Carburetors: VC42 vs VHA

[Pancho]

Let's talk about the differences between VC42 and VHA carburetors.

2013-10-22 07.42.37 (Medium).jpg

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.

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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.

2013-10-22 07.45.06 (Medium).jpg

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Of course there are other differences, let's write about them.

Cheers,

[miller]

Fantastic information Pancho, thanks for the write up!

[G60michael]

thanks for the wright up Panco.

I never had a VC42 Carby so i cannot comment on that Carby. I have had a few VHA on my G60's and they seem to work ok, i have had mine rebuilt and it works a lot better, i think a lot of people prefer to swap the Hitachi Carby for a Stromberg, i don't know the reasons why, but i think easier to get parts for and better economy.

Good point with the Filter Lids, just realized that they were different a few weeks back. The VC is a lot bigger than the VHA in the picture. I also noticed the Choke leaver is in completely different spots.

I would like to hear other people stories and tips on the Carby on the 60 series

[RiverPatrol]

Great information! Thank you for the write up. I have only had very little experience with the VC, but now I know some things to look for.

Are rebuild kits for both carbs readily available?

[bosque]

Thanks for the great shots. The most impressive aspect of this carb is that double venturi.

[Esteban]

Great info Pancho, and the photos even better. Very clean carburetors.

I have used extensively both carburetors, since my 65 came with the VC42, and the 74 that I used to have was fitted with the VHA.

The VC42 was always a smoother one, and didn't move from its setup at all. The accelerator plunger, with the leather piston, indestructible. It was always better on fuel consumption.

The VHA was the more powerful one. Very crude internally with very few parts, and simple to take it appart. The plastic cam on the outside for the accelerator diaphragm wears constantly and creates some flat spots and backfires. The diaphragm also needs some attention from time to time.

Regarding top speed however, both are exactly the same, but you can get quicker with the VHA. And the issue with the top speed is very simple: the P engine can not go beyond 3800 rpms by design (I'm talking an unaltered engine, as it came from the factory) so the top speed is there, no matter what carb you put. The camshaft and valve train max out at those rpms.

[Pancho]

Are rebuild kits for both carbs readily available?

Yes they are, but only for VHA type. Here you are a picture of how it looks.

Carb VHA kit.jpg

About the VC42, I called Colombia one year ago and they said yes, they are available.

[RiverPatrol]

Good to know. I already have a kit or two for the VC42 but could use a couple for the VHA. Thanks!

[G60michael]

Good to know. I already have a kit or two for the VC42 but could use a couple for the VHA. Thanks!

Leslie if you need a H410 Kit for a VHA i can put you onto some Warehouses over here. We all know how hard VC42 kits are and no one makes them any more, but today i brought a VC42 Kit which Fuel miser Kit Number is HT409,and also scored a bargain VHA kit they ad sitting on the shelf for years. Fuel miser no longer make these kit for a fair while now but a local parts store tracked one rare kit down and when asked how much it was he said its the last one left, and got a bid of a discount but still wasn't cheap. I know i don't own a VC42 but if i do find one day i will have a kit for it.

Kit numbers are

HT409 - Hitachi VC42 61- 1/69
HT410 - Hitachi VHA 2/69- 80

Correct me if I am wrong, but that's what fuel miser book said

[RiverPatrol]

Thanks Michael. The FuelMiser HT409 sounds correct for the VC42; I'm pretty sure those are the kits I have. I'm sure I could Google some warehouses there, or use the same one I got the VC42 kits from. Thanks for digging up the kit number.