What size fan for VW Polo rad?

[jps]

Just getting things together to put in a decent sized order to CarBuilderSolutions - what size fan have people used on the VW Polo rad? I'd assumed i'd go for the biggest I could fit across it - until I saw a photo the other day of a small fan (probably about 6 inch diameter) that just covered one side of a rad...

[jps]

If anyone is interested - coincidentally the same question has arisen over on Locostbuilders, with a range of answers collecting: http://www.locostbuilders.co.uk/view...php?tid=194033

[SeriesLandy]

10inch seems to ring a bell. I got a spal one off eBay that is really powerful. If it kicks in its normally off with 30seconds. I think I spent about £50-60 on it so not cheap but better than buying twice like I normally seem to do.

[voucht]

I don't have a Polo radiator (I have Mercedes 190E), so I can't give you the exact size, but as a guideline, I would recommend that the diameter of your fan should be as close as possible to the short size of the radiator's core.

For example, if your radiator's core is 300mm x 250mm, then the fan diameter should be as close to 250mm as possible (10'').

Puller fans are more efficient than blower fans, and it is recommended to install the fan behind the radiator rather than in the front when you have the room for that. We do have enough room on the Roadster with these small OEM radiators, the font frame being leaning backwards.

There has been a discussion here last year about ducted and non-ducted fans. I still think that a good fan do not need to be ducted, as long as you make sure that it sticks to the radiator's core (no gap between the fan housing and the core.) It also will not need as much room as a ducted fan.

Hope this will help

[Stot]

I have a 13" ebay 80w job on my polo rad and its a perfect fit but its not really quite good enough for my MX5 in hotish weather. A 120w one may be better but I have changed to a Mercedes rad to start and I'm thinking about putting a SPAL VA10-AP70-61A fan at the back of it in place of the ebay one.

The Spal is as thin as the ebay one around the edges but is around 160w and moves a heck of air. The motor is a bit thicker but thats ok as theres loads of room in the middle of the nose. I expect it to be around £100-£150 if I can find one so not cheap but I dont like overheating.

Cheers
Stot

[K4KEV]

I have been out and about and hoon all the time, I have also been out on most of the hottest days and my temp gauge goes up to one spot (4 out of 10 scale) and it does not shift from that spot no matter what I am doing so the fan I have at 12" and a polo rad with polo stat through a relay is doing its job perfectly I have even mounted my number plate that it partially obscures the rad and still no change .....and this is a stage 2 turbo lump so I think the polo rad and a 10-12" puller fan is more than up to the job (I was surprised too)