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Bmsluite
Bmsluite New Reader
7/20/21 11:25 a.m.

In reply to Keith Tanner :

OK, I think I will run a bigger dual pass one then. I might be able to run a pretty big one since the dual pass has the fittings all on one side which mean I don't need to leave any room for the 90° fittings coming off it.  I will get you a picture of what I'm talking about when I get home to the garage.  

frenchyd
frenchyd UltimaDork
7/20/21 12:39 p.m.

In reply to Bmsluite :

Others have given you areas to look at. One other area is Oil Surge.  Track tires and the attending heavy braking will cause the oil ( which at 200 degrees is thinner than water) to flow to the front away from the oil pickup.  
 Even a few seconds without oil at the pickup  will cause metal to metal contact.  Not only does that heat up the oil further, it isn't good for the bearings. 
   Some people can use a surge reservoir ( like Accusump) as a temp fix. But realize that once the oil pickup gets oil it's going to send it to everyplace  including the reserve sump. Rather than the bearings first and then any bypassed oil will fill the reservoir. 
     Serious racers with an oil surge problem go to a dry sump.  It's not cheap. A 3 stage pump is probably going to cost you $800 plus tank, plus drive system, hoses etc. 

Toyman01 + Sized and
Toyman01 + Sized and GRM+ Memberand MegaDork
7/20/21 1:13 p.m.

In reply to Keith Tanner :

I run 1/2 or less quart overfilled on track. The bottom of the oil cooler is about the same level as the bottom of the oil pan so drain back should be minimal if any. 

In reply to Bmsluite:

As to oil temps, I don't have an oil temp gauge mounted. After my first TT, it was obviously overheating the oil just going by the color change. When Mobile one goes from clear and gold to a dark honey brown over 100 minutes of track time, you have a problem. My first thought was the engine was failing, but I did some reading and learned that controlling engine oil temps is a common problem with the VQ. 

Since I was less concerned about hitting a specific temp than I was keeping the temps down, I shot the parts cannon at it and went with one of the larger Derale coolers that would fit in the space, their 180-degree oil thermostat, and their fan control. Before the parts cannon, even with the Koyo radiator, the engine temps would climb above 230 over 3-4 laps requiring a cool-down lap or two. I can only imagine how bad the oil temps were. With the oil cooler, Derale's 180-degree fluid thermostat, and fan thermostat, engine temps are rock solid, on and off the track. I can run the full 20 minutes without having to watch the gauge. That was enough to tell me that the oil cooler is pulling an enormous amount of heat out of the engine. The oil also doesn't look abused. Good enough.

 

 

 

 

Bmsluite
Bmsluite New Reader
7/20/21 1:43 p.m.

In reply to frenchyd :

Will a baffled oil pan with a lowered pickup help any with this issue? They do make one for my application.  It is $300 and adds another quart of oil.  Plus it is finned for extra cooling although I doubt that does much if anything at all to cool the oil while actually driving.  Maybe while the car is sitting it does.

Bmsluite
Bmsluite New Reader
7/20/21 1:48 p.m.

In reply to Toyman01 + Sized and :

I did my first track day with this car without an oil cooler and overheated the water.  Upgraded the rad. Checked the oil.  The oil was super dark afterwards.  That's when I decided to slap on an oil cooler.  Felt I was playing with fire. 

I am an electrical technician by profession so I, of course, wired up a temp guage.  Invaluable.  Cost under $100 including gauge, sensor, sensor adapter, and a 3d printed holder specific to the car.

 

Really wish you had temp data to share but I do appreciate your input and feedback.  I will slap on a larger cooler that is also dual pass.  We can then see what the numbers say then.  Next track day isnt for another 5 weeks so I have time

frenchyd
frenchyd UltimaDork
7/20/21 9:55 p.m.

