An M.G. Locost Build
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October 3, 2012
Cooling

Wow, October already. Last October we were flailing away on parts for the front suspension, and we didn't seem to notice back then how much earlier the sun was going down each night. This October we're working on a car instead of a workbench, and we don't really like the fading daylight, but I guess we'll adapt. In any case, we think it's better to be working on a car, and not just parts for a car.

  Hoses apparently made for an M.G. Locost
click to enlarge

Our Locost cooling system went together incredibly fast. We had imagined ourselves experimenting with a whole series of hose and pipe arrangements, and running into at least fifty clearance issues, all culminating in having to rebuild large sections of the frame. So we budgeted beaucoup hours, but in the end it turned out that all the generic Gates hoses we bought fit perfectly, and all we had to do was clamp them on. Incredible. If the rest of the build goes this well, we'll be driving the car next Tuesday.

Lightweight 16-gauge cooling system bracket  
click to enlarge

We still had one more task to finish up, and that was to make a support bracket for the 10" length of stainless steel pipe connecting the two lower radiator hoses. (In the picture above, pretend for the moment that rolled up cardboard looks just like stainless steel.) Not surprisingly, we had the exact materials we needed for this bracket in our spare metal bin. Even more surprisingly, we didn't make the bracket out of 1/8" steel tubing. Not that we didn't want to, but the bracket needed to bend slightly, and we thought we might have better luck with 16 gauge.

  Lightweight bracket tacked in place
click to enlarge

One thing that helped make short work of the cooling system is our decision to forego installing the MGB heater unit. As I think we've probably mentioned, the heater unit is massive, and would take up pretty much all of the rear engine bay shelf. Also, since air from the heater is directed downward, installation would require cutting a big hole in the engine bay shelf, and then adding a bunch of ducting, since this hole would not open to the cockpit, but to the transmission tunnel, which doesn't really need the extra heat.

At some point we're going to have to attach an electric fan to the radiator. The regular engine fan is useless with the radiator so far away. We're not counting this as part of the cooling system because it's electrical, and we're ignoring the electrical system right now because we have no confidence we'll be able to do it correctly, and imagining massive electrical failures down the road doesn't give us the sort of incentive we need to continue with our other work.

So the cooling system is basically done, although we still need to attach a catch tank to the scuttle firewall, which we can't really do right now because we don't have a scuttle firewall. The catch tank is intended not so much as an overflow or expansion tank, but as a means for filling the cooling system. The Locost book has you filling the system at the thermostat, unbolting it each time you have to add water, but I don't think they quite understand exactly how often an M.G. cooling system needs to be filled.

Extra low c.g. of the Locost radiator  
click to enlarge

Of course the normal procedure would be to fill the cooling system at the radiator. There are several reasons why we can't do this. The first is that the top of the radiator is several inches below the highest point of the cooling system, i.e. the aforementioned thermostat, and would therefore fill up long before the cooling system itself was full. The second reason, and actually all the rest of the reasons, are pretty much superfluous, since this is the only reason we really need. So we're adding adding a catch tank to the scuttle firewall. Once we have a firewall.

With the cooling system out of the way, we have only a couple of things left to do before we can pull the engine. One of these is the exhaust, a task we hope will go as fast as the cooling system. Once the engine's out we can strip the chassis, finish up all the welding, and paint the frame. That'll be a major step in the build, because after that we can start installing things for real, for the final time. Almost hard to believe.

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