Mike,
Steel heads run warmer than aluminum heads however I think if it's the
original rad and core it's time for a new one. My 66 1600 ran "warm" also
despite a relatively new recore, and going up hill I could watch the temp
gauge rise and down hill it would go down. The 2L rad I had recored last
week is a better core than the one I had installed about 20 years ago as it
has more fins per inch.
I would occassionaly get spikes too and it may have to do with cavitation or
the thermostat, I was never able to figure out which despite changing the
thermo and burping the coolant system by squeezing the lower rad hose when
filling it up. I do know that bubbles in the coolant can make an engine run
hotter and Redline waterwetter is suposed to help by lowering surface
tension and creating a sheeting action. I used it and saw a minor lowering
of my temperature. Additionally, run a weaker antifreeze mix as too much
antifreeze lowers the ability of the heat exchange. Water is the best
coolant but not very good at preventing corrossion. A higher pressure rad
cap should also help but I never tried that - yet.
I did notice after disassembling my original 3 main engine that many of the
coolant passages were restricted by casting flash. I was amazed at how much
flash was blocking the passages but my H20 block seemed much better in that
regard but I still Dremeled out all the passages.
Additionally, do you still have that water valve on your manifold which
controls flow to the heater core? If not I would suggest you drive with the
heater valve open. I noticed that when I closed the heater valve my car
would run much hotter but I didn't have the valve on my manifold.
Is your air guide still on? I heard this helps a lot too. Fortunately I have
a new one which I will mount on my new rad and hope it helps keep my stroker
cool.
Mike
----- Original Message -----
From: "Mike Harper" <roadsterdude1600@yahoo.com>
To: <datsun-roadsters@autox.team.net>
Sent: Monday, April 30, 2001 8:48 AM
Subject: Overheating Problem (Return from RA)
> A great weekend at Road Atlanta with SEROCers. More
> on that later, as I have time to catch up on E-Mail
> and make a Loooong posting about the fun. However,
> this is the un-fun part, and I want to pick some
> brains B4 I prepare to start work on the 1600.
>
> The "heating" gremlins were out in force this weekend,
> as Brad Holmes had some overheating problems in his
> beautiful 2000 Solex car on the way from Alabama. We
> all tweaked the car during the weekend trying to
> pinpoint it, and I left the crew to return to
> Charleston SC while they were still fiddling, so I
> hope it went well.
>
> I was very proud of my old 1600 on the trip out, and
> while there, commenting that the temp pegged on 185
> the whole trip. I spoke too soon! About 1/2 way home
> I began to get temp spikes, so I stopped to check.
> Everything looked fine, the water was circulating, and
> I thought at first it may be a guage problem, because
> it would rise to 240-250, then return to 190 for
> several miles B$ repeating. I stopped & removed the
> thermostat. Thought that solved it because it did
> great for 20 miles or so B4 repeating the above
> antics. Drove 40 more miles of Interstate with
> occasional spikes, returns, until it spiked and stayed
> for a mile or so. I stopped again, and this time it
> was damned hot! I tightened an already tight fan
> belt, brushed bugs off my radiator, cheched for
> leaks/seepage, said some words over it, used my last
> water supply & the meltings from my cooler to top
> everything off, and drove another 4 miles B4 stopping
> again. This time sure that I have a real problem.
> Lost the gasket to my pressure cap, and was lucky
> enough to be near a friend's house in Aiken SC.
> Called, and hobbled in a few miles at a time. That is
> where my car is now, 150 miles from home, with a
> heating problem I need to fix at first op. I do not
> think I did any damage, but I seek advice. New water
> pump installed 1 year, 1000 mikes ago, original
> radiator with some "weld" repairs around the fittings
> (PO), coolant changed last year, 4 bladed fan w
> shroud. Where do I start? I am thinking a recored
> rad just because, and new pressure cap for starts, but
> wondering if these symptoms mean anything to anyone
> from experience. The spiking & returning thing kind
> of threw me, but may be symptomatic of something.
>
> BTW, the fuel guage was constant. I know the voltage
> reg under the dash controls both & I was hoping for an
> erratic fuel guage too, but no, It is definitely
> heating.
>
> Thanks for your patience with this loooong post!
>
> Mike Harper
> '66 1600
> Charleston SC
> Yahoo! Auctions - buy the things you want at great prices
> http://auctions.yahoo.com/
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