I've heard from numerous people (some very reliable, some questionable) that they are the same exact engine with an extra cylinder "slapped" on. Sorry I don't have a definite answer for you.
Short block 16v engines rods are 144mm long with a 20mm pin, tall block engines rods are 159mm with a 21mm pin.Golden91CQ said:Aren't 16v rods 21mm wrist pin and the 5 cyls 20mm?
Rallyfreak202 said:I've heard from numerous people (some very reliable, some questionable) that they are the same exact engine with an extra cylinder "slapped" on. Sorry I don't have a definite answer for you.
Try bolting up an AAN intake manifold to a 16v cylinder head. :wink: I have seen an AAN intake with an end lopped off & a block off plate installed on a 16v engine. The 4 &5 cylinder engines of this era are very similar.
The rods in the 7a NA 20valve engines, 3b & AAN are the same rod. The drilled hole in the rod is used to allow pressurized oil to lubricate the piston wrist pin. Without this passage the wrist pin relies on splash oiling to keep it lubricated. Pressurized oil helps keep the wrist pin cooler and allows a greater load carrying capability as there is now a film of oil for the wrist pin to "float" on. I suspect this is just an upgrade in the performance capabilities of the rod design. Not much weight difference between the 16v & AAN rods.vwnut8392 said:my brother has AAN rods, pistons, turbo manifold that's modified, and a K24 all from an S4 engine fit to his 1.8 16V engine so i know it all interchanges. I am talking about the actual structure of the rod. like the AAN has an oil passage in the middle and the 16V doesn't. whats with that? i understand that a tube is stronger than a solid structure plus the hollow AAN rod would be a little lighter.