early ulh heads

[jorrow]

What does the one slash, two slash, etc. marks on the bottom of the head refer to, ...years used or compression....? thanks jeff

[Rub]

The marks are compression markings based on the combustion chamber volume. 1 slash the lowest and 3 being the highest.
Robbie

[jorrow]

So I take it ULH would be a three?

[Rub]

Generally that would be the case, however any compression could be had on any engine as desired by the owner. Commercial units usually had the lowest, also export units to countries with poor fuel. Most U and UH models were medium with UL and ULH being high. The heads also may have numeric coding on them reading 10.5,9.3, or 8.2 with the lowest number being the highest compression. And high was only about 6.5 to 1.
Robbie

[jorrow]

thanks rub....

[8 valve]

4-sale in germany,check the video
Harry
http://www.youtube.com/watch?v=xYmVydE0nxY

[Steve Slocombe]

There was an unmarked VL/U/UL/ULH 9-bolt head used 1936-47 which was the low compression one with 10.5 cubic inch capacity. These were seen on those 1942U sidecar bikes that went to South Africa, and others. The one bar heads were 9.3 cubic inch 'medium' compression, this having been called high on the 7-bolt heads used up until 1935. The two bar one was 8.2 cubic inches capacity and called high. The three bar one seems to have been a rarely seen special order head with 7.3 cubic inch capacity. The ULH probably took the two bar high compression head, but I've seen 36VH bikes fitted with the one bar heads, either because they were used on sidecars, or maybe police bikes wanting softer compression for patrol. Note that you can the see the bars from outside the bike when judging.

[Neil74]

That's a nice running FlatheadThanks for the link Harry