>it has in it an odd motor (to me). No Nissan markings on the valve
>cover, has the intake manifold on the left (passenger side), with two
>mikunis that look alot like solexes. he said they were 40MM. the head
>is sporting two plugs per cylinder.
>the thing sounded like it had some getup and go!
In an '85 it was probably a Z-24. Did it say NAP-Z? 2400cc with a
crossflow 8 plug head designed for lower emissions rather than with any
performance gains. I'd have to look to be absolutely sure, but I do think
Nissan Comp offered a dual Solex/Weber manifold for it along with at
least a couple of cams. The Z-motors (20/22/24) were basically
evolutionary versions of the L-series, with the crossflow head. The Z-20
and 22 share the same deck height as the L-20, which is 3/4 taller than
the L-16/18 blocks. The Z-24 is another 3/4 taller yet. Engine mounts at
a different angle than the L-series, too.
These bigger motors have been fairly popular swaps for the 510 since it
really is pretty much a bolt-in. Most of the time the Z-head will be
replaced with an L-head because even though it's crossflow, the Z-head
wasn't designed for power or torque and there's not enough meat in the
casting to allow this to be corrected. Also, since the Z-24 block is
taller than the L-20/Z-20/Z-22, there's no off the shelf timing chain
set. You have to make one, usually using a Mercedes chain with a master
link. Then you have to deal with the hood clearance issue caused by the
taller block. Consequently most use either the Z-22 with an L-head, or
drop the Z-22 pistons/rods/crank combo into a bored L-20 or Z-20 block.
This is the motor that I'll be building for our street 510. Basic idea is
the same as replacing a 265 or 283 Chevy V-8 with either a 350 or a 383.
Same external size with a bunch more cubes for torque.
For a really in depth discussion of all of this, check out the L-series
specs on Jason Gray's site at:
http://home.att.net/~jason510/Motorspecs.htm
Jason has also put together a number of other very informative pages off
of his <http://home.att.net/~jason510> main page. A couple of the pages
on Webers and ignition are applicable with virtually no alteration to the
R and U motors in the roadsters.
Because of the already mentioned height and complexity of using the Z-24
block, most who want more than 2200cc motors are going to the KA-24 which
offers the further advantage of EFI. There are at least a couple of
really nice KA powered roadsters running around NorCal, AFAIK. I think
Bill Kenyon had his for sale. Wonder if he did in fact sell it?
FWIW, Ron
Ronnie Day
ronday@home.com
Dallas/Ft. Worth
'71 510 2-dr (Prepared Class Autocrosser)
'73 510 2-dr (Street Toy)
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