Geo Hahn wrote :
> > Mine doesn't overheat but I've done about every trick in the book to try
> > to help it stay cool in AZ summers. Let me know if you want a quick
> > run-down of those items.
Joe Maher replied :
> Could I get a run down of those item?
Here's a few things I've learned. First the ones that work for me :
1) Have the radiator recored with a modern core and no crank hole. Or, at
the very least, have it professionally rodded out and tested for efficiency.
This was the "magic bullet" for me ... my stock radiator flowed OK but had
really lousy efficiency. Apparently there was corrosion (or just air space)
between the tubes and the fins, blocking heat transfer.
2) Make sure the vacuum and centrifugal advance are both working. (We're
talking TRactor motors here, those of you with no vacuum advance will just
have to suffer. Or convert.)
3) Replace the carb jets and needles if they haven't been done recently or
you've ever found the needles to not be properly centered.
4) Make sure the water jacket inside the engine is clean, and is kept that
way. If water doesn't positively gush out when you open the rear drain
valve, chances are there is crud piled up behind #4. It can be very
difficult to remove by simply flushing ... best to take it to a radiator
shop and have them chemically flush it. (For some reason, the good
chemicals are no longer sold over the counter ... maybe because modern cars
won't stand up to them.) If flushing won't get it, you'll have to remove
the liners and use a wire brush (which I did with the engine still in the
car).
5) Whatever thermostat you use, make sure it opens fully by 195F or so.
This can be tested on the kitchen stove, with a pan of water and a candy
thermometer (but be sure your SO isn't around if you use her candy
thermometer).
6) Make sure your temperature gauge is accurate. Originals can be rebuilt,
or physical replacements can be had fairly cheaply (mine's a "SunPro", cost
about $25 at Pep Boys).
7) If your problem is idling or stop-and-go traffic, fit an electric
radiator fan. I removed my original fan entirely, and installed a 16"
Hayden behind the radiator, I never have any trouble in traffic now.
8) Use only distilled water and antifreeze. The antifreeze is only for
corrosion protection where I live, but you have to run something, and the
"anti-rust treatment" they sell at Pep Boys will interfere with cooling. I
ordered some "No-Rosion" on FT's advice, but never received it and the
vendor will not answer the phone or my emails. Change the coolant every 2
years even if it looks fine. Glycol never wears out, but the anti-corrosion
additives do, and you need to flush out the acids anyway.
9) As recently mentioned, I run 7 psi instead of 4. Don't know that it made
a big difference (but having a cap that didn't leak definitely helped). I
also don't have the optional heater ... don't know if the heater core would
withstand the added pressure or not.
10) Be sure the shroud around the radiator is in good shape. Early TR3A
(like mine) did not originally have a shroud, but it's a very worthwhile
(and factory approved) retrofit.
And the things that didn't work for met :
A) Water wetter. Theory sounds good, others say it works for them, but I
couldn't tell that it made a difference for me. The maker also says it will
inhibit corrosion ... my system crudded up just as fast as with distilled
water.
B) Sleeved thermostat. Again others swear by them, I couldn't tell the
difference.
C) Blocked thermostat bypass (as an alternative to a sleeved thermostat).
Made no difference that I could tell.
D) Do not run more than 30% antifreeze (unless needed for cold weather
obviously). More antifreeze will raise the boiling point of the coolant,
but it also reduces it's effectiveness as coolant. Pure antifreeze won't
boil over, but the extreme heat will damage other things (Dad's TR3A
eventually swallowed a valve).
Other's have had different experiences ... let's hear them !
Randall
Lakewood, CA - but with occasional trips into the Mojave desert
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