Colonel H

Thank you all. I take the points about whether or not it fits properly, and that remains my overriding concern. On the other hand, if it wasn't an improvement, then pressumably it wouldn't be in existence as an after market product. Logic would suggest the first person to trial the concept didn't look at the outcome and think 'it's not as good as the Triumph 4 speed + O/D, so I will therefore actively market a sub-standard product'. The Market would have dictated long ago that if it was no good, we wouldn't be having this forum. I imagine the debate is more about whether its perceived superiority (questionable, it seems) is worth the extra money. Of course it is no good for a purist in the Classic Car world, but simply from a functionality point of view, it is fair to give it consideration. I intend to speak with Mike Papworth before being committed one way or the other. At present, I am very much in the 50/50 zone. Thanks again chaps...Robin

I didn't know anything about this subject until today. Pleased to see it appears to be a well trodden path. I am presently making several improvements to my GT6 MK3. Amongst other things, it needs a new overdrive and gearbox. There are several problems that indicate this. I have spent the afternoon at Jigsaw Racing which has been great fun, and illuminating. Over and above some Improvements to the engine we discussed options for gearbox and O/D replacement. I was not pushed in one direction or the other, but had it explained that if I was doing both, perhaps I should consider the Ford type 9 gearbox. It's approx £1000 more expensive than doing normal overhaul of the triumph units, but I get a more modern 5 speed gear box, which is apparently stronger, smoother, better for cruising, and better spare parts availability (although hopefully not required). I am a bit torn as I liked my O/D before it failed to function, but I think a more modern 5 speed may be a better solution. I am sure I wouldnt be interested unless I happened to be having my old ones out anyway, so perhaps this is a good opportunity for improvement. Are there any other GT6 owners who wish they done the type 9 installation... Or more importantly, wish they never had?! Many thanks, Robin

Robin, Clive, Pete, I was going to ask a similar question to the question posed by Robin, but in my case (I am also a Robin... So this could get confusing!), I have a GT6 Mk3. I got some excellent advice on this forum a month or so ago after requesting advice on where to take my car for an engine overhaul, and after a fair amount of research the two companies that suit me Geographically are Triumph Spares Worcester (Dave Saunders) and Jigsaw Racing, Corby (Mark). Both companies (and individuals) seem to be highly regarded. On the subject of Carbs, Dave's opinion was (I quote) "it would be a huge mistake to exchange Stroms for SU". Conversely, Mark's strong view is that I need to get rid of the troublesome Stroms, and fit modified twin SU (from a Dolomite). I was interested how two experts could have such polarised views. Neither would accept central ground that each have their pros & cons,and perhaps it's a 'win on the swings, lose on the roundabout' type decision. Sadly, it was at least a month ago, and I cannot remember in detail what the pros & cons are, and I remain confused! I do recall Mark saying needles for Stromburg 150 are very rare, while at the same time Dave saying a Newley rebuilt pair of Stroms are superior to SU (perhaps Dave can get all the spare parts for effective overhaul?). If any GT6 owners out there have a preference for one or the other, which a good reason, I am sure we would all love to hear. My interest is having a very good,well tuned road car engine, rather than a track car (which it is not). Which reminds me... On visiting two separate rolling road facilities a couple of moths ago, both places were definitely encouraging the use of SU over Stromburg. No doubt in their minds. Perhaps they are easier to tune up? Or perhaps they need regular re-tuning, which would be appealing to the rolling road place?! (Apologies for cynicism!) Regards Robin D

Thank you for that update Cookie, it is only as a result of this forum that I have become aware that I probably have the wrong diff. I will be fascinated to see. By your comments, I should in theory have a 3.89.... And if I don't, I should source one, or perhaps consider a 3.63. When I say 'consider' ..... what exactly am I considering?! I assume the bigger the ratio, the faster the car might go, but with less torque. The smaller the ratio, a slightly slower speed, but more torque and grunt? Perhaps handy for overtaking, which is something I don't risk at present. Prior to this forum, I would probably have thought it can't make that much difference, but seeing that most have identified my diff as a probable culprit for low speed (80mph) at 5000 RPM, I need to pay attention to the subject. Are diffs like gearboxes, in that they need occasional overhaul, or are they fairly maint free (just incase I need to source a replacement for my car)? Regards Robin

