Sucking Wind

With essential decision made concerning engine, adapter, and intake provisions, its time to tackle the super headache of the scoop for the radiator...not to mention the radiator itself.

The Fellows Speed Shop Radiator solution.
The entire radiator, including the scoop, is all custom
 fabricated, just for this application.

The creme de la creme unit is made for Fellows Speed Shop in Birmingham, England, UK. Its boxed in design and novel plumbing solves massive numbers of engineering challenges, and it is a wholly custom fabricated unit.The pictures of it in this post are all from the prototype, which was fitted to a 1961 VW Samba, owned by photographer David Hall. This means that, as a custom cooling solution, is covers the entire range of the Bus, from 1950, through the 2005 air-cooled Brazilian T2c, as well as the first four years of Vanagon production which were air-cooled, sufficient to push a heavy, non-aerodynamic Bus around with a Subaru boxer engine. This is remarkable, and justifies the price they're asking for it in British Pounds.

Radiator test fitted in place.
About a 100mm (4 inch) drop for the scoop
beneath the frame rails.

That doesn't fix the fact that I can't afford that! In the build / buy / outsource logic that I described at the beginning of this blog, this would be an 'outsource' as this is a custom, purpose built component made specifically for this application. I'd buy a generic product to scratch this itch, but there are none. (What fool converts an aircooled vehicle to liquid cooled? Apparently only the clever chaps in the UK and Australia. Not here.)

So my 'choices' are:

1. Spend 1/3 of the total cost of the project on one component.
2. Show the production photographs to custom fabricators here in the States and have it reproduced here (lowering the cost from about $1000 to possibly as low as $600.)
3. Examining the design carefully, source a COTS (Commercial-Off-The-Shelf) product designed for a specific vehicle and application and built in mass production quantities which will lower the price. Then adapt my own boxed in scoop based on the Fellows design.

The boxed in radiator solution from Fellows has the following attributes that I'm going to follow:

• The scoop has zero air leakage. All air drawn in to the scoop for cooling (either by convection, fans above the radiator pulling cool air up, or by air being forced into the scoop by forward travel of the vehicle) must go through the radiator.

• The Fellows scoop is a thick gauge of aluminum. (By eye, I'd estimate about 10 gauge.) The components are not bent, they are cut from individual pieces and then welded together. Welding aluminum is ticklish work, and mistakes are expensive. But based on the shape of the scoop, I see no reason not to fabricate it in steel and use a heavy gauge metal brake to bend it up. I don't presently have access to such a brake, but we're talking about a maximum of six cuts and four bends, so I suspect that, armed with a very very clear plan of what I want done, I should be able to get this through a fabricators shop for minimum money. 

Lots to look at here, though this install is on an old 61 Bus:
Note holes cut in the rear frame member as inlet to the radiator.
Note the outlet exits through a cut hole in the side member.
You can see the brackets that suspend the radiator at the rear,
as well as seeing the pins on the front of the radiator that
will support the front when those brackets are installed.
Behind the rear frame member, you can see the custom bent
coolant tubing running back to the engine, both the inlet
(on the right of the picture,) and the outlet at the bottom left.

The selection of radiators is going to be a completely different problem. Their radiator is custom built for the application. As you can see from the pictures, their mounting is all fabricated, and even the inlet/outlet for the radiator is a custom job. (Most radiators have tanks at either end, and the inlet/outlet is usually perpendicular to the bulk of the radiator. In a situation like this, where we want everything possible to lie flat, that considerably limits our options.) The pressure relief is not built into the radiator (as it is on most American radiators, so this limits our options still further. Finally, Fellows has gone to the trouble to take as many bends out of the return as possible, which is part of why they cut through one of the frame members for the return and then reinforce the hole with a welded on, wrap-around reinforcement plate. All of this makes for a truly beautiful, refined installation. If you're in the UK, don't bother following my lead: just go to Fellows Speed Shop and buy their products.

So we need to find a radiator that:

1. Sheds sufficient BTUs, even in the compromised location.
2. Will be easy to mount, and easy to remove for maintenance while being solidly affixed so that inadvertently catching air won't cause you to lose your entire radiator assembly when you land.
3. Will not be prone to getting air trapped in it, possibly causing issues with filling and flushing coolant.



The custom Fellows Radiator prototype initial test fit.

4. Has inlet and outlet in places where they can be routed back to the engine without performing extreme modifications to the body.

The more than this the observations about the project go along, the greater the likelihood that welding will be required, somewhere along the way, not necessarily on the body itself, but on a component to be added to the body.