The "Roof 16" aftermarket OHV cylinder head for Dodge Bros.

[Bill Crowell]

I just love this brochure!

The Dodge Bros. 4-cylinder motor was a flathead, but (then) well-known automotive engineer Robert M. Roof designed an OHV head with 16 valves, and the valves were larger than stock. Apparently it really perked the DB motor up. The original DB flathead had "L-shaped" combustion chambers, but the Roof head had round chambers.

Here's the brochure. I hope you enjoy reading it. I think it's a classic.

http://users.innercite.com/bcrowell4/other_files/roof_head.jpg

 

[Bill Crowell]

They were discussing the Roof head recently on the Dodge Bros. page of the Antique Automobile of America site. Apparently the Roof head produced so much power that the crankshaft and main bearings would fail if the driver kept the power on too much, too long. The early DB 4-cyl. engine had 3 main bearings and a non-counterweighted crankshaft. They put 5 mains in the engine in 1927, only to have the 4-cyl. discontinued the next year when Chrysler bought DB and went to 6-cyl. engines.