Fitting air conditioning to an MGBGTV8
Gordon Hesketh-Jones has used his V8 for many European and Nordic tours with his trusty navigator Jennifer and often thought of an air con modification until, in 2012, he finally decided it was time to go for it. Here he describes the installation. (Dec 12)

Based in modern premises near Coventry, the main Clayton company designs, supplies and maintains the air-conditioning systems for commercial coaches and buses, with several major fleets under their maintenance wing and has more than 50 years of automotive air-conditioning experience. Their managing director, Geoff Insley, has always been a classic car enthusiast and over the years has developed air-con systems for a wide variety of classic cars. They now have standard kits for installation into the Jaguar XK120 to XK150 range, although they most frequently work on the "E" type models. In fact during my visits several "E" types were in the workshop for complete engine and body rebuilds together with an air-con system. Standard designs have also evolved for the TR4 to TR6 range and are very popular. There are now two separate companies -one for commercial coach fleet work and another called Clayton Classics which is our interest. The contact at Clayton Classics is Phil Beveridge on 02476 691916 and www.claytonclassics.co.uk

I first met Geoff at the incredibly wet and soggy MG Car Club's Silverstone 2005 meeting (the first year that we had a huge lake in the middle of the V8 Register's marquee, which made the AGM interesting), where he showed his MGBGT with air-con on the MOSS stand. Having just returned from a painfully hot tour of Greece, Hungary, Romania and Bulgaria the air-con was of immediate interest to me so I offered to have my car used as a prototype for a V8 version, but the small matter of the 300 miles between Coventry and my home in West Cornwall made this impractical.

Geoff could however see the heat generation problems in the V8 engine bay and in due time bought one for himself and set about designing, installing and long-term testing a system which could fit into the over-crowded V8 engine bay without exacerbating the already serious potential overheating problems. His extremely smart V8 (Black 0974, formerly owned for many years by Dave Wellings) is now their works demonstration car. A simple test drive is enough to prove immediately just how efficient and unobtrusive the system is. See their website for more information.

Lifting the bonnet you see the aluminium radiator with the condenser and a pair of roller-bearing 12v DC 9" waterproof long-life SPAL WA07/AP7/C315 fans mounted in front of it. These fans will each deliver around 631cfm of airflow in a low-load situation but if we assume that the condenser plus radiator constitute a strong resistance to airflow in the order of 0.8" H2O, then each fan can deliver 212cfm. At that load they will draw around 8.8amps each. Having said that, the airflow through the condenser and radiator is a real gale when tested in the workshop! These fans have circular frame bodies so the airflow is focussed and directed into the condenser and radiator, unlike the standard V8 fans which have primitive unshrouded blades which thresh around and rely on the forward movement of the car to move the air through the radiator.

Why an expensive aluminium radiator? Quite simply the cooling of the V8 is marginal at best and in traffic jams in hot weather I have often seen the temperature gauge in my V8 climb as far as "2-o-clock" which is an unhappy experience. With the air-con installation the extra mass, airflow obstruction and heat generation of the compressor and other equipment will make the overall engine cooling situation even more marginal, particularly in a car that does not have either RV8 manifolds or a louvered bonnet. It is for this reason - better safe than sorry - that Clayton includes the lightweight aluminium radiator (with absolutely beautiful welding along the top seams) in their standard installation. Aluminium is basically a far better thermal conductor than the metals used in conventional radiators, so these new units not only heat up more quickly but also emit/dissipate the heat from the coolant more quickly. For the same reason Clayton also strongly advise that Evans Waterless Coolant is used - this will operate over a range of -40C to +180C - unlike water which can effectively boil and bubble around the engine hot-spots thus losing its cooling effect and putting strain on the hoses. Due to the wide temperature range of the EWC there is no need to have a pressure cap on the expansion tank. In addition the Evans liquid is less likely to cause engine corrosion so of course with this temperature range it is simply used all-year-round and there is no need to use

anti-freeze. Information about the Evans' products for use in Classic or Vintage cars can be found on their website at www.evanscoolants.co.uk .

Clayton recommend that when they fit an air-con installation, at the very least a complete set of five new hoses are fitted for the heating and cooling system. They consider the modern silicone-rubber hoses are far better and safer than traditional standard rubber hoses, so I opted for these. My heater control valve had been playing up so I asked Clayton to replace this (as they were changing the hoses anyway) and during the installation work they found that the bearings in the water pump were going so I asked them to replace this too. Subsequently the 38 year old Otter switch had failed - according to Clive Wheatley these are no longer made in Ottery St Mary in Devon but in the Far East and are no longer reliable, so I bought a Revotec variable fan controller, from him but Kenlowe also sell similar controllers.

The air-con compressor is located low down on the nearside of the engine driven by an additional fan belt - see photo - whilst hidden from view but near to the nearside horn is the Receiver/Dryer unit which holds the pressurised refrigerant liquid prior to its delivery to the Evaporator unit, together with a small pouch containing a desiccant (drying agent) to extract any moisture which might have entered the system during the initial assembly and charge of the refrigerant.
Substantial reinforced rubber hoses run from the compressor along the nearside of the engine bay then enter the cabin via new holes to the left of the windscreen washer box. Hidden behind a neat aluminium plate at the far end of the passenger's footwell are the Evaporator with its own small radiator and the three-speed fan which distributes the cooled/chilled air to various parts of the cabin. This fan - like the SPAL fans - was noticeably quieter at slow or medium speeds than the standard MGB heater fan. Fitting this plate (since re-carpeted) means losing approximately 4" of legroom; however the distance from the plate to the base of the seat back-rest is still 43". In other words, the space intrusion is far less than the Land-Rover sourced installation seen in Japan spec RV8s which, by the way, comprises 33Kg of the weight of the RV8. By contrast, the gross weight of the total Clayton installation for the V8 (including the new aluminium radiator) is 27 Kg - from which has to be deducted the 10.5 Kg weight of my old steel radiator leaving a net increase in weight of 16.5 Kg - a mere flea-bite compared to the weight of The Noble Navigator's luggage!

There is a certain amount of freedom of choice as to where one chooses to site the various air-con outlets shown in the photos. We chose to have four scroll-type devices adjustable for direction and volume; one was mounted onto the above-mentioned alloy plate so as to cool the passenger's feet and legs with another in the driver's side footwell. Two more were neatly mounted underneath the glove-box where there are also the switches for the three-speed fan and for the temperature control. These controls are easily accessible from the driver's seat. During one test at the Clayton factory I saw the chilled air output measured at 4C, which should cope with most requirements! Finally we asked for an "eyeball" outlet at the far nearside end of the dashboard to provide yet more cooling for the passenger/navigator - and also instant demisting of the nearside window in damp conditions.

Clearly having air conditioning installed during the damp and chilly English Autumn means that we will not feel the full benefit until well into 2013, however having waited some 28 years to get the system installed we are quite happy to wait a few more months. I will of course follow the standard air-con instruction of running the system for ten minutes or so once a month through the Winter and at other times when it has not been used.

See an illustrated two page note as a useful guide to this installation. V8NOTE458
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