Theo,
At 05:04 PM 1/14/99 -0700, Theo Smit wrote:
>Hi all,
>
>Just had my radiator and heater rebuilt. Replaced the existing 4 row standard
>core with a 4 row high efficiency core.
Snip, Snip, Snip . . . . Yada, Yada, Yada . . . Snip, Snip, Snip . . .
>I rebuilt the voltage regulator with some solid-state parts and that fixed
that.
>
>After all that, it was still easy to get the water temp to go way up just by
>driving hard for a minute or two, which leads me to the following hypotheses
>and potential fixes:
>
>1. The rad is plugged up from not being driven very much over the last 9 years
>(that's how long the PO had it; I have no idea about what happened before
>that). I'll consider this problem (if it was one) solved.
Inspection of the old core would have been useful in determining whether it
was a likely or possible suspect.
>2. The engine fan is not pulling enough air. This doesn't hold water
because at
>any speed over about 30 MPH, the fan doesn't do much for radiator airflow.
>3. The pusher fan is blocking enough of the grille opening to matter. Since
>it's not very well mounted I'm going to remove it and do some testing this
spring.
Is it really a "pusher" fan, or a just a "puller" fan mounted on the front?
If it has a flat pancake style motor, it will block a lot of air and hurt
the cooling at highway speeds. Your idea to take it off is a good one; at
least until you get the baseline established.
>4. The oil cooler is blocking enough of the lower valence opening to
starve the
>rad of cool air. I'm thinking about replacing the oil cooler with a
smaller one.
I think the value of an oil cooler for most Tigers is questionable (my
apologies to all you Tiger Mk-II owners) and there are alternatives. For
example, you might consider a high capacity oil pan if it doesn't have one
already. I used to have a Mazda RX3 oil cooler. It's real slick - has a
thermostat that bypasses the oil until it gets to a reasonable temperature.
If you're driving in freezing weather (like I guess you have there now) a
non-thermostat oil cooler could actually cause your oil to run too cold.
>5. The air in the engine compartment is not getting out. This can be fixed by
>blocking the horn holes (to prevent air bypassing the rad) and then fitting an
>air dam or some other kind of front spoiler. I don't know if I can create one
>that won't look dorky.
These measures will provide modest improvements. Louvres in the hood will
help some too. I use a chin spoiler from an '89 Taurus. Nobody's exactly
told me it looks "dorky". Probably doesn't do a whole lot of good either
though.
>6. The ignition timing is set way wrong. Haven't checked this yet. I know,
this
>is the easiest thing to check.
Most of these engines run best with about 12-16 degrees initial and 32-36
degrees total advance full in at about 2500 rpm. (Based on a totally
mechanical distributor.)
>7. The car (according to the PO) has a 289. Sure hope it's not a rebored
260 or
>a 'way overbored 289...
Don't panic yet Theo. There are a lot of factors that affect how hot an
engine runs; like compression and clearances. And I wouldn't assume
anything unless you know the PO a whole lot better than it sounds like you
do. You can check the casting numbers to determine if it's a 260 or 289 and
what year.
A sixth hypothesis might be that your water pump is lame. One way to
diagnose this would be to check the temperature drop across the radiator
(inlet versus outlet). Get two thermocouples and place one at the inlet and
one at the outlet. If you can drive around and watch the temperature drop
under various conditions you will be able to determine if the water pump is
doing a good job. Of course, the less the temperature drop the better the
pump is working. I'd want to see something in the range of 10-20 degrees F.
Maybe the PO talked to the same pump rebuilder I did and he talked him into
cutting off every other impeller vane so the pump wouldn't pump as much
water so the water would have a chance to cool off before it went back into
the engine - well, you know the story.
Snip, Snip, Snip . . . Blah, Blah, Blah, . . . .Snip, Snip, Snip . . .
>I also re-lubed the heater blower motor's bearings (that's a fun one),
I need to do this too. Mine complains bitterly when I run it (which is
almost never, but you never know when you might need to use the defroster
to clear up some mist on a foggy San Diego morning).
>I hope I didn't bore anyone to death with this essay.
>
>Theo Smit
>tsmit@novatel.ca
>B382002705
>
Always a treat to read you postings Theo.
Bob
Robert L. Palmer
Dept. of AMES, Univ. of Calif., San Diego
rpalmer@ames.ucsd.edu
rpalmer@cts.com
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