Trashing the Stag Design

[Rigid]

There's also a lot of mechanical engineering in a missile test system.

It's hardly rocket science -

[davidf]

A lot of the myths come from Clarkson's TV programme - 'Who killed the British motor industry". I think he correctly picked out the Stag as symptomatic of what went wrong, but then got his detail facts very wrong. One of the most outrageous statements was - 'who thought it a good idea to weld two Dolomite engines together', as if this was some ridiculous 'after-thought' to get a V8 engine without any proper planning. The origin of the Dolomite and Stag engines are well described in a couple of articles - worth the read just to give you ammunition to shoot down the pub experts.
In this one, https://www.aronline.co.uk/history/the-rover-triumph-story/1963-the-big-year
start reading at Developing new engines for Triumph
And also this one https://en.wikipedia.org/wiki/Triumph_slant-four_engine
Personally, as a chartered engineer, and having run a Stag engine I built myself in 1984 for almost 100,000 miles in 2 different Stags, I think the design is excellent. So, if the design was 'excellent', how did it become the Triumph Snag?
Unfortunately, the answer lies in one simple QC failure at Beans Industries, the foundry acquired by Standard Triumph in the mid 1950's, which cast the engine blocks. Inspecting my new short engine in 1984, I first noticed residues of core sand in the water jackets, but then thought to check over the engine for other cast passages, and found the oil passage from filter to transfer housing almost blocked with its core residue. A series of escalated complaints led me to Canley, by then the Unipart Major Assemblies depot, where my host was the chief inspector. Believe it or not, they had a comprehensive inspection department which would take sample stock assemblies (engines, gearboxes, etc,) from across the BL range and strip and inspect them. In our discussions, he admitted he had been an inspector at Canley in Triumph days. They were aware of the core-sand problem in the water jackets of the V8 block castings - "if they were really bad, we cleaned them before they went on the machining line". But when I showed him the oil passage in mine, he was surprised, and said they had never thought to check that! By this date, they had just 6 Stag short engines left at Canley, so he called a fork-truck driver, one of his fitters, and brought all 6 down to an inspection bench. We found one good one! All the others had the defect which I had found and they had never noticed throughout the Stag production period.
So, Stag engines have 3 major failure points
* Overheating - remember the inspector's comment about core sand in the water jackets - if they were really bad, we cleaned them. How bad was "really bad"? There are many stories on this forum of people getting cupfuls of sand out of the water jackets. Was that within the design scope of the cooling system?
* Crank failures - lubrication by sand-bearing oil is probably not within the design scope of the crank bearings!
* Timing chain failures - I have seen a post on here which confirmed my hypothesis of the time - a grain of sand carried in the oil to the timing chain tensioner and getting stuck in the spray hole. This would increase the tensioner load on the chain, but more critically, starve the chain of its primary cooling and lubrication.

So, my final summary: if the design is rubbish, they will all fail. The fact that many people on here have achieved very high mileages, and mine almost 100,000 miles which used to include a lot of continental summer holidays with a family of 4 and a caravan, proves that the design was fine, and the failures must be from other causes. I suspect some of those were poor maintenance, but the QC problem mentioned above must have played a major role in destroying the reputation of the Stag, and, as it was their 'flagship' car, Triumph, and as it was one of their premium marques, BL.
So, Clarkson was right to highlight the Stag, but for the wrong reason!

[Goldstar]

David, David, David…. You should know better than to use logic and common sense in these circumstances. I agree with everything you have said. Great to get a chartered engineer’s viewpoint.

[Wheelz]

...........................So, my final summary: if the design is rubbish, they will all fail. The fact that many people on here have achieved very high mileages, and mine almost 100,000 miles which used to include a lot of continental summer holidays with a family of 4 and a caravan, proves that the design was fine, and the failures must be from other causes. I suspect some of those were poor maintenance, but the QC problem mentioned above must have played a major role in destroying the reputation of the Stag, and, as it was their 'flagship' car, Triumph, and as it was one of their premium marques, BL.
So, Clarkson was right to highlight the Stag, but for the wrong reason!

Hear hear! Journalists note: instead of repeating the old worn out rhetoric, quote this from those who know. It's a revelation! The Stag design was good!

[Chris01573]

When I bought my Cometiq gaskets from engiunuity the chap I spoke to said they do not have the cranks hardened which I found interesting considering their link to the late Tony Hart...

