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+--- Thread: Radiator dimension (/showthread.php?tid=3738)
Radiator dimension - Nick Salmon - 09-01-2020
In terms of height, could someone please tell which is the smallest standard A7 radiator? I am considering altering the rad position on the Special and the one on there at the moment (which I think is probably off a Box) is too tall for where I want it to fit.
RE: Radiator dimension - Belinni - 09-01-2020
From an earlier forum post:
According to Bill Williams there are 3 sizes of radiator cores fitted to the A7: 14.5" 1923 - 1926 (mag engine), 16" 1928 - 1931 (early coil) and 17.75" 1931-1934 (box)
So the early Chummy type is the smallest.
(Note these are core sizes only, excluding top and bottom tanks).
RE: Radiator dimension - Nick Salmon - 09-01-2020
Many thanks!
RE: Radiator dimension - Graham Honnor - 09-01-2020
I had exactly the same problem with my special just before Christmas when I decided to alter the front bodywork
and lower it by 3".
In the end, the cheapest option for me was to pick up an old rad. with a knackered core and have it recored with a
shorter core and sell the good rad. that was in the car.
Coincidentally, I had the new core shortened to 14 1/2" instead of 17 1/2".
New 3 veined core plus new studs soldered into the bottom tank and resprayed for £200.( + £10 for the old rad)
RE: Radiator dimension - Nick Salmon - 10-01-2020
Here comes a naive question...
Will any simple radiator with a top and bottom outlet/inlet work on the thermo-syphon principle? Purely hypothetically, if I put say a BMC Mini rad into the Special, would it function?
RE: Radiator dimension - AustinWood - 10-01-2020
The header tank needs to be above the engine to allow the hot water to rise into it. If the radiator is lower a pump is needed.
RE: Radiator dimension - Howard Wright - 10-01-2020
Hi Nick
If, as Jim says, the header is above the engine then I think any rad will work. How well it works depends on lots of factors. On my previous special the radiator specialist put a Vauxhall Cavalier core between the original tanks and that seemed to work well. I’ve just had a new core put in the header and bottom tanks of the current special. Not sure what that was intended for but we’ll find out once the engine is built.
I guess it’s a question of suck it and see?
Cheers
Howard
RE: Radiator dimension - Steve Jones - 10-01-2020
As long as the header tank is above the engine then the thermo-syphon will work. It's basic physics. However, there's no need to wander around looking for a modern radiator with dimensions that will achieve this. Modern radiator cores are supplied in large units and your radiator man will simply arrange to have a suitably sized section cut from this to a size that fits your needs. That's also the cheaper option compared with modifying an existing modern radiator to fit.
Steve
RE: Radiator dimension - Graham Honnor - 11-01-2020
That's exactly what I did.
The old rad I picked up was from a Ruby so all the fixings and pipe connections
were in the right place.
I'm sorry I didn't make it clear in my earlier post that it was an Austin 7 old rad
that I'd used.
The local company I used will also post you the radiator when it's done.
RE: Radiator dimension - dchw1975 - 04-02-2021
Hi,
Are the correct dimensions for a core to fit in a nippy shell, 14.5" or 16" please?
David