Just need the F and L, though. I know the rest.

that picture i posted is an L


another type of engine: flat 6---horizontally opposed cylinders like in the old Tucker Torpedo [edit: whoops Sol already talked about those]

Don't forget that V-engines come in several flavors: 90 degree offsetted cylinder banks, 60 degree, etc. If you want to get really wild there are the radial airplane engines with a dozen cylinders in one plane and a single crankshaft journal

Ok, that pic wasn't there earlier. That looks like a two stroke engine. It doesn't seem to me that would be a good setup for a four stroke engine. I wonder why GM was using it?

yeah i edited that picture in. No, that is most definitely a four stroke. Two strokes have ports in the side of the cylinder wall.

crap-i had a picture here but it'* probably copyrighted

You see, with the valves beside the cylinder in the block like that(back to the L-head engine), there is no longer a need for pushrods or rockerarms, and the head is simply a bolt-on cap. Very useful in small engines. I've never heard of an L engine in a passenger vehicle before, but then i don't pay much attention.

Ok, yeah, you're right. Brain fart. It just seems like that would make the clearence volume (combustion chamber) too large for a truck engine to run at anything higher than like a 7:1 compression ratio.

I want a breakdown of it all if someone can do tis for me.

hey John Deere Boy, splain me nail-head motors?

John Deer Boy is right. However, the "L4" engines used in the *-series trucks are actually I4'*. They are just called L4'*. The Horizontally Opposed 4 is also called an "H" engine and was used in VW type I, II, and III cars, as well as Subaru. The Horizontally Opposed 6 is called a Boxer engine (Porsche). Flat head V 8 engines had L heads on a V block. The L heads are not very effiecient as the combustion charge is not evenly distributed in the power stroke. This evolved into the wedge head, then the semi-hemisphirical (most common today), then the Hemi (Ford and Chrysler used these starting in the '50'* and ending in the early 60'* and early 70'* respectively--with the re-introduction of the Chrysler hemi recently in the Ram Trucks and Durangos). The problem with the Hemi is that it requires a very large head, and thus takes up more space and is more coslty to produce. It is perhaps the best (most efficient) design of combustion chamber available. After the hemi came the over head cam engines, and finally the variable valve timing engines.

Saab made some V4 engines for their cars in the early days, along with some in-line 3'*. Mercedes made turbo diesel 5'* (in-line), and of course GM is doing it in their midsize truck line. Throughout mechanical engine history many configurations have been attempted, but the most reliable are the common ones used today--namely the in-lines, the V'*, and some of the opposed engines. W'* are still relatively new, but seem to be a good configuration.

An L4 should be an inline four. It'* a less common way than I4. That'* how I know it.


Inline-six is where it'* at, for me Smoother than a V6, usually more powerful, but generally less fuel efficent.

ah yes, the ill-fated nail-head motor. GM had to abort this model because redneck mechanics thought it only took one common tool to work on them.