Front Oil Cooler Installed

[widebody911]

I finished my front oil cooler install this weekend. My first observation is that this is a *much* larger project than it would first appear. In hindsight, I would have done a bit more research before diving in. I think I was a little over-confident after the last oil cooler project and bumper project went pretty easily.

Quick version: I have a 77 with a 3.6L that I track occasionally. I had a carrera cooler in the passenger fender and a Mocal in the driver's fender. Temps were OK on the track so far, but ambient temps were only in the 70's. I drive the car every day, and in the summer, temps get upwards of 110F

I bought a Setrab cooler from Patrick Motorsports, and an RSR bumper from Rennsport. The cooler is (approx) 24x2.5x7, which pretty much fills the RSR cooler opening.

First I installed the bumper, sans cooler. This went on without much fuss, although I had to fab my own brackets to make it fit correctly.

On to the cooler! My first test was just to set the cooler into the installed bumper, and everything looked great. Hint: next time, do this with the oil fittings on! I marked the outline of the cooler, got out the saw, and cut open the lower trunk. I drilled 3 holes in the top tab of the cooler, hung it with some bolts, and did another test fit - lookin' good! Then I put on the fitting and tried it - uh-oh! The fittings on both ends interfered with the RSR bumper! They hit on the part that curves back toward the car! Ooops! I spent considerable time experimenting with cooler and fitting orientation in an attempt to solve the problem without cutting. Nope. Fine, deal with it later.

Next I fabbed the "box" for the cooler, or more correctly, for the air from the cooler. I used 16ga sheet metal. My kingdom for a shear and a brake! Lacking such, I hand cut the the long pieces and welded them together @ a 90 degree angle - tricky, but doable: I clamped them to a piece of 3" square tubing as an impromptu "jig". The box ended up being 3" deep and 4.75" tall. I would have liked to have gone deeper, but I wanted to keep the spare tire, and with this setup, I can still easily remove it. I hand-cut the sides for the box out of the same size metal, and welded it all up.

From there, it was easy. Cut the existing oil lines, screw on the fittings, then fab 2 simple brackets for the bottom of the oil cooler. I also have a factory "crash bar" that I'm going to add.

The result? I idled it in the driveway for a bit to get the temps up (and while I cleaned the mess in the garage!) Once the thermo kicked in and send oil to the front, I drove it around the block. The temps drop fast once you're moving! I took it for a drive on the freeway last night, and even under spirited driving, the temps get down to the 180-190 range! I opened it up last night on the way home from a date, took it up to about 125 or so for about a minute, and then it was surface streets to the garage. The temp didn't clear 190. When I got home, the front cooler was barely warm, but the supply line in the fender was hot.

I still need to secure the oil lines properly, and I'm going to POR-15 the box (didn't want to do that until I knew I was done) and I need to add a reinforcement or two to make up for the metal I removed. I'm also going to modify the bumper opening to route all of the air thru the cooler.

more pix (and eventually text) at http://vintagebus.com/howto/bumper/

[VWpete]

" I opened it up last night on the way home from a date, took it up to about 125 or so for about a minute, and then it was surface streets to the garage. "

Thom--Your dates must live this 911 stuff!!!!
Did you show up with that big tail, mismatched bumper, and SRD's w/ 5 points? Hehe... "what you see is what you get ladies!"
Your project looks great... I'm amazed at how long it takes me to finish a project and you're alreaddy starting new ones by then!
Good Luck,
Pete

[Chuck Moreland]

I can see you took the driver side cooler out. Did you retain the passenger side carrera cooler in series?

Good job, all that air flow should really keep your temps down this summer.

How much do think the setup weighs with brackets, fittings, hoses and all?

[widebody911]

Originally posted by Chuck Moreland
I can see you took the driver side cooler out. Did you retain the passenger side carrera cooler in series?

Yes, I kept the Carrera cooler & fan - that should help out in stop-and-go traffic. I have a Hayden thermostat setup on it, with an override on the dash. I'm thinking about swapping the Carrera cooler with the MoCal and a SPAL fan; I think the Mocal is a better cooler.

How much do think the setup weighs with brackets, fittings, hoses and all?
Not sure - it didn't occur to me to weigh it. The Setrab cooler probably weighs ~3lbs more than the MoCal I removed, and removed about 5' of braided line.

The final touch will be to replace my dented oil lines.

[widebody911]

Originally posted by VWpete
Thom--Your dates must live this 911 stuff!!!!
Did you show up with that big tail, mismatched bumper, and SRD's w/ 5 points? Hehe... "what you see is what you get ladies!"

Maybe that's why I'm still single...

"No, I'm not trying to feel you up, I'm just helping you with your harness..."

Here's your USRDA of Irony: the 911 is (possibly) keeping me from getting dates (it's scared away a couple of them now), which keeps me from (eventually) having a wife and kids, which would keep me from having time (and MONEY) for a 911...

Spooky!

