GT6 VW Golf radiator upgrade

[haggis]

Hi Everyone, I'm about to undertake a radiator conversion on my Gt6 Mk1. There are several options I've heard about but the VW golf radiator seems the easiest conversion, can anyone advise me on the best size? there appears to be 2 different varieties available core sizes 525mm x 320mm (overall 620mm x 320mm) or 430mm x 320mm (overall size 530mm x 320mm), based on my measurements they both would appear to fit and there is no difference in price.

 

So the reason for the swap is I've spent so much money now on getting my GT6 on the road, that everything this year is coming down to economics.

I've been quoted £200 for the recore and a VW radiator is £29.00, so it pretty much a no brainer on finance.

 

Just not sure what size to choose? from my understanding the standard set up in good condition is ok ish, which means to me it could do with a little more capacity and a modern core which is why I'm considering using the smaller VW radiator, but every conversion I've looked at shows the bigger rad.

 

Is bigger better in this case? I understand there may be some over cooling from a too large radiator, and obviously you have to buy 2 fans to fit as well!

 

Any help greatly appreciated.

 

Thanks

Haggis 

 

[Dave C]

Haggis,

 

I went down the re-core of original radiator (and original fan) route and so far it's been ok. The problem is I'll only find out if it's not ok when it's too late if that makes sense?

 

For that reason I've been tempted by the Golf radiator.

 

First off you can buy a used Golf radiator on eBay together with the VW fan for next to nothing.

 

As far as size goes I suspect either would be fine. I think some people have possibly got a bit carried away and have fitted the biggest they can squeeze in. Over-cooling is not desirable.

 

There's a guy called Roy Lacey who has done a very nice job of it. You can find his description of the conversion, photos and video on the Internet. I think he's in the club, I thought I saw his car at Santa Pod.

 

He would be a good person to talk to...

[haggis]

Thanks Dave, I was tempted to re-core the original but the cost seemed ridiculous and it seems slightly small even for modern standards, not concerned about originality either so the golf conversion seems good, I had considered that people might have gone all in for the bigger one which is the reason for the post really.

 

I think I've seen Roy laceys' video on You tube, but i'll see if I can find anymore info.

 

Cheers

Hag

[Clive]

Use the larger rad. I used a very secondhand smaller one on my last zetec spit, it was OK, but died when the car rolled.bi have fitted the larger one this time, and the extra cooling is very evident. some of that from being new, but a 25percent bigger core has to be useful.

If you can fit it, I would also use a few fan and cowl, they are amazingly efficient.

[haggis]

Hi Clive, thanks for the response, will a single fan be ok on the larger rad( 12")? I've never heard of a few fan, was going along the lines of revotec as the do a m22 fan control unit that fits into the rad rather than the hose. I had assumed I would need 2 fans for the larger one?

 

Thanks

Hag

[JohnD]

I don't think that "extra" cooling g capacity will be a problem. The thermostat is what regulates cooling, and you can choose within reason what temp you wish to run at.

 

A bigger rad for hot countries, or when you will work the engine hard. But, in SofS I have a Honda rad a bit smaller than the OE, and for 1600cc. It works well!

 

John

[John Bonnett]

I fitted a MK2 Golf GTI radiator to my GT6 and found it adequate in most situations. If you take that route, you will need a header tank and I found that the MK4 Astra one fitted very nicely. I managed to install the radiator almost vertically and used two GT6 bottom hoses which was convenient.

 

Here are one or two pictures which I hope will help. If you need any help on the plumbing side let me know.

 

regds

 

John

[Clive]

Sorry, VW fan. Flipping autocorrect!

[Colin Lindsay]

"from my understanding the standard set up in good condition is ok ish

 

I went down the re-core of original radiator (and original fan) route and so far it's been ok. The problem is I'll only find out if it's not ok when it's too late if that makes sense?"

 

Plenty of unfounded rumours that it's ok-ish, (plus no doubt the very occasional personal experience) but it's the silent majority with the standard system that speak volumes. I've never had any overheating problems in 21 years of GT6 ownership; I just kept the cooling system well flushed and had the radiator recored to an uprated core when the car was rebuilt about 2003. Even with the VW system, the only way you'll find out if it's not suitable is when it lets you down, same as the original system, but again a good pump, thermostat and clean core work perfectly well. When it does cause problems you'll find it's a failure in a component rather than the original design that lets things down.

I've absolutely no objections to owner upgrades but every time I read how terrible the cooling system is, or the brakes, or the suspension, it makes me want to jump on my soapbox!

[haggis]

Thanks Everyone, and special thanks for the pictures john, that looks like a real professional and well thought out install and good to see the rad stayed vertical (ish) makes it look more normal.(which i like)

 

Can I ask what fans you used? I have Kenlowe 12" but its a blower, so was planning to shell out on a new suction fan, was looking at Revotec as they have the lovely M22 screw in fan controller to fit the VW rad (£65), but my budget may only stretch to a single 12" fan plus all the bits at their prices. 

 

I think your fans and controller may be original VW? and did it take long to do?

 

As Clive mentioned the original VW fan and shroud sounds good, but i'm assuming this is where the radiator angle changes drastically as they seem to stick out miles.

