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Dear people who developed the stag engine.


GreenV8Machine

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It drives me nuts, try undoing the nuts, stud shears, get nut off, lock off with 2 nuts another stud, stud shears, weld bigger nuts to stud, stud shears. All but 2 sheared studs out, surely it should move? wobble, nothing, hammer it, nothing, block of wood and sledge hammer, nothing, tie engine lifting eye on head to beam across 2 post lift, lift car up with unfixed head, no head movement.

I mean who thought, hmmm, we have a crappy slant 4, lets weld 2 together and refuse a better engineered, stronger, tested engine, for our new mk2 2000 with the roof cut off.

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GT6_User_and_Abuser wrote:
All but 2 sheared studs out, surely it should move? wobble, nothing, hammer it, nothing, block of wood and sledge hammer, nothing, tie engine lifting eye on head to beam across 2 post lift, lift car up with unfixed head, no head movement.


Toast it with oxycetalene usually works; but don't melt the head! However as you have sheared the studs I think you may have to resort to drilling them out!


GT6_User_and_Abuser wrote:
I mean who thought, hmmm, we have a crappy slant 4, lets weld 2 together and refuse a better engineered, stronger, tested engine, for our new mk2 2000 with the roof cut off.


You mean old, push rod design when overhead cam is the way to go? Worse bit is the waterpump at the top of the system with no header tank. Buy an EWP, shame about the slant studs (I blame Saab).

There was no way Triumph engineers were going to let that American cast-off into their new car. The Stag should have come out as a 2.5 straight 6 withe the 3 Litre V8 going in the Saloons and Stag when it was developed.

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I think the problem lies with the title of this thread......surley no one did develope it!

Agree with MR B a 150bhp 6 pot would have done the job untill the V8 was ready but by then it was all a bit late for BMC etc
Triumph should have been sold off as a seperate entity circa 1974 you never know we might be raving about the new W12 Stag right now!

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GT6_User_and_Abuser wrote:
I mean who thought, hmmm, we have a crappy slant 4, lets weld 2 together and refuse a better engineered, stronger, tested engine, for our new mk2 2000 with the roof cut off.


There are several reasons why that was not a viable choice.
Rovers own production capacity was stretched so supplying the Stag would mean less output.
The Triumph V8 already had about 4-5 development by the time Triumph got into bed with Rover.  Triumph was not about to waste all that investment and certainly not going to throw even more away in order to re-engineer the car to get that other lump in there.
The idea behind the TV8 is that it and the slant 4 were to be the new family of engines - with the idea that the V8 be put in other cars inthe future.  There was apparently even talk of a slant 6 and a V12 based on the same principle.

Back then Triumph probably had a different future in mind than the way it actually turned out.

I'd also blame previous spanner monkeys and lack of maintenance rather than the designers.  There are more things in life that go sour if you don't treat them right.

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GT6_User_and_Abuser wrote:
It drives me nuts, try undoing the nuts, stud shears, get nut off, lock off with 2 nuts another stud, stud shears, weld bigger nuts to stud, stud shears. All but 2 sheared studs out, surely it should move? wobble, nothing, hammer it, nothing, block of wood and sledge hammer, nothing, tie engine lifting eye on head to beam across 2 post lift, lift car up with unfixed head, no head movement.

I mean who thought, hmmm, we have a crappy slant 4, lets weld 2 together and refuse a better engineered, stronger, tested engine, for our new mk2 2000 with the roof cut off.


there's irony for you,

get all the studs out and the head still won't come off,you'd think with it stuck that fast the gasket would never fail :-/i bet you could drive it and the bloody thing would still not budge.

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Richard_B wrote:






You mean old, push rod design when overhead cam is the way to go? Worse bit is the waterpump at the top of the system with no header tank. Buy an EWP, shame about the slant studs (I blame Saab).

There was no way Triumph engineers were going to let that American cast-off into their new car. The Stag should have come out as a 2.5 straight 6 withe the 3 Litre V8 going in the Saloons and Stag when it was developed.



Hah! American cast-off that's still in production having topped well over a million units and an 'old' pushrod design capable of double the Stag output with little work and 100lbs lighter!

IThat said t is a damned shame that that they didn't get the Stag engine right; it's the perfect size, perfomance and noise for the standard car, however after two failures and some head nightmares I went via the Rover route; now up to 5 litres!

