What the heck is this?

[flbenz]

I have a 76 450 sl and as I was searching parts diagrams I came across this one for a "Fuel Cooling System" with a little note "for Japan only".

So, obviously it was some attempt to cool the fuel lines, but why only in Japan? And why keep it in the engine compartment where everythings is so dang hot anyway? How do you think this thing worked?

Finally, does anyone know of fuel cooling system ad-ons that were used in the U.S.? My 450 is the year with the cats in the engine compartment, so there is a real vapor lock issue.

[nhdoc]

The later cars (my '88) had a system like this. The fuel circluates in a heat exchanger around the AC refrigerant return line which is what that attachment is. It is basically spliced into the refrigerant line which runs from the evaporator back to the compressor's suction side and is pretty cold, so the fuel is cooled by running through this whenever the AC is running.

If you have AC in your 450 you could probably retrofit this system from a junked later car into yours if you experience vapor lock issues.

[flbenz]

thanks Marty
that explains it. I do have AC on this car so will start studying that option