A ‘Heinz 57’ Triumph Stag
This time of year is always very busy for me. I am secretary of the Queensland Triumph Sports Owners Association, and our AGM is in February which requires considerable input from the secretary. I have also been on the organising committee of our annual Mac’s Bridge Car Show, which is in May. Operating any event in recent years has been like walking a tightrope; we had to cancel our 2020 show due to restrictions, but were lucky to be able to proceed with the 2021 event during a subsequent relaxation of COVID restrictions. We had been concerned about this year’s show when the omicron variant struck and other clubs had to cancel events in January and February, but restrictions are again being relaxed, so we remain hopeful.
Queensland, like the rest of Australia, has seen additional regulations recently to limit the size of gatherings that has resulted in cancelled club drives and events, so my Stag has been spending extended time parked in the garage. In the meantime, I have been assisting a fellow club member with an upgrade on the differential and driveshafts on his Stag.
When he purchased his car, it had been retrofitted with a Leyland 4.4-litre V8 engine, which is quite a common conversion in Australia. The engine was designed for the Leyland P76, a locally designed and built car that was to compete with the Australianbuilt Holden Commodore and Ford Falcon that dominated the saloon car market for many years. BMC/ Leyland had traditionally imported CKD kits from England and assembled them in Australia, often with modifications to make them more suitable for local conditions. Cars such as the Morris Minor, MGA and Mini were cases in point and similar to those driving on UK roads, whereas others such as the Austin Lancer based on the Riley 1.5 and the Austin Kimberley based on the Austin 1800 were both visually and mechanically different from the originals.
The P76 was an expansion on this theme, but received a mixed reception when launched. Then the increase in fuel prices and all sorts of warranty issues resulted in lower than forecast sales and a short production run, not to mention losses for Leyland Australia. The engine was an aluminium V8, a redesign of the Rover V8 to increase capacity closer to the Holden and Ford V8s of 5.0-litres. Being of similar dimensions to the Rover V8, the P76 engine can be retrofitted into a Stag engine bay. In fact there are unconfirmed stories of Leyland Australia fixing warranty claims by replacing Triumph V8s with the Leyland V8.
An automatic Stag with a retrofitted Leyland V8 is undergeared, and there are various ways of improving it. In my Stag I have a ZF HP44 automatic with an overdrive fourth gear fitted behind the TV8. However, in my friend’s case the differential is to be swapped for a Ford 9in unit. The Ford 9in diff is usually fitted to a solid axle, and is a favourite with modifiers because of its strength and the availability of a range of new parts for ratio changes or uprating torque transmission. My friend’s differential had been previously modified with changes to the rear of the housing to enable attachment of the Stag
mounting plate. However, the front was standard Ford, so he had to get a front extension manufactured to match the standard Stag front housing with a bracket allowing the attachment of the suspension subframes. The internals of the housing comprised an extension for the input driveshaft running on bearings with a front oil seal. The input flange was machined to match the standard Triumph propshaft.
The new diff was to be installed with new locallymanufactured driveshafts that came complete with new hubs running in their own bearings, so overcoming the weakness of the Triumph design where the hub is retained by the stub axle and so any failure here results in loss of a wheel. The driveshafts used in this kit are from a Toyota Camry and have an adapter to attach the inner end to a standard Triumph diff output flange. The only problem with fitting to the Ford diff is that the inner face of the output flange is close to the body and has tapped holes for set screws as there is insufficient room to fit nuts. Therefore, the adaptor that came with the kit could not be used as we required a cotton reel type adaptor so nuts could be fitted in the gap. There was only a small groove in the centre of the cotton reel that restricted the available space for the nuts. This, together with the fact the Triumph flange had four fixings and the Toyota six, required some juggling to allow space for all the nuts. I had to draw a full-scale layout on my trusty drawing board to ensure correct spacing of the fasteners.
Meanwhile, I have just recently changed my two-post hoist for a four-post lift, the reasoning being that the hoist is going to be used for servicing and repairs, and it is much easier to drive a car onto a four-poster than locate the arms of a twopost under the vehicle – recent problems with my hip mean that I have to take care getting up and down to locate the arms. I was able to quickly sell my two-post and purchase a four-post from a local supplier. I manufactured some brackets to fit to the uprights so that the power cable was run overhead to the hydraulic motor, keeping
“I had to draw a full-scale layout on my trusty drawing board”
the floor free of cables. I also fitted a 240V power board adjacent to the hydraulic power pack with an overhead supply that enables mains-powered lights or a battery charger to be used on the car without leads dragging on the floor.
I still have a couple of modifications to complete on the hoist. The ramps used to drive on are raised with the hoist and are fine when the hoist is lifted high so you can walk under, but become a hazard when a vehicle is partially raised as there is insufficient room to walk behind the ramps when the roller door is closed. I am investigating if I can hinge them so they can be raised after the vehicle has been driven on, but this will require changes to the mechanism for releasing the safety latches at that end.