..And Richard I promise to come to your meeting work/rain permitting.  Hopefully the car is now sorted!  When are you meeting next?

All the best,

Steve.

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Must admit I like the RV8 engine after going through several SD1s and P5Bs -  the V8  engines never missed a beat,
I love the  Triumph 6 pot for its robustness,but I just dont have any faith in the Triumph V8-I never even owned one my opinion based on threads like these!
I guess a really well rebuilt one looked after should run and run,apart from the head studs what is its worst design fault? what big cock up did they not sort out before putting into production? or was it just badly made and none of the "Marina" mechanics in the dealers knew how to service it?

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stoutgoose wrote:



..And Richard I promise to come to your meeting work/rain permitting.  Hopefully the car is now sorted!  When are you meeting next?



Next meeting at Potters is on 11/05 we get together on the second monday of a month.

Alex

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ajp wrote:
Potters? where is potters?



Mytchett near Farnborough!  :)

Fuzzy_Harris wrote:
On the stag dvd , one of the development engineers said that Harry Webster would never have signed the stag engine off until it was right, who was the muppet who did ?


The muppet was Spen King, Achitect of the Range-Rover, was shifted to Triumph after Harry Webster was moved to salvage the Austim Morris disaster unfolding...

of course the trouble was the Stag needed strengthening to reinforce the shell after the roof was removed, this put the body weight up so a more powerful engine was required, the 2.5PI would not meet American emission regulations so the V8 was fitted, the extra body weight and the more powerful engine then meant that bigger brakes were required, this then meant a move to 14" wheels to accomodate the larger calipers and discs......

Then the project was delayed so when the board asked for a restyling of the MkI 2000,  Michelotti styled the MkII, which then came into production before the Stag and they didn't even use the same front panels (wings, bonnet, headlight panel, valance, radiator surround)

So what started as a pretty convertible version of a 2000 became the Shag!  ??)

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ajp wrote:
Must admit I like the RV8 engine after going through several SD1s and P5Bs -  the V8  engines never missed a beat,
I love the  Triumph 6 pot for its robustness,but I just dont have any faith in the Triumph V8-I never even owned one my opinion based on threads like these!
I guess a really well rebuilt one looked after should run and run,apart from the head studs what is its worst design fault? what big cock up did they not sort out before putting into production? or was it just badly made and none of the "Marina" mechanics in the dealers knew how to service it?


You're on the right track concerning 'Marina' mechanics that didn't know much about it.  Put into context, it was a rare engine for them to service.  The whole BL line was at their mercy with Jaguar, Rover, Morris, Austin etc.  The Stag was therefore a rarity and it wasn't unheard of to use 100% water in the cooling system suring the summer - no corrosion inhibitor with obvious results.  Such things are basic knowledge to us, but for someone who is accustomed to working of BMC A series motors it is not.  My one and only experience of letting someone else work on my engine was also less than satisfactory.  The mechanic  (years of RV8 experience) said the timing was all wrong.  The guy never looking in the workshop manual I gave to him so I had to explain that the TV8 uses cyl. no. 2 for its timing, not no.1.  The reason is obvious to those who know the history of the TV8, but not for the rest.  This is the kind of thing that can render a TV8 useless - basic knowledge of the specific engine at hand.
Also there was some poor build quality going with stories circulating of casting sand still being present in the blocks.
What also killed the reputation was cheaper and substandard parts such as head gaskets.  This is what Fuzzy Harris refers to.  Harry Webster had a lot of clout and things happened the way he said they should happen.  Trouble was he was transfered over to Austin and the replacement may not have had the same ammount of clout.  At the end of the day the bean counters probably had a little say in the matter and a cheaper gasket was commissioned instead of one that worked.
Obviously we know that with good maitenance a Triumph V8 can be rather good.  The specialiststs such as Tony Hart have done their thing to enhance the reputation but one thing still does hamper the Stag and that is bad quality parts.  I've had some experience with crap parts - fortunately not critical parts or  at least I found the faults before being critical.
I once saw someone mentioning that if you treat a Ferrari engine with equal disregard it too will end up being a bottomless pit for you to shovel money into.

