05 September 2015

L14-4V and L18⋅R-4V Part 1

For interests and interested readers' sake only! :-)...I present this post.

The L18⋅R-4V bears possibly identical specs to my 120Y B210 LZ18!

All opinions are mine alone and should be taken with a grain of salt! :-)

Following on from my previous post of the Formula Pacific L14-4V the following are some details of the engines offered.

These all refer to the later version of what we call the Nissan 'LZ' series of engines. The 'LZ' prelabel are used by the western world in reference to this Nissan engine series. The earlier version of the cylinder head had the smooth camshaft cover. The cylinder head was cast as a single piece incorporating the camshaft bearing journals and tappet bores.

By later version, I mean the cylinder head version that comprises 3-layers much like Cosworth's BD series engines.

Top camshaft cover.

Picture above does not show the camshaft cover.


1) Cylinder head

2) Camshaft journals and tappet holder

3) Camshaft cover

Offered for sale...one time in our past! 70s and 80s...possibly ex-stock of parts ran out and stopped by early 90s.

Dowels and bore info.
The names of the later version of the 4-valve L series 4-cylinder engines were:
1) L14(4V) or L14-4V
2) L18R(4V) or L18⋅R-4V

Two bore sizes were offered for the L14(4V) while the L18R(4V) had only one.
They grind cast finish of the L blocks to a smooth surface to help oil return to sump faster.

Enlarging radius of edges of the main bearing caps where it transitions onto bolt cap seating surface for stress concentration reduction.

Engine block oil/water gallery plugs and other mods for 4V head.

Interesting! Use of 'honing' plate. I can see it's more than 2 inches thick, possibly 3 inches or more.

I'm guessing the following:
1) Special honing sequence by cylinder numbers are given, 2-4-1-3 then 3-1-4-2.
2) Check of taper and roundness at depths of 20%, 60%, 100% in positions A and B.
3) Taper and out-of-round were not to exceed 0.02mm.

Engineers were serious about getting their bores round and straight cylindrically!

This seems to indicate the machining specs for depth and cylindrical recess diameter at the top for installation of the Nismo Z-ring/Gasket combo.

Also shown is the deck flatness tolerance of 0.03mm max measured with a straight edge in that manner.

Lastly bottom shows a breather piece install spec.

No comments:

Post a Comment