Stock oil cooler is unhooked

[BlownMX5]

I am installing my new TDR intercooler. In the process, I removed my Moss oil cooler and filter relocation because there isn't room in the "mouth" now for it and I couldn't come up with a reasonable alternate location for it. This oil cooler/filter relocation kit has an aluminum fitting that attaches to the stock oil filter mount which is where the large oil hoses attach. Once I removed that in preparation for putting the oil filter back in the original position, I noticed that my engine builder didn't bother to reattach the coolant lines that go to and from the OEM oil cooler at the base of the filter. I assume he didn't attach them because

I had him do the coolant reroute
I have a remote IAC
I had an aftermarket oil cooler anyway
He probably didn't want to hassle with running little coolant lines all over the place. So, my question is: how important is the stock oil cooler? Is it OK to leave it disconnected? If not, maybe I can somehow extend and use the coolant line that is currently running to the IAC. I don't want to have to mess with that fitting at the rear of the head. Although, now that I think about it, that might be where one of the IAC lines is coming from.

[bogey]

I don't know if it is critical, but replumbing it in should not be hard. Just connect it in series with the IAC line.

[Tom @ Fast Forward]

With the aftermarket oil cooler, I wouldn't think the stock one to be too necessary. I removed the running lights and mounted my oil cooler behind the passenger side one.

[Kyp J]

I have seen comments in the Mnet about that being used in cold weather to warm something up quicker. Don't know the theory but that was what some of the "rocket scientists" said.

[BlownMX5]

I have seen comments in the Mnet about that being used in cold weather to warm something up quicker. Don't know the theory but that was what some of the "rocket scientists" said.

Yes, it does seem strange to me to use hot coolant to "cool" the oil. Maybe it's purpose is just to warm the oil up quicker? If that is the case, living in southern California, it probably can be left disconnected.

Can anyone describe how it actually works?

[Steve]

I would recommend re-attaching it... in fact, without your other cooler I would say it is critical that you do.

Yes, the stock cooler helps to warm the oil to proper temperature more quickly. It also helps to keep the oil at a stable operating temperature. In an ideal world, your oil and water temps should be close to the same (190 degresse F) and this type of cooler does a good job of that on a stock engine. A boosted engine in a track car will overload the stock cooler (although it still helps) so an additional air/oil unit is beneficial.

On every track car I build or service I never remove the stock cooler, even when adding a second air-to-oil unit. Typically, on cars with big front-mount IC's I put the cooler in the passenger front bumper area and add an air duct from the mouth (or fog light opening on NB's.)

It's easy to do: the water should come out of the small fitting on the back of the head, (points to the passenger side) through the cooler, then the IAC, then to the front of the engine at your old water outlet. I do coolant reroutes all the time and always leave the stock cooler hoses in place, so you shouldn't have a problem there. The benefits of warming the oil more quickly (and more stable temps overall) is worth the minor effort of a couple of hoses.


Steve

[BlownMX5]

Thanks for your insight, Steve. I had already disconnected my aftermarket oil cooler, so I'll just have to put it all back together and figure out a way to hang it behind the RF corner somehow. I have my IAC mounted remotely on the right-side of the firewall and I think the coolant line that feeds it is coming from the rear of the head. I guess I can just reroute that to the stock oil cooler and then return back to the IAC.

Anyone know what size those hoses are?

[Steve]

On an NA they are 8mm. Most guys use 5/16 hose 'cause it's cheaper and available at the corner store. I don't think it would be a problem to go to the IAC first and then the cooler so you could do that if the routing is easier.