Rear fender oil cooler mount details, How I did it |
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Rear fender oil cooler mount details, How I did it |
IronHillRestorations |
Sep 25 2018, 05:01 PM
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#1
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I. I. R. C. Group: Members Posts: 6,761 Joined: 18-March 03 From: West TN Member No.: 439 Region Association: None |
After I made a post about my alternate location for an auxiliary oil cooler, I thought more details would be helpful.
First let me say that this was a piece of cake for the current project, as the right rear quarter panel was removed for rust repair and chassis stiffening. Due to the difficulty in properly locating the forward mounting holes, I don’t know how feasible this is for a car with the engine installed. When I put a (slightly smaller) cooler in this same area 25 years ago, I made no notes or kept any of the measurements, I just made it work, but at that time it was done with the engine out of the car. After trial and error fitting of a cardboard mockup, I picked a Mocal 34 row, 235 matrix cooler, which measures 260mm by 280mm, or roughly 10 5/16” x 11 1/8” which doesn’t include the -12AN fittings. This is what I think to be the largest cooler you could get in that area ahead of the right rear wheel. This cooler has a capacity of .75 quarts, which is .20 of a quart more than the kit BAT offers to upgrade a 911 front oil cooler. This is a case where bigger is definitely better. Since airflow in the rear quarter panels isn’t as good as the front fender , I added a 7” Spal puller fan that will be mounted directly to the oil cooler with a plastic mounting tie kit, which are very sturdy round zip tie fasteners that make it easy. The fan will be wired with a relay to a switch on the dash or an automatic inline switch (to be determined later). On my old install I tried to make the fan automatically switched, but it ran too much and the fan died. A testament to this set up is that I never knew the fan died, and oil temps never got over 220* even in the hot Tennessee summers. Since this is going to be a widebody hot-rod with flared rockers, I’m toying with the idea of incorporating a scoop in the rocker flare, but that too is undetermined. Here’s a hardware list, that doesn’t include any oil lines, thermostat, or relay wiring for the fan. 1 Mocal A34A12 34 row -12AN 235 oil cooler 2 Mocal/Setrab ABKT-235 oil cooler bracket for 235mm core 1 BAT ABKT1 cooler/fan mounting tie kit 1 M8 x 1.25 x 60mm fully threaded cap screw (13mm hex) 2 M8 x 1.25 x 50mm fully threaded cap screw (13mm hex) 12 M8 washers 8 M8 x 1.25 nylon insert nuts 1 M8 x 1.25 weld nut Even with the fender off it took more than one attempt to get it in the optimum location, which is as far forward as possible without interfering with the outer suspension console. Using the suspension console as the baseline level plane, the cooler is tilted down at the back about 5* give or take a degree. Just for reference Here's what the cooler looks like mounted. It's pretty big. I wanted to make sure the cooler could be installed and removed with the fender on, I made sure there was no interference. I had the fender on and off several times during the test fitting process. With the fender off it was easy to use the bracket as a reference where to mark and drill the 5/16” front mounting holes, which are 70mm apart. |
burton73 |
Sep 26 2018, 01:37 PM
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burton73 Group: Members Posts: 3,655 Joined: 2-January 07 From: Los Angeles Member No.: 7,414 Region Association: Southern California |
Suck the fan air through the vent. The only way to test it to try it but I do not think that the ways guys are hanging them next to the exhaust and under the trunk would work as good as it is much hotter there. Vent and sealed duct will force outside air into the cooler. It will need to be tried to see for sure. Take and idea and test. isn't that what the factory does. That is where all of technology comes from. Yea fancy testing in a wind tunnel but the fan will pull air from the outside if set up that way
Bob B |
tomeric914 |
Sep 26 2018, 02:46 PM
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#3
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One Lap of America in a 914! Group: Members Posts: 1,263 Joined: 25-May 08 From: Syracuse, NY Member No.: 9,101 Region Association: North East States |
... but I do not think that the ways guys are hanging them next to the exhaust and under the trunk would work as good as it is much hotter there... Under the trunk works on 4 cyl cars with oil coming from a spin on adapter between the filter and engine. That oil is more liquid than on the 6 coming out of the engine. It's also on an engine with ~100hp. I ran one under the trunk with my 4 at track events for a couple of years and was successful at keeping the oil less than 220 deg F even on the hottest of days. When I tried the same thing with the 3.0 six and a 12x12 Setrab cooler with a 12" diameter puller flowing a noticeable amount of air, I was seeing 260 deg F. Location was part of it; the fact that the oil is really foamy at that point (especially close coupled) was the other part of it. That same 12x12 cooler in front laying flat keeps my oil temps at the track and street at about 190 deg F using a 200 deg F thermostat. I would theorize that the distance from back to front along with the many turns to get there reduces the foaminess of the oil. Also consider the weight of the cooler, fan, oil and lines attached to the whole assembly. The 4 studs holding it on may not be enough in the long run, especially after hitting a few good bumps. By no means am I dissuading the OP from what they are doing. Your mileage may vary, etc., etc. |
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