Stage 2 tuning

[andrew suffolk]

Hi, 

I'm now on my 4th Vitesse convertible and it's approaching restoration time. Specifically, the engine is on its way out and will need replacing/ rebuilding.

I recall from my youth that Moss offered a wide range of tuning parts for the Vitesse but these days they only seem to do Spitfires.

My question is:

If I am to get a new engine, is it worth  getting one that is stage 2 tuned? What are the unknown unknowns? Will I need to upgrade the carbs, exhaust, suspension etc? Is it worth getting a triple Weber conversion? Is there a specific order in which to replaced parts if the restoration is spread out over a year or two? 

Any advice or recommendations gratefully received.

Thanks

 

Andrew

[Clive]

The first thing is what do you want from the car? Are you going to use it just locally and pottering about? long distance touring? Trackdays and maybe sprint/hillclimbs? 

And driving style. Most Triumph owners rarely rev the engine beyond the mid range, if you start tuning for power it implies you will be exploring the red line on a regular basis.

For 90% of owners, a well built and set up engine is ideal. Trouble is finding somebody to do just that and use quality components. You haven't mentioned which variety of engine this is, mk1 or mk2. either. That will make a difference...

So more information required!

 

[JohnD]

Andrew,

By far the biggest boost in performance is to fit a 2.5L engine, and if you intend to replace your old one, I'd say that's the way to go.    If it needs serious rebuilding, rebores, new pistons etc. all the better.  "There ain't no substitute for cubic inches"! 

Some mods to that must be done during the rebuild.    A TR5/early TR6 cam shaft with wider duration than others, while a line-bore to accept cam bearings is optional.     Flowing the inlet and exhaust ducts in the head, and matching them to the fuelling device and exhaust manifold chosen.     Skimming the head to raise CR to 10.5.   Fitting the largest inlet valves and steel seats for the exhaust valves.  Undoubtedly a new duplex timing chain, with a vernier cam sprocket as an option.

Fuelling: Webers are an attractive option, but you will need the right manifolds to fit them, as for a GT6.   If you are willing to fit more kit to supply the fuel at high pressure, and consistently through the corners, Lucas PI preserves a vestige of historicity.

Exhaust:   I'm a 6-3-1 fan, but 6-2-1s are easier to fit, and easier to source.    Don't go for the 'wheel-barrow' double oulet, unless you really like the look, there's no advantage.   2 1/2" pipe.

Transmission:   The OE Vitesse gearbox is man enough to take the 2.5L, but needs a rebuild, as does the differential.    An LSD?  Optional for road use, as are major mods to the axle, which is weak, under competition conditions and enhanced 2.5L power.

Brakes: Again for road use, unless you live on an Alp, rebuild and use OE, but vented front discs and spaced-out calipers are a useful mod.   No need to mod the rears.

All the engine mods contribute, in the same way as 'marginal gains' in sport, each contributing a tiny increment, can multiply the benefit, but by themselves nothing significant.

Oh!  And you have a convertable?   The roof of any Triumph Herald clone is weak, and you don't even have one.    Consider, and put at the front of the budget list, a roll-over bar.     If you are planning a perfomance improvement, you are going to use it, even if it's on the road.    And you can drive like a granny and still get turned over - did you see this?  The driver was lucky not to be crushed:   https://www.youtube.com/watch?v=4NGqcr7DKBc

 

[dougbgt6]

Andrew,

Club shop do stage 2 engines for most models, worth a look from a reliable source. 

Doug

[Clive]

Doug, I really worry when a builder calls it "stage 2" with few details. It really needs a power/torque graph to show the difference between it and a std engine. As well, as specs like cam, compression ratio, what has been done to the head and so on. As well as what distributor curve is required, of better supply engine with matched distributor, carbs etc all set up ready to go. 

But really, the OP has not said what he wants from the car/engine. Before anybody gets too excited about expectations. After all, I could suggest he contacts Enginuity or suchlike and buy a full race engine, but that would be a terrible choice of specification although ultimately the most powerful. Not to mention the costs involved, at a guess I reckon it is easy to spend £10k+ on a top spec engine package.

