Mahle Barrel Installation
 

I'm thoroughly confused about the installation of my Mahle barrels on my 1980 119cs

I have 2 books, one of which is Wayne's which show 2 ways of installation. I am comparing the larger fin area vs. the shorter relative to the bore. I reviewed the photos I took when I disassembled the engine and it shows large fin down... but the engine had been rebuilt at some point.

Help! Which way is up? Large fin or short fin?

Thanks in advance!

Install with large fin down

The forced air from the fan hits the top first. That air is heated and then makes it's way to the bottom. The bottom of the cylinder needs more surface area to keep up with the top. Fins down.

Lindy