[Joeaksa]

Thom,

Nice pics on the webpage! Good information. I am thinking of taking my 85 model backwards and installing pre-73 hood, fenders and spoiler ala RS clone and what you are doing and showing in the pictures really help.

One thing that does not look good for my conversion is that I have A/C on my car and want it to stay there. Had hoped that with the older type of spoiler on the car there would be room for both the cooler and A/C unit up front. After looking at your pics it looks really tight and not sure how or if it will both fit there.

BTW, buy a old beater (I am looking for a Volvo wagon right now) to drive on dates! If the ladies do not like you for the car, then find one that has her head screwed on correctly!

Joe

[RarlyL8]

Hey Thom - I'm thinking that I may have to do something similar when the new motor is in.
Do you use a higher temp thermostat on the front cooler? The reason I ask is that is seems to me that the fender cooler w/fan should do the cooling until it becomes overwhelmed, then the additional heat is passed on to the front cooler. The system would regulate the temp more closely this way.

As for the dates - I have a friend who comes from a wealthy family. When he was in Med School he got ahold of a very ratty Chevy Citation to use as a date car. Headliner was falling out, lots of rust. Lived in a crappy neighborhood next to a nice one, told the girls he was a lab tech. Figured any woman that passed that test was a keeper!

[widebody911]

Maybe make the box deeper and mount one behind the other? If you're willing to toss the spare, you can get about 7" or so. I could have gone another 3/4" on mine, but I didn't want to make it too hard to get the spare in and out.

Originally posted by Joeaksa
One thing that does not look good for my conversion is that I have A/C on my car and want it to stay there. Had hoped that with the older type of spoiler on the car there would be room for both the cooler and A/C unit up front. After looking at your pics it looks really tight and not sure how or if it will both fit there.

[widebody911]

I'm using the stock thermostat.

When I first installed the 3.6L, I only had the Carrera cooler w/fan. Temps were within the 'safe' range, but pretty hot by my standards - ~220 in normal driving, 230 a couple of times on hot days stuck in traffic. Remember, the 3.0 and 3.2 engines with a Carrera cooler can get hot, and they have an 'onboard' cooler which the 3.6 doesn't have.

Originally posted by RarlyL8
Hey Thom - I'm thinking that I may have to do something similar when the new motor is in.
Do you use a higher temp thermostat on the front cooler? The reason I ask is that is seems to me that the fender cooler w/fan should do the cooling until it becomes overwhelmed, then the additional heat is passed on to the front cooler. The system would regulate the temp more closely this way.

[RarlyL8]

Let me rephrase my question.
Does the stock thermostat have the ability to regulate flow to the cooler(s) in small enough increments that will allow the temp to stay at a stable 190F? OR will the temp see-saw as large amounts of cool oil are allowed into the system when it opens?

[widebody911]

I have no clue. I don't know of any way to tell if the cooler is open or not at any given time.

Originally posted by RarlyL8
Let me rephrase my question.
Does the stock thermostat have the ability to regulate flow to the cooler(s) in small enough increments that will allow the temp to stay at a stable 190F? OR will the temp see-saw as large amounts of cool oil are allowed into the system when it opens?

[Chuck Moreland]

The thermostat is not an on-off switch. It opens progressively as the temperature rises. I believe it is about ten degrees F from full closed to full open.

So no concern about having "too much" oil cooler. As long as you have a thermostat there really is no such thing as too much oil cooler.

If you want to observe this for yourself, let your car idle up to temperature. Put your hand on the two oil lines just ahead of the thermostat.

You will notice that the supply side gets warm and it will be a couple of minutes before the return side gets warm.

The oil pump is moving lots of oil so why does it take so long to make the trip through the cooler? Because the thermostat is just beginning to crack open and it's metering a small amount of oil to the cooler.

[Joeaksa]

Thom,

That was my only idea as well, moving things back a bit. Problem is that you need airflow through both cores and thats key to cooling.

Sure looks nice and will get to measuring and see how it looks.

Joe

[RarlyL8]

That answers my question Chuck. I was concened that the thermostat would open too fast due to being "tuned" to open for a smaller system. This would start a less than desirable temperature occillation.

Now another question. Assuming the above mechanics are correct, if you grossly over coolered the car to the point that the thermostat only "cracked" slightly under normal use, would it be likely to malfunction that one time a year that you took it to the track and thrashed it (due to lack of use)?

[widebody911]

I've tested the thermo element before with a heat gun, and it does open quite slowly, even with that much heat being applied directly to it. It closes even more slowly!

[s scholze]

Hi,
Great job. Great photos. Great text.
I began the same type of project on my '79 SC but put it on hold until I could find more info and a success story like yours. I told them it would work! Where's that box of cooler............?

SS

[phe]

widebody911, you are my hero !!!

Any chance to get the part # for the cooler?

I am in the process of searching one.

What do you think about the 930 flatnose central oil cooler? That is the part I was searching for, but your seems to fit well also.

Philippe