Oil Cooling System Advice

[DCOP]

The time has come to add additional oil cooling for my 70 RS tribute car. I have a slightly modified 2.7 with Weber's that usually runs at normal temps. This years warm New England summer has me thinking otherwise. The more I search the more confused I get. I have an RS front bumper but do not want to modify the front pan. Although I do like the look of a front mount cooler. Can I use a stock set-up from a later model year SC fender mount set-up or do I need an early set-up to assure the plumbing will work? Will the battery boxes be a problem? I do not track the car and do not want to pay a small fortune for a set up. Any and all advice would be greatly appreciated. Thanks Darryl

[911pcars]

2.7 liters is the threshold engine size for add'l oil cooling in most climates. No chassis modifications are necessary to fit a bumper-mount cooler within the RS bumper opening. As for hardware, use the system for SC 911s. You'll need flex and hard lines from engine and oil tank to the front, the factory oil thermostat, some AN hose adapters, short lengths of AN hose and a cooler sized for the front mount. The archives has much information and hardware details.

Sherwood

[Grady Clay]

Darryl,

With your ’70 (and type 911 transmission) it is a bit complicated but do-able.

Your first decision is - do you want to have the engine compartment appear as a ‘70ST racer?
If so, you want the ’70-’71 911S oil system with the race mods (large oil filler).
This is doable but expensive as the parts will be difficult to source.
(It is also a pita when adjusting #4-5-6 intake valves.)

The ‘easy’ solution is the oil system ’74-’89 that Sherwood references.
Your ’70-’71 unique adaptation is the outlet hose from the engine (under #3 cylinder) that must go over (not under) the transmission and find it’s way over the wheel-well to the thermostat/pressure relief valve ahead of the RR wheel.
This is basically a custom extension to the factory 20 mm ’70-’71 only oil hose.
I recommend you use a complete new 25 mm hose with a straight fitting in the middle (to relieve any torque from the 90º fittings at both ends).
There is a Porsche fitting for your crankcase (a ’72-> part) that adapts to the larger hose fitting.

You also will need a custom hose from the thermostat assembly to the (smaller) fitting on your oil tank.
Properly routed over the wheel-well, this also needs a middle straight fitting given two 90º end fittings.

These parts are available from Porsche 911 Oil Cooler kits - Elephant Racing
… and get five stars from me.

I recommend that you have your oil tank rebuilt. It has rust inside.
There are some (relativity invisible) quantity and baffling improvements available.
Here is a Pelican thread:
Oil Tank Repair... who to use and who NOT
There is a lot more on this subject and some controversy.

I also recommend you use a higher ratio engine fan in warm weather.
The 1.82:1 ‘Turbo’ configuration is the highest with stock Porsche parts and should have been delivered on every 2.7+.
This is an ‘easy’ fix and cools the most important heat-producing pieces – heads & cylinders.
In many situations, this precludes other cooling.

Best,
Grady

[DCOP]

Thanks guys for your quick responses. It appears that I have a couple of options including the front mount cooler. Looks like another project to add to the list. Cheers! Darryl

[BoxsterGT]

DCOP-

Just wondering how you solved your front oil cooler fitment. I am working on a system for a 71 911 right now. The motor is a 3.0 911SC w the original exhaust & hard oil line across the rear.

To add to the difficulty, with fat tires (245/50 -16) at the rear there was a concern about tire rub so we are running the hoses up & over the wheel well. Had to make up some special fittings, but it looks like it will work out OK.

Will post some photos when done.

Len

[DCOP]

Hello Len,

Quite frankly, I have not altered the cooling system yet. She ran cool during the Fall and now she is tucked away for the winter. Grady had a great reply but got me thinking that perhaps I may need some professional help, with the project I mean....hehehe. Still debating what to do? I would be very curious to see pictures of your set up and a description of what you decide to go with. Good luck with your project!

Cheers, Darryl

[BoxsterGT]

Just sent the 71 rear hoses out today. He is using a SC Thermostat & lines up to the front but has kept his original oil tank. His 3.0 Motor has the stock exhaust configuration and rear routed oil pipe. The entire oil system uses 30mm lines, hoses & fittings except for the oil tank inlet which has 26mm threads. For that we made a custom Hose End. Its the unusual spiral S shaped fitting in the photo.




Hope to have installed photos next week from the customer.

I can show you a set we made for a 911SC with SSI heater boxes..............




Please excuse the fitment, its an old SC with 200k+ miles of New England Salt & Sand and who knows what else winters. The SSI boxes are 25 yrs old and still function properly. The rest of the car has seen better days. It is one we had out back we are using for mock-ups when designing & fitting custom hoses. Once we are comfortable with the layout, we build a fixture so we can make more of the same.

The oil cooler we are using is this one by Setrab....



We make up our own front hoses connecting from the Factory thermostat & lines that run along the rocker panels.

More to follow as we build the front part of the system on an old 72 we have out back.

Len

[DCOP]

Hi Len,
Tried to send PM but your box is full. Interested in pricing for the 2 custom lines or perhaps a complete system? Feel free to send me a PM.
Thanks
Darryl

[BoxsterGT]

Hi Darryl,

Just click on my user name and an email link will come up. Cannot send photos by PM's.

