Unusual 3.2 build

dpetteng · 07-03-2019, 10:59 AM

So, any purists stop looking now.

My restorer is building my 1971 vw camper van with air ride and a 1985 911 3.2 which has been rebuilt by Neil Bainbridge on PMO carbs.

I obviously need to run oil coolers which are positioned between the front chassis rails and need to run hard line aluminium from the engine and back again.

I have a JIC fitting flange tool but can not get hold of lengths of aluminium oil pipe in the UK but have found a general aluminium warehouse who have 3/4 lengths of pipe.

What gauge pipe should I be using for oil lines? Am I right in thinking using aluminium will help with the cooling as they should vent some heat along a 3m length?

Any opinions or ideas welcome!

dannobee · 07-03-2019, 11:08 AM

Yes, aluminum would help with cooling. Is brass or copper tubing available there?

Flat6pac · 07-03-2019, 11:10 AM

I’ve always made the point that the oil lines along the sill need to be kept clean because the trombone or radiator is not the only cooler on the car but everything from the thermostat forward displaces heat.
Bruce

Trackrash · Trackrash's Garage

Brass would be a lot easier to work with for fittings and bending.

I just measured a steel SC oil line and it is about 1.6mm thick or about .063".

BoxsterGT · 07-04-2019, 04:34 AM

Subscribed, as this is just what I love to see.

However, this does not exist in our minds unless we see PHOTOS.....

Also, a comment about aluminum tube...I have been told this must be well supported to prevent vibration, as aluminum tube may crack under certain conditions.

PHOTOS please.

Len

BoxsterGT · 07-04-2019, 06:37 AM

Here is my project.......

...with a 996 3.4 motor. I must admit it has stalled over the past year, but I am now ready to resume the task.

Let's see yours.........

Len

Trackrash · Trackrash's Garage

BTW, if you haven't seen this post it is well worth the read.
Porsche Powered Mid-Engine Double Cab

dpetteng · 07-04-2019, 12:17 PM

Happy to show some pics, will get some tomorrow. Thanks track rash, that measurement really helps. I guess I can get copper or aluminium, I guess I was just assuming aluminium was the correct way. I need every bit of cooling I can get so hard lines will really help.

dpetteng · 07-04-2019, 12:21 PM

OK, so I had a look and I can get brass, copper or aluminium in the size track rash has suggested. Any idea what would be best?

dpetteng · 12:45 PM

Interesting from the scientists:

Copper has a higher thermal conductivity, and therefore is superior to aluminum in processor cooling. Copper is better at conducting heat than aluminum, but aluminum is able to radiate the heat into the air better than copper because of its lower density

I want venting to the air so aluminium I guess

dpetteng · 06:00 AM

So, as requested a few pics of my build. The engine was fabbed in and fitted before its rebuild.

safe · safe's Garage

Quote:

Originally Posted by dpetteng

Interesting from the scientists:

Copper has a higher thermal conductivity, and therefore is superior to aluminum in processor cooling. Copper is better at conducting heat than aluminum, but aluminum is able to radiate the heat into the air better than copper because of its lower density

I want venting to the air so aluminium I guess

Get a good oil cooler, like a large Setrab, put in in good air flow and worry less about the oil line material. The oil lines do cool but they are a bad oil cooler compared to a proper oil cooler.

BoxsterGT · 05:03 AM

This is what I am using....

along with 30mm late 911 Hoses & fittings. It's the same as used with the 73 911RS.

I would love to help you with this, as I make up custom Fuel & Oil Hoses for most Porsche models, but the Atlantic ocean is too much in the way and shipping costs would be prohibitive.

Len.Cummings at verizon.net

dpetteng · 07-09-2019, 12:30 PM

so my challenge here is that there are no openings at the front of a VW van so we are having to put them between chassis rails and channel the airflow through them somehow. This is also the issue with a large straw so trying to get every bit of cooling I can. Quite simply, the shape of a van is not suited to a front facing oil cooler.

Len, I am a novice when it comes to oil systems on 911's. could you simply describe the fittings I will need from my engine, to the cooler and back to oil tank? I can't find a simple picture of the oil flow from the engine

safe · safe's Garage

Quote:

Originally Posted by dpetteng

so my challenge here is that there are no openings at the front of a VW van so we are having to put them between chassis rails and channel the airflow through them somehow. This is also the issue with a large straw so trying to get every bit of cooling I can. Quite simply, the shape of a van is not suited to a front facing oil cooler.

Actually you don't need a large opening for an oil cooler, or any cooler for that matter. If you can duct the air from the opening to the cooler the "ideal" opening is about 1/3 of the cooler size.
I read it in some book and if you look at the 944 turbo its exactly how Porsche did it for the intercooler. Opening is the full length of the cooler but only 1/3 of the height. I did the same for my front mounted oil cooler.

Trackrash · Trackrash's Garage

Quote:

Originally Posted by dpetteng

so my challenge here is that there are no openings at the front of a VW van so we are having to put them between chassis rails and channel the airflow through them somehow. This is also the issue with a large straw so trying to get every bit of cooling I can. Quite simply, the shape of a van is not suited to a front facing oil cooler.

Len, I am a novice when it comes to oil systems on 911's. could you simply describe the fittings I will need from my engine, to the cooler and back to oil tank? I can't find a simple picture of the oil flow from the engine

Do a GOOGLE search for "porsche 911 oil lines" and click on images.

The factory uses a thermostat between the motor, cooler and tank. The factory uses 30mm fittings. BAT and others sell the fittings. You can either use hose fittings or there are fittings that can be soldered to brass, like the factory used. Depending on what oil cooler you use many have AN fittings as opposed to the factory metrics.

You probably should consider a fan, if you will be stopped in traffic.

dpetteng · 07-10-2019, 06:04 AM

That's really useful. So what were the original hard lines and trombone cooler made out of? Aluminium? Copper? Brass?

safe · safe's Garage

Quote:

Originally Posted by dpetteng

That's really useful. So what were the original hard lines and trombone cooler made out of? Aluminium? Copper? Brass?

Brass, copper can work harden if it vibrates and crack.

Trackrash · Trackrash's Garage

Quote:

Originally Posted by dpetteng

That's really useful. So what were the original hard lines and trombone cooler made out of? Aluminium? Copper? Brass?

It varied. Porsche used aluminum originally. Then the lines in the rear went to steel, and the lines going to the front went to brass.

Keep in mind that there were rubber hoses as part of the setup.

To say that copper or brass is less durable than aluminum is highly questionable FWIK.
Here is my old setup. Red arrows are steel '83 SC with a crimped hose fitting, Yellow is a reusable factory aluminum hose end adapted to a steel SC line, blue is an Aeroquip stainless hose, below is the factory aluminum '71 oil fitting to the oil cooler.
Not shown are the lines going to my front cooler which are brass and copper.

You can better see how the rubber lines integrate here.

dpetteng · 07-10-2019, 12:24 PM

Thanks, so I am assuming the rubber hoses are to account for body flexing? So all I have is the engine and pipe going from one side of the engine to the other plus the tank. I was thinking of using a conversion fitting from the engine pipe from the 30mm to AN12 then run flexi from there to a local thermostat, brass hard lines from thermostat to the front oil coolers then hard lines back to thermostat and flexis from thermostat to the oil tank, would that work?