• General
  • Air Oil Cooler lines - Lengthening

I'm trying to figure out what direction I should go with the B230FT I'm piecing together to put into my 940. Originally I was going to use a later heat exchanger with the water cooling, and then later decided to go the aircooled oil cooler route.

What I'm currently stuck with is:

- Going to be using later style radiator, so won't fit in the original location

- If making lines longer, spend more for AN lines or get Pirtek/enzed to make new OEM lines

- Original ferrules probably not designed to be loosened/done up without replacement

- Kinda want to do it right the first time, but which way is the most right?

Do I:

a) Cut the end of the hard line, weld/braze/solder some -10AN fittings with new lines and cooler

b) As a) but somehow adapt the original oil cooler to AN with adapters

c) Get AN adapters for sandwich plate and AN lines from there (no hardlines)

d) Get pirtek/enzed to make up new lines to length for the original hoses with stock everything else. 

For option C I've seen people crack the sandwich plate from adapters that thread too far in. I don't want that.

I've never made up AN lines before but how hard can it be, right?

Have you got the oil only sandwich plate on the extension arm, or the oil-coolant sandwich plate?

The sandwich plates are different, but the arm is the same.

oil only = p/n 1276680-4

oil/coolant = p/n 3507371-7

They went to oil/coolant from 1992 on.

(ref = group 22, pages 249 and 251 of the 940 pre-93 parts book)

The part no. is usually found somewhere on the part.

I've got both, but I had to decide between the two so I'm planning on using the air/air oil cooler with the thermostat. I liked the compact nature of the Water/Oil cooler it wasn't in good shape. The question posed here is whether I adapt the oil lines on the Air oil cooler to use AN fittings or not basically.

I got the Air/Air one with the engine from a 1991 B230FT 940 which is what's in those pictures and was in better shape than the Water/Oil cooler I got from a 1998 B230FK I imported (everything from the UK is rusty from factory it seems).

There were some minor difference between the relocation arms between 1991 and 1998 but not much worth mentioning (same part numbers though).

One thing I'm partly considering (source of inspiration here) is

New oil cooler with -10AN fittings, something a little bigger than OEM400-series push-lock hoses (secured with oetiker clamps?)-10AN push-lock fittings to oil cooler and hard linesWelded -10AN fittings to hard lines

I'll then cover up the lines with something a bit more abrasion-resistant. As long as it'll suit the required pressure it should be ok? I've read conflicting reports about using clamps on push-lock fittings so not 100% on that. I'd probably trust it more than my first attempt at doing the other style of aeroflow/speedflow fittings though.

Ended up going down to my local Pirtek, having a good old chinwag with the guy there about it all. He advised against using the compression fittings more than once since the ferrules should be replaced once they've been loosened, as I thought.

So it was decided to adapt from the M16x1.5 fittings on the sandwich plate, and convert to AN/JIC with these adapters that have some cool captive o-rings as part of their assembly. Still need to confirm if they're not going to be threaded in too deep and they'll seal properly as I don't want to crack the casting. They kindly offered to machine it down if it was too long.

I'll run flexible hoses from here instead and probably use a new cooler rather than adapt the original small unit. At least that way I can keep a complete oil cooler setup and haven't hacked up anything.

The stock units are all reusable bsp fittings except for the adapters that thread into the sandwhich plate (standard metric to bsp) which just use aluminum crush washers

The later style oil to water cooler is better as it will warm the oil in cold weather and cool better in summer as the oil will stay within 5c of the water temp. There are good reasons that most everything modern uses an oil to water sandwich plate config

Hm, I took the lines with me and they seemed pretty convinced that the little ferrules on the swaged hard lines aren't reusable. Oh well.

Though I had both, the condition of the water/oil cooler was not great. The water lines and jacket were 100% caked in mud and rust and took a lot of cleaning to get water flowing. After reading that the donut coolers can get pinhole leaks in them, I decided that out of the two, that it was less risky to go with this cooler since the car it came off had quite low milage for a 1991 940.

I was hoping to use the water cooler because it's a way cleaner, neater and easier install and I'd probably have it in the car by now, but such is life. Can you buy the water/oil sandwich plates new? A quick search of the usual places didn't turn up anything. If they're available I'll look into getting one for the next engine I do.

Yeah, I've probably made this harder for myself than need be :(

http://www.skandix.de/en/spare-parts/cooling-system/oil-cooler/oil-cooler-engine-oil/1021938/

Ah yep, thanks for that. I remember seeing it at skandix now you've given me the number. I think I'll continue with the air/air cooler for this one and keep that in mind next time. It's not a trivial expense regardless of which way I end up going, though I do like the idea of not having oil lines all over the place. Sigh.