External Oil Cooler

[2-0turbo]

what about using the stock air to oil, oil cooler?? there is no thermostat on that, I got mine off of a 90 laser and there was defiantly no thermostat on it.

That is because the thermostat is built-into the oil filter housing assembly. The brass colored hex plug pointing down at about a 45 degree angle (viewed from the front of the engine) is the thermostat assembly. Check your DSM manual; it gives guidance on how to check to make sure it is working. If the oil doesn't reach 180, it simply doesn't allow flow to the cooler. However, my experience is that some oil is flowing into the cooler all the time.

 

[TommyDSM]

How about the Hex Plug in front of it? Does oil always flow through that? Because I have my Turbo Feed going to that... It doesn't just feed only when opens i hope...

 

[sweet97]

Front feeds all the time. The cooler gets the oil from the side of the housing. Mark

 

[snox135]

If you feel you Really really need a tstat go for it, I personally do not run one have over 8000 km on my car with the swap with ZERO problems running an external oil cooler, IMO there is no need for one and talking to a few engine builders around see no problem with the setup I run either.

So to those reading this take any info you get with a grain of salt and do some rearch spend extra $$$ on parts you don't need if you wish.

I agree you should always take everything you read on the internet with a grain of salt and do the research for your self.

For those who wish to read on what Mocal says about oil thermostats look here

When oil temperature exceeds 180°F the thermostatic valve closes, allowing 95% flow through the oil cooler. At temperatures below 180°F the valve is open, with 90% of the oil bypassing the cooler. The remaining 10% of the oil flows through the cooler, maintaining constant system pressure, preventing air pockets and eliminating cold oil shock. That is how most oil thermostat housings work.

One more thing to those installing a oil cooler. I know it's common sense but make sure you hook up the supply and return lines correctly to the cooler. I say this because I have seen people hook them up backwards before.

 

[terefic181]

2-0turbo

That is because the thermostat is built-into the oil filter housing assembly. The brass colored hex plug pointing down at about a 45 degree angle (viewed from the front of the engine) is the thermostat assembly...

^TRUE

If you check the URL in my post on the previous page you'll see the factory schematic etc.


Another interesting tid-bit:

"Some experts estimate that the wear on the rings of an internal combustion engine is as high as 0.001" per 1000 miles of operation when the oil temperature is below 170 degrees F. If the maximum allowable wear is 0.006", how long can you run your engine when the oil temperature is below 170 degrees before you wear it out?"

From:

http://www.gi.alaska.edu/ScienceForum/ASF7/747.html


So it's possible, you may not be aware of any problems not running an oil cooler bypass valve, although the problem may still be present.

According to this report, if utilizing an air cooled oil cooler, your oil temp ends up being less than the estimated temperature of 170 deg., for extended periods, then you will be having premature wear issues.



Tom

 

[TommyDSM]

One more thing to those installing a oil cooler. I know it's common sense but make sure you hook up the supply and return lines correctly to the cooler. I say this because I have seen people hook them up backwards before.

On the Cooler, how do you know if its the inlet and outlet? Arent' they the same? If not then which port should go where on the Cooler?

 

[snox135]

It depends on how you mount your oil cooler and what style of cooler you have. If you mount it so the outlets are on the side (both ports on the same side of the cooler). Your supply line will connect to the bottom port and the return line to the top port. If you have a cooler with ports on oppsite ends makes sure you mount the cooler with both ports on top. Then it won't matter which is which. Although some people will mount it at a slight angle (2 to 5 degrees) and hook up the supply to the slightly lower port. Or you can mount it with one port on the bottom and the other on the top. Then you would hook up the supply to the bottom and the return to the top port.

Basically you need to hook it up so when oil is fed to the cooler it fills up the cooler with oil before returning any oil to the engine. If it is hooked up the other way your cooler will not do an efficient job of cooling the oil. Because the oil cooler will not be full of oil and you will only be using a small portion of the coolers surface area. Plus it can introduce air bubbles into the oil lines which will cause foaming.

 

[TommyDSM]

I see, Now I understand... Good thing I have both ports on top then

 

[Eagle 5]

http://www.dsmtuners.com/forums/showthread.php?t=145227&page=2&pp=25&highlight=oil+cooler+hose+size

go there for another discussion awhile back about oil cooling and what size lines to use and why etc.

hence, why I use -10AN lines for my external oil cooler.

 

[TommyDSM]

Going with an external setup, could it lower my oil pressure? Im using B&M 8x11x1.5 Race Cooler, with -6AN Lines. Not sure if I damaged my Oil Pressure Gauge Sender when I over tighten it... but is there anyway to check? I think I'm going to get a new oil pressure switch and factory oil pressure sender...