In reply to Bmsluite :

I cannot say for sure if you're having a oil surg problem.  Those temps tend to tell me you are.   You can check. Get a really fast reacting mechanical oil pressure guage.  With a short large diameter oil line. Picking up pressure towards the back of your engine on the main oil passage. 
 Then focus your Camera  on it for an entire session. The bigger diameter the gauge  the more definitive the answer. 
   Watch the session. Look for telltail flickering under heavy braking.  
      Just to give you an idea of how serious the problem is. In 1953 Jaguar discovered it to be an issue. They tried all the standard tricks, deeper sump, baffles,  swinging pickup, reserve pressure tanks, etc. by 1954 they settled on a dry sump and post race tear downs confirmed the solution worked.  After 1954 the factory never raced again without a dry sump.  
 Group 44  built a V12 and tried all the tricks.  Went to a dry sump etc etc etc. 

Me? I tried overfilling deeper sump (22 quarts), baffles.  You should see the size oil Cooler I had. After every single weekend I pulled the engine and replaced the bearings.  Finally I bought a Dry sump. After that never once replaced a set of bearings. In fact the engine still has those bearings, cool oil temps, and that's about 50 years now.   OK the last 5 years it's been in the Packard museum  on display.  And a few years it sat in my garage unused. 
    Winning those races. Or dicing with the Factory restored Aston Martin DBR2 driven by  Sir Sterling Moss, during the week long Vintage event. Never once was oil an issue. 

Bmsluite
Bmsluite New Reader
7/21/21 6:10 a.m.

In reply to frenchyd :

I can slap an oil pressure gauge in there somewhere and report back.

260 is definitely too high though correct? This is a modern engine.  The LS guys say under 300 is ok and some modern M3s seem to run fine with 250-280 Temps.  I'm assuming that's not going to lend itself to longevity though. Ideally I would like to hover around 230-240. 

I am going to have to do some fabrication to get a bigger oil cooler in there but I will report back once it's done

fatallightning
fatallightning Reader
7/21/21 7:02 a.m.

The 911s/Caymans we track regularly hit 260 oil. Porsche motorsports NA says even up to 280 is fine, although we find that a little distressing.

frenchyd
frenchyd UltimaDork
7/21/21 12:53 p.m.

In reply to Bmsluite :

Make it a mechanical one.  Electrics don't tend to react quickly enough to see the dip. 

L5wolvesf
L5wolvesf HalfDork
7/21/21 1:04 p.m.
ross2004
ross2004 Reader
7/21/21 1:32 p.m.
frenchyd said:

In reply to Bmsluite :

Make it a mechanical one.  Electrics don't tend to react quickly enough to see the dip. 

Some electronic gauges may be slower than a mechanical, but a good electric and data logger can be invaluable. Usually these oil pressure dips are happening at times when you're definitely not watching a gauge. This one for me lasted roughly 7/10ths of a second- I can see it in the log, and see the warning light flicker out of the corner of my eye.

Bmsluite
Bmsluite New Reader
7/21/21 7:07 p.m.

In reply to ross2004 :

I have data logging software and cable that hook my laptop to my car.  Next track day I will data log it and report back. 

jfryjfry
jfryjfry SuperDork
7/21/21 8:04 p.m.

Don't overthink it.   It's not hot because your bearings are running dry.  A bigger oil cooler with proper ducting will probably solve it. 

Barb_Dwyer
Barb_Dwyer New Reader
7/21/21 8:10 p.m.

In reply to Bmsluite :

Could you share images of how the coolant is blown and where it is mounted? There would probably be a good place to start.

Bmsluite
Bmsluite New Reader
7/22/21 7:32 a.m.

In reply to Barb_Dwyer :

Bmsluite
Bmsluite New Reader
7/22/21 7:34 a.m.

In reply to Barb_Dwyer :

It is mounted pre radiator on the bottom side of the undershroud.  It worked like how the screenshot picture if the BMW show.  I have a shroud I put over it when not on track.  If you take off the shroud when driving around it drops the oil Temps 10-15 degrees F.  So it is working quite well.

