool any thing with side mounted radiators.

2. Cooling the scavenge oil is the most inefficient way to cool the oil because most of what goes through the cooler is air. A proper oil cooler/radiator does an excellent job of separating the air and the oil. Your tranny cooler is nearly useless in separating the air and oil.

3. I would use a good screen type oil filter on the scavenge oil. If you put the filter before the cooler then you will make a significant improvement in the cooler efficiency. Save your money and keep the tranny oil cooler.

4. You can add a small but efficient cooler on the pressure oil where the bike originally had an oil cooler. With the original cooler system (even the cooler itself) and your tranny cooler you might get the job done.

5. I have used oil/water inter coolers and over sized water systems. In fact I use hot engine water to cool the oil. This gives me oil temperatures about 30 to 40 degrees above the water temps. My Zetec FC runs way cooler oil than VDs with this system. I also have to run a thermostat in the water system to get the temps up.

I haven't applied any of the to the bikes yet but I plan to to do what I have found to work.

I was hoping you'd chime in, Steve. :-).

A single VD water radiator would fall way short of 300 sq. in., so I guess I should discard the single VD water rad option.

My current transmission-type cooler seemed to drop the oil temp from 273 to 242. Does that indicate that it is doing a good job? Or should it be doing better?

Since so much is at stake, I'm leaning towards replacing the tranny type cooler with a better one.

[Fred Michael]

Just to be sure I am reading your post right. Your pump is pushing the oil through the cooler, not sucking it through, correct?
If you are sucking it through, it will never cool properly. It must be on a pressure side of the pump.

Fred

[formulasuper]

As a reference: My RT5/stock Suzuki Hayabusa 1300, except for drysump, uses the original 17" X 12" X 2" core sized SuperVee radiator with a 5" X 12" inlet, original SV 9" X 7" X 2" core sized Mocal full flow racing oil cooler using all AN-12 fittings & hoses, & same size 12" X 5" inlet. The stock Busa oil pump supplies 100% of the oil flow directly thru the filter & the engine with the oil cooler restrictor being removed & the oil cooler ports blocked off. The dual scavenger pumps force the oil thru the cooler & then into the dry sump tank. The electric water pump is sourced from a Supercharged Ford Lightening intercooler system & the Busa thermostat has been removed. Air bleed lines run from the top of the radiator & the top of the upper cylinder water hose outlet back to the header tank which the top of is slightly higher than the highest water level in the engine. No water or oil temp problems. Since the Busa & the 1 liter engines produce about the same HP I would think the cooling requirements would be about the same, possibly with the 1000cc engines requiring more cooling because of being under greater stress turning about 3k higher RPM. However that difference may be offset with my car weighing 150 lbs more.

[RussMcB]

Just to be sure I am reading your post right. Your pump is pushing the oil through the cooler, not sucking it through, correct?

Correct.

[formulasuper]

Russ, I believe to calculate cooling surface area you have to multiply the length X the width of each row then multiply by the number of rows.

[S Lathrop]

Radiator surface area is simply the lenght x width of the cooling core itself.

The core thickness is only necessary to assure that the volume of water will pass through with a minimum of restriction.

Increasing the core thickness gives diminishing returns compared to core surface area. Simply put, the first row of water tubes heats up the air so the second row cools less because of hot air. There may be less air drag with thinner cores as well.

Since the Kawasaki uses a oil water exchanger, what is your water temp?

Also you may not really have a problem because all that is really important is the oil temp after the Kawasaki intercooler. Do you have any idea what that is?

[RussMcB]

Since the Kawasaki uses a oil water exchanger, what is your water temp?

Max = 222 degrees F.

Also you may not really have a problem because all that is really important is the oil temp after the Kawasaki intercooler. Do you have any idea what that is?

You want me to add a third oil temp sensor?! :-).

I suppose I could move the oil temp sensor from the remote oil tank to the line from the remote oil filter/heat exhanger, but I'd need to convince myself that it's worth the effort. Would the benefit be that I would know the oil temp being introduced into the engine? I kinda thought I was getting that from the remote oil tank, but I see your point. That doesn't tell me what effect the Kawasaki heat exchanger is having. My hunch is not much, though, based on the size of the small water hose to and from the heat exchanger. The hose is probably 8-10mm ID.

[Art Smith]

Russ-

given a much better idea now of your lubrication sub-system schematic, more thoughts under the umbrella of the previous disclaimer:

1.) hope you're using AN-12 thin wall tube or hose with high flow fitting for the supply side to the stock pump......

2.) also hope your dry sump tank is above your stock pressure pump so there's always some positive head on the inlet side of the pump..... with the stock pressure pump, a tall dry sump tank would be better than a flat one!

3.) it's my sense the quality of job your current oil cooler is doing is irrelevant; the oil temperature in the sump is 242F. the stock pressure pump is adding something and clearly 250F oil isn't a good thing for your engine or its life expectancy!! what does the factory manual say for recommended oil temperature???

