Carburetors: VC42 vs VHA
Posted: Tue Oct 22, 2013 10:41 pm
Let's talk about the differences between VC42 and VHA carburetors.
Here are some of them.
As a general information VC42 were made up to Jan 1969 and VHA from Feb 1969. Both are single barrel and the venturi (the throat) size is 36 mm which means the flow capacity they can manage is about the same. However, and here it comes the interesting part about the performance, the VC42 has a main jet sized as 135 while VHA is sized as 175 both at sea level. I think this made the Patrols produced after Jan 1969 been faster than the previous ones, in fact, the speedometers in Patrols up to Jan 1969 showed 120 km/h as a maximum speed, while Patrols after this date had 140 km/h.
Other differences are VC42 has two main parts, the one which essentially is the throat made of heavy aluminum and the other which is the throttle body made of steel both attached by bolts and sealed by a gasket. In the other hand VCH is a single body made of light aluminium walls and as consequence smaller than the VC42. This is a concern when someone wants to interchange them mainly because the air filter cap and its nozzle which connects to the carburetor is different for one other. The next picture shows both air filter cap, note the diameter and the length of the nozzle are not the same. Another big difference in the design is that VC42 has two booster venturi while VHA doesnt have any. Booster venturi helps fuel to be accelerated and atomized, so there is a better combustion in the chamber. Of course there are other differences, let's write about them.
Cheers,
As a general information VC42 were made up to Jan 1969 and VHA from Feb 1969. Both are single barrel and the venturi (the throat) size is 36 mm which means the flow capacity they can manage is about the same. However, and here it comes the interesting part about the performance, the VC42 has a main jet sized as 135 while VHA is sized as 175 both at sea level. I think this made the Patrols produced after Jan 1969 been faster than the previous ones, in fact, the speedometers in Patrols up to Jan 1969 showed 120 km/h as a maximum speed, while Patrols after this date had 140 km/h.
Other differences are VC42 has two main parts, the one which essentially is the throat made of heavy aluminum and the other which is the throttle body made of steel both attached by bolts and sealed by a gasket. In the other hand VCH is a single body made of light aluminium walls and as consequence smaller than the VC42. This is a concern when someone wants to interchange them mainly because the air filter cap and its nozzle which connects to the carburetor is different for one other. The next picture shows both air filter cap, note the diameter and the length of the nozzle are not the same. Another big difference in the design is that VC42 has two booster venturi while VHA doesnt have any. Booster venturi helps fuel to be accelerated and atomized, so there is a better combustion in the chamber. Of course there are other differences, let's write about them.
Cheers,