The radiator in my Formula just spring a leak at the joint between the left plastic end tank and the core.

RockAuto has a Spectra Premium unit for $87. I've used a Spectra Premium gas tank in my E30, and it was a very high quality piece. I'm definitely ok with this brand. The photos on Rock show one with a trans cooler. This makes sense, as they only need to make one model for a small market, but my car is a stick. The auto trans radiators still have the same cooling capacity as a manual trans radiator, right?

AutoZone has their house brand Duralast for $110. Does anyone have experience with this unit?

Any other brands or types I should seek out?

There are many threads on the Champion 3 row radiator. There will be some mild work involved to get it to fit. I myself went with this: Radiator

It has worked out great. I also upgraded the fan while i had everything apart.

[This message has been edited by Spadesluck (edited 07-21-2019).]

I purchased the Spectra oem style radiator(ordered off Amazon) and it works fine. Mind you I have partially dented coolant tubes and this radiator still keeps the temperature normal. Unless you're really beating on the car I think the Spectra will be fine. The Duralast one is likely a rebranded Spectra one but has a lifetime warranty. You can ask them at the counter who the maker is.

Also, I believe there's no difference between manual and auto radiators.

quote Originally posted by Spadesluck: There are many threads on the Champion 3 row radiator. There will be some mild work involved to get it to fit. I myself went with this: Radiator It has worked out great. I also upgraded the fan while i had everything apart.

I replaced my Fiero radiator as part of the 3800SC swap. I used the Champion 3 row and it has been working great up until last week. It developed a serious leak while on the alignment rack and stopped after leaving a 12" puddle of coolant on his shop floor.

I checked it out and found a problem with the drain plug setup. Its a plastic thumb type plug with a slot cut parallel to the threads so it will drain without fully removing the plug. (There is no stop so it will come all the way out). There is an O-Ring that goes on this threaded plug and it gets compressed between the radiator drain port and the flange on the drain plug.

There is no capture groove on the flange or the drain port leaving the O-ring exposed to the elements. In addition as you tighten the plug your compressing the O-ring causing it to spread wider and wider beyond the limits of the flange. As I tried to tighten the plug with only my finger & thumb, as designed, the O-ring split leaving me in a worse situation and more coolant loss.

To make matters worse the drain port in the radiator is a non tapered 1/4" thread so a temporary plumbing plug won't get you out of a pinch. For now I cut a gasket out of some gasket paper and used that for a seal.
Even if this setup didn't leak its still a bad setup. The port actually drains into the radiator support area so there is no way to catch it in a bucket. The coolant just runs all the way across the width of the radiator. Better off just pulling the lower hose . I'm definitely going to redesign this setup.

Sorry for the rank and getting worked up..

ps: Maybe this is the same character that designed those seals that got the space shuttle into trouble.

Spoon

------------------
"Kilgore Trout once wrote a short story which was a dialogue between two pieces of yeast. They were discussing the possible purposes of life as they ate sugar and suffocated in their own excrement. Because of their limited intelligence, they never came close to guessing that they were making champagne." - Kurt Vonnegut

Sealing is the hardest thing OEMs do. That's why I'm hesitant to go with other than OE replacement unless I have a good reason to.

I ordered the unit from AutoZone and it should be in tomorrow. They said the manufacturer was SPI, which is almost certainly Spectra Premium. The photo on the AutoZone site is the same as the photo on Rock Auto for a Spectra Premium unit, so I felt pretty comfortable ordering it.

quote Originally posted by Will: I ordered the unit from AutoZone and it should be in tomorrow. They said the manufacturer was SPI, which is almost certainly Spectra Premium. The photo on the AutoZone site is the same as the photo on Rock Auto for a Spectra Premium unit, so I felt pretty comfortable ordering it.

That's probably what I used too. I got mine from Autozone too but I have no idea of the brand. No issues at all and its been a bunch of years already. Hopefully they're still just as good. It might have been cheaper to order from Rock or Amazon but I always worry about shipping damage on something so big and bulky, thus necessitating having to ship it back. No thanks.

