Oil Coolerless with Use of High Grade Synthetic Oil.

[Poodles]

Really just an educated guess that it doesn't really work well. I don't think anyone is willing to devote that much time and effort to investigate the stock oil cooler system. The principle that it works off isn't ideal by any means and appears to be a half assed way of designing the system. Considering the size of the cooler its only a guess that the amount of heat it gives off is not very significant and likely not adequate for high hp applications. I admit that having the cooler is likely better than nothing, but is it necessary? I guess we have to decide that based on an educated guess (or trial and error) seeing as there's no hard data.

Oil cooler is designed like the intercooler, which was one of the best ones every factory installed up unit recently. The main faults I see with the factory cooler is lowering pressures and if the oil temps get really high it will cause a drop in viscosity and pressure with the potential to open later or not at all.

 

[Devin LeBlanc]

I didn't say having an oil cooler is a bad Idea... I said that in my opinion it is not 100% essential to have.. I have 70PSI cold start up oil pressure at idle, 20 PSI completely warmed up, And 50 PSI fully warmed up at 3500 RPM's, 70PSI @5000+.. That is on the original oil pump and bearings that have 141,500 miles.. That is warmed up after beating on it and boosting it hard on the track..

 

[3p141592654]

The stock system is very reliable, it has no thermostat to fail, and increases oil cooling proportional to rpm. Its weakness is it dumps oil through the cooler during warmup.

 

[grimreaper]

Also consider the stock oil cooler acts as a bypass. It only cools a portion of the oil. On a bone stock motor it obviously passed toyo's R&D. I wouldn't bother with a full flow until pushing into the 300whp range, but thats just an opinion.

 

[CyFi6]

The stock system is very reliable, it has no thermostat to fail, and increases oil cooling proportional to rpm. Its weakness is it dumps oil through the cooler during warmup.

Though it's reliable, is it effective? It probably increases oil warm up time marginally but after everything is fully warmed up does it do its job well of keeping the oil cool and up to what point? Those are things I would be interested in knowing, though i don't expect anyone to put the effort into testing all that.

Also consider the stock oil cooler acts as a bypass. It only cools a portion of the oil. On a bone stock motor it obviously passed toyo's R&D. I wouldn't bother with a full flow until pushing into the 300whp range, but thats just an opinion.

How do we know that it wasn't more of a marketing item than it was an actual performance item?

 

[grimreaper]

look at it from a different angle...
If toyota did not need to spend the money for the oil cooler setup, they wouldnt. The cost savings on 100,000 cars is significant at a production level.
Lets pretend.
Oil cooler setup cost toyota $50 as a whole system. (bulk manufactoring etc..)
Thats $5,000,000.00 just in oil coolers.
Do you think they would spend that just for marketing? I dont, but maybe they would..

 

[suprarx7nut]

look at it from a different angle...
If toyota did not need to spend the money for the oil cooler setup, they wouldnt. The cost savings on 100,000 cars is significant at a production level.
Lets pretend.
Oil cooler setup cost toyota $50 as a whole system. (bulk manufactoring etc..)
Thats $5,000,000.00 just in oil coolers.
Do you think they would spend that just for marketing? I dont, but maybe they would..

I really dont think they would. That's a lot of money thrown to waste. It's not as if the cooler was a major selling point or anything. It serves a purpose.

I would love to see some good recorded data with a very good oil temp gauge and record similar runs with and without the cooler. Put both versions through a common test and then test the oil afterwards. I bet the cooler would prove beneficial.

 

[jetjock]

i don't expect anyone to put the effort into testing all that.

You expected wrong. The technique was no different than establishing the efficiency of any heat exchanger: the delta T across it was measured. The stock cooler works and as reaper pointed out Toyota wouldn't have put it on the car unless it was needed and did something.

I say again: stop thinking about only the oil and start thinking about what it comes into contact with. It does little good if an oil can handle high temperature if that temperature shortens the service life of other parts.

