From: erik@peewee.nwc.navy.mil (Erik van Bronkhorst       Code 3814                               Phone 939-1421)
Subject: Re: 240Z-280Z Problems
Organization: NAVAIRWARCENWPNDIV, China Lake
Date: Thu, 12 Nov 1992 18:06:30 GMT

In article <BxKyAD.Fu@news.cso.uiuc.edu> mchaffee@ux4.cso.uiuc.edu (REAL LIFE?!?!  HA!!) writes:
>tavernin@rm1.interlan.com (Victor Tavernini) writes:
>
>>I'm thinking of buying a 240Z, 260Z, or 280Z and was wondering if any
>>specific model/year had any serious problems ... besides rust :-)
>
>The earlier the better.  IMHO, the best Z-cars (the new 300 excluded-maybe)
>are the very first ones, that is, the 69-70-71.  After 71 (or was it 72?)
>emissions controls just slogged down that lovely 2.4-liter engine and made it

73 was the smog-dog year for the 240.  It is also the last year they were
made.  The 260 was made in 74 with the same engine (+200cc whooopeee) as
the 73 (smog-dog carbs).  The 75 260 had fuel injection.  Neither worked
very well.  In 76 the first 280 came out with a brand new injection system,
engine, and rear suspension.  Performance buffs prefer the lateral or
"Chapman" rear struts of the 240 (&260) to the semi-trailing arms of
the 280s.  All 280s including ZX have the same dumb semi-trailing rear susp.

>most icky to drive.  Datsun's solution:  Bigger engine, heavier car, no more
>power - the 260Z.  STAY AWAY.  The 260 wrecked the original concept of the 240
>so well, Datsun took it a step further with the 280Z.  The emissions controls 
>were awful from '72 (or was it 73?) right up until they started using EFI.  I
>can't remember whether there were any Z's (as opposed to ZX's) that used EFI,
>but I still think the best choice is a 70 or 71 (the 69's are VERY RARE).  
>Even though the 280 accelerates a little faster, the 240 is so pleasant to
>drive.  It handles better due to less weight and it's more fun to drive due
>to razor-sharp throttle response.

According to all published test results I have seen
the Datsun Z cars *decreased* in acceleration linearly with time from their
inception until the first 280ZX Turbo appeared.  In other words, any stock
240 is quicker than any stock 260 or 280.  The ZX Turbo broke the cycle
beating the early 240 by a tick.

>One caveat on a Z:  My dad has an early '71 240Z, and overall it's been remark-
>ably durable and stuff (admittedly, he IS the original owner and it only has
>40,000 miles.  It's not for sale.)  but there's a problem with the head gasket.
>If you lug the engine, it likes to blow head gaskets, so remember:  If you want
>to pull serious power, make sure you're above 2000-2500 RPM when you do it.  And
>make sure you use premium gas.  It really needs the octane.

True.  240s don't *make* any power below 3000 anyway so if you know how
to drive this should not be a problem.  They need all the octane you can find.  
They can be a bitch to get started on cold mornings, this is the one nice
feature of the 280.  With their FI they start right up and you can actually
drive them without having to warm up for 5 minutes.  Plus the 240 takes 
another 10-20 minutes of stop and go driving (probably less if freeway) to
warm up enough to respond when you put your foot down...

Although I have not heard of (nor had) any head gasket problems, they
are known to occur in engines with iron block and aluminum head as the
Z cars have.  The difficulty is the difference in expansion rate and amount
between the two materials.  I maintain that if the head and block are 
sufficiently flat, the head torque is properly maintained, and the engine
is properly warmed up and driven, there should not be anything to worry about.
-- 
Erik van Bronkhorst KC6UUT DoD#4342585443 AMA#[classified]
"Truth is false and logic lost, now the fourth dimension is crossed..."