Disclaimer. My car isn't stock so electrolysis could be blamed on me.

I've owned a koyo for about 7 years now. It finally gave out on me last year.
It was great for the first few years. Then it developed pin holes. I assume from electrolysis. I had the holes repaired by a shop($40) and I was back in action.

It eventually went bad last year as it got more pin holes and wouldn't cool. I think it just started to get filled with crap and some tubes were blocked off.

I installed a new Koyo last year and now with a Ford Taurus fan, my car runs at 180 degrees in 100 degree weather. It withstood 20 minute hotlap sessions in 80 degree weather with no issue.

Koyo gets my vote.

Electrolysis never occurred to me as a risk especially given the aluminium rotor housings embedded and perfectly grounded in the keg dont seem to crumble away. I Googled it and found a couple of interesting links.

This one seems to be for Toyota FJ 4x4s with Chevy Vortec swaps and a lot of them have leaking aluminum rads. There is a contributor who specializes in managing corrosion in natural gas pipelines (who states that he is not a car rad expert). They mention that it is important that

1. the rad be well isolated from the chassis
2. you run an anticorrosion additive, not just distilled water (or worse tap water)
3. that you change the coolant annually
4. that you check the ph of the coolant regularly to ensure it is still as akaline as the originial coolant.

They note that Flex-a-lite makes a sacrificial anode you can install in your rad. The natural gas guy commented that the protection afforded by an anode will be very localized.

On the Ron Davis rad site there is a customer comment about their rad failing because of electrolysis. They have an electrolysis testing procedure here.

Here's another test procedure from San Carlos Radiator.

Interesting stuff. Maybe all those Koyo failures weren't Koyo's fault. Koyo's warranty doesn't cover damage from electrolysis.

Fun fact - Koyo rads aren't made Japan. They are made in Indonesia.

Gonna try these tests this weekend.

Thanks man... Thats been another subject Ive been trying to research. I actually just spent a few mins around the forum and did not find much.

So besides changing your rad fluid often, and using proper 50/50 mix, make sure the rad is not grounded to the car? How do you go about doing that, when you have to bolt it to the car?

The kid installed the rad so I'm not sure but I believe the steel brackets bolt directly to the aluminum rad but there are rubber isolators around the bolts that connect the brackets to the chassis. I think you'd want to check that the rad and the brackets don't connect directly to the chassis.

I won a CX racing radiator on thier facebook contest.. So this came in today, looks nice. 2 row radiator.
https://fbcdn-sphotos-a.akamaihd.net...23086958_n.jpg

My car won't be running soon, but i noticed the radiator doesn't have the coolant sensor bung, will that be an issue?

Which one? The one that goes in the bottom for the 3000 rpm start that most people unplug anyways, or the buzzer sensor that you can just cut the connector off of, crimp on a ring terminal, and ground so you'll never have to worry about that damn thing going off again?

^^^hahahahhaha

The top sensors is a coolant level one. It can be removed by grounding it to the chassis.

That's actually a great example of adding electricity into the radiator and causing electrolysis.

That sensor grounds out via the coolant so the electricity will have to travel all the way back to the engine and ground out OR through the radiator if it is grounded locally.

OK, let me dispel some rumors about this electrolysis thing. As a submariner, electrolysis plays a big role in my daily job. We have to worry about corrosion in our NUMEROUS heat exchangers (that pump seawater through them :( ), but also electrolysis can be our friend (it's how I breathe underwater for so long :) )

So is isolating the radiator going to prevent the electrolysis from eating away the aluminum in the radiator? Yes, and no. You have to have an electrical current moving through the electrolyte in order for this process to happen. It's more like electroplating, since the soft aluminum gives up ions more freely. So, why are we getting current through the radiator? It's because the current is looking for an easier path to ground, and most likely can't get there through your normal engine grounds. So say, for instance, you turn the key and start the car and all the current is looking for a good ground. Are your engine mounts good grounds? No... they're usually rubber (unless you have solid metal mounts like me). So where else could it go? If there are literally no other grounds (assuming your ground straps are completely ripped off) it's either going to try to go through the rear wheel bearings (yep, I've seen that one) or your radiator, if it's grounded. It travels through the engine, the coolant, through the radiator, to the chassis, to the negative terminal of your battery. Over time, it's either going to wear out your rear wheel bearings, diff bearings, etc, or your radiator.