4.) another way to solve your challenge is with a oil to water heat exhanger with a 100micron or less in-line filter in front of it installed between your scavenge pump and the dry sump tank. if your current radiators won't keep water temperature in the neighborhood of 180F with the oil to water heat exchanger installed call the good folks at C&R to order a pair of double row Visteon core radiators. to Steve's points above and information from C&R, you should only expect an additional 25% of cooling from the second row (higher temperature air to second row and slightly less air flow from higher air flow pressure drop across the core). 25% should be plenty AND there's no bodywork changes required............... water and oil cooling sized properly for hot weather will present some challenges when the weather is mild or cold. you'll need some low drag smaller inlet "inserts", core blanking plate(s), or driver accessable valving for temperature management. on 1600cc FF engines (6750rpm max) that the pundits would agree has normal bearing clearances, I've measured >5hp between 180F and 200F oil temperatures using state of the art light weight synthetic racing oil (NO other changes). oil temperature management is a big deal horsepower wise with lightweight oil and is a BIGGER deal with heavier weight oils (measured). it's my guess that the higher crank speeds, stock bearing clearance, and lack of crankcase vacuum in stock 1000cc engines makes their horsepower output far more sensitive to oil temperature than either my 1600 Kents or 2-liter Pintos................... a quick look at a viscosity versus temperature plot for any modern synthetic racing oil will shead lots of light on the "whys"; viscosity AND bearing clearance are in the numerator of the journal bearing drag equation............

5.) if your after market scavenge pump supplier offers oil/air seperators you can delete the 100micron or less inline filter; it's a far better solution given it's offered AND you have the space for it and the hoses.

Art
artesmith@earthlink.net

[Brian]

pretty much you could eliminate the two sensors you now have and replace with just the one sensor in the location recommended by Steve. The only temp that's relevant is the temp of the oil being introduced directly to the bearings. Similarly, the only oil pressure that's relevant is the pressure of the oil being introduced directly to the bearings. A good place to read oil pressure and temperature is in the main oil gallery, if that's at all possible. Definitely after all coolers, filters, significant bends or turns in the oil path, main bearing drillings, etc. for the engine.

Anyway, it sounds like you are indeed running a tad hot, and need to look at things a bit. The oil in the sump being used for the clutch and gears is too hot, anyway. That's the rub with a dual purpose oil system. The oil has to be in good shape for both tasks. I'd be getting me the biggest real full flow oil cooler I could find and wack it in the side pod in the oil scavenge line to tank. I like the in-line screen filter idea too. I have several of those but never had a good reason to use one. Again, always push through a screen or a filter unless you just plain can't (like the pickup screens in the sump itself).

Brian

[RussMcB]

Thanks, Art (& Brian).

The oil line from the remote oil tank to the Kawasaki oil pump is -10. Length is about a foot and the oil tank is higher.

I'll assume Kawasaki's suggestion for oil temp is probably not 250 degrees. :-).

I'm thinking (hoping) that a lot of the mini-improvements suggested here, including a better oil cooler should help. High dollar custom C&R heat exchangers are out of the question. If my set-up requires major changes then I'll have to abandon ship. I'm on a budget that shouldn't even be playing in the F1000 arena.

PS. The two different oil temp senders were important to me because I wanted to see the temperature drop after the cooler. If I only had one sensor I wouldn't be able to tell how well the oil cooler was working.

[Brian]

Just had a funny idea. You could tell how well the oil cooler was working by taking a reading with one of those little infrared temp guns, on the inlet fitting to the cooler and on the inlet fitting to the dry sump tank. Be tough running along side at full speed to do, though!

Anyway, might give some useful data. At this point I'll confess that I never had a car that I didn't have to tape up at less than full summer heat. Just lucky I guess, although I've getting into a VD soon and probably will have more fun with that.

[High Desert Racing]

Guys,

I like this thread !!!!
I don't know if this would be any good or not?


http://www.speedwaymotors.com/p/1776...temNo=91015180

Found Googling the Web.

Ed
FB 34

[RussMcB]

Ed, that looks nice, but it's still a single tube design. Sounds like the better route is what some people call a "full flow" design (not sure if that's the right term) where the oil has many, low resistant paths thru the cooler.

I'm leaning towards something like the Earl's Temp-a-Cure "Narrow" design. It's the tall one in this picture.

http://www.earls.co.uk/earls/coolers/temp_a_cure.html

When laid on its side, it mimics the VD radiators (two fittings on one end). They are available in different lengths.

[sidney]

I think these are a little cheaper than the Earl's. We ordered a 44 row 115 size, and plan to put it in front of the rad.

http://www.batinc.net/coolers.htm

[RussMcB]

Thanks, Ian. Looks great, but I think It's a bit more than the Earl's. I called BAT and it's in the $400 neighborhood (vs. $300 for Earl's).

[High Desert Racing]

How long a time did Bat say for the Mocal cooler?
Did you order it with AN ends?

I think this is the page for the Earl's US catalog

http://www.holley.com/types/Temp-A-C...%20Coolers.asp

I see that the 50 or 60 row might fit with the Earls' or the Mocal in the VD.