Dear John, Steve, Jon, Clive, Mike, A raft of interesting thoughts there. Many thanks. John, I haven't been around the bazaars enough to hear about the diff ratios, and the self assessment method, so that is a great piece of info. I'm not well equipped with tools, but do have axel stands, so once I have worked out where it is safe to jack up the car, and position axel stands, I will give that method a go. Sadly work takes me abroad tomorrow for a couple of weeks, so there will be a delay before I report my findings. With regard to the Vitesse, it is indeed a fine looking car, and on hot days in the GT6, with it's fairly cramped cabin, a slightly larger, open top Triumph does hold appeal! One day maybe! Steve, in my heart of hearts, I know you are correct, and that perhaps I should do the carbs, gearbox, O/D, and seemingly most importantly check I have the correct diff, before I commit to £££ on engine overhaul. The more reckless side of me suggests it is worth getting it all done in a 'oner', the main appeal being I then consider it a new car, with me as first owner. Body work and paint is now 'as new'. I don't intend selling, so perhaps it is an investment in a long future. But you are right, that sentimentality comes at a cost, where perfectly good cheaper options exist. I gather a vote in favour of doing it all together, is that I will save quite a few mechanic hours removing and replacing gearboxes and engines if it all gets done simultaneously, rather than over time. Possibly a weak argument. BTW, I gather engine overhauls have two generally accepted levels. Stage 1 and Stage 2. The latter being a more extensive (and expensive) overhaul including things like improved gas flow (but I am not sure what that involves, or it's true merit). Jon... Good call, and I've done it. GPS and speedo match almost perfectly at all different speed ranges. Clive, I live near Salisbury (Amesbury to be precise). I enjoyed my visit to CCK in Sussex, not least because It was a fabulous drive on the A272 there & back. They are great hosts, and clearly know their stuff over a range of Classic Cars, but not specialists in Triumph, over and above other Marques. Your thoughts are similar to Steve (above). Points noted. Mike, reading your advice compounds what has been said above, and as a result of all your comments, I have now decided to hang-fire on a full engine overhaul because there is actually no categoric evidence it is required. The measures you have collectively mentioned above will cost much less, and by the sound of things, may well produce the outcome I need. Thanks for recommendation of Dave Saunders. I will touch base. Course of Action is therefore as follows. 1. Ideally try and find a normal, well set up, GT6 MK 3 close by. Compare. 2. For my own interest... Ascertain if I have correct diff. Act accordingly. 3. Gearbox and overdrive to overhaul (gearbox needs doubleDclutch to go down) 4. Carb rebuild, and any sensible improvements that can be done to the engine without a rebuild (cylinder head perhaps). 5. Re Assess.... But by the sound of things...hopefully no further action imminent. Gentlemen, thank you for your time, effort and advice. Regards Robin

Hello Again Kevin and Scrpamann (Colin) Sage advice from both. Thank you. The possibility of an incorrect Diff is looking quite likely. Being new to the car, I know very little of its history, other than I am the 13th Owner (according to V5), but i am trying not to be too superstitious about 13! Again, if I take it to a company such as Jigsaw, or similar, i imagine they can take a look and rectify if required. I could do without the extra expense, but no point in overhauling the other three items, only to have the wrong diff. With regard to the 2.5 Litre engine option, I dont like the idea, and quite glad there isnt an overwhelming argument for having 2.5 fitted. To be honest, I think it is probable that the engine and gearbox are all original for this car (certainly engine number matches the V5...even though the number looks as if it has been stamped on with individual letter and number stamps, and is a bit tricky to read), so I will request that I get my own units overhauled and returned, rather than exchange units. Colin, the Rolling Road test said compression was 'fine', as was oil pressure, which is why they were a bit bemused by low BHP at back wheels. (61 BHP). I should have asked for a printed report. Perhaps the Diff again? I am not sure how they do their calculations. I agree with your points about mismatching egines with gearboxes. Surely its tempting fate. I am only after a slightly improved version of the original new car, not an entirely different beast. Hopefully that is a reasonable aspiration. Regards Both, Robin.

