320i -> 323i parts
Look at two images below of a BMW E21 engine bay. The Chestnut Red car is mine with a M10 4-cylinder engine (320i) and the Blue car has a M20 6-cylinder engine in it (Josh’s beautiful Alpina C1 2.3 which started out as a Euro BMW 323i). My goal is to replace my M10 engine with a M20 engine using the factory engine and transmission E21 mounting parts so I don’t have to design and fabricate a custom solution. Thankfully I am but one of a long list of people who have already accomplished this and in the course of my research have encountered a few others attempting to do this in 2024 as well.
Thank goodness for the Internet because a gentlemen by the name of Todor Kalaydjiev published a wonderful guide on how to do this in 2008-2009 and his webpage is still up at: http://www.todor.info/repair/e21swap/ Thanks Todor! If anyone knows how to contact Todor please let me know as his entire library of conversion photos from 2015 is now a dead link.
Todor lists the parts needed to do the M20 conversion and so using that as a guide I am starting to assemble the various bits needed. I stumbled upon a 5-speed overdrive 323i transmission on eBay located in Greece and somehow the seller pinged me on WhatsApp after the purchase. Based upon the seller’s many positive reviews on eBay I followed up and asked my Greek parts supplier 🇬🇷 about other 323i bits I needed to chase down. In my mind I was dealing with Milos Columbo, the Greek Smuggler character in James Bond For Your Eyes Only played by the legendary Chaim Topol. My actual Greek contact, Sotiris, was equally as helpful as Milos was for Mr. Bond and a few weeks later a large heavy box showed up at my front door containing a 323i trans, a subframe, engine mounting arms, and a 323i driveshaft (see the top picture).
My 320 to 323i part conversion parts list guide is a work in progress but mine includes the part numbers and I will continue to update it as I make progress. Here is the link to my E21 Reference Google Share drive folder: https://drive.google.com/drive/folders/1j3Ty1dEpt4A4-ucNlvSna17ariHGw4HR?usp=sharing
Additional M20 conversion references I was able to dig up:
Thanks to MR below for providing Todor’s Bimmerforum thread: https://www.bimmerforums.com/forum/showthread.php?848310-M20-engine-swap-into-320i
https://douging.smugmug.com/Cars/1980-E21-323i/E21-323i-M20-Motor-Swap/
M20 conversion for a BMW 2002: https://www.bmw2002faq.com/forums/topic/124242-m20-conversion-for-dummies/#comment-106020
There is still one big item missing, an actual M20 6-cylinder engine. I leave that story for next time…