 

Thanks

hag

[John Bonnett]

"from my understanding the standard set up in good condition is ok ish

 

I went down the re-core of original radiator (and original fan) route and so far it's been ok. The problem is I'll only find out if it's not ok when it's too late if that makes sense?"

 

Plenty of unfounded rumours that it's ok-ish, (plus no doubt the very occasional personal experience) but it's the silent majority with the standard system that speak volumes. I've never had any overheating problems in 21 years of GT6 ownership; I just kept the cooling system well flushed and had the radiator recored to an uprated core when the car was rebuilt about 2003. Even with the VW system, the only way you'll find out if it's not suitable is when it lets you down, same as the original system, but again a good pump, thermostat and clean core work perfectly well. When it does cause problems you'll find it's a failure in a component rather than the original design that lets things down.

I've absolutely no objections to owner upgrades but every time I read how terrible the cooling system is, or the brakes, or the suspension, it makes me want to jump on my soapbox!

 

 

I totally agree with you Colin. Manufacturers spend millions on developing and optimising so why change anything? In my case, I was faced with a very expensive re-core or a brand new Golf radiator for twenty six pounds delivered. There is absolutely nothing wrong with the standard cooling system and the only reason I deviated was for economic reasons. The Golf rad fits in so well that i don't think the chap who bought the car from me ever realised it wasn't standard. 

[Clive]

Regarding controllers, there are loads of std ones with varying on/off temps, I use one that has a dual switch. And they are about £10 a time. Ideally something that switches on mid 90s and off at a few degrees over your thermostat temp.

 

Also here I agree that the std cooling system should be OK, i know if a couple where recored rads still ran warmer than ideal. And even Colin opted for a more efficient core. Just to be safe. But it is a matter of economics, pure and simple. And the fact the Ali rads weigh virtually nothing, a helpful place to save some weight.

[Mike R]

Just to add to the discussion on whether the GT6 cooling is ok as standard ....

My GT6 has a standard radiator (not recored) that I chemically cleaned a few years ago. I never see overheating, whether round town or at speed, with one notable exception.

 

Recently driving to LeMans had 2hrs of walking pace stop start driving in high 20's ambient temperature. By the end the temp had reached just under the red on the guage, but no signs of boiling. When I calibrated the guage previously just under red is where 100 deg C lies on my car, as 13psi water boils at 120 deg C it looks like I still had a reasonable amount in hand. Although I must admit by that time I was getting a little nervous.

 

So, for me a slight improvement in "stuck in traffic" cooling might help in the most extreme conditions - I've put a slight cowl around the fan side of the radiator to help with this as when air flow is measured the fan definitely sucks in some air from the sides bypassing the radiator - this is as well as the cardboard cowl on the grill side.

[haggis]

Hi everyone, thanks for all your comments, I agree that the standard radiator would be fine, I have a crank fan and standard rad on my 1600 Vitesse and its great, took her out yesterday in the heat and the needle sat at just under 'N' for normal temperature for the whole day.

 

The GT6 is a different story, the radiators core looks original to me and having checked the pump, heater rad & thermostat is looking like the culprit of my overheating issues. 

 

To be honest if I could afford the recored original I would, as messing around with modifying hoses and building new rad brackets sorting out electrical bits is going to be time consuming, but I like a challenge, and if it gets her on the road quicker and is cheaper then I'm up for that.

 

Still love to know if John can remember what fans he used?

 

Thanks

Hag

[John Bonnett]

 

 

Still love to know if John can remember what fans he used?

 

Thanks

Hag

 

 

I used Pacet.  I've not tried them but I believe Spal are very good. Best to avoid Ebay "Cheapies". 

[efp]

Slight detour, and possibly inappropriate plug, but I had my Spit Mk2 radiator, which obviously is a bit larger, recored by a very nice chap at A1 Radiators in Banbury for about £115. Slightly crap repaint, but cant complain. You might want to ask around a bit more. The smaller GT6 rad might come in a bit cheaper

 

I had bought a new one from Canleys which turned out to be a copy of a US spec 1500 one which while it worked and fitted fine, came to offend me in having a slightly different shape, no fan shield , drain tap or indeed Stanpart name pressing. But I am a tad anal about originality.

 

Can't pass any intelligent comments on GT6 cooling obviously, but I'm happy.

[Dave C]

Another vote in favour of A1 Radiators, Banbury........

[haggis]

Hi again and thanks for all your comments. I did decide to go down the golf radiator and so far the conversion is going well, there was just one question I had about whether the new fan should be on a permanent live or an ignition live?

My original was on the ignition and after the engine had stopped the temperature would rise to 120' immediately before slowly cooling, which I found slightly distressing, i'm guessing this is normal, And doesn't do any damage to the engine?

I was considering a permanent feed so the fan would 'run on' after the engine stopped as all modern cars now do, but the fan instructions doesn't recommend this because of the potential battery drain.

 

 

Thanks

Hag

[Clive]

use perm live(via a relay etc triggered by the fan switch)and it shuts off after a few mins. I wouldn't worry about draining the battery...