Window Shopper: Rubber-Bumper MGB

Story By Alan Cesar


• The Limited Edition model added alloy wheels, side stripes and a front spoiler.

• It’s the practical choice for a fun daily driver.

• All the complaints levied at them can be easily corrected.

It’s easy to hate on the so-called rubber-bumper MGB. Smog laws choke its engine, headlight height laws raise its ride height, and bumper laws require that big, black schnoz, ruining its elegant look. It’s the ugly stepchild, the one who’s not so focused or driven.

If you look past its apparent flaws, however, you find a practical, pleasant and well-rounded family member that will be less demanding, less problematic than the single-minded favorite. The rubber-bumper variety may not be the best choice for a sporting B, but for something you’re going to drive often—even daily—it’s a far better option.

First, those rubber bumpers are much more practical. City dwellers know all too well the perils of parking on the street: banged-up bumpers. Anyone who lives in Chicago, New York, Los Angeles and the like either finds private parking or resigns themselves to always having ugly bumpers from the inevitable contact. The latter is a pricey proposition with an MGB: Replacing a dented bumper will lighten your wallet by $250. No one likes that.

Its ride height has practical advantages, too: You’re less likely to scrape bottom on steep driveways, which makes for less stressful merges into traffic when you already have to scoot over two lanes and make a quick left before the light changes. It also makes you slightly more visible to the behemoth automobiles on the road today, making the aforementioned maneuver slightly less fraught with peril.

What else? The steering ratio is slower. Yes, that’s a bit less sporty, but with today’s wider tires and stickier rubber, it also means your arms aren’t fatigued after a trip to the downtown cinema. Its gauges are bigger, easier to read at a glance, and light up more brightly at night. Creature comforts are improved: The windshield wipers have a pulse feature and the blower fan has two speeds. The interior received an update, too, with a glovebox and console as well as the ultimate nod to hedonism: a clock in the dash.

You’re still not sold, we know; the power loss is a big deal. Those emissions regulations meant wheel horsepower in the 40s. That’s a heart-sinking number, but consider this: Usable power was essentially unchanged. The hurt comes above 4500 rpm, but torque down low—where you usually want and need it for street driving—is almost the same as with the earlier cars.

So what’s the damage? Expect to pay $12,000 for a show-winning Limited Edition example, but your average car—something you wouldn’t be afraid to drive on the street—will be in the neighborhood of $3500. Nicer ones will fall near $5000. Reasonable indeed.


We spoke with Carl Heideman, master mechanic and owner of Eclectic Motorworks. He regularly parallel-parks a rubber-bumper MGB and considers them the best option for a daily-driven vintage drop-top. He shared these tips with us.

The power loss still stings, doesn’t it? Good thing you can easily convert the single Stromberg to dual carbs, either SUs or Webers. Be careful with aftermarket conversion kits: Some are good, some less so. The original-equipment cast manifold from earlier cars works well for this, too. This will bring up your wheel horsepower to the low 60s. The original Stromberg carb also tends to need more frequent tuning. With the twin SUs, you should only need to adjust them every 50,000 miles or so.

For better handling and a lower ride height, just install the springs from an earlier car. If you really want the classic MGB look, chrome bumper conversion kits exist—but installing them involves careful cutting, welding and painting, and the kit alone will set you back $1200.

Still need more oomph? It’s a low-compression engine, which means it’s perfectly suited to a supercharger. The buy-in isn’t low—budget $4000 for the Moss Motors kit—but you’re looking at 80 wheel horsepower and gobs of instant torque.

If you’re keeping the Stromberg, watch that automatic choke. Three screws hold it onto the carburetor body, and if they get loose, bad things happen. The car will run rich, which makes the catalytic converter run red hot. Fuel will also drip from the choke and land—you guessed it—directly on the hot cat. Make sure the choke is present and working, or convert it to a manual choke. That is, unless you like fires.

Speaking of fire: All cars have the overdrive wiring harness, whether equipped with overdrive or not. The harness can chafe and short out, causing a fire of its own. Either add a fuse to this circuit or, if you don’t have overdrive, just remove the harness.

In the late ’70s, people started to realize that storing their convertibles in the winter would keep rust at bay, so later cars tend to be better preserved. Look for rust in the usual places: the leading edge of the rear fenders, into the rocker panels and the floor. Also check the bottoms of the doors.

Check for cracks on the door by the vent windows; that’s a weak part on the door. Cracking is a sign that the bolt-on windshield assembly is not properly aligned. Loosen the bolts and adjust the windshield so it doesn’t put stress on the door.

The best interiors are in the 1977-’80 cars—that’s where you’ll get the two-speed blower fan and pulse wiper, for example—and they received a major overhaul all over. The brake system also got a booster, and anti-roll bars returned to the suspension. The radiator moved forward, and electric fans replaced the belt-driven fan. The electric fans can fail, however, as can their thermoswitch. If the temperature starts to climb, check both of those components before moving on to the rest of the cooling system.

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View comments on the CMS forums
pwbag New Reader
5/8/19 9:13 p.m.

How about painting the front snouts.?  Single  45 DCOE, somebody has a "head" for it?. Little better cam, Tejas, probably other states it beyond the "testing"?

would love some thoughts? Out side the box or a direction to a web sight . 

Keep me from  a Miata   or Alfa,










wspohn Dork
5/11/19 12:19 p.m.

Bit more to bringing the rubber bunper cars up to the stock level of the earlier cars. Need new cam, pistons, valve springs, twin carbs with manifold, exhaust manifold and downpipe, and extensive suspension revamping.  And if you spend all that money, you are just back to the starting point of the early cars.

Trade off is that the chrome bumper cars likely need significant money spent on derusting, so.....

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