Datsun Coupe Range

The 160Z was not a car we saw in Australia and, I believe, was more or less a South African-only model. Australia’s closest relative would have been the 120Y Coupe. As such, I’m not too sure about the way the fuel lines were routed from the fuel pump to the carburettors, but in the case of the larger 240Z Coupe which also used twin carbs, the fuel system in the engine bay consisted of a common fuel rail with rubber hoses leading to each carburettor.

So, for the pressure to be uneven in the two carburettors, you’d probably need to have a restriction or blockage in that rubber line or a problem with the needle and seat of the carburettor in question. The thing is, I’m not sure how you’d know you had a pressure differential unless you’d fitted an external pressure gauge to each carburettor’s supply line, as Datsun certainly didn’t provide such a gauge.

Perhaps you mean you have unequal vacuum at each carburettor and this is a much more common scenario. You can check for this with a vacuum gauge, noting whether one carb is `pulling’ more vacuum than the other with the engine running. From there, you can use the adjustment screws on the carburettor to match, or 'balance' the two carbs so they contribute the same effort in making the engine run.

This sounds simple, but it’s actually a job for a specialist who understands old carburettor designs and how to make them work properly. It’s a bit of a dark art, but rally workshops and mechanics that specialise in classic cars are a good place to start looking.

By the way, my information suggests that the carbs on your car are made by Hitachi and, therefore, are more likely to be a Japanese copy of the SU carburettor that has been turning motorists into mechanics for decades.

IT'S hard to put a value on an old car. So much depends on finding a buyer who wants one. Find an enthusiast and you'll do better than by selling it on the open market. Assuming yours is in very good condition, you could expect to get $1500-$2000. You could try the Nissan Car Club of Australia, ph: 9513 0414.