Improvements to the original heating system.

I purchased my pre-cat Griffith in May 2005, having driven it through last summer it quickly became apparent that I needed to improve its ventilation system,

On hot sunny days the hot temperature in the cockpit, even with the roof off was almost unbearable. Not only the temperature but the smell of exhaust gasses tried to spoilt my enjoyment.
Having read posts on the PistonHeads forums regarding these issues I decided to improve the ventilation during the winter months.
It’s a well known fact that the early cars suffer with inadequate heating and ventilation, so my first task was to investigate what I thought was wrong my particular car.
Firstly the blower motor had never worked since I had bought the car; this is situated behind the N/S headlamp so this was the first task.
Having removed the headlamps it was apparent that the motor had seized up, its location not being user friendly as far as maintenance is concerned.

The motor is attached to a simple mounting bracket which supports the motor and a rather crude apron to divide the inner wing cavity from the intake and motor outlet. I stripped the motor and carefully carried out repairs to make it serviceable. Thia picture to the right  shows the original repaired blower motor re installed with replacement hose ducting, with headlamp removed.

Repaired Blower

Once reinstalled and switching on the motor it worked fine, however, it uses the inner wing cavity as a ducting to feed the hot/cold and distribution (feet/demist) control box. VERY POOR!!

This Pictures shows the replacement ducting routed over the N/S inner wing, the yellow material is the sponge to seal the inner wheel arch.	Replacement ducting
I decided to install 100mm ducting between the motor and partway towards the control box.  I placed within this duct a smaller diameter hose (45mm) which I then connected to the central adjuster vent in the centre of the dashboard, this gives me a fresh blast of clean air when needed.	The 45mm Ducting

The inner wing cavity used on the Griff leaked like a sieve, there are several holes made during manufacture within the inner sill to the inside of the cabin. In addition it also leaked around the control box.
Using duct tape and sponge these holes were plugged to stop the escape of this air.
This resulted in an adequate air supply when switched on over both the windscreen and foot well. I also set up the control flaps of the heater box which were also in need of adjustment.

Drivers foot well ventilation.

During this improvement I realised that the later Griffith 500 had drivers foot well fresh air ventilation, I had seen on pictures of damaged Griffs, a blower motor mounted at the rear of the OSF wheel arch. This seemed like a good idea to me so I decided to see if one could be placed behind the OSF headlamp. Once the headlamp was removed it became apparent there is just enough space to accommodate the blower motor and ducting.

This picture shows the home made mounting for the Nova heater motor before mounting to the O/S inner wing.	Home made mount
The Nova motor installed complete with flexible ducting. At the bottom right hand side is the fresh air inlet for the motor.

A Vauxhall Nova blower motor was mounted very similar to the NSF, with the exception of having to cut a fresh air supply in the inner wing next to the radiator intake. A flexible 100mm reinforced nylon ducting was mounted to the outlet of the motor and guided over the inner wheel arch and into an existing hole within the driver’s foot well which happened to just fit perfectly! 

Theres just enough space for the re installation of the O/S headlamp.
The flexible ducting passing over the O/S inner wheel arch onto wards the drivers foot well.
The flexible ducting exiting the O/S inner wheel arch into the driver’s foot well.
A small speaker grill was fitted over the ducting to finish off its appearance which looked quite nice.The only remaining job to complete was to wire the blower motor through a relay fed from the back of the alternator main feed; the relay trigger was then supplied from a micro switch mounted on the steering wheel cowl.	New Vent

I now posses a Griffith with plenty of controllable heating and fresh air supply, ROLL on summer.

Hope this article may be of use to those in the same position I found my self. Regards Dave Skelly.