L20b with a Z series slant?

[motavated]

Look carefully at this pic... See the extra holes for the mount bracket positioning? In the passenger side, it also has an extra set of holes. I took this engine of a 720. Is it possible to use a z series 5 speed trans on this engine with Z22 engine mounts? Were these L20b's slanted like the Z series engines? I just looked at a 79 engine l20b engine. And its does not have these extra holes... Thanks!

[datzenmike]

The Z series sit more or less vertically in the engine bay. The L series sit 'tilted' over to the passenger side about 12 degrees. I suppose you could use Z series mountings and position the L more vertically and use a Z motor transmission... but the intake and exhaust will be tilted down toward the steering column, carb and oil pan will also be tilted. I guess you could use a Zseries oil pan and pick-up but the dip stick will read wrong.

[motavated]

Ah! Thanks!

[datsunaholic]

The reason for the extra holes is by 1980 (actually, by mid calendar 1979) all L20B blocks were actually Z20 castings. If you look between #2 and #3 cylinders there's an angled flat surface on the block, which is where they would machine flat and engrave the Z20E or Z20S engine designator and serial number. L20Bs prior to the 1980 model year didn't have these extra castings.

 

Since the L20B and Z20 were virtually identical, it made sense to make one casting then machine them to whichever spec they used. I have several of these late casting L20Bs. The serial number all end with "W" on a separate machined pad. I've also seen L16s with the same weird NAPS-Z castings, though in those cases they are likely a Z18 casting, used for "crate" replacement engines.

[datzenmike]

Doug, you have filled in a huge gap. There was a block on here, supposedly an L16 or 18, that had the Z boss on the driver's side. I asked if it was a z20 block but don't remember if it was answered. Makes total sense.

[datsunaholic]

That would be me. I've seen another one posted here too. The "crate" L16s weren't all that uncommon at one time, showed up as low-mile Japanese used engines too. Mostly had non-EFI W53 heads on them.

 

This is an L16, but you'd never know it unless you looked at the serial number:

 

 

The "proof" of it's crate-engine origins is the 2 dipsticks: one for rear sump apps, one for front-sup apps. They didn't know where the engine was destined.

 

 

 

One of my late L20Bs, but with the Z20 casting bosses on the driver's side. Identical to the engine queried about in the post:

 

 

The curious thing is that both of the "late" L20Bs I have with the NAPS-Z castings and extra mount holes are for some reason painted Chevy orange.