What makes an L-head 6 an L-head?

[MIClassicGirl]

Can one of you guys answer this for me? (I know....that really is a dumb question here!) I asked my husband cause he's a mechanic & I got a blank stare! I've read the engine on the Victory Six is one of these & I was wanting to know why it's called that. I understand V8's, flat-heads and all that stuff, but not sure on this one. Thanks! Shannon

[keiser31]

They are called "L heads" because the pistons are on one side of the engine and the valves are off to the side/top.....like an upside down "L". NOT a dumb question at all.

[Phil 32DL6]

Shannon...Look at the attached picture while standing on your head and all will become clear!

[MIClassicGirl]

Ohhhhhhh!!! I get it! Was there a reason for being designed this way? I think my husband will find it interesting too! Thanks guys!

[Rusty_OToole]

They were designed this way for a reason. In the early days there were many variations on where the valves should go. OHV, T head, F head, L head etc.

The flathead or L head configuration was popular because it was simple, cheap to build, easy to service and repair, and if a valve spring broke (common in those days) the valve did not fall into the piston and wreck the engine, in fact the engine would continue to run almost as well as ever. The valve mechanism was also very quiet.

The down side was, other engines (OHV and OHC and F head) were more efficient.

This changed in 1921 when Harry Ricardo of England introduced the Ricardo cylinder head design. It increased the compression of the flathead and made it more efficient, and competitive with the more complicated and expensive OHV designs.

After that the L head or flathead engine was king for 30 years. Nobody built any other kind of engine except for a few firms that had pinned their reputation to the OHV design and refused to back down, like Chevrolet Buick and Nash. And a few very expensive, very powerful luxury and sports cars that featured high performance overhead cam engines like Duesenberg, Stutz, and Bentley.

As for who made up the names L head, F head, T head, OHV etc I believe it was invented by someone writing handbooks or parts catalogs who needed a shorthand system of classifying the different engines.