[Chris01573]

I just fired up mine after a full rebuild, Started with acid dipping, then crank gound & hardened, rebored, NOS Camshafts, valves, seats, head skimmed, block tickled. Rebuilt waterpump, dizzy & strombergs. ... So basically everything... https://www.youtube.com/watch?v=o6hsCbRvzPQ

[richardthestag]

when I first bought my current stag a smeg over 30 years ago it had covered just over 97k miles. failing oil pressure led me to rebuild the engine which was abandoned due to 3 broken main bearing caps. that said the rest of the engine was still in original spec, standard crank with , pistons and unskimmed heads. It was the original engine to the car. Nowadays folk scoff at an engine lasting "just" 100k miles whilst conveniently ignoring monumental failures mentioned by Goldstar and others above, BUT back in the 60s this was seen as a major step forwards in engine design.

Was it car is the star where they did the sound test on the stag v8 and confirmed what everyone else already knew, stag v8 is just about the best sounding v8 this country has produced...

3 times I have been close to selling my stag, first was to trade against 450SEL 6.9 first owned by James Hunt, secondly was to trade in for a beautifully restored XJ12C and more recently because I just wasn't using it. In all 3 events just driving the car had me thinking "what on earth are you doing?" and because I love the ride, the noise and the feel of the car I still have it.

[richardthestag]

Mike Brewer, Quentin "Hairdresser" Wilson, Ant Antstead, Alexei Sayle etc have all sung from scripts as to how crap the stag is for "clicks" on mainstream TV. Everyone* loves a bit of car crash TV after all

Top Gear more recently has perpetuated the myth that all British Cars are crap and that you must own an Alfa to even be considered seriously as an enthusiast.

But like all media, it is mostly guess work and the bits that are not, well they are made up, so you just ignore it.

Lots of people are like sheep and too easily led. Difficult to lead them unless you resort to tactics used by mainstream media and governments so best leave them to being led and fully vaxed etc

We know the Stag is an awesome machine, if someone else doesn't share that view then it is there loss

In summing up I present this image of my car at the South Molton Vintage Rally 2013, one of these BL products almost destroyed the company and was instrumental in destroying the brand. The other kept the company afloat for a fair few years.

IMAG0525_zps735744a4.jpg

[flying farmer]

Amazing how many of the supposingly crap car are left compared to that real rarity to the left of it

[flying farmer]

When I bought my Cometiq gaskets from engiunuity the chap I spoke to said they do not have the cranks hardened which I found interesting considering their link to the late Tony Hart...

They will probably run for 30,000 miles on an unhardened crank (thats the guestimate from the history file that came with my Mk2 stag when I bought it)

Thats probably 10 years or more for the average stag owner these days, no chance of a warranty issue.

Totally useless if you cover a lot of mileage, and more to the point the crank will need grinding yet again and will soon become scrap

[trunt]

I Think you will find this is closer

Fact File
Sold/number built: - 1970-77/ 25,877 Mk1 and Mk2 (MK2 from Feb 1973). The latest figures from DVLA are 8,428 either taxed or SORN’D. As only 17,819 were for the home market, that is a survival rate of 47% (in reality there are others which are not taxed or sorn’d so the rate is probably 50%+) which is very good as the car got the name “Triumph Snag” in the seventies. Just out of interest, the rate in Australia is just under 60% but I would expect that in USA to be a much lower figure as they just love to scrap things early. To help put the survival rate into perspective popular vehicles of the day such as the Morris Marina and Ford Capri manufactured in the UK in the hundreds of thousands during the same period have a less than 1% survival rate.

some of this came from Peter Robinson

A quick count here shows are about 600 Stags listed in the USA TSC register, i.e. around 20% survival but there has to be more that never registered so still a significant number

[MikeParker]

Mike, in my experience the crank sprocket doesn't last long enough. What about getting these case hardened before fitting? (or Nitrided etc).

On my first timing gear rebuild, I changed the sprockets as I foolishly thought that replacing with new parts would always be a good thing. I now realise how wrong that is. When I changed the original sprockets, at 85K, I don't recall there being any significant wear. On my recent overhaul at around 150K, there were virtually no teeth left on the replacement crankshaft sprockets. That seems to be a common experience. We certainly should try and source some hardened sprockets. I did have a couple of conversations with potential suppliers, but they seemed nervous about possible liability for subsequent failures. Certainly worth pursuing in my view.