I just don't think it is large enough.  I have ordered a larger cooler that is a dual flow bar and plate style.  I am going to fab it up in the same manner. 

Bmsluite
Bmsluite New Reader
8/6/21 5:33 p.m.

UPDATE: I installed a larger oil cooler.  About to start the testing. This is a dual flow all aluminum one.  The fittings are larger and less restrictive and I have noticed a smaller pressure drop with this one.  Something I was concerned with since it is dual flow.  

I have a manometer now so I can test the pressure difference top and bottom of the cooler. This will give me a baseline of how much air is actually traveling through it.  

 

I have some ideas of how to both increase pressure on the top of the cooler and to lower the pressure on the bottom side.  Will provide data and more pics once testing begins.  Aerodynamics fascinates me. 

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
8/6/21 5:40 p.m.

Watching with interest!

Jcamper
Jcamper Reader
8/6/21 7:23 p.m.

Here is my take:

You had an overheating of the engine event. Yes, probably spiked oil temps during that, as evidenced by oil color. 
 

That was your only issue. Those oil temps you are seeing are fine. Don't add weight and a failure point known as an oil cooler at all. Don't forget that as the oil gets hotter it will be cooled more and more by the coolant filled block. Run quality full synthetic and go work on actual racing problems, not perceived. 
Jcamper

Bmsluite
Bmsluite New Reader
8/6/21 8:19 p.m.

I already have some data. Went out tonight and got some readings.  There's a huge pressure drop the faster I go.

  At 30 mph it's only about 0.20 Kpa.  This is the same drop I see from my ac blowing through the air filter in my house.  At 60 mph it's 0.90.  Tomorrow I'll get on the highway and see what the pressure differential is going 100 or more.  The system absolutely works.  

I also made a block off plate as well for this system so I'll get to see the overall temperature drop tomorrow on the highway.  More data to come soon. 

Bmsluite
Bmsluite New Reader
8/6/21 8:21 p.m.

In reply to Jcamper :

Cooler is already in there.  I'm. Not too worried about the weight. For me a lot of the fun of tracking is tinkering with the vehicle.  This is fun for me.  Seeing how my grassroots engineering actually affects my track car.  It's literally the name of this forum 

Toyman01 + Sized and
Toyman01 + Sized and GRM+ Memberand MegaDork
8/6/21 8:54 p.m.

In reply to Jcamper :

Except that the VQ engine is known for overheating the oil in high ambient temps. On the VQ37 in the 370z, Nissan puts the ECU into limp mode at oil temps above 280 to protect the engine. At a guess, the plastic parts like timing chain guides don't like high oil temps and high rpm. Nissan's answer to this problem on the Nismo cars was to add an oil cooler to control oil temps. 

Bmsluite
Bmsluite New Reader
8/6/21 9:19 p.m.

In reply to Toyman01 + Sized and :

Exactly, hence me making this cooler. I can easily get my car into limp mode on track on a hot day.  I have the VQ35HR engine which does the same 280F limp mode trick as the 370Z engine. 

Bmsluite
Bmsluite New Reader
8/7/21 1:08 p.m.

More data! 

At 80 mph with block off plate:  203F

At 80 without block off plate (full air flow) : 176F

Nearly a 30 degree drop.  I couldn't get it above 185 zipping around on the highway and doing pulls.  Boy does this thing dissipate heat.  Highly recommend these dual pass oil cooler.  Especially those who are limited with space. 

Going to make a louvered lower plate and some turning vanes next to see how those effect the temp drop. 

 

wspohn
wspohn SuperDork
8/8/21 12:07 p.m.

I use a Mazda cooler on my old British race car. Needs a thermostat or careful warm up on the street as they had plenty of capacity as the rotary engines they were used on sprayed oil on the inside of the rotor for part of their cooling (as I understand it - Keith can correct if it is wrong).  Let me race in 100 F. weather in California without any issues.  Don't know if that would be an option for your car.

 

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