Hi all,
Just had my radiator and heater rebuilt. Replaced the existing 4 row standard
core with a 4 row high efficiency core. I suggested the Modine H69H core number
(that was out on the list a few months back) and they told me that was not any
Modine number they ever heard of. Anyway, they located a suitable core (Pacific?
that was a name they dropped), had it shipped to Calgary overnight, and rebuilt
the rad the next day. It looks pretty good; I guess the real test won't come
until this summer. The core has the tubes on 7/16" centers; not really tight
spacing but still better than what was there before. The rad is a little thinner
than before but I probably won't gain too much there.
For what it's worth here's the recent history and my plan for the cooling
system:
When I got the car last summer, it was outfitted with an electric pusher fan in
front of the rad, a 6 blade Ford fan on the engine, and the stock shroud. No
thermostat. The heater control valve was missing and replaced with a piece of
straight pipe, while on the other side (the heater outlet hose) a
petcock-looking valve block was inserted into the hose. I should have looked at
this more carefully; it turned out to be a shutoff valve, which was in the 'off'
position. Judging by the amount of sludge and corrosion packed into the hose on
each side of this valve, it had been 'off' for some time, and cranking the
control open would not have done me any good. Oh yeah, there's an oil cooler,
about 4" high and about 20" wide, mounted in front of the pusher fan, taking up
most of the lower valence air opening.
On driving the car, the water temperature was all over the place. Eventually got
around to replacing the thermostat, which is when I found there wasn't one. Some
of you will recall my earlier 'what's the thread on the F4B thermostat housing'
postings. The lower (towards the camshaft) hole was comprehensively destroyed by
someone (the PO's mechanic?) helicoiling the hole, then pulling the helicoil so
that any bolt put in there would crossthread. I managed to remove the old
helicoil and then grind a bottom tap so that I could rescue what was there, and
put in a new helicoil and stud. The new thermostat housing just fits between the
studs and the water pump housing - yay.
Drive the car some more - the water temperature is WAY up. Off the gauge. But
the car runs fine. Grab a thermocouple and meter from work, jam it between the
rad hose and the radiator outlet neck - OK, the gauge is not reading correctly.
I checked under the dash, to find that the instrument voltage regulator is
grounded to the dash. After mounting it to the dash _rails_, it started to work
intermittently. Instead of getting high readings all the time, I'd get zero
sometimes, and OK readings sometimes. 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.
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.
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.
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.
6. The ignition timing is set way wrong. Haven't checked this yet. I know, this
is the easiest thing to check.
7. The car (according to the PO) has a 289. Sure hope it's not a rebored 260 or
a 'way overbored 289...
Did I mention that the heater didn't work? You know that with that shutoff valve
turned off, the coolant in the heater doesn't circulate, and if what's in there
is not good enough to survive a -30 degree weather blip, it really wrecks the
heater tanks. I had to pry the sides of the tanks back in to get the heater out
from its mounting place. Fortunately I had another heater assembly lying around
for the rad shop guys to rebuild. I'll save the old heater for when I need to
practice my tinbashing and soldering skills.
I found a heater control valve from an early-Eighties Honda Civic (not quite
what SS suggested, but close) and I should be able to restore close to original
heater functionality to the car. I also re-lubed the heater blower motor's
bearings (that's a fun one), and afterward I found that the current draw is 1A
on the 'high' setting with no blower on the motor, and about 3 A with everything
assembled (i.e. squirrel cage on the shaft, and the whole thing mounted in the
plastic blower housing).
I hope I didn't bore anyone to death with this essay.
Theo Smit
tsmit@novatel.ca
B382002705
|