[jjstecher]

I am not smart enough in this area to debate or even begin to offer suggestions here but I can show you what my car looks like with a 2007 GSXR at Road America during a race on a 83 degree day. Basically two laps in we had a full course yellow and then back to racing for the final 7 laps. This is on a Stohr F1000 with a single water and single oil cooler and a wet sump. Straight water with Water Wetter and 20-W50 mineral oil.

Oil temp (red line) was taken at the outlet of the motor before the cooler as I have always been told by engine builders you want to know the temp of the oil coming off the bearings (as its closest to the temp of the oil thats effecting them) not going into the motor. I wish I knew the drop the cooler was providing Russ so I could tell you but I dont.

Water temp (green line) peaks at 208 when behind someone in traffic but is routinely 185-195. I have the stock thermostat with no bypass.

Oil pressure (blue line) is consistent between 20-60psi depending on where in the RPM range I am and the curve stabilizes as the oil temps do.

One chart has the z-axis in degree's and the other is in psi since I couldn't get them on the same page.

[jjstecher]

Also I disagree with the person who posted that Suzuki recommends no more than 140 degrees for oil temp. Thats flat wrong. They say to measure pressure at x,xxx RPMs with the oil temp around 140 degree's but never in the manuals I have do they say 140 max. In fact calling up the local dealer here just now the head tech said 220-250 is normal in a race bike and is ok if you are changing it frequently and using the correct viscosity.

[Art Smith]

John-

interesting data; thanks for posting it!

what is the water radiator and oil radiator core sizes??

what do temperatures and oil pressure look like on a 95-100F day? in traffic??

Art
artesmith@earthlink.net

[RobLav]

I just received my Earl's cooler - 5 X 15.25 X 2. $171 at Summit Racing with free shipping.

EAR-81610ERL - It's a -10 - I'm stuck with -10 because that's the fittings on the dry sump oil tank. Looks like it is going behind the left radiator.

[sidney]

Thanks, Ian. Looks great, but I think It's a bit more than the Earl's. I called BAT and it's in the $400 neighborhood (vs. $300 for Earl's).

Thanks Russ. Just saved me $100. I owe you a beer. We'll be checking to see if we can get the 15-1/2" in front of the rad on the Tatuus. The bigger the better.

[sidney]

I just received my Earl's cooler - 5 X 15.25 X 2. $171 at Summit Racing with free shipping.

EAR-81610ERL - It's a -10 - I'm stuck with -10 because that's the fittings on the dry sump oil tank. Looks like it is going behind the left radiator.

You can always use a jump fitting to get the hose size up from the tank. If you can make the -12 hoses fit, you'll have less drop through the hoses.

[jjstecher]

John-

interesting data; thanks for posting it!

what is the water radiator and oil radiator core sizes??

what do temperatures and oil pressure look like on a 95-100F day? in traffic??

Art
artesmith@earthlink.net

Hey Art I will get you a measurement when I get a shot. The radiator is a custom size for Stohr but the oil cooler is a Setrab unit that is standard as I have bought it before from HRP.

[glenn cooper]

And that beer could only be redeemed at a Regional, eh Ian?
Bad Coop!

[High Desert Racing]

Russ,

I have thought about your original thoughts and John's comments on the Stohr and
I feel the best approach is one side water 22x8x2 and oil cooler on the other side 18.5 X 8.25 X 2 Earl's 26000 Series .

I will let know how it works on my VD.

Ed

[sidney]

And that beer could only be redeemed at a Regional, eh Ian?
Bad Coop!

Man you are cruel. This is a thread jack, but I'll be running my share of Nationals, but I gotta get the car going first. Let's see, National at La Junta or Regional at MPH? I'm so torn.

[Messenger Racing]

Do the national at La Junta and I will buy you the beer and help crew! I would love to see another Tatuus conversion so we can compare notes on our designs. We will be there with a friend in his CSR.

Jay Messenger
Muleshoe, Texas USA

[RussMcB]

Thanks Russ. Just saved me $100. I owe you a beer. We'll be checking to see if we can get the 15-1/2" in front of the rad on the Tatuus. The bigger the better.

Here's what I ordered from Summit Racing. Notice that it is back ordered, I guess it is not a common size.

EAR-26008ERL Engine Oil Cooler Expected Arrival 7/4/08 $310.69

http://store.summitracing.com/partde...0&autoview=sku

Yikes. I just went back to recheck the dimensions. The price just went up about $60. Sorry about that. My sale probably triggered that. Or maybe it was diesel prices. Or the price of exotic cooler materials. Or global warming. :-).

[carnut169]

Sounds like a tight fit Russ.... I'm sure you've got it figured out but my radiators are only 8" tall, and the length of your cooler does not give you much room for fittings.

[RussMcB]

Yes, I was going for max size. I think it will fit. The oil cooler can extend farther forward than the water rad if needed. I'm also contemplating altering my stock RF-95 sodepods. If I do that I'm not as limited with packaging.

I was looking at this picture of Phil Picard's car, and thinking that the air inlets could be wider:

http://www.apexspeed.com/forums/atta...2&d=1212240143