The hoses above were made for a specific combination of veh & motor. If you give me details of what you have I can advise on how to proceed. The best combination is using the factory 911SC thermostat & lines.

What was used when you made the 2.7 engine swap? Do you have the original 70 911 engine oil cooler, tank & lines? I have both 26 mm & 30 mm hoses in stock so this can still be done w the good factory pieces.

Len

[bullethole]

one slightly less expensive option for the cooler (than the setrab) is to use an Earls. Theres a thread that contains alot of information on using one, you will have to get metric to AN fitting conversion fittings, but when i did my front cooler, the earls option was about 60% of the cost of using the setrab front cooler, I used a 60 row earls, with -16an fittings

[BoxsterGT]

I have the front half with cooler & hoses mocked-up on this 72 coupe, and it was quite an easy job. It takes 2 meters of hose and (3) straights & (1) short 45. Of course, I still must fit the RS front bumper. Initial measurements look good.

I will post photos once I get my camera back from being repaired (I dropped it BOO HOO ).

Len



Edit: Ha! Famous last words for the first sentence. Easy job............NOT with these fittings!

[DCOP]

Can't wait to see the finished project....too bad about your camera

[JeremyD]

Originally Posted by bullethole

one slightly less expensive option for the cooler (than the setrab) is to use an Earls. Theres a thread that contains alot of information on using one, you will have to get metric to AN fitting conversion fittings, but when i did my front cooler, the earls option was about 60% of the cost of using the setrab front cooler, I used a 60 row earls, with -16an fittings

+1

I have two big Earl's coolers on mine -

[BoxsterGT]

Well, this weekend the front half of the cooler system should be done. The fitment of the RS front bumper required a lot more effort than I expected. In fact, the bumper has been on & off at least a dozen times. Glad I have this old rusty tub to test fit everything.

Had to make various changes in the mounting system, and going back to using the original Setrab mount kit with modifications seems to work the best for me.

The issue was the clearance of the M30 hoses & the unique angles of fittings needed. I had to change the routing & also the lengths of hose to make it work without binding anywhere.

Expect to have my camera back on Monday, so I will post a few photos.

Supposed to be warm here as well, so the garage doors will be open.

Cheers,

Len

[BoxsterGT]

Well, I am back at it after a weekend of family duties. Did not get the front half done, but at least made up the beginning of the lines/hoses at the rear. This is the return from the SC thermostat to the 66-71 911 Oil Tank............




Not crimped yet until both this Return Line/Hose & the Feed Hose from the Motor up & over the tranny to the Regulator are finalized. They all use the full 30mm OD hose & M30 fittings that are original on a 911SC hard line set except for a custom 26mm fitting at the tank.

More to follow.

Len

[BoxsterGT]

Got more done on it this weekend.

DCOP- Please email me, I have questions & answers for you.

Len

[Trackrash]

As usual Grady sums it up well.
My solution, since I'm cheap, was to add on an entire SC setup. I purchased used the hoses, hard lines, thermostat, and the trombone from an '83 SC. Since I plan on putting in a larger motor in the future I also installed a Carrera oil tank. As you may know the oil line size and oil capacity was increased in '72.
My solution required that I adapt my fittings coming from the motor. To do this I cut off the upper pipe at the yellow arrow and made up a custom adapter. The oil hose at the blue arrow is the line from the motor to the tank originally. I replaced that line with AN-12 hose many years ago.

At first I just ran the trombone. It worked fine cooling my 2,5 on the track. Looking ahead I new I wanted a front cooler, which is now installed. It is a modified RX7 cooler. The front bumper is custom.

[BoxsterGT]

Nice install Gordon. Going to a later oil tank has its advantages.

In my case, I want to keep this as original as possible. Don't want to cut the chassis or remove the RH battery box or cut a duct into the nose. It all has to clear without issues. The values of these cars are slowly going up and some day it may have to be returned to stock.

I plan to use a M30 fitting at the case & run a hose as you have done for the feed to the SC regulator.

The return line I have shown in post #15 above has a M26 fitting on the old SC line so it will fit nicely to the oil tank.

What size tires are you using at the rear? Do you have any tire rub or clearance issues?

Len

[Trackrash]

I don't have a duct in the front. Without it there seems to be enough clearance for the cooler.

The '70 tank is probably OK on a street car. The later tanks have larger fittings, larger flow capacity, and the newer higher flow filters.


In your case you may want to try using just the trombone and see if it does the job. It worked for me even with the battery battery box still there.

The tires in that picture are Toyo RA-1s 225/55 16 on 8" Fuchs. There is no rubbing, however I rolled the fender lips and have about 2 degrees camber. The rear flairs are SC. I also have a set of Khumo V710s 245/45 16 on some custom wheels. They fit, but regardless of the larger size, they don't measure much bigger than the Toyos.

[BoxsterGT]

Started modifying the 911SC rear lines to fit this 70 911T. Nothing is final yet, still have to make up the M30 hose over the tranny to connect to the feed hose to the reg.

edit: this first layout was in fact too low, as Gordon advised me in the next posting. So, I will try again. Still hope to use the leftover SC rear hoses, just hate to throw them away but we will see.

Len