Adding an Oil Cooler to my healthy 4, What should I consider? Options

[Joseph Mills]

Now that my engine is back together with higher compression I need to consider some additional cooling.

In 80-90 degrees ambient temps, at 3800rpm highway, it runs 200-210-215. So next summer in mid to high 90's, it's going to need some help.

I really don't want to install a cooler up front. But are there any alternatives? Rear fender well? Rear trunk with cutout? Engine bay?

Any specifics or brand models would be most helpful. Pics?

[Demick]

I'm considering this one for mine. Mounted under the rear trunk. I don't want to plumb to the front either.

Derale Atomic-cool oil cooler

Demick

[dmenche914]

The temp might be a bit on the high side. I have found that the temp gages (not so much a sender issue) can vary a good amount. So before going to the trouble of adding a cooler, go ahead and confirm your temp reading if you haven't already. Also see if some thing else might be done to correct the temp problem, some time you may not need an extra cooler if something else can be fixed/adjusted

If you can buy borrow or what ever a nice digital thermal couple, with a long enough sensor wire, then stick it down the dip stick hole. Digital thermal couples are usually very accurate. Or calibrate your s with boiling water.

Also see if timing, or mixture cannot be adjusted to lower oil temp. A lean mixture, or over advance will cause overheat for example.

Check that there is no mechanical problems with the car, like dragging brakes, slipping clutch that can cause over heat.

Be sure all the sealing rubber is in place, and all sheet metal. Missing spark plug hole seals, the seal around the oil press. sender, the seal around the enginebay, etc... all are critical for cool air entering the fan, or prevent leaking of precious cooling air. You must have the warm up flaps installed, even if you do not have the warm up bellows thermostat, they are needed to direct the air even in the "warmed up" position, so without them, your cooling air does not get where it should.

If it is indeed too hot, , and every thing is good, then you must have a powerful motor (lucky you!!!) that really requires more cooling than the stock cooler can provide.

Use one of the oil filter "sandwhich" inlet/outlet adaptors. Keep use of sharp right angle fittings to a minimun . Cooler locations are limited. Do not put it inside the engine bay, as it will dump heat into the cooling fan. It must be in a good air flow to be effective, and an electric fan can be useful. It should be protected from debries. A thermostat is needed to allow oil to obtain a good temp, too cold an oil is also not good. If cooler is in front of car, copper pipe is great to run in the rockers, just braze on a threaded fitting on each end so accept a hose , or just clamp a hose over the ends. The copper pipes a tough, and can add too the cooling.

If you have too hot oil, a check of the head temps is a essential, if the heads are getting too hot, cooling the oil more will not help them much if any, they will still be over heated. Overheated heads crack and drop seats early, so be sure this is not happening.

Good luck on the oil problem. I hope it is simple, so you do not have to add a cooler, Usually the type IV motor can stand a pretty good increase in performance without the need for an external cooler. If you have a really big motor, then you will require one.

Please let the list know the motor details, this will help us know if you truely need an extrenal cooler or not.

What is the compression set too? Stroke, bore? Cam, valves, injection/carbaration system?, and anything else.

[Joseph Mills]

I'm considering this one for mine.  Mounted under the rear trunk.

That cooler looks cool. (IMG:style_emoticons/default/biggrin.gif)

Mounted in the space above the tranny?

Or? (IMG:style_emoticons/default/unsure.gif)

[Demick]

Yes, under the rear trunk to the passenger side of the tranny. With about 1" of space between the cooler and the trunk floor. The fan is designed to be reversible, so it can be used either to push air through the cooler or pull air through the cooler.

Under the rear trunk isn't the best place for a cooler since there is no source of cool air. So the air used to cool the oil will be fairly warm. But the cooler is fairly big and with the fan I expect it will be more than adequate to knock 20-30 degrees off your oil temps.

Demick

[Joseph Mills]

The temp might be a bit on the high side.  I have found that the temp gages (not so much a sender issue) can vary a good amount.  So before going to the trouble of adding a cooler, go ahead and confirm your temp reading if you haven't already.......

dmenche914,

Thanks for all the tips - you covered a lot of good ground. However, I have pretty well been thru all of them. I haven't finished all my tin issues yet but am getting there. Your list made me mentally double check what I have done.

