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Mike R

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Everything posted by Mike R

  1. Thanks all, interesting discussion. Totally agree the only way to really know is the rolling road. The only thing that doesn’t quite make sense to me is why would the throttle be less restriction than the air valve? At full throttle the throttle is a thin disc parallel to flow obscuring maybe 5% of the bore, whereas the air valve is a fat piece of metal slap bang in the middle of the air flow obscuring maybe 40% of the bore. The only thing is the air valve has smooth transition in and out so you get pressure recovery (as per Bernoulli) which you don’t get with the throttle butterfly. So, yes it may give very little, but it can only help, and was more about me tinkering than anything else! cheers, Mike
  2. Dear Triumphants, Like many I like the idea of a little more oomph in my GT6, but then I rarely go over 3000rpm and never over 4000rpm. So this is a little improvement I made a few years ago to hopefully increase power in the lower rev range. The concept was to fit the weaker stromberg dashpot springs combined with richer needles. Before anyone rushes to condemn, read on, and see what you think. The thinking is that at peak power 5500 to 6000 rpm, 105bhp the carb air valve will be right at the top of its stroke and give little or no obstruction to induction air flow. However, at 3000rpm, power is more like 60bhp. With power around 60% of peak, induction air flow will also be significantly lower and so the air valve will sit significantly lower in the carb. The air valve therefore becomes a restriction when at full throttle at lower revs. See sketch below. The air valve is lifted by suction from the air as it flows over the carb bridge, which is balanced by downward force provided by the weight of the valve plus the force of the spring. So weaker spring reduces the downward force, and so the valve sits higher. Now to change the needles and get it right across the rev range needs ability to test under load. This I achieved by installing an exhaust lambda sensor with a gauge in the cabin so that I can measure air fuel ratio as I drive. (See Buckeye triumphs website for excellent description of how to do this ) So I bought and fitted the weaker springs. This made the mixture so weak that the engine would not run. This is good because it shows it’s had the desired effect of the air valve sitting higher. I’ve heard it said that Strombergs have few needles available, but that wasn’t my experience. Burlen produce a little booklet for a few quid that lists about 30 odd needle profiles for CD150 carbs and detail the precise needle diameter profile for each. It took me a couple of trial and error attempts to get the right needles utilising the Lambda sensor and testing on the road, but I got there. It may be a bit of wishful thinking, but she did feel a little more responsive. To sum up .... * The air valve at lower rpm will be a restriction in the induction system to some extent (although not sure how much) * Weaker carb springs has definitely made the air valve sit higher for any given engine load and therefore be less of a restriction (how much less is more debatable) * Changing the needles has increased the fuel flow so that the mixture is correct for the new air valve position across the rev range. * Because the air valve sits higher, the carbs will max out at lower revs that a standard GT6, so my improvement in usable power is at the expense of peak power. As most power improvements are focussed on peak power, I’ve never seen anything like this suggested. I’d be interested in anyones thoughts. Mike
  3. I feel really chuffed .... just completed fitting my new windscreen to the GT6. Thought I’d pass on a few things I learned along the way. Firstly, the spitfire and GT6 magazine has a good set of instructions http://www.triumphspitfire.com/Windshield.html but, there are a few other things as well * Hang the seal for a few days so it takes approx the right shape. * The suggestion to use masking tape to hold the seal on the glass is a good one, otherwise it just pops off as you move to the next part. I had a piece of tape every couple of inches. * Leave the seal taped onto the glass for a few days, it settles into its new shape and the masking tape can then be removed. * Think carefully about the right string / cord for slipping round the seal. Too thin and it can cut the rubber as you try to pull the seal lip over the screen surround. Too large and it will trap between seal and metal and be very difficult to pull. I used 2mm nylon, it did start to cut the rubber at one point, but worked ok if careful. * Heat is your friend. The rubber becomes much more flexible the warmer it is. I had an electric heater sat on the engine and a hairdryer to use as needed. Warm each bit of rubber before trying to pull the seal over the metal rim. * The corners are tricky, the cord doesn’t want to pull. But keep working it, and keep using that hairdryer and it does eventually move. * As you work round the amount of cord left in the seal gets shorter, so when you pull it just pulls through rather than over the metal. Have to keep an eye on this because you don’t want to lose the end. Either work each side alternatively, or hold both ends of the cord. * When finished, some parts didn’t sit fully home. Again judicial use of hairdryer whilst pushing the screen into place made the seal move gradually home. And then there’s the chrome strip.... The reason I needed the new screen was because the old one leaked. It was fitted by one of the mainstream windscreen companies, but I discovered the leak about a year later because of lack of use in the rain. The reason for the leak had 2 parts I believe: 1. The fitter used no sealant 2. The chrome strip fits in the single slot in the outer part of the rubber with the other side of the chrome strip sitting under the rubber seal lip. This means that the seal lip doesn’t seal as well to the surround. I’d be interested in anyone’s thoughts on this? For this reason I’ve decided not to fit the chrome strip.