 

[2-0turbo]

2-0turbo
^TRUE

Another interesting tid-bit:

"Some experts estimate that the wear on the rings of an internal combustion engine is as high as 0.001" per 1000 miles of operation when the oil temperature is below 170 degrees F. If the maximum allowable wear is 0.006", how long can you run your engine when the oil temperature is below 170 degrees before you wear it out?"

From:

http://www.gi.alaska.edu/ScienceForum/ASF7/747.html

Now that is interesting. I have the factory thermostat on my filter housingt. I think the combination of an external cooler and Moroso aluminum oil pan (over 7 qts oil capacity) can keep my oil temps as low as 140F in during cruise--I've seen 135 on a cool summer night. This is with a digital temp probe in the pan. I hit 220F on the track (roadcourse) this weekend running 10W30 Castrol GTX. You know, I used to have a Nissan truck I put some of those temp-a-labels on the oil filter and I never saw oil temps over 150F. I ran it to 190K miles. A Cessna 172R during cruise at say 9K feet will see oil temps at about 150F--you might see 170F if you're lucky, since it is usually not over 50F at that altitude even during the summer.

I may have to investigate this more. I'll try putting cardboard in front of my cooler and see if I can keep the oil temps higher. I'm not sure why my thermostat is not doing it's job. I tested it per factory manual and it worked fine. I did try to prime my engine with the oil cooler disconnected and got quite a bit of oil from the ports. I'm not sure if that indicates a problem or the low viscosity oil doesn't seal well on a metal/metal oil thermostat seal.

 

[terefic181]

2-0turbo > A Cessna 172R during cruise at say 9K feet will see oil temps at about 150F--you might see 170F if you're lucky, since it is usually not over 50F at that altitude even during the summer.

Just another tid-bit:

The URL below has several notations addressing low oil temps in plane engines and indications to correct it, if it is less than 170>180 degrees. Although their reason was due to water accumulation and corrosion because of water not being removed with correct heating of oil.


http://www.stittind.com/Oil/Aircraft_Lub.htm



Tom

 

[2-0turbo]

Just another tid-bit:

The URL below has several notations addressing low oil temps in plane engines and indications to correct it, if it is less than 170>180 degrees. Although their reason was due to water accumulation and corrosion because of water not being removed with correct heating of oil.


http://www.stittind.com/Oil/Aircraft_Lub.htm



Tom

Good link. Lot's of good info in there and a good bit is applicable to automobiles. I'll have to see what I can do to get my cruise oil temps up around 180-190. I understand the problems, but I just like the idea of feeding nice, cool oil to my bearings. I have a theory that many DSM "spun rod bearing" stories could be averted. I believe it is due to high oil temps in the bearing. Maybe detonation too.

 

[terefic181]

2-0turbo Quote:> ...I just like the idea of feeding nice, cool oil to my bearings. I have a theory that many DSM "spun rod bearing" stories could be averted. I believe it is due to high oil temps in the bearing.

I also, certainly agree with cooling down things with an oil cooler. Heat is still our main enemy.

The plane notations (water accumulating), I'm not sure would necessarily apply to most of our turbo'd engines. Due to the fact that when your pushing boost, I'm sure you get the temps up well past these target numbers.

In your particular case, as you said, possibly the combination of an oversize pan (more oil=lower temps) and utilizing an air cooled, oil cooler is more than the system can support and still keep the numbers up with normal street driving. I don't have any numbers for oil temps with and without a cooler/bypass valve. In most cases it may not be an issue, but without the data you never know.

So maybe the 170>180 deg. number is a mark we should, at least, try to stay above due to some reported downsides, and maybe even collect some data, as to oil temps along the way.



Tom

 

[Hammer_Gaidin]

Does anyone happen to know where we could pick up an oil temp gauge setup...that would be very helpful for those of us planning on trying something?

 

[2-0turbo]

So I blocked my oil cooler off with cardboard yesterday and went driving. Around town stop and go it gets up to 175-180 now. But, a long drive on the highway still sees it dropping down into the mid-150 range. Hotter than before (by 15 to 20 degrees), but still too cool if you follow all the posted advice on the aviation websites. This leads me to believe that big oil pan and extra capacity are keeping the oil much cooler. Maybe I need a blanket on my oil pan.

You know BMW's are typically designed for high-speed operation. My 2000 325i had a 7-quart sump and no oil cooler. Humm..... I didn't have an oil temp gauge, but I'm guessing the BMW knew it wouldn't be an issue or they would have equipped it with a cooler. Interestingly enough, the E46 M3 DOES come with an oil cooler.

 

[TommyDSM]

Is it possible to install the Coolant Cooler from a 91+ onto the 90 Oil Cooler Housing? Then you would have both, and see what the oil temp would be...

 

[Chiefsublime]

what about using the stock air to oil, oil cooler? there is no thermostat on that, I got mine off of a 90 laser and there was defiantly no thermostat on it.

There is a thermostat on the stock external air to oil cooler. You just didn't recognize it. The first pic is all you see of it on the OFH.

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