 

[CyFi6]

I say again: stop thinking about only the oil and start thinking about what it comes into contact with. It does little good if an oil can handle high temperature if that temperature shortens the service life of other parts.

Makes more sense now, didnt take as much consideration for the temperature of the actual parts.

You expected wrong. The technique was no different than establishing the efficiency of any heat exchanger: the delta T across it was measured. The stock cooler works and as reaper pointed out Toyota wouldn't have put it on the car unless it was needed and did something.

But just because there is a high delta t across the cooler itself doesn't mean a significant amount of heat is being removed from the engine as a whole, correct? That would tell you that the heat exchanger transfers heat at a decent rate, but if you don't have a high volume of oil flow through the cooler then what good is it?
For instance, a stock radiator might have 30 degree delta t with 1 gal/min flowing through it, but slow the flow to .25 gal/min and you will have a much higher delta t.
I'm probably just not understanding how the test was done, maybe you can clear it up for me?

 

[hvyman]

Oil cooler is a lot smaller than the radiator and it does not always have hot fluid flowing through it so it has time to cool down with the wind.

A condenser that is clogged with debris in the fins can effect airflow on the radiator. The oil cooler is right up front No blockage except debris on itself.

 

[Zumtizzle]

Okay Guys, Once again Pi/3p, and Gary/Alex have forced me to think for myself instead of handing me answers. I'm surprised no one else beat me and did some thinking.

On what basis do we know that "the stock cooler really doesn't work well".

Does someone care to post up oil temps with and without the oil cooler under various scenarios?

http://en.wikipedia.org/wiki/Scientific_method

I wouldn't say "it doesn't work well"! Afterall it is a heat exchanger. But "crappy" compared to a full flow setup with Mocal T-Stat and Stacked Plate Exchanger.

My mentality behind it is synthetic ester/polyalphaolefin oil, can take the beating of temperatures, and not lose viscosity.

Actually it has been loosely by a member of supraforums years ago named Dean Marcum who bypassed his factory oil cooler using hose and said his "oil temperatures skyrocketed". But, again I felt i shouldn't care about "skyrocketing" temperatures due to use of synthetic oil. But, I felt something is missing in my mentality. Which led me to the next post quoted.

Crack me up. As if the oil itself is the only issue that should be considered.

When you said this I started thinking about what the oil sees. Bearings, cylinder walls, crank journals, oil pump, cam lobes, cam journals, and oil squarters. Detonation came to mind.

I also looked at composition of TriMetal bearings as Clevites are used on this motor.

http://www.substech.com/dokuwiki/doku.php?id=engine_bearing_materials&DokuWiki=4bd56a9a1db17...

The stock system is very reliable, it has no thermostat to fail, and increases oil cooling proportional to rpm. Its weakness is it dumps oil through the cooler during warmup.

I'm not really worried about "dumping oil" through the cooler at warmup. If it means some help in detonation protection.

You expected wrong. The technique was no different than establishing the efficiency of any heat exchanger: the delta T across it was measured. The stock cooler works and as reaper pointed out Toyota wouldn't have put it on the car unless it was needed and did something.

I say again: stop thinking about only the oil and start thinking about what it comes into contact with. It does little good if an oil can handle high temperature if that temperature shortens the service life of other parts.

And indeed it does something. Having a bypass heat exchanger is still a heat exchanger none the less. I need to stop thinking in oil pressure, and just oil, and thats what I did.

While the bearings can take the heat. A VERY Vital Part in creating dynamic compression creates lot of heat on the oil system; The Turbocharger! Think about it guys! the heat from building boost being carried by the lubricant then transfered to the cylinder walls and the underside of the pistons! DETONATION!

I now feel stupid for being so not thinking of this earlier.