My car runs 180-200 around town, which comprises most of my driving, other than autocrossing (where high temps are not a problem). One could argue I don't really need a cooler.

But for those times when I do want to kick it on the highway, or participate in a few DE's next year, I think I will need it and I do want the added protection.

Thanks! (IMG:style_emoticons/default/beer.gif)

[Joseph Mills]

Under the rear trunk isn't the best place for a cooler since there is no source of cool air.  So the air used to cool the oil will be fairly warm.  But the cooler is fairly big and with the fan I expect it will be more than adequate to knock 20-30 degrees off your oil temps.
Demick

I guess not an ideal location. But since it's real work will be for when the car is at speed, at least there will be a lot of air movement period.

Okay. Your hard sell worked. I'm sold. (IMG:style_emoticons/default/laugh.gif)

[Joe Bob]

Yup...check the temp....use a hand held pyrometer. I have a couple if you need a loan.

Good gauges are a must. If there is an error on the gauge, it's worthless, worse than a girlfriend on a crackpipe......200 bucks in gauges is better than a 4k rebuild.....

Use a MOCAL cooler....do a google on BAT and MOCAL...they are in FL. Tell them ya know me....for some reason they like me and will cut ya some slack....

[Joseph Mills]

...use a hand held pyrometer.  I have a couple if you need a loan.  

If there is an error on the gauge, it's worthless, worse than a girlfriend on a crackpipe...

That's generous of you to offer Mike.

Both the gage and sender are new VDO units. One would think they would be accurate to a degree or so. (IMG:style_emoticons/default/unsure.gif)

Alright. So I must confirm their accuracy. I'll check around with some locals for a pyrometer.... then I'll call you. (IMG:style_emoticons/default/biggrin.gif)

Thanks again... but I would appreciate it if you would not disparage my girlfriends. (IMG:style_emoticons/default/wub.gif)

[Joe Bob]

My dad had her first..... <_<

[Joseph Mills]

My dad had her first..... <_<

Ha!

Gee. That kinda makes us cousins or somethin' (IMG:style_emoticons/default/biggrin.gif)

[bernbomb914]

I installed one under the rear trunk with a fan. I built a bracket to tilt it toward the wheel well were the air might be cooler. I havent driven it yet to test its effectiveness. and will install a DTM with a cooler built into it when jake gets to it.

Bernie

[bob91403]

I installed one under the rear trunk with a fan. I built a bracket to tilt it toward the wheel well were the air might be cooler. I havent driven it yet to test its effectiveness. and will install a DTM with a cooler built into it when jake gets to it.

Bernie

(IMG:style_emoticons/default/agree.gif) Screw the oil cooler. Jake's DTM is the only way to go. Add your name to the list. (IMG:style_emoticons/default/boldblue.gif)

[Joseph Mills]

I installed one under the rear trunk with a fan. I built a bracket to tilt it toward the wheel well were the air might be cooler.

Thanks Bernie. Would you happen to have a pic? (IMG:style_emoticons/default/rolleyes.gif)

[Jake Raby]

Run it through the winter and by the summer the 914 DTM will be available..

If you want an external cooler look into a setrab from aircooled.net

[bernbomb914]

Joseph I will take a pic when it quits raining as the car is outside on jack stands as usual

Bernie

[eeyore]

Jake,

On the DTM with the non-stock oil cooler (ahead of cyl #2), will the oil cooler get air from the DTM or will additional ducting / fan be necessary?

[Jake Raby]

It will get air from the shroud as normal, BUT the air will also be scavenged through the cooler duct with a pipe that will have a serious venturi effect..

This will increase the shrouds ability to give even more air to the cylinders as we can restrict the shroud outlet due to the venturi..

Basically the faster you go the better it will cool.

[eeyore]

It will get air from the shroud as normal, BUT the air will also be scavenged through the cooler duct with a pipe that will have a serious venturi effect..

I like that. An oil cooler with a cool side and and hot side, and airflow, as opposed to being pressed up against the trunk floor and getting relatively no air, but plenty of exhaust heat.

[Jake Raby]

Yes, and it makes use of the otherwise useless area that the surround tin will create for the DTM to be sealed in the engine bay....

I put alot of thought into this one..