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Great replies all very intresting cheers

I am tempted once  the snag is back on the road with its RV8  to get a TV8 to strip and rebuild as a long term tinker and eventually put it back in -would be very intresting

So does the TV8 lend its self to tuning ? what sort of BHP can they give ou?, were they not intended to be run with injection fron the start?

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I think you can get more out of a RV8 than a TV8 - but remembering that the smallest RV8 is 500cc larger than the Triumph unit I guess that goes without saying.  Still, per capacity I reckon the RV8 is more tuneable and should you want silly power you could opt for a larger capacity RV8 of up to 5000cc.  Do that and you'll really need to upgrade the driveline and getting better brakes would also be a wise idea.  In all, extra power comes at a greater cost than just engine mods.

The original idea was for the Stag to have a 2.5l V8 but due to low rpm torque being very poor it was decided to go for 3.0l instead.  Some of those 2.5l engines were fitted with Lucas fuel injection but both it and carbs couldn't sort the poor torque.  I'd guess that due to fuel injection not being fitted to the North American market TR6 due to it not passing emissions tests was ultimately one of the reasons of the choice going to carburation rather than injection - the North American market was intended to be the largest for the Stag.  Canley Classics have an injection manifold in the museum: http://www.canleyclassics.com/triumphmuseum.asp?article=staginlets.xml  
Also I recently saw a 2.5l V8 engine block on ebay.  Nice to see some of these rare parts still in existence.

AS for power out of the TV8, Tony hart got something like 280 out of the one in his Modsports car.  It had 4 Weber carbs among other modifications.  I think his general idea was to prove that the basic block was capable of such output without premature demise.  He later tuned up another for Historic racing and it was strangled by regulations to use standard carburation, yet he got something like 190 out of that one.
By starting off with an engine in good condition or rebuilt, one can add some exhaust manifolds and a Holley carb for something like an extra 20hp.

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I've not heard great things about tuning the TV8 but then not many people have tried.  The RV8 is a complete bag of bolts though and not worth spending anything on to tune.

If you want a more powerful V8 in your Stag - buy a crate engine from the states.  Something like a Ford 302 is compact and will pump out 300BHP in stock form and tuning parts are dirt cheap because there is the demain to get them mass produced.

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....If you like cast iron lumps!  

Personally I find the RV8 a nice engine to use and work on, with parts being as you say 'cheap as chips'.  Light and easy to tune.  Admittedly 300bhp is about the maximum you will get from a RV8 without resulting to major expenditure and modification.

Each to his own.

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302 is not much heavier than RV8 and considerably more compact.  RV8 has cult status in UK mainly because it was the only readily available V8 for many many years and not due to particular merit.  More choice these days - I rather like the Audi V8 but may be too wide across the heads to go in a Stag..... (might eat the transmission a bit quick too)

Nick

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Ford small block is a much better engine than Rover V8. It has powered all manner of sports and racing cars through the years and is smaller and with alloy GT40 heads is lighter than the Stag Engine. It's block is low and light thanks to thinwall casting techniqes. It's exhaust ports face down too rather than horizontal like a rover . This makes fitting decent headers much easier.

Remember the sunbeam tiger had a small block 260/289 but the Rover 215 cui didnt fit!!!

Oh and yes I have considered fitting a 'crate' motorsport alloy headed 302 SB with 350bhp stock hp to my saloon  ;).. hence the research

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Having owned cars with both Rover, and Triumph V8's for many years my preference is still with Triumph's effort. Triumph engine is very much more 'sporting' with a nice rev limit of 6,500 rpm which can be used with impunity (if you have a good un!). Rover is an old slogger with a low rev limit even when tuned.
I wonder what happened to that ex Leyland development chappies project to build a 32 valve Stag motor? He was a good way down the development of it last time we spoke a couple of years ago.

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Yes I like my rebuilt Stag engine with:

1.Ported heads ("hard not to improve them" quote from my head man)
2.Monarch extractors (bolt straight on rather than 2 days at the exhaust specialist Rimmers version my mate bought  :-/ )
3.Fully balanced and lightened flywheel

Rev's nicely to 6000+ although if I was honest my tuned PI is more pokey from 5000rpm on... guess thats a camshaft thing... still I'm happy with 10mph to 110mph in 3rd - 3rd OD   :) :)

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