Now I know why 1JZ/2JZ Guy's have to rebuild turbos, and engines so often. :biglaugh:

 

[jetjock]

Don't forget elastomer parts Zum. The oil may be able to handle it but how helpful is that if it hardens all the seals, gaskets, and hoses? It's no different from power steering and automatic transmissions except for the number of parts. Sure, some elastomers are rated at temps the oil will never seen but they'll still take a hit on service life.

Remember, all this stuff cooks from the inside-out and the damage develops unseen. Leaks, increased oil consumption, smoking on start up, hoses that begin to shed bits of themselves into the fluid stream. Ugh. And some people wonder why their valve cover, main, and stem seals die an early death or why shafts end up being grooved...

That said too cool is also bad. If the oil doesn't reach at least 185 F it won't get rid of the water put into it by the combustion process. When that happens it ends up making acid. It's the same reason short trips are considered severe service when deciding oil change intervals. It's also why an engine should never be idled in storage.

It's among the worst things someone can do to it. Change the oil *before* the car goes into storage and don't start it again unless it can be driven at least 30 minutes. But I digress...

 

[Poodles]

Also keep in mind compared to water/coolant, the oil is in direct contact with all friction surfaces. Cooling effects of cooling the oil are substantial, as any air cooled VW or porsche owner will tell you. That's less work for the rest of your water cooling system to do.

EDIT: Also great points there JJ, forgot about the seals...

 

[CyFi6]

Everyone is still forgetting the real question though...How much heat does the cooler really remove? Does the stock cooler actually make the difference between damaging oil temperatures in the engine and safe temperatures? JJ already established that there is a temperature drop from one side of the cooler to the other, but that doesn't tell us whether or not the engine would be safe with/without it and under what conditions.

 

[Nick M]

Crack me up. As if the oil itself is the only issue that should be considered. Especially cracks me up about Devin, who drives a modded car in Vegas, without a cooler, refuses to use anything but off branded dino oil, and actually thinks everything is fine because he's driven 2000 miles "without a problem"...

Now how do you expect me to make a comment about a thread full of fail when yo do this?

 

[jetjock]

You just have to try a bit harder Nick. I've read enough to know you can do it

I don't want to be too hard on Devin because he actually comes across as pretty sharp. He just seems misinformed about oil is all. Wouldn't be the first otherwise sharp guy to have that problem.

I forgot to mention something else about all this that relates to the oil itself. When viscosity is lowered from an increase in temperature the oil can become aerated. If that happens the air in it can generate a large amount of heat from compression, further elevating oil temperature and lowering viscosity that leads to more aeration. Not a good thing.

 

[Devin LeBlanc]

JJ, After doing tons of reading, Ill admit I didn't know as much as what I know now at the time I posted.. I was misinformed.. I will definitely be getting an oil temp gauge to monitor Oil temps..

Since I'm on this topic, What could I do about having 70-80PSI oil pressure cold start up and then after warming it up it only being at 14-18PSI

Thanks

 

[jetjock]

Well, if those numbers are at cold fast idle and normal hot idle there's not much wrong with them. They indicate you're using a heavier oil than needed though. If those numbers aren't at idle you should first verify them with a trusted gage.

Then, assuming the engine checks out, select an oil that gives you around 10-15 psi per 1000 rpm. Use either a Group III or Group IV. My preference these days is for IIIs. An HDEO like Rotella or Delvac will also be ok even though they're heavier. Imo Group V lubricants are expensive overkill for a street engine. I'd still use them in tranny and diff though.

Truth is when you finally learn about oil in depth you'll come to realize much about it is splitting hairs. The irony is if you're not careful you'll end up obsessing over it just as much as those who haven't a clue. They're operating on hearsay and myth while you'll be fussing over mostly meaningless details. Try not to let that happen

 

[Nick M]

Then, assuming the engine checks out, select an oil that gives you around 10-15 psi per 1000 rpm. Use either a Group III or Group IV. My preference these days is for IIIs. An HDEO like Rotella or Delvac will also be ok even though they're heavier.

I use hydrocracked. Knowing just how good they are now, I can't justify that price for a 4 or 5.