[dougbgt6]

Clive,

I'm sure you're right. I'm not really the guy to ask about stage 2, I prefer the GT6 2 litre engine to the more powerful TR6 2.5 because it sounds better.

I was just pointing out the club have stage 2 and worth investigating, I believe Uncle Pete has been around the factory.

Doug

[Clive]

Nah, all the 2 2.5 sound about the same. Pros and cons to them all! But always z good sound. 1600 sounds a bit more refined? It would bevrudevto say twee. Saying that the works vitesses were 1600, and they sound brilliant. Some are still used for events, one was on the 10cr last year.

But within all old car clubs there is a desire to "improve" when most just want a reliable, solid engine. As I said, most drivers never go near the red line. I went with a friend to a magazine photoshoot at bruntinthorpe, a few years ago. He let me have a drive, but got all twitchy when I went past 4000rpm! He had never done that despite lots of go faster goodies. 

[Bfg]

9 hours ago, andrew suffolk said:

Specifically, the engine is on its way out and will need replacing/ rebuilding.

Good morning Andrew and welcome to the forum.

"the engine is on its way out" doesn't tell us whether it's  leaking, smoking, rattling, overheating, difficult to start, or just feeling lethargic in performance.  Nor have you yet expressed what has been already been done to address any such issue ..to have arrived at the replace/rebuild crossroads.  The reason I prompt such questions is because if it is just lethargic (a performance issue) and you haven't rebuilt the distributor and had the car professionally tuned - then you could be landing yourself with big bills which were not at all needed. 

A few points to note are ;

• if you replace the engine for another - then unless bought from a reputable (read : expensive) source as fully rebuilt and guaranteed - then you might well be replacing one lot of problems for another  ..which may still need a rebuild to rectify.    
• If you follow John's advice and go for a different engine, then beware that ancillaries and exhaust may also need changing, and those parts in good order will also cost a bundle.
• Again if you go for another engine and then need to rebuild it - well simply put.. you can't then take the best bits from the two engines to make one good one.
• the cost of a stage-2 tuned engine is considerably more than a close to standard spec one. 
• If it's of concern replacing the engine will detract from matching engine numbers and the vehicle's originality.
• If the engine in you car is just worn out - then quite possibly so are most of the ancillaries too.  Ancillaries include anything but the bare engine, so we're talking about carburettors, distributor, pumps (water and petrol), exhaust, starter and gear ring, clutch, alternator, coil and electrics, and so forth.  I'm rebuilding a four cylinder wet liner TR engine at the moment, doing most of the work myself and the cost is likely to be £1800 for the bare engine (..you can double or triple this figure for a professional rebuild).  But my total cost  ..together with reconditioning the ancillaries will be over £4000.  Admittedly this involved activities which I gladly passed over to the professional specialist. For example, fully reconditioning the twin SU carbs cost over £400 - but I know that without really good carburettors and a fully reconditioned distributor - then anything I might spend in the machine shop, or on pistons, camshaft, etc  would be a waste.  

Tip : all else being equal - your car will run better on five-cylinders than it will with the ignition timing just 10^o out.

• Triumph, like all motor manufacturers,  designed and build their cars with ease of driving, tractability, smoothness in operation, performance and economy at the top of their criteria. They had to be competitive with other makes and they had to make a car that was desirable to own and economical to run.  The engine's characteristics were balanced with the ability of the car's chassis, suspension, brakes, and steering ..in short, the car's overall 'feel' and handling.    When you up-rate anything - you change the balance of characteristics in a car you obviously really enjoy (your 4th Vitesse convertible).  So for example ; if you tune the engine to stage-2 and swap to triple carburettors - then you will  (..and it's not a maybe)  loose something of the pleasant docility of a six cylinder in a lightweight car. The handling & steering might cope but when you really use that extra performance it will feel nervous ..simply because the car lacks structural stiffness. And the driving experience / feel of the engine and carburettor induction noise will be markedly different, as to a lesser degree will vibration, but you'll notice the car rattles more.  Starting may be a little more temperamental, and keeping everything in tune will take a whole lot more trouble and cost. Even from just starting off,  you'll need to use more rev's when driving to keep the engine in its power band.  And of course fuel economy will take a dive.      

