Description
The Vincent Black Lightning was built with two styles of racing cylinder heads. In 1950, the factory designed a head for the Grey Flash which was also then used with record breaking success on some Black Lightnings, most notably those of Rollie Free and then Burns & Wright. This second type of head is called "The Big Valve Head" or "The Burns & Wright" head.

Big valve heads feature an enlarged intake boss and intake tract leading to a 2" diameter intake valve. Otherwise, they replicate the other racing heads with polished ports and combustion chamber spheres. With such large valves, they flow much better at high revs than other heads and allowed the motorcycles to establish many speed records.

Two batches of these Big Port Heads were produced by Vincent. The first batch went on Rollie Free's own Lightning and then others went on the works Grey Flashes.

USA parts distributor, Harry Bellville had tremendous customer interest in these parts in the 50's and is said to have sent gifts of turkeys, liquor and more to wheedle the manufacture of a few more sets of the precious heads. Apparently it worked as 24 additional heads were produced having 2" intake valves and a 1 3/8" tract.

Big Sid Biberman noted that the design may have been somewhat flawed as oil tended to puddle around the lower guide area. Prior to serious racing, he recommends the lower guide be lengthened above the floor of the casting and a return line for oil to the tank be installed. Further, Sid says the exhaust valves are rather thick and heavy as installed so they should be machined down for max performance. With these modifications, he believes that 7,500 rpm is permissible with the use of S&W springs and special keepers. Lastly, he thinks the ideal carb to use for speed records is the 1 3/8" AMAL GP 2, even though this is NOT the original carb but a later and larger one than original.

Condition
The set of two BIG VALVE HEADS are in the same condition. While they show signs that they have been run at one point, they are very fresh. Importantly, they carry a set of the correct inlet and exhaust valves, peculiar to these heads. Lower valve guides are installed. Springs, rockers, upper guides, etc can be added as with any Vincent engine as these are not special pieces to Big Valve heads.

Examine the set of photos of these heads to see how polished the ports are. The heads are clean, no fins are missing and in general are in a very fine condition. With the needed few items mentioned, they should install and run extremely well. Persons with a good understanding of Black Lightnings will recognize the large inlet port face as belonging to the famous Big Port Head. Correct for the Vincent Black Lightning motorcycle engine.

History
These two heads were sold to the HVG as being a part of the spares package accompanying the Burns& Wright record attempt in this country at Bonneville in the 1950's. Acquired from the then importer, Harry Bellville, along with other spares from this record effort, they passed into the hands of two US collectors after Mr. Bellville ceased operations.

Pricing
COntact Us for pricing

Documentation
As no title documents exist for these cylinder heads, HVG will offer a bill of sale incorporating the information given above to the new owner.

This item cannot be purchased from the website. Please contact Harris Vincent Gallery to make purchase arrangements.