Rb Engine Track Work Temp.

[jnrevo]

Hi Guys.

I was running my R32 on the weekend at wakefield on a pretty hot day.

I just wanna to know what engine temperature do you guys run on your RB?

I back off when my engine reach 100c. That is only about 6 hot laps of sunny condition on low boost and 6 hot laps on cloudy condition on hi boost.

When engine temp 100 degree C, the intake air is about 60 degree C. Is this normal?

[GTSBoy]

Engine temp and intake air temp are not necessarily connected. A hot engine will make for hotter air in the engine bay, so if you don't have a cold air intake then, yes the air temp will go up. And if the inlet air temp sensor is on the plenum, then it will generally get hotter with the engine as well.

But if you have a cold air intake and a decent intercooler, then air temp shouldn't track with engine temp too strongly.

R32s water thermostat is set at 82°C or something similar. Much less than 100°C anyway. The intention of the engineers was that it would run closer to 85°C than 100°C. It won't get hurt if you run it up at 100°C, but you are getting closer and closer to the point where stuff can start to go wrong, so it is wise to back off when it starts getting hot and give it a cool down.

What you should do, instead of relying on coolant temp to indicate how hot the important stuff in the engine is (which is the oil), is install an oil temperature gauge. That way you can back off when the oil temp is over 120°C, regardless of the coolant temp.

If you don't have a separate oil cooler, then you'll probably find that the oil is getting up to the limit as the coolant is getting up to ~100°C anyway. If you do have or put in a separate oil cooler, you'll probably find that you canrun the coolant at 100°C a lot longer without the oil getting too hot. But even better, because you're ripping extra heat out of the engine with an oil cooler, the coolant should actually stay cooler anyway.

[KiwiRS4T]

If you have the stock radiator consider taking it to a radiator shop to get the top tank taken off and the core cleaned out (and possibly replace top tank if yours is plastic). The stock water temp gauge is a bit all or nothing so if you are planning on regular track work then aftermarket gauges for oil and water temp and an oil pressure gauge would be a good investment. If you don't get an oil cooler then a good synthetic engine oil will give you a bit more margin of safety.

[Roy]

All good advice, but the real question is how modded is the engine? And how was it tuned. The real problem with engine getting hot is what is happening to combustion temps as the head starts to get real hot with 110deg c coolant running through it rather then 85 deg C. If the thing has been given a load of runs on the dyno with no bonnet closed and no dyno fan to get temps up to what the car sees on the track and is running a tune with ignition and fuel levels required for that temp then you dont have so much to worry about re a hole in a piston.

From there its a concern over a spun bottom end and its about oil quality and quantity. I did almpst two Bathursts with no oil cooler and drivign until then engine light came on. Thing was it was on a fresh sump of Mobil 10W60 and later Castrol Edge 10W60 at the start of every track day....knowing that over the 5 or so sessions through the day the temps and loads the oil was seeing was probably going to be breaking it down.

The other thing I will suggest when running largely a std setup is shift at or around 6,500rpm and you will find temps stay lower longer. Its only when I started using all the revs that the temps climb faster.

[R31Nismoid]

After 6 laps even most med/soft semi's would be past their use by? Same for brakes? 6 laps @ Winton on a warm day is pretty good regardless but depends what you are doing with the car i guess.

Would depend Troy said - how modified is the motor? Sounds like it might need a better radiator perhaps (and as others have said, what is the oil temp?)

I could get a solid 6-7mins out of my GTR with 360rwkw and a tri-pass radiator before water got to a point it was a problem (100degrees) on a 28 degree day. Obviously had a big oil cooler, ducting and that type of thing to boot. Oil would be right on 100 then as well usually.

It was either oil or water getting too hot to pull the pin - I wouldn't keep running one to spite the other so if water was 100, but oil only 100 - I'd come in anyway rather than keep going rather than go that extra min/two type of thing.

[LANDSCRIBBLE]

So is a 10W60 best for track duties? Would it be ok for the street?

[R31Nismoid]

Ran Edge 10/60 in daily, in all my built motors over the last 8 years or so. Perfectly fine.

[Ricky_Bobby]

I am yet to put my 33 on the track early next year, have an aftermarket radiator and thermo's. Will be interesting to see if I run into temp issues.

As for the RB oil surge issue, I guess we will see. Until reading the topic on SAU forums I never really heard of it being an issue on RB motors , never had the issue on my R32.

Might have to record my temps for each session and see if I can compare with others ?

[Tonks]

I am yet to put my 33 on the track early next year, have an aftermarket radiator and thermo's. Will be interesting to see if I run into temp issues. As for the RB oil surge issue, I guess we will see. Until reading the topic on SAU forums I never really heard of it being an issue on RB motors , never had the issue on my R32. Might have to record my temps for each session and see if I can compare with others ?

I'd stick with the stock clutch fan and shroud, just personal experience and unless you have a shroud for the thermos they wont be too effective.

