An M.G. Locost Build
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October 12, 2014

Last month we made the near-fatal mistake, right here on this website, of attempting to place our M.G. Locost into the highly reliable category. This is a mistake for any older British car, and the real error on our part was losing sight of the fact that our Locost is 75% British by weight, and possibly also by volume. Right after our recent round of minor cosmetic and ergonomic upgrades, we suffered a rash of parts failures that included the fuel pump, water pump, tach, tires, and possibly a few more that we've managed to forget about. None of these failures left us completely stranded, but a few left us partly stranded.

We've been told that all of these failures could've been anticipated by anyone with enough common sense to realize that 40-year-old British hardware should not be expected to last much longer than 40 years. Of course that's one way to look at it, and everyone's entitled to their opinion. On the other hand it's also possible that if something has worked for 40 years, it's proven itself and should therefore last forever. Which just makes sense. Which is why the sudden failure of our 40-year-old water pump caught us totally by surprise. Luckily we still check the temperature gauge from time to time.

  40-year old engine block still holds water
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To its credit, the water pump never did stop pumping. The cast iron impeller still spun freely in its bearings and continued to push coolant gamely into the cylinder head. Unfortunately it also pushed coolant gamely onto the ground. Apparently the 40-year-old bearing seals decided to pack it in. Fortunately, removing the pump on an MGB is a simple process, so long as it's been done previously, or the car is less than 20 years old. Unfortunately, if the car is much more than 20 years old, like for example 40, then the bolts attaching the pump to the engine block have long since seized.

The four holes in the block for the water pump are drilled all the way through into the water jacket, and then tapped for threads. When the pump is bolted to the block, the ends of the bolts—and over the years the bolt threads in the block—are exposed to whatever corrosive elements might be found in the coolant, like for example water. After 20 years the original bolts have finished cold-welding themselves to the block, and the pump is no longer removable by non-destructive means. However, as luck would have it, that's not the end of the story. A few years after the bolts seize, something good happens.

We decided against reusing these  
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Starting we would estimate at around year 25, the bolt threads, having rusted all the way through, begin to disintegrate. By year 40 the threads are just about gone. The bolts are now little more than rusty pegs securing the pump to the engine block by sheer force of will. With just a little effort, bolts in this state can be twisted and pried out with screwdrivers, wrenches, pliers, chisels, or whatever tools you might have on hand, or can borrow, and the shocking result of all this corrosive mess is that the threads in the cast iron block are still good!

  New pump much shinier than the old one
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We had to chase the threads with a 5/16"-24 tap to scrape away the old bolt thread residue, but when we installed the pump, the threads in the block provided enough grip to allow the new bolts to be torqued to the requisite 15 ft.-lbs., and possibly beyond, although in an effort to secure at least a modicum of common sense we didn't actually test this out. Against our better judgment we did apply a tiny amount of RTV to the new gasket, and we're pleased that the new pump hasn't yet sprung a leak, although the guy who has to remove it 40 years from now will not be happy about it.

The fuel pump was a different story. The 40-year old pump valves that we didn't replace two years ago when we had the chance had been working overtime to coax fuel in the direction of the carburetors. The resulting rapid firing of the solenoid soon fried the contacts, and as a consequence the pump would operate for only a minute or two before dying, and had to be jarred back to life by the standard method of a sharp rap on the pump body. Unfortunately, most of our drives last more than a minute or two, and stopping every mile or so to climb out of the car and bang on the pump seemed to be adversely affecting our average speeds.

German fuel pump with minor fitment issues  
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So we replaced the pump with a new German version of the standard British SU fuel pump, and despite minor differences in the pump layout that turned a 30-minute installation job into an all day affair, we did get the new pump installed, and at the same time replaced a couple of fuel lines that we're necessarily destroyed in the process. The German pump seems okay, although we've found it still has to work overtime on occasion, due we believe to some incorrect assumptions on the part of our erstwhile fuel tank manufacturer.

The fuel tank has two ports, an inlet that serves as a return line in modern EFI applications, and an outlet that feeds the fuel pump. As it happens, both ports are on top of the tank. On the one hand this allows them to operate relatively leak-free, on the other it requires our barely-adequate pump to suck fuel out of the top of the tank through a long tube not much bigger than a straw. The new pump seems to handle it okay, but someday we'd like to relocate the outlet to a spot about an inch above the bottom of the tank, where it'll probably leak but will at least preserve our German fuel pump for future generations.

Other fixes this past month were less critical. One morning the rev-counter stopped counting, and we had to buy a new one. Not new in the sense that it was recently manufactured, but in the sense that the seller claimed to have pulled it apart and cleaned it up. Despite its high price, buying a new tach turned out to be not as difficult as installing one. Climbing under our instrument panel is not possible for anyone older than five, and child labor laws being what they are, installation required reaching way under the dash, which in turn required a total disregard for all of the wires, cables, pipes and other fragile components under there. Along with a healthy selection of Band-Aids.

