Radiator/Coolant Flush

[FuryInferno]

Hey guys..

It's been a little while. Anyways, I recently brought my Z on a trip from Birmingham, AL to Bakersfield, CA and along the way I ran into a little radiator trouble. During the trip, one of the vertical lines (which I assume are tubes which carry the water) chipped, thus causing my radiator to begin leaking.

I pulled over for the night and used some of "Bars" radiator sealant. It was this horrible looking brown'ish gunk that I seriously thought twice about pouring into my radiator. =( But.. It seems to have done the trick.

Now, 4-5 months later, I'm going to flush the radiator, possibly a chemical flush, but I'm somewhat concerned about what this will do to that sealant gunk, if anything? Aside from changing my radiator completely, does anyone have any suggestions or recommendations about how to go about getting my Z ready better geared for this hot California heat? =P

Money is a issue, sadly.. =(

[e_racer1999]

honestly, a radiator is where it's at. from what i hear, you can pick up a decent one at your local pick-n-pull for ~50

[DaveN]

With only one leaking tube you might want to just have a radiator shop clean & repair the one you have. They'll put soldered plugs in both ends of the bad tube, a negligible capacity loss, and with the tanks off for that it's no big deal to make sure the rest of the tubes are clean inside. Salvaged radiators often need that much, and you know the history of the one you have.

Re summer heat -- Just search old threads, this subject has been beaten to death. Early Z's have marginal air flow through the radiator at low speeds and RPM, and when not moving allow too much recirculation of heated air back to the front of the radiator. Adding an A/C condenser just cuts the air flow further. The most effective fixes I saw during 10 years in Houston started with a clean radiator and added various combinations of electric fans, fan shrouds, front air dams or BRE style spooks, and a seal (which can be just a sheet of plastic or coated cloth), to block the opening between the lower radiator support and the air dam or stock valance. Some owners put in oversized radiators, but those who started with air flow improvements got better results at equal or lower cost.

My own A/C equipped 72 had a BRE style spook which included the lower seal, a fan shroud, and ran a 192 degree thermostat year round to minimize temperature cycling stresses on the head and head gasket. The only condition it couldn't handle was a large traffic jam on a 95+ degree day with a light breeze coming from the rear of the car.

[Zsomething]

I'm going to flush the radiator, possibly a chemical flush, but I'm somewhat concerned about what this will do to that sealant gunk, if anything?

If the gunk worked once. It should work again, probably. If the flush causes the leak again. I'd say just put some more sealant in.

Alternatively, I think a new after-market radiator would be around $100-200. Or you could roll the dice with a junkyard pull (which might have similar issues).

But based on what I've read, most people have luck with improving flow through the engine bay. So, some combination of: front air-dam, hood vents, and electric radiator fan could help too. (Not exactly the cheapest route, though.)

I found these links (Your mileage may vary):

http://www.datsuns.com/Tech/aerodynamics_and_cooling.htm

http://zhome.com/Care/z_cooling.htm