oil cooler ideas

[6year6]

I am collecting parts for my six conversion. We are attempting to wedge in a 3.0 with FI where a mere 1.7 once lay. I have the oil tank, tin, motor mount and a dirty old wrecked 82 911 sc that starts right up, as well as parts stripped off 2 914's. I've read with a conversion of this magnitude I must consider oil cooling. I've seen front mounter auxiliary coolers both with and without fans. Any thoughts, advice, direction, offers on this topic?

[TRE Cup]

We've done a number of conversions over the years, as well as upgrading real 6's for better cooling. It is a matter of budget on how you can do it. Best bang for the buck is getting -12 aircraft hose, fittings, and running the lines along the passenger side rocker. The driver side would be the logical choice, since the tank is mounted there, BUT that would mean pulling lines into the driver compartment just to the left of your foot ! Live in cold climate? ok, but otherwise i don't think you need a 200 degree foot warmer , eh ?

So , run them down the passenger side. A factory thermostat would be best, but pricey and adaptor fittings are needed. BAT ltd in florida sells -12 hose/ metric end fittings for the T stat.
We run the hoses into the front wheel well, up the rear side, poke holes next to the washer bottle in the wheel well, then under the tank, thru the separating wall. And then to the front where the cooler will reside.
A nice install will use the replica of the GT oil cooler shroud, or you can fashion your own using aluminum sheet. On my own 6, i used a 23" long nascar cooler (admitted overkill for a smaller motor) but it compares very well with what the real GTs used., We made up aluminum panels to shroud it properly and cut a nice rectangular opening in the bottom of the front trunk to exit the air.
There are assembly line holes in the front trunk face, between the bumper and valence. We popped out the rubber plugs there, the drilled similar sized holes between them. It is adequate to supply air to the cooler. A general rule on oil cooler exit openings: approx 65% of the surface area of the cooler is good. This allows air to "soak" up the hot air, before being forced out the bottom of the car.
I put a small lip spoiler on the forward edge of this bottom exit to promote a lil more negative pressure in that area and help reduce lift. I also run a front air dam/spoiler to help reduce air from under the car

I simplified this somewhat, but feel free to ask questions

[rfuerst911sc]

I don't have the expertise of the TRE guys but here is what I'm doing on my 3.0 GT clone. I'm going to install a front mounted oil cooler but not IN the trunk. Instead I'm installing it on the outside of the tub under the front bumper. I'm going to fab up a " box " around the cooler in the original valance. When I'm done it will look similiar to the oil cooler opening on the RS + RSR 911's. I'm using a Mocal -12 thermostat and I'm going to run one line up the drivers side and one up the passenger side. For a cooler I'm using a Mercedes Benz diesel oil cooler made by Behr, a nice stout unit. I don't have any pics because my cars being painted. Good luck with your project.

[TRE Cup]

The mercedes cooler is an excellent choice, once you have the -12 fittings installed, for motors up to 2.7 AND lots of air getting to it (if high compression)
Some of Behr units that mercedes uses are pretty large and would satisfy larger motor requirements

i am a little concerned with it being mounted under the car though. It would be in a very vulnerable spot.

[rfuerst911sc]

Originally Posted by TRE Cup

The mercedes cooler is an excellent choice, once you have the -12 fittings installed, for motors up to 2.7 AND lots of air getting to it (if high compression)
Some of Behr units that mercedes uses are pretty large and would satisfy larger motor requirements

i am a little concerned with it being mounted under the car though. It would be in a very vulnerable spot.

It's not mounted under the car, it is in the front where the tub goes from vertical to an angle. The bottom of the cooler will be aprox. where the front A-arm mounts are maybe just a touch higher. The cooler has aprox. 3-4 inches behind it so I believe air flow will be good. This cooler came with the oil line fittings. I took them to my local hydraulic shop and they welded on -12AN fittings. Hopefully this will work as planned. If for some reason it doesn't work I can always go back to the cooler mounted in the trunk. I will have sacrificed the front valance only, no big deal

[rfuerst911sc]

I found some pics of what I'm doing. It's a work in progress

[TRE Cup]

I see
its still out there in harm's way, imho, but a much easier install and effective with getting tons of air

[rfuerst911sc]

Originally Posted by TRE Cup

I see
its still out there in harm's way, imho, but a much easier install and effective with getting tons of air

No argument on it being vunerable to a front impact but I'm going to box it in with metal and will install a screen to help control rocks and debris. Other than a front impact I think I'll be O.K. with good airflow. It's hot in Orlando a good 8-9 months out of the year and I didn't want any cooling issues. With a stock 3.0 with Weber carbs and headers plus the engine mounted oil cooler I think I'll be all set. Time will tell.

[Scott Walshaw]

For what its worth I thought I would share my 914-6 front cooler install solution. I have a 2.2 S w/webers and I installed a "mocal" 170 degree thermostat w/12AN fittings low on the firewall, almost directly behind the driver's seat. The lines are routed through the area under drivers side rocker panel (replaces the vent lines for the gas vapor recirculation system) and routed up the inside of the driver's side wheel well into the inside front portion of the trunk (you'll need to cut access holes) and connected to a "radiator" style cooler (if I recall mine was the smallest version and purchased from the same source as the thermostat). The cooler is positioned behind the round body access holes behind the bumper (just push out the rubber covers). If you want more air flow you can use a hole saw to cut additional openings between the existing ones. I installed a piece of window screening material as a dirt barrier over the outside openings. I have a stock metal lower valance and I just cut a rectanuglar opening in the top of the valance to correspond with the dimensions of the cooler opening. This notch is only visible if you bend down and look under the license plate area...very subtle and effective (if you run a bra like I do, you'll also need to cut a corresponding opening in it). I fabricated an enclosure from a sheet of lightweight aluminum obtained from Home Depot. The enclosure is angled down to the floor of the front trunk and attached with sheet metal screws. I also used a hole saw to make an air "exit" area that the aluminum box is mounted over (note: there should still be room for a collapsible spare in the trunk...otherwise you'll have to use the factory option of locating the spare in the rear trunk using the hold down point in the rear trunk) If you will be racing you'll likely want to use aeroquip type lines and fittings, but I used the stuff used on large construction equipment. It is more flexible, has a high temp and pressure rating and is much easier to work with. Since the lines are mounted in unexposed areas I would recommend this solution for "every day" use. The stuff I used was called "Parker push-loc" and you should be able to find it and the applicable fittings at a heavy equipment dealer or servicer. In conclusion this install has been in place for almost 20 years without problems and my engine temp has NEVER gone over 200 degrees, even flat out hill climbing the Mount Rose highway to North Lake Tahoe on the hottest day of the summer. I have a similar setup in my 911 (that's another story) which does as good a job, with the A/C running full blast. Hope this helps, Regards, Scott