[kwilford]

Jimmy, I happened to see this on eBay. Looks good in the photos, and the seller's ratings are very good:

1302078 Radiator Fit Opel GT 1.9L 19 S Coupe 1968-1973 All Aluminum | eBay

Find many great new & used options and get the best deals for 1302078 Radiator Fit Opel GT 1.9L 19 S Coupe 1968-1973 All Aluminum at the best online prices at eBay! Free shipping for many products!

www.ebay.ca

Not cheap at $384USD, but can't be more than the Splendid rad including shipping, and they seem to have it in stock.

And since I placed this item on my eBay watch list, I was just offered it, for the next 48 hours, at $350USD.

 

[terrylewisac]

I could be completely off base here but aren't all/most modern cars today fitted with an aluminum core rad?
And require a 50/50 mix.

 

[opelgtboy70]

Incorrect! OGTS even states in their ad for the aluminum radiators that they require a 70/30 mix:

https://www.opelgtsource.com/search/3541/details

<<< New aluminum radiator for Opel GT's equipped with an automatic transmission. Recommended for Summer driving and for performance-built Opel GTs. Installs in original location, and outperforms original-style radiators. Works with original mounts, and adds a convenient drain plug! (Note: Designed for automatic transmission Opel GT's - Manual transmission GT owners see our part #11023A). Requires a 70% coolant/distilled water mix for operation. >>>

I had one of the Honda aluminum ones for a while, using a 50/50 mix, and the fluid turned into brown goo.

You said you need a special coolant. That is incorrect.....regular coolant is fine. Just use the proper mixture.

Karl

 

[The Scifi Guy]

Gordo, any chance that your experience with said brown goo had Dexcool mixed with green ethylene glycol?

No, just the green stuff at 50/50. As I recall, when the Honda radiators were a thing, a few other people had reported a similar problem.

 

[Autoholic]

Keith Lundholm had a post recently about aluminum radiators and corrosion. The brown goo would likely be oxidized iron from your engine block in the coolant. When there are dissimilar metals involved in a cooling system, galvanic corrosion can happen.

Aluminum radiator electrolysis problems

We received a car some time back with an aluminum radiator from Gil’s first batch. Car had numerous electrical problems and running issues, even burned up a fusible link. Didn’t matter as we are doing a restoration on it. Fast forward and we are installing the radiator back and we have leaks...

www.opelgt.com

The solution is not to change the mixture of your coolant. You need to add a sacrificial anode.

 

[wilderbry]

$350 is what I paid in expensive, high overhead So Cal to get mine triple cored when I did the engine rebuild. Always at or under half way with a 195° high flow t-stat.

Keeping the radiator isolated from the chassis & regular 50/50 radiator fluid changes are the most critical things you must do to keep ahead in the battle against the corrosion with the stock radiator in my experience.

You are correct in isolating the radiator from the chassis to prevent electrolysis damage to the aluminum radiator. A higher glycol content also reduces this process plus reduces the corrosion process.

 

[Justion337]

I have one of the latest ogts aluminum rads I might sell.

 

[Frozen Tundra GT]

I have one of the latest ogts aluminum rads I might sell.

Im still interested, let me know.

BUMP!