  4. For info ... I know the issue around ethanol in petrol and R6 vs R9 spec hoses has been discussed at length ... but found this link .... explains the differences very well. http://www.volksbolts.com/faq/fuelhose.htm
  5. Ok, thanks Doug .... gives me somewhere to start I’ve got plastic fuel filter pre mechy pump ... so either filter no good (were cheap off fleabay) or bits from the hoses. I might just change the rubber hoses from filter to carbs as not sure of the provenence ... think I bought R9 last time, but probably fleabay again. Ta, Mike (used to know someone called Dan)
  6. Thanks Pete, I’ll investigate when I get a chance ... or the car forces me too! Hopefully will be ok to get me home Monday ... although nothing too disastrous at the mo. ta, Mike
  7. Dear helpful fellow triumpheers .... This one is stumping me slightly ... I’ve posted in fuel section because the symptoms point me towards fuel ... but see what you think. 3hr journey in GT6 mk3, mostly on dual carriage way / fast A road / some motorway. No problems at all for first hr till came to start stop traffic. Temperature rose a little to not far from the red, but still no issue. Got past the traffic and back on fast road and cruising at 70 got a loss of power for a second or 2. Then normal, and then power loss again. Not total loss, but a definite problem. Then running fine again for another half hour. Until leaving the motorway another section of slow traffic. After joining the next section of fast road got the same symptoms for a minute or 2 again. Then fine for the remaining hour of journey including dual carriageway 70 mph driving. My thoughts were fuel vaporisation from the periods of slow traffic? Although seems odd that didn’t affect until past the slow traffic. Or maybe the infamous rubber slivers? Although, would expect fuel blockage by slivers to affect more often. Being so intermittent very difficult to troubleshoot anything. Thoughts? Mike
  8. My GT6 fuel tank produced lots of rust particles that caused carb issues ... then blocked the filter that I installed to catch the bits ... I used the Frost petrol tank sealer kit. It’s a multi stage process to degrease, kill rust and then seal. Particularly important is to ensure tank fully dry before adding the sealer... think I used the Mrs hair dryer for a few hours (on the tank not me). Tank has to come out to do it all though. That was 10 years ago ... and no problems since. So my experience good with this product. https://www.frost.co.uk/auto-maintenance/automotive-tanks-products.html Mike
  9. Ahh I see now, didn’t realise there are 2 bearings each side, with the carrier held by inner bearing bolted to front casing. I do find that differential drawing difficult to follow. Well many thanks ... I’ve learnt something today. It did seem to significantly improve noise though, so maybe an acoustic affect as mentioned earlier ... but time will tell. Just wanted motorway driving to be a little less painful on the eardrums. Pete ... thanks for the tips - I’ll keep a note of those for the next time I’m delving around in that area. ta, Mike
  10. Thanks for comments ... As I understand it bearing whine increases with load / throttle, wheras too low pinion pre-load can also cause whine... but are on deceleration / part throttle like mine. If you look at the early comments on this thread its fairly consistent about that. Also, bearings relatively new ... at least in terms of miles. Must admit .... I thought looking at the workshop manual that the pinion is held in the front casing and the crownwheel in the rear via the half shaft bearings, therefore the amount of mesh could vary with tightness of the casing bolts? Sorry have I got this wrong? ta, Mike
  11. A little update on this topic .... a reminder .... I had a whine on the diff when at 70 or more which was worse on part throttle. Opinion is that pinion bearing pre- load is wrong and this agrees with other online research I’ve done. I’ve just had the rear suspension apart to do the rotoflexes. Whilst I was there, thought I’d take a look at the diff. Its a collapsable spacer type with the Nyloc nut under the tamper proof cover. I thought about giving the pinion nut the smallest of tweaks to increase pre-load, but lost my nerve as no way of knowing what is correct. Then I checked the casing bolts, and found every one slightly loose. About a quater of turn brought them to the correct torque (based on my calibrated arm!). It got me thinking ... is it possible that slightly loose casing bolts has meant that the casing gasket isn’t fully squeezed leading to lower bearing pre-load? I.e. the 2 halves of the casing were sitting slightly apart? Well with the casing bolts tightened I took her for a spin on the A180 up to 80 ... and it appears much improved. Although that was a quick 5 minute test .... time will tell on a longer run. what do you think? Mike
  12. Good point Pete .... actually the ratchets jammed against the ground and the car rotated around the jammed driveshaft. Luckily it landed back on its wheels and I could continue on my way. 😳
  13. Well I got the old donuts off the car and they were worse than I thought. Split Virtually all the way through on one side, only took a little pull from me to split. Has anyone had a rotoflex donut fail whilst driving? Will it do damage? I’d forgotten what a b****r of a job fitting the couplings is. Getting the bolt holes aligned by adjusting the spring lifter tool height, jacking the vertical link up and down a few times. Crow bar to try and force it .... and eventually magically it works. Maybe that CV conversion might be on my Xmas list.