Thanks Kevin, Yes, Mark is Persuasive on the phone, but certainly not pushy. I found him to be patient, and helpful....like any good salesman! Presumably with engine renovation and enhancement, there are diminishing returns with every additional feature, with items lower down the list costing extra, but perhaps not adding a significant enhancement. I am a bit vulnerable to exploitation, as I really don't know much about mechanics and engineering, so can't be too specific with my requirements. That's why I seek a trust worthy, reliable supplier who hopefully won't sell me something I dont need! Basically, it needs to be the best available solution for road going, everyday use (despite it only getting used on a Sunny weekend type of basis...but as frequently as often... As I know they need regular use). Hopefully, you get what you pay for at Jigsaw, so I won't rue the decision. I got a recommendation for Mick Papworth from elsewhere, which is encouraging. It might be a tad tricky dropping the car off at Jigsaw (if that is the chosen place), and asking them to send the gearbox + overdrive elsewhere... Because apparently they do the overhauls themselves. I am presuming there is some benefit from 'one stop shop'....especially if I needed to enact a warranty. There could be some serious sloping shoulders from one company to the next! Apologies for cynicism! Thank you for your advice Kevin.

Dear TSSC members, I'm new to the club, and new to forums for that matter, so interested to see how this works. I bought a lovely 1973 GT6 MK3 in the summer. Previous owner lavished much love and attention to restoring the body work, but other factors meant he needed to sell before getting stuck into the inner workings. I've had a great couple of months using it, but I think time has come for improvements. Whilst it makes a lovely noise, depressing the accelerator produces more noise, but no discernible performance! Max speed is 80mph at 5000RPM. Interestingly, a rolling road test at CCK Historic in Sussex recorded good oil pressure and good compression, but only 61BHP at back wheels. Another factor is engine temperature gauge is off the scale (hot side) within 3 minutes of driving normally, but a laser heat recorder fired at different parts of the engine indicate its actually running at correct temperature. I have changed the temperature sender unit, but same result. Anyway, I am getting off subject here. The overdrive has recently failed, and speaking to people 'in-the-know' it sounds as if the Conical clutch is worn out. Symptons are strange rev fluctuations in gears 2-4 (regardless of position of switch, which is now always 'out'), and the car now won't reverse. That was a bit awkward in the Waitrose car park when it first happened! I have therefore taken the decision to have all three items reconditioned at the same time over the coming few months. Not only that, but I want my engine improved to the best available road-going performance (this one isn't for racing). I have chatted with a few 'suppliers' including CCK in Sussex, Southern Triumph in Bournemouth, Jigsaw Racing in Corby, Slark Race Engineering in Amesbury and the TSSC themselves. The general consensus is that Gearbox and O/D is a fairly simple overhaul, with no special options. Engine however can have various bells and whistles, all at cost. It seems a 'stage 2' overhaul with the stromburgs to be replaced with SU (from Dolomite, or machined to fit), would create the best outcome at sensible cost (a relative term, but I imagine this will all cost a bit North of £5-6K?). I note talk of Weber Carbs, but they are apparently excessive for these cars. I Also note talk of putting a TR6 engine in the GT6 (and now would be the time, if ever), but no significant advantages over getting my own 2.0 litre engine running well. I am leaning towards Jigsaw for all this, but all suppliers are knowledgeable, and seem to offer a slightly different angle and opinion on the subject. The purpose of this lengthy post, is to see if anyone else has jumped through these hoops, in particular with Jigsaw, and have any thoughts! Thank you.