1955 two-cylinder F1 engine

the size of the nuts used maybe giving a false impression of the valve cover length, they appear to be quite small over those used on a typical V12

it makes sense the length, it is a chain driven dual over head cam engine, so the length of 2 cylinders + the chain drive enclosed

the 'towers' are crank case vents, with a 13:1 CR i'm sure blowby would be an issue

the "thumper" name was used to describe typically the single piston engines of early motorbikes, like the harley 250cc and 350cc enduro/dirt bikes, there were some 2 cylinders as well, the name may have carried over to those

 

4.6" bore x 4.5" stroke, 175 hp @ 4500 rpm (http://forums.motorlegend.com/vb/showpost.php?p=291558&postcount=31): I think "thumper" applies.

 

For many years there was a "trash heap" in the back of the factory, which included many used up and odd engines, mostly racing types. Sir Anthony Bamford was finally able to persuade someone there to cut loose with a pile of that junk, and Anthony found among them what he thought was a four cyl. engine: 4 ports on either side so what else could it be? It was quite a while before his tech tore into it and found what until then was only an unconfirmed rumor of a 2 cyl. engine. Further inquiry at the factory elicited the response that it had threatened to shake itself apart on the test bed.
I used to have a few pix of it but they seem to have become lost in cyberhell. Oh well.

 

Amazing. Thanks for sharing..

 

Hans Tanner has a article and pictures in his Revised 4th edition of "Ferrari".From what I understand the engined suffered from severe vibration which could never be corrected. Also the best the engine could do was 175 hp at 4800 rpm on the bench. tongascrew

 

Forgot to mention Tanner article in the Ferrari Owners Club magazine of July/August

 

Forgot to mention Tanner article also in the July/August 1974 issue of the Ferrari Owners Club magazine. tongascrew