  14. Hmmm CV conversion .... must admit I am tempted. But then I try to keep any modernisation to minor bits that are easily reversed. So for now its donut’s for me. If ever the Metalastik’s become unavailable that’ll be the time to jump. For now I’m hoping for 10 more years of trouble free donuts. I’m sure there’s a Homer Simpson moment in there somewhere .... mmmmm ... donuts!
  15. Thanks Pete ... but I think you misunderstood slightly. The new donuts are fine. The photo was just to show the word metalastik moulded into the rubber... in case anyone doubted they are metalastik. Mike
  16. Having just found one of my rotoflex couplings rubber coming away from the metal I searched for the OE Metalastik couplings. Managed to find them in stock at Race parts : http://race.parts/ In the usual teadition .... other suppliers are probably available and I have no connection to this supplier. They are expensive at approximately 4 times the price of aftermarket ones, but then the aftermarket ones I fitted about 12years ago only lasted 1 to 2 years at 2000 miles per year. The Metalastik ones I fitted after that have lasted till now over 10 years. Hence, 4 times the prices for around 8 times the life and a whole less hastle. A good example of where paying for a better part is worth it ... although life of these obviously yet to be proven. I thought I’d just let fellow Rotoflexer’s know the Metalastik’s are still available as the usual suppliers don’t seem to have them. regards, Mike
  17. Ahh the font of all knowledge Mr Wikipedia tells me the 10p piece came out in 1968 ... so this must have been one of the first. good ones going for £2 on ebay .... not sure mine would count though. Mike
  18. This ammused me so thought I’d share .... Just fitting shiny new exhaust and found this washer used on one of the exhaust clamps. Probably could have bought 10 washers for that price! It’s dated as 1968 and “10 new pence”
  19. I also fitted ss bumpers from Harrington - xmas prezzie from the Mrs! Fitting a little tricky - think I had to modify something ... possibly an elongated bolt hole ... can’t remember what now . Also one side had to be pulled in a bit by doing up the bolt along with a bit of physical work. Although it wasn’t very far out. Overall though very pleased now ... still shiny and got to be about 6 years now. Whereas rechromed ones previosly started pitting within a year. Mike
  20. The shaft on my wiper switch broke a few years back when knocked getting into the car. Found this article on rebuild of the switch including replacing shaft with a steel version. Worked for me. http://www.aircraftresourcecenter.com/GT6/001-100/002-wiper-switch/00.shtm
  21. I knew I had read it somewhere .... this is copied from Club Triumph magazine about this very issue .... it talks about the guidance creating “an administrative issue” and goes on to say: b) A post-1960 vehicle in the ‘historic’ class will from 20 May be entitled to exemption if it is a VHI, but the existing due date for an MOT test may arise prior to the next re-licensing date for that vehicle, which is the first date for making a declaration as a VHI, and (c) As DVLA uses calendar year of manufacture and as the rolling forward of VED exemption occurs only in April of the relevant year, to define eligibility for the ‘historic’ class, there can be a substantial lag (in some cases of over twelve months) in the DVLA process between a vehicle being forty years old, and therefore entitled to MOT exemption if a VHI, and the date upon which the vehicle qualifies for the ‘historic’ class, entitling its keeper to make a declaration as a VHI. Following discussion with a representative of