  New tach visible from the driver's seat
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The new tachometer seems to work about as well as the old one, which wasn't all that good but at least it doesn't bounce around like the speedometer. The new tach is much brighter at night, which may have something to do with the aforementioned cleaning, but that's only a theory, and not nearly enough to motivate us to pull the speedometer apart. By far the best news about the new tach is that we can see it much better than the old one. This has nothing to do with the device itself, and everything to do with the latest and undeniably final version of our M.G. Locost steering wheel.

Ultimate classic British steering wheel  
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The ultimate wood-rimmed steering wheel for any classic British car is a Moto-lita. Everything else is a knock-off. We of course could never afford a genuine Moto-lita, ergo our penchant for knock-offs. We really liked our original wood-rimmed steering wheel, but it was huge. Because it was a gift from my generous girlfriend it took us almost a year to replace it, although once we made the decision it took only minutes to find a cheap knock-off on eBay. The new wheel was the right size, and it steered the car, but we all knew it would never look good.

My generous girlfriend seemed to agree. Unsatisfied with the 1970s muscle-car look of our purportedly leather-wrapped steering wheel, she went online to research wood-rimmed wheels, and chanced upon the Moto-lita website. Not nearly as frightened as I was by the cost, possibly because the prices on the website were in pounds rather than dollars, she ordered Moto-lita's finest 13" wood-rimmed wheel and had it shipped air freight from the U.K. That wheel is now on the car, and if anyone out there has a 1970s muscle car in need of a 13" steering wheel wrapped in some kind of leather-like substance, let me know.

As we promised earlier this year, we bought new tires for the car. Finally. We got General Altimax HPs in 185/65-14, a model popular among the MGB crowd for excellent dry traction. We were okay with the 10-year old Bridgestones that came with our donor, but two things. First, we had to keep the tire pressures at 40 psi, which is just about exactly twice what 185-section tires would require on a 1500-lb. car, and second, we had a blow-out. It wasn't a bad one. We never actually felt it, and it had no effect on drivabilty, we think in part because the blow-out didn't occur on an actual road wheel, but on the spare.

  New sticky soft tires
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In retrospect it probably wasn't necessary to keep 40 lbs. of pressure in the spare, since we don't actually have any tools in the car to replace a flat. But the spare was a little too small for our carefully-designed and poorly-built spare tire mount, and it fit better with more air. Unfortunately the spare was not a 10-year old Bridgestone, but rather a 40-year old original equipment Kleber, and sitting for hours in a hot parking lot on a 100-degree day with 40 lbs. of pressure was too much for it. The air exploded out the bottom, shredding the belts and splitting the ancient rubber at the seams.

The reason for our excessive tire pressures was a sealing issue with one of the front tires, most likely due to sitting flat on the donor for several years. Below 40 psi the tire would leak air from between the bead and the rim, and would be flat within hours. 40 psi applied enough pressure on the bead to keep air from squeezing out. Naturally we couldn't drive around with one tire at 40 psi and the rest at 20, so we kept them all at 40. This of course had a negative effect on tire grip, but we didn't complain and still enjoyed flinging the car into turns, even if the tires gave up a little too easily.

We did occasionally complain about the ride. Although not out loud. At 40 pounds of pressure, the Bridgestones were only slightly more forgiving than the wheels on the Flintstones cruiser, and while the Locost suspension and driver's seat did an adequate job of soaking up bumps, depending as usual on your own definition of adequate, without any help from the tires the really big bumps would jolt us right out of our seats. We always thought we could do better, and at one point we even considered installing softer springs, although we ditched that idea when we realized how much work it would be.

Back in action at a Lotus club meet  
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As it turns out, softer tires did the trick. Not only do the flexible sidewalls soak up all of the minor road imperfections, and a few major ones, but they also allow the tread to stay in contact with the road in the turns, and the car finally out-corners my Miata. The handling was always there. Instantaneous response to the controls, zero body roll, awesome feedback. Now we have the grip to go with it. We should've done this months ago, but the donor tires were brand new, and we've always had a problem throwing away parts that still look good.

We now think we have all of the major issues of our 40-year-old British hardware resolved, the engine, transmission, and rear axle of course being indestructible. While we are no longer claiming any favored position on the automotive reliability spectrum, we are planning to enjoy what's left of the summer by flinging our Locost into high-G turns with our gorgeous Moto-lita steering wheel, without worrying about what repairs may or may not come next. We do have a couple of ideas for winter projects that involve the exhaust and cooling systems, but we'll leave those for a possible future report.


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