Some replacement radiators may work fine for a stock engine, but I used the Champion 3 row because its larger, provides more cooling area and because my 3800 engine is modified. The shortcomings of the petcock on the Champion is a concern. It most likely needs an upgrade but mine has held so far.

------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

You get local w/ a lifetime warranty and you should be fine unless you have other problems attacking coolant parts like weak or no Coolant.
Example: Many put 50/50 mix in a car after a coolant flush. Problem is car has trapped water in the Block, radiator and other places that weakens the new 50/50 mix and won't protect the rad or anything else.
See my Cave, Coolant Fill

Note that All Replacement radiators are AT type w/ AT heat exchanger in one tank. Your guess to cut down # to inventory? Is correct.
if use w/ stick cars, get plugs to seal the AT cooler. Cooler Unused, It won't leak normally but road salt etc can get in and attack it and cause a leak months to years latter. just pipe sealer and hand tight to keep out crap.

Many old rad's after decade is use can have problems and all metal units are often is included.
I had to get all metal units build in the 70-80 and older fix or replace.

Solder and metal can stress fail after 10+ years and that's when you have good coolant.
Weak or No coolant and radiator and/or heater core will die.

Plastic tanks will last 20+ years but after 30+ years and driven every day or not, Heat, load and pressure can, often will, stress then crack the inlet tank sides as covered in my Cave, Radiator Failure.

But I've seen Metal Tanks fail too. OE solder can crack anywhere and even brass/copper can fail. Fixing them even by rad shops often won't last long.
Many towns, even small towns, had 1 or more rad shops back in the 80's and earlier to fix hundreds of damage rads.
One Real Big Reason most hated Al Cores and Plastic tanks is "old school" shops couldn't fix them w/o getting equipment And Training to work on them.
Next is Al cores hated running w/ weak or no coolant more then copper/brass but even they hated running like that.
And that's before you have electrical problems making coolant to be a ground return path to the alt and battery. That can wreck the rad, heat core, and even rubber hoses inside out. (This is why some will use a Volt meter in the coolant at the rad cap etc and on the engine w/ HL etc On to load the grounds.)

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave

Actually, it appears to be leaking at the seal between the plastic end tank and core.

quote Originally posted by Will: Actually, it appears to be leaking at the seal between the plastic end tank and core.

Is still same problem. Plastic and gasket there wears out over time, more so on inlet side after 30+ years. Or Weak/No coolant, the "water" can corrode the aluminum face where the core meet the gasket etc.

I just replaced my 32 year old OE radiator about 6 weeks ago. The plastic tanks finally gave up the ghost. Small cracking, brittle. I ordered one from out jobber Napa. I'm pretty sure it is the same as a Sprectra Premium. But they will warrant it. It fit the same as the OE one. And haven't has an issue with it running a 3800 n/a. That has been in traffic with upper 90 degree temps. However this is with automatic and originally had A/C. In my experience, have seen people have more problems with the all aluminum units and are costly.

I've had zero radiator problems with my Northstar cooling system in the original radiator on my Northstar car...

I am sure any radiator can have its problems. For me personally my aluminum Ebay radiator has worked great for me.

A lot of aluminum radiators have problems because they're welded assemblies that do not have adequate provisions for dealing with thermal fatigue, due to constant temperature cycling. OEMs are VERY good at designing for that, so the OE copies, especially when built by a Tier 1 supplier are going to be the longest lived.

I didn't know that any OEMs designed radiators, I'd think that they'd specify an interface and delegate the design work to the Tier 1.

As an example of design handoff, I heard through the grapevine that a particular fuel tank manufactured by Spectra Premium was in fact designed by Spectra Premium for the customer.

At my workplace (Tier 1/2), build-to-print is quite rare, customers usually want a turnkey solution.

[This message has been edited by pmbrunelle (edited 07-23-2019).]