             For my own four cylinder engine, which I do like the characteristics of - I'm simply taking the cylinder bore from 86mm to 87mm, I've gone for a lighter flywheel, and I've replaced the damaged camshaft with one that has a fine reputation for tractability / pulling power in the low to mid range (legal) speeds, rather than high speed. I'm retaining a mechanical cooling fan but changing that for a lightweight plastic one (buy coincidence off a Vitesse).  That's it - the carbs, exhaust and most everything else were imo to a good design specification anyway, and so my parts were totally refurbished to bring back to 'as new' condition.

I'm not saying you, or anyone else, shouldn't tune an engine  - I'm just giving you a heads-up re. your  " What are the unknown unknowns? "

Pete.

[Pete Lewis]

with any dreams  that make a mountain of costs that may be added 'fun' but rational thoughts must involve the expected miles  you cover

there's no point in a +5k engine just to do 500 miles a year  and there is a lot of those about

we all like to tinker and twiddle but without the development and engineering of the manufacturer or a deep pocket rolling road  specialist 

there are wonderful reasons to keep it as it says on the tin .. 

as for rebuilds  the club uses Ivor Searles   an amazing place,  engines are re manufactured not re conditioned 

Pete 

[thescrapman]

I am not convinced economy was top of Triumphs list of criteria when they decided to stick a BW35 on the back of a PI engine.

[Pete Lewis]

Ha  we had a 35 on on test in  a 2 ton commer walkthru  we came to a halt on a   1/12 hill  4.203 diesel engine flat out  torque converter on fire   that wasnt economical either   the idea was soon scrapped 

a type 65 was much better 

Pete

[yorkshire_spam]

28 minutes ago, Pete Lewis said:

Ha  we had a 35 on on test in  a 2 ton commer walkthru  we came to a halt on a   1/12 hill  4.203 diesel engine flat out  torque converter on fire   that wasnt economical either   the idea was soon scrapped 

The manifold on that Commer is perfect for converting Series 2/3 Land Rover's to the 4.203 engine if I remember correctly. 4.203 wasn't a great engine by modern standards, but it was a damned sight better than what Land Rover were offering at the time!

 

[Pete Lewis]

Ha i remember when alternators were introduced  on the 4.203 we had to add a whopping crank  pulley to get enough  revs and add a 5watt  warning bulb to bring the cut in speed down 

the days of reliability rather than horses ,   we had an awfull  0E160  made by   Standard   completely gutless thing    brit rail had hundreds of them in  Batam tractor units 

flat out about 40 mph down hill 

Pete

[GT6M]

Ye can spend a wee fortune on a 2L an get what, 20  HP, an 15 FT/LBs  of T

at generally higher revs if a cam is fitted

 

BUT, bung in a 2.5, ye got aboot same HP, { if its a late engine } 

early engine { 270 cam }  will give 110+  an 150 Ts

thats alot of Ts at low revs too

and, yer fuel use could well be less, as yer no work,n the engine

esp if ye bung in a 3.63  = 3.27 instead of the 3.89

if ye got OD, then a 3.63 be ideal.

 

M

[Nick Jones]

2.5 is indeed the way to lazy power. It will find the (many) weaknesses in power train though.

Nick

[dave.vitesse]

If you just want to improve the performance by a small amount then retaining the 2 Litre makes sense. But a highly tuned 2 Litre would probably be unpleasant to drive in traffic and to live with for most people.

The 2.5 Litre can deliver the performance without over tuning for road use. But as Nick points out the gearbox and diff can suffer through the extra torque.

Dave

[yorkshire_spam]

Since the OP hasn't been back I wonder if we've scared him off?

[dave.vitesse]

Hope not.

Dave

[Graham C]

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