So yes, isolating the radiator is a good idea, but most importantly....

... after years of preaching it....

... ground your engines!!

My 18 year old has an MR2 turbo. When their engine grounds are deficient they dont get a 3800 rpm hesitation, the throttle cable heats up and glows red.

Grounds are good!

Yes, they are.
Before I sorted the grounds in the FD it destroyed three braided steel clutch hoses, trying to ground through them. Melted the inner Teflon liner, the exterior looked fine.

All this talk about rads got me pondering my Godspeed, which had developed a small leak last year and been shelved since. I cobbled together a pressure setup, pumped it up with a bicycle pump and it held for nearly an hour (@ 10psi).
Not sure I believe it's OK but decided to try anyway.
Removed bellypan and fan from old rad:
Attachment 710080

This is a Lincoln Mk VII, 18" blade diameter:
Attachment 710081

For reference, the Taurus fan is 17", Volvos are 16".
I actually prefer the Volvo fan (it's very nicely built and has air bypass flaps in the shroud) but the Lincoln is the best fit on the GS radiator:
Attachment 710082

I filled the gaps in the shroud where it's cut away to fit the hose bungs with two blocks of foam:
Attachment 710083

The foam helps seal the shroud so the fan has to pull through the rad instead of sucking through the gaps.
In theory.

I was all prepared to make brackets but used zipties instead...they're quick, easy and more than sufficient to hold the fan in place.
Simpler=gooderer.

Attachment 710084

She's run long enough to open the thermostat- with no leaks yet!- and is now cooling down so I can top her off.
Will know tomorrow how the rad is working.

Cool. Is that a new AAI system?

Could be.

Hmmm... Not like you to hold out on us! I'm sure we'll all be looking for a new thread! Let's see, you've done "Descent in Madness" so maybe "Clokker's Exercise in Self-Immolation"... No. That's reserved for fuel system mods. Maybe "Clokker Experiments with Tracheotomies"

Maybe, maybe not.
As is my custom, I've identified what I think is the most difficult part of the "next" project and am exploring solutions.
With success, it may move forward or it may not.
It's actually something I've been toying with for a few years now.

I like the pics. Good learning stuff. does the MK VII fan move a lot?

I believe that if the rad was tilted more, the car would hover so yes, it moves quite a bit of air.
It's very quiet though, I can rarely tell when it's running.

Thread hi-jack !

my Koyo rad doesn't have any "Fan shroud kit" ... Is it missing or ?

well not like I can do anything cuz I bought the Koyo rad lonnnng time ago. Just wondering.

hows it working? does it leak?

here is a tip to taurus fan users- instead of hacking the shroud to fit around the hose heat the area up with a heat gun and using a piece of pipe push it in a little.

^I did something similar.

I cut the little sections out and then inverted them so they recessed in. Then just epoxied it back together.

Nope, so far, so good.
Weird, huh?

Have you happened to note the thread pitch for the bung in the upper radiator pipe on the Godspeed? Is it 3/8"?

So does the Godspeed rad cool better than stock or not? I also saw one post that said the dual core design may be harder on the stock water pump. Then someone else says that is a theory. Then someone else says they think the stock may be just as good. I'm considering getting one but if it puts more stress on my water pump I would rather go for a single core. Since I have an s4 I would have to aquire s5 brackets. So what is the best choice?

Thats the exact same questions I've been asking... I think this thread confused me a lot more than help me...

I ordered a godspeed, and it ended up leaking somewhere between the fins, and I could not repair, but before that...

First the radiator cap it came with was bent and damaged, and did not work. The stock radiator cap still would not make a tight seal, and leaked a little too.

Then the drain plug had a medium sized drip the second I installed it.

Went through all the BS to put it in... take it out... send it off...(That fkr made me pay to ship it back... This was almost 2-3 months ago.) And I've yet to hear back from the vendor (who is on this forum).... frankly by this time he can keep that pile of shit and Im gonna go save up for a koyo. I dont need this headache if it damages the car, much less will it even hold water like its supposed to...


(Now Im kinda worried I did a little damage to my motor since that shit would not hold pressure....)