First thing for overheating problems, Take the Radiator out and take it to a
good radiator shop and have it rodded. I believe that will cut short your
search for the problem. Pat
----- Original Message -----
From: Robert Giel <giel@earthlink.net>
To: datsun-roadsters <datsun-roadsters@autox.team.net>
Sent: Saturday, August 18, 2001 12:03 PM
Subject: New to list w/questions (a bit long)
> Hi Group!
>
> I am very new to this list and will introduce myself and my
> car in another message later on, if that is appropriate. I
> must tell you, in advance, that my introductions to the
> Datsun roadster (back in 1976) were all negative, so you
> might not want to hear them!
>
> I have so many questions about my car, but let me start with
> one or two.
>
> I have a 1966 SPL311 1600 with the original engine (78K+
> miles.) I am at a major disadvantage regarding this car as
> I have never seen (let alone had) the owners manual. The
> few Chiltons service manuals I have are worthless when it
> comes to operating the car or what to expect from it. I
> don't know the power curves for the engine, or shift points,
> or fuse values, etc. I do know, I am farther from having it
> back on the road than I originally thought.
>
> First, Should I feel unfortunate that my car has the
> original R engine (with an aluminum head)? I have been
> reading on this list that all roadsters tend to overheat,
> and that the thermal expansion difference between the
> aluminum head and cast iron block creates all kinds of
> problems when (not if) it "overheats".
>
> Is the roadster a reliable vehicle? I don't notice that any
> of you mention "babying" your stock cars on the road. Among
> all the members on this list, it looks like somebody drives
> their roadster under almost every possible driving
> condition. So, it appears nothing is preventing the
> roadster from going anywhere that other cars go, including
> deserts, mountains, in town, coast-to-coast, etc.
>
> Can anyone help me understand the overheating problems
> frequently mentioned on this list. What causes them and
> what, if anything, is done about them?
>
> 1. The temperature gauge reads from a low of 130 degrees
> Fahrenheit up to 250 deg. F with a center reading of 190
> deg. F. which implies both a linear gauge, and an
> approximate operating temperature.
>
> One of my Chiltons manuals says the R-engine uses a 176
> deg. F (80 deg. C) thermostat. That would mean a fully
> opened working temperature of 191 deg. F, (88.3 deg. C.)
> which matches the midpoint of the temperature gauge. Again,
> that makes sense, but it does not tell me what temperature
> is "overheated" and when to expect potential permanent
> damage.
>
> Short of piston seizure or a blown head gasket, what defines
> "overheating" in the ":R" engine? When should I be
> worried? When should I pull off the road and read a good
> book, or risk losing the engine?
>
> Strangely, I also read (in the same Chiltons manual): "When
> heater output is insufficient, the original equipment
> thermostat may be replaced with one having a higher
> temperature rating." It never mentions how much higher but
> the idea of making an engine that already tends to overheat
> run even warmer to improve the passenger comfort strikes me
> as "ill-advised". Speaking for myself, I think Id look for
> another jacket or even a parka if I had to.
>
> What happens when you drive in arid zones like those found
> in California or out in Arizona? What about driving in the
> mountains (my favorite kind of driving) and the extra work
> of climbing, higher RPMs, and the effects of the higher
> altitude when you get there? The coolant boiling point
> drops by 2 deg.F per 1000 feet increase in elevation,
> (thats 20 degrees lower at 10,000 ft.) what effect, if any,
> does that have on the overheating problem?
>
> The system has a MAXimum coolant system pressure of only 6
> pounds. A 50:50 antifreeze to water mixture boils at 230
> deg. F (110 deg. C.) The boiling point raises about 3.25
> deg. F for each pound per square inch (6.895 kilopascals) of
> additional pressure. That means the 6 pound system would
> start to boil over (and out the pressure cap overflow) at
> about 250. deg. F (121 deg. C) which matches the temperature
> gauges highest reading (on my car.) Does that mean by the
> time you see white steam, it is too late?
>
> What is everybody doing to keep things cooler and avoid the
> heat damage? Bigger fans? Bigger radiator (is there room?)
> or what? I was hoping to keep things as original as
> possible on this car, but not if it means ruining it.
>
> Finally, is there an archive of this list? If so, please
> let me know where it is, so that I dont have to ask as many
> stupid questions in the future.
>
> You folks are really wonderful, and the enthusiasm you all
> display for your cars and each other is magnificent,
> contagious, and inspiring. I look forward to meeting as many
> of you as possible and someday being able to contribute to
> the list, instead of just taking from it.
>
> TIA
>
> Bob Giel
> --
> Life is short, Start with Dessert!
> and remember:
> When man ultimately meets his Maker, he will have to answer
> to Him
> for all of those G-d given pleasures of life, of which he
> did not take full advantage.
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