I'm looking at getting a new fan off GKtech and fitting it with the sr clutch and seeing if that helps to lower temps. From their tests looks pretty damn good.

With the oil surge I just overfill my 32 a full 5L bottle goes well, never had an issue

[MrStabby]

So is a 10W60 best for track duties? Would it be ok for the street?

"the oil should be as thin as possible and just as thick as necessary"

If you're running an oil that thick, you tend to make less power and use more fuel, but you've got a large safety factor when the engine is under stress. If you're going to use it, be extra careful to make sure the oil is fully up to temp before driving hard. Of course if you loose oil pressure through surge all bets are off.

Personally i prefer to run a thinner oil and keep oil temps in check with a cooler, as IMO its a better overall solution for me. YMMV

[Roy]

Even if I had a built engine with all the coolers in the world...I would sacrifice 3hp and run the higher viscosity oil. Molded RBs make more hp than competition race engines and are just crappy production engines with loads of compromises. If I had a purpose built competition engine designed for the power, revs etc then sure the balance and tolerances of the engine would be suitable for lighter oils.

[LANDSCRIBBLE]

Ok, thanks guys. I might try a 10W60 come next oil change. What would you say the optimal oil temperature be until the beans can be given? I have been letting it get up to 60-70C before i step on it, on a warmer day it will sit around 78-85C driving normally. I've yet to properly track the thing yet, just wondering.

[Hanaldo]

I always get my oil up to full operating temperature (~80°) before it sees any boost or high revs at all.

[jnrevo]

Thanks for the info.

It is a built engine.

Rb26/30 with twin gt2871 running about 500ph at all four on E85.

The tune is pretty rich as far as I can tell.

The oil is edge 10w60. Oil cooler look pretty big.

However the oils temp on the track is higher the water temp.

On a hot 35deg c day. Oil get up too 120deg c on about 4-6 hot laps.

Where water only get up to a 100deg c where I back off.

Would a fan on the oil cooler help? My oil cooler sit on the right side in front of the front driver wheel. There is a hole of 30mmx140mm for air flow.

Would it help if I put the oil cooler at the front and buy a larger oil cooler?

[GTSBoy]

Ducting is the answer. Like this

http://www.skylinesaustralia.com/forums/index.php?app=core&module=attach&section=attach&attach_rel_module=post&attach_id=412754

Edited December 30, 2012 by GTSBoy

[jnrevo]

Look alright.

I've got a 10" fan for the oil cooler now. I'm going to try that first and see how it go. Also i have got the air con fan to run all the time now. Hopefully it might help.

Will keep u guys up date.

Is it true that thermo fan don't really work over 100kms?

[GTSBoy]

Thermo fans don't really work at all. At speed they actually make thnigs worse. If you had no fans at all, then at 100km/h there would be plenty of air pressure ahead of the radiator to push air through the fins. Would overheat when stationary of course, but that's not the point. Thermo fans have a lot of blockage area across the core. A big motor hub and big, usually poorly designed fan blades directing the air flow in strange (generally undesirable) directions. Plus all the framework and mounting tabs. All that subrtacts from the available area of the core. It's just fortunate that most radiators are plenty big enough to work with the area that is left over.

But the thing that a lot of people say is 100% true. You do not need more than the original viscous clutch fan and its shroud. At low (vehicle and/or engine) speed those things pump plenty of air. At high speed, because of the placement of the fan away from the core, they don't really block much flow area.

The air-con fan on Skylines is really just an emergency fan for when the car is overheating. That's why there's only one and it doesn't block the whole core.

[Risking]

Ac condenser fans have nothing to do with engine temperature.

They are there to draw air over the condenser to dispiate heat from the core so the air con can maintain temperature

A good cooling system that's operating properly won't need a fan when the vehicle is moving at all. Even stationary it should be able to maintain temperature for some time frame.

We don't run fans on any of the cars we build that are purely circuit driven. They are warmed up, parked on the grid then moving.

A supercar will maintain 68deg for its sighting lap, 78deg sitting on the grid maybe rise to 80deg when the lights are on then drop to 68-70 for the entire race.

Off the shelf PWR core, ducting done right and no fan. I've just done a 180sx with the same type of duct, PWR core and no fan.

Above post is correct about the fan reducing surface area flow through but the ducting is by far the most important part.

[GTSBoy]

Ac condenser fans have nothing to do with engine temperature.

Not on an R32 at least.

http://www.skylinesaustralia.com/forums/topic/153378-r32-have-your-overheat-fan-turn-on-with-your-ac/

[abr33]

Not on an R32 at least.

http://www.skylinesa...n-with-your-ac/

Im pretty sure 33 ones are the same. theres a switch on bottom of radiator that is all that turns my fan on. on gtst anyway. the ac doesnt to my knowledge control fan whatsoever. I have twin thermos pushing with override switch in cab for a/c when very hot weather. (gets over 46 regularly here in summer)