Thunderhill was Hotter than the Holy Hinges of Hades yesterday. Miata overheated and cracked radiator. The plastic on top cracked. Limped it in to the paddock, patched it with JB weld, refilled it with water, and got it home without incident. Temperature stayed constant, and nice and cool, at 65-70 on the fwy.
Any recommendations for the best value in a replacement radiator? I figure this is probably a good time to upgrade to an all-aluminum unit with some better cooling.
Also, any other damage I should check for? The car lost the majority of it's coolant and was limped in for the last half of the track (3-5 minutes). Is this likely to have damaged the water pump? I would think I'd have noticed issues on my drive home if it had.
I just replaced my own with one from NAPA. It's a stock unit with plastic top and bottom. It has inputs for an Auto trans oil cooler so maybe it has more rows than than the stocker since auto rads for Miata's are supposed to have more rows. I may be wrong on this.
Either way..mine was $127 out the door. The least expensive all metal rad I saw was around $220 on google shopping.
give
http://www.radiatorbarn.com/
a try. They have stock and aluminum. I ordered a stock 99 radiator from them, it was very cheap and shipped very fast.
I just had to replace my Miata's radiator, too. I got an all-metal replacement from RSpeed.
I have a Koyo Radiator (www.koyorad.com, I think) that I got off of e-bay. $133.00 shipped, high quality, easy installation. It still has the fiberglass-plastic top and bottom, but the previous one lasted 14 years and 230,000 miles, so I'm not concerned about the longevity of this one. It also survived a full-out track day.
Don't get confused with the extra lines coming off of whatever radiator you end up buying. It seems as if everyone is just manufacturing the unit for the automatic Miatas since they're a bit thicker and work just as well. Those lines are used for the automatic transmission and won't contain any fluid unless you have the auto tranny - you don't need to do anything to them if you have a manual. Buy a new radiator cap as well.
Edit: Koyo customer support is awesome! I called about the extra lines and the guy I spoke with was able to clearly explain their purpose. I even asked him about a few other things about the Miata (which was new to me then) and he was able to help me there as well.
Aircooled,
Thanks. They seem to have only one style for the '94. It appears to be all dual core and aluminum. There aren't a ton of details though, so I can't tell if they mean that just the fins are aluminum (duh) or if it's all-aluminum construction. I think I'll give them a call on my lunch break.
A lifetime warranty is also very nice.
You're also a Cali-heat guy. Have you taken your 99 to the track since the new radiator? How has it faired in what kind of heat?
David, ooh, that RSpeed radiator sounds nice. Copper/Brass core too! And cheaper than the Koyo race radiator that is on e-bay.
aircooled wrote:
give
http://www.radiatorbarn.com/
a try. They have stock and aluminum. I ordered a stock 99 radiator from them, it was very cheap and shipped very fast.
+1
Also be sure to order the automatic version. As mentioned by others its a bit thicker and offers slightly better cooling. All of mine ordered from them were for stock replacement and were all metal so no need to buy a pricey aluminum version to avoid the cracking issue the stock piece has.
Salanis wrote:
David, ooh, that RSpeed radiator sounds nice. Copper/Brass core too! And cheaper than the Koyo race radiator that is on e-bay.
I figured Joe (owner of RSpeed) is a good guy and wanted to support those who support us enthusiasts. I just got whatever stock-type radiator he puts in his customer cars. No muss, no fuss.
I put a Koyo all aluminum model in my old track Miata. As I recall, there were three models, stock thickness, 37mm, and 55mm (or something close to that). I ran the 37mm. I think the 55mm is more popular with the SM crowd, but the fan shrouds may need to be trimmed to clear larger sway bars.
I'm still on the factory radiator on my street Miata.
Always opt for an all metal one.
Aluminum if your weight consious
But always; all metal.
Why risk the extra seams of a three piece with plastic tanks?
Obviously going all-metal. How would the copper/brass core of the RSpeed one compare for cooling abilities and weight to an all-aluminum one from radiatorbarn?
Salanis wrote: ...You're also a Cali-heat guy. Have you taken your 99 to the track since the new radiator? How has it faired in what kind of heat?...
It was never tracked, and has since been sold, but certainly did fine for normal driving. The original did exactly as yours did, cracked. The replacement was all metal, as I suspect all the replacement ones are. I am also pretty sure all the replacement ones are the automatic style (since they fit fine). Makes you wonder why they made them with plastic to begin with (although I suspect that is why the replacements are so cheap, lots of people replacing them).
Just a point of reference but...
With our Civic LeMons car I was told to ditch the factory all-metal unit in favor of a platic tanked aluminum core for their more favorable response to flex. The theory was that an older all metal radiator would be brittle and not hold up to much flexing of the ratiator before a crack/leak developed.
That's just one take on it (and not necessarily my take), submitted for your consideration.
All that said. I replaced my miata radiator with an ebay plastic tanker. The original (maybe?) was leaking at the crimp joint between end tanks and core. The ebay unit worked fine (I think it was a basic Koyo) for cooling on the street. It held up to a t-bone collision (this car being the t-bonor) as well as any radiator would...it didn't.
Clem
The stock Miata rad is a single core design. The auto cars add a second core. So they're twice as thick.
I find it very funny y'all are getting radiator advice from Aircooled. 
That's like asking me what Dimmycrat to vote for. 
