> Date: Tue, 25 Jan 94 11:29 EST
> From: jeb@mtqua.att.com
> Subject: Click & Clack on Bleeding Cooling Systems
>
> The discussion of bleeding cooling systems reminds me of a tip I
> picked up from the "Puzzlah" on Public Radio's "Car Talk" show.
> The answer to the puzzler was that when the crusty old mechanic
> was installing a cooling system thermostat, he pushed the thermostat
> open and kept it open by sticking a couple of aspirin tablets in it.
> Then when everything was assembled, coolant could flow into the
> engine even though it was cold. The aspirin tablets would soon
> dissolve and the thermostat would operate normally.
>
> I've always wondered if starting the engine up with no (or little)
> coolant in the block was such a good idea. The temp sensing side
> of the t-stat is in the block, right? Surrounded by just air
> before the coolant starts filling the block. Seems like there might
be
> some hot spots develop before the coolant starts circulating and
> filling the block.
>
> Jim Beckman jeb@mtqua.att.com 1955 A-H 100
Having the thermostat exposed to a head full of air rather than
coolant is likely to be disastrous. Air, even hot air, is not likely
to contain enough heat to cause the thermostat to open in a timely
manner. If you have ever lost coolant suddenly, you can probably
verify that hot air sometimes will not even cause a high reading via
your temperature sending unit.
It is not really a good idea to have a thermostat that totally seals
off flow, even after the system is full and bled. A tiny amount of
leakage is helpful for allowing air bubbles to migrate to the radiator
cap, and a little flow past the closed thermostat helps it sense that
the engine is warming up; if the flow is truly stopped, it may be
quite a while before the heat from the engine makes it to the
thermostat housing to cause it to open.
Most thermostats therefore have a bypass feature. Some have a notch
or hole in the flange to allow a tiny amount of leakage, and others
have a notch in the seat of the thermostat valve itself. Other
systems have a plumbing scheme that effectively allows flow around the
thermostat housing. The Jaguar V12 thermostats have "wiggle pins"
which are actually holes in the flange with a tiny pin with a rubber
ball on one end; theoretically the ball will seal the hole when flow
tries to go one way, and the wiggling of the loose pin will prevent
air bubbles from stopping the opening from the other way.
If your cooling system has the possibility of the thermostat totally
plugging the flow, you should drill a 1/8" hole in the flange of the
thermostat before installing. Install with the hole upward to
optimize the passage of trapped air. The tiny bypass will have no
negligible effect on the operation of the thermostat, since the
thermostat will still modulate to allow just enough flow to maintain
the proper engine temperature.
> Date: Tue, 25 Jan 1994 16:04:15 -0800
> From: Roland Dudley <cobra@cdc.hp.com>
> Subject: Silver Streak
>
> Following a "start simple" strategy I bought a set of points and a
> condenser at a local parts store and installed them first thing.
> One thing I noticed about the replacement parts was that they were of
> much better quality than the ones they replaced. First off, the old
> condenser mount consisted of a piece of stamped sheet metal rolled
into
> semi-circle to retain the condenser body. Since the metal was very
soft
> it didn't have enough springiness for this purpose. Secondly, this
> condenser has caused problems in the past.
Glad to hear you got your problem licked, and with very little expense.
I dunno how much your engine has in common with the low-performance
289 that was in the 1966 Mustang I used to own, but I can vouch for a
couple things: First, the variance in the quality of tune-up parts is
extreme. Steer clear of any "pivotless" points. I never had any
trouble with the clamped-type condensors because I used a washer that
helped the clamp hold the condensor securely. Also, I had to change
the plugs every 5000 miles, regardless of which brand I used, or the
car would start misfiring big time even though the plugs coming out
always looked clean and unworn.
By the way, it seems to me you've gottalottadamn gall to discuss this
Ford on the british-cars list. The AC Bristol beer can the car is
based on may have been British, but there ain't nothin' British about
that stumbling motor or the Texan that put the contraption together!
:-)
> Anyway, the new condenser is soldered to its mounting so that source
of
> ground woes should be cured.
I sincerely hope you mean that the condensor is tack-welded to the
mounting, as many of them are. I would not trust solder in this
environment.
> Another long postponed job tackled was the the steering
rack-and-pinion
> gaiters clamps. Oil has been seeping past these clamps every since I
> installed new gaiters last summer.
It may sound chincy, but I have had the greatest success securing
gaitors (and CV joint boots for that matter) with wire. Choosing a
suitable gauge baling or other steel wire, wrap it three times around
the gaitor or boot neatly, tightly, and closely placed - preferably
right next to one another. Often it helps to wrap the wire around a
rigid metal object, such as the housing or tie rod adjacent to the
gaitor, prior to sliding it into place in order to establish smooth
bends in the wire. Twist the ends together while pulling tight. Do
not pull TOO tight, so as to not deform the gaitor or cut through it.
After creating a twisted section about 3/4" long, cut the excess off
and bend half the twisted section over the other half to prevent
exposure of sharp edges.
Regardless of reports from others, I do not recommend using zip-wraps
on gaitors or boots. The plastic deteriorates and pops off within a
year or so.
> Also it appears that some of the oil has been leaking
> from the gear box itself. This rack is essentially the same as on an
> MGB and has two access plates. One is on the top and the other is on
> the front. Each plate is held by two bolts. The front plate
appears to
> be the leaker. I tightened all the bolts some, but I was reluctant
to
> tighten them too much. I'll be keeping a close watch. It might be
> necessary to replace the plate seals.
I'm sure a couple stripped holes on those access plates would make
your life rosy. It would seem only too easy to remove the covers and
make a gasket from generic gasket material, or to seal them up with a
sealant.
--
--- Kirbert
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| Kirby Palm, P.E. |
| palmk@freenet.tlh.fl.us |
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