An M.G. Locost Build
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June 20, 2013
Cooling

While it's great having all of the bodywork on the car, parts are no longer quite as accessible as they once were. Case in point is the exhaust. It took us all of five minutes to remove the exhaust before we started the bodywork, because we could reach through the chassis tubes with a wrench, and even better we could see exactly what we were doing. To re-install the exhaust we had to first cut a big hole in the body panel, which admittedly we only have to do once, but in order to fit the exhaust pipes to the manifold and get the nuts started on the studs we actually had to crawl under the car.

  Hole just big enough for exhaust pipes
click to enlarge

Even from that vantage point, lying on the groubnd abnd looking up, reaching the manifold studs is difficult, because some of the frame rails are in the way. The studs are easier to reach from up top in the engine bay, but then you can't see them because they're hidden below the manifold. Not that it's any easier to attach the exhaust in an MGB, although it probably is, but we kind of got used to the easy access afforded by the open Locost chassis. I guess we'll deal with it, but don't expect us to be taking the exhaust off the car anytime soon. Or very often.

We also had fun mounting the spare tire. We'd planned to have a pair of bolts protruding from the rear cross brace to attach the spare, but even before we installed the rear body panel we knew that wasn't going to fly, because the gas tank is in the way. We could've removed the tank to install the bolts, but that was way too much work for just a spare tire, so instead we cut two 7" lengths of 1/2"x20 grade 5 threaded rod, with the idea that we'd stick them through the cross brace from the outside, with a nut on either side of the cross brace to lock the rods in place. Which would've been really simple without the rear body panel in place.

Spare tire mounts poised to spear the gas tank  
click to enlarge

Instead we had to slide a nut between the tank and the rear panel, and hold it there while we threaded in a stud. We couldn't hold the nut in place with a box wrench because box wrenches have an unfortunate bend that prevents their use in skinny areas. So we used a magnetic probe, which has its own issues because the rear panel is not vertical, but is in fact slanted, and in the wrong direction from a nut-fitting perspective. Also, magnetic probes are indiscriminate about what kind of steel they stick to, and the nut is not large compared to the rear cross brace.

But we persevered, and got the spare tire mounted, and were able to move on to something more productive, the cooling fan. We bought a 10" Spal fan from Summit Racing after several abortive attempts to squeeze a Miata fan between the radiator and our Aussie cross tube at the front of the chassis. We would've liked to have at least one Miata part on our car, but unfortunately Mazda made their cooling fans too big. The Spal fan fits easily, and our only challenge was figuring out a way to mount it.

  High-tech electric cooling fan
click to enlarge

After discarding several promising designs that looked like they'd be too hard to make, we came up with something that we think will work based on a couple of assumptions, the first being that it's just a fan and worst case scenario it falls off the car, hopefully before cutting up the radiator, and the second being that because the fan pulls air through the radiator, we'll get some added support from the resulting suction. Also, our design has the further advantage of being light and made from one of our favorite fabrication materials, one inch wide strips of 1/8" steel.

The design incorporates three short strips of steel. One strip goes from the bottom chassis rail to the bottom of the fan, providing vertical support. The other two attach to the sides of the fan and either radiator mount arm, locating it laterally. All three strips provide a certain amount of rotational and fore/aft support, which should be augmented by the aforementioned suction. At least in theory. The design does seem too simple and light to work, but we've been known to over-engineer things in the past, so maybe this makes up for it.

Fan switch is right below the temperature gauge  
click to enlarge

The fan only has two wires, same as the heater fan on the donor, so wiring it up was simple. All we did was run a pair of wires from the heater fan leads in the engine bay to the new Spal fan, and hook up the heater fan leads under the dash to the switch from the donor, a switch that actually says FAN on it, which will help to reduce the confusion when the car starts to overheat. More sophisticated implementations would use some kind of temperature-sensitive switch in the cooling system to activate the fan, but that's clearly too high-tech for our build.

As we look at the car now, with all of its roughly-hewn body panels clecoed to the chassis, it hasn't escaped our notice that we're just about done here. Most Locost builders at this point would have driven their car by now, and we would too if we had a driveshaft. Of course we can't close the book on the bodywork until the fenders are on and everything's painted, but most of the building is done, and for the first time in this rather long and arduous process, we're raising our odds of completing this thing to higher than 50/50.

  Almost a car
click to enlarge

Not that much higher of course, but better than even money. The only major task we have left is the windshield, and that's only a major task because of the windshield wipers and defroster, neither of which is likely to impress us with its ease of installation. The rest of the tasks are one or two-day jobs, and we don't expect any of them to severely tax our admittedly limited automotive skills, although opinions on this may vary. Interior work notwithstanding, we still plan to wrap up the bodywork phase of this project by the end of July.

All of this talk about completing the Locost makes us wax philosophic, and maybe even slightly nostalgic, and since none of us wants to read any of that, we'll move on to our next task, which will probably involve something like installing the headlights.

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Comments:  
posted June 25, 2013 at 02:05:57  
Just awesome, Nick! BTW, while your adding headlights, I'm looking to remove mine from my Miata
 
posted December 28, 2016 at 20:09:02  
- So cute!! I love hand and foot prints too!! I am gonna try this! Love your craetiveness and happy you are feeling more like yourself again!!Jenna recently posted..[]