The early 1,057 cc (64.5 cu in) version had a lower compression ratio than the Viva saloon  (7.3:1 rather than the usual 8.5:1), producing 47.8 hp (35.6 kW) gross, or 40.3 hp (30.1 kW) net, both at 5200 rpm.
In 1967, the HA received the engine of the changed Viva.
This 1,159 cc (70.7 cu in) was essentially the same as the earlier powerplant; although net power was down to a claimed 32.2 hp (24.0 kW) at 4600 rpm.
It ran on the lowest rated fuel and was fitted with a  17 mm (0.67 in)-bore carburettor for even higher fuel mileage.
The later models powered by the 1256 cc engine offered 48 hp (36 kW) gross at 5400 rpm, or 39 hp (29 kW) net at 4600 rpm.
By 1977 only net horsepower ratings were offered, with power up to 31.7 kW (42.5 bhp) at 4800 rpm.
As for all three generations of HAs, the compression ratio remained 7.3 to 1.
For the lighter duty HA 110 there was also an 'Economy' version, with a CD carburettor (constant depression), a redesigned manifold, and a different camshaft.
This version offered up to 30% lower fuel consumption, although power did drop to 18 kW (24.4 bhp) at 3800 rpm.

The HA soldiered on in production for twenty years, until 1983, where it was supplanted by the short lived Vauxhall Chevette based Bedford Chevanne which was in turn replaced by the Bedford Astravan / Bedford Astramax.
Despite the fact that the Vauxhall Viva upon which it was based had gone through two further model generations, the bodywork of the HA van stayed the same until its eventual discontinuation in 1983.
The 1,159 cc (70.7 cu in) engine arrived in 1967, followed by a 1,256 cc (76.6 cu in) in 1972.
A pickup was also made by Martin Walter (Dormobile) - who also made the Beagle conversion - and by Walker Bodies of Watford.
Made in very small numbers (believed to be around 60 in total) only a handful of these survive today: they were originally sold to companies and private buyers directly through Vauxhall/Bedford dealerships.
The early 1,057 cc (64.5 cu in) version had a lower compression ratio than the Viva saloon  (7.3:1 rather than the usual 8.5:1), producing 47.8 hp (35.6 kW) gross, or 40.3 hp (30.1 kW) net, both at 5200 rpm. In 1967, the HA received the engine of the changed Viva. This 1,159 cc (70.7 cu in) was essentially the same as the earlier powerplant; although net power was down to a claimed 32.2 hp (24.0 kW) at 4600 rpm. It ran on the lowest rated fuel and was fitted with a  17 mm (0.67 in)-bore carburettor for even higher fuel mileage. The later models powered by the 1256 cc engine offered 48 hp (36 kW) gross at 5400 rpm, or 39 hp (29 kW) net at 4600 rpm. By 1977 only net horsepower ratings were offered, with power up to 31.7 kW (42.5 bhp) at 4800 rpm. As for all three generations of HAs, the compression ratio remained 7.3 to 1. For the lighter duty HA 110 there was also an 'Economy' version, with a CD carburettor (constant depression), a redesigned manifold, and a different camshaft. This version offered up to 30% lower fuel consumption, although power did drop to 18 kW (24.4 bhp) at 3800 rpm.
The HA soldiered on in production for twenty years, until 1983, where it was supplanted by the short lived Vauxhall Chevette based Bedford Chevanne which was in turn replaced by the Bedford Astravan / Bedford Astramax. Despite the fact that the Vauxhall Viva upon which it was based had gone through two further model generations, the bodywork of the HA van stayed the same until its eventual discontinuation in 1983. The 1,159 cc (70.7 cu in) engine arrived in 1967, followed by a 1,256 cc (76.6 cu in) in 1972. A pickup was also made by Martin Walter (Dormobile) - who also made the Beagle conversion - and by Walker Bodies of Watford. Made in very small numbers (believed to be around 60 in total) only a handful of these survive today: they were originally sold to companies and private buyers directly through Vauxhall/Bedford dealerships.
Bedford HA