Grinding a 6 volt Bell Housing to Accept a 12 volt Flywheel

Darryl Auch
Darryl Auch of Darryl’s Air-Cooled Engines, of Neosho, MO, has been building Air-Cooled VW engines since he was 12 years old.
In this video, he demonstrates How to Open Up a 6-Volt Transaxle Bell Housing to accept the larger 12-Volt Flywheel. Most everyone in the industry has done this at one time or another, he said. Horsepower jumps from 40 to the more capable 1600 dual port in these 1950 to 1966 Volkswagen 6-Volt models.
As you watch, you’ll notice he walks you through each step, gives advice on the tools used for grinding purposes, and covers what parts or products you will need to purchase from Mid America Motorworks.
If you choose to upgrade the starter as well, you’ll need to visit mamotorworks.com and order a starter nose conversion bushing converter which is part number 382-621. This item is identified as Bushing, 1949-1966 12 Volt Starter with 6 Volt Transaxle on our website. In the OEM Air Cooled Volkswagen Transaxle from the VW Factory, this brass bushing is pressed into the hole of the transaxle bell housing where the starter passes through to meet the flywheel. This bushing is for a 12-volt starter being installed into a 6-volt transaxle only.
The bushing supports the starter shaft, aligns it with the flywheel, and prevents it from chewing up the soft metal of the bell housing, which is usually either magnesium or aluminum. It also provides support for a more positive connection between the starter gear and the flywheel during the engine starting process.
Other items you may need to purchase are the 200mm clutch and pressure plate and the flywheel. Mid America offers these as part numbers 384-400 and 355373 at mamotorworks.com. Our 1963-1970 200mm Clutch Kit is manufactured for a proper fit (once you’ve modified the bell housing) in your 6-Volt Air Cooled Volkswagen and is made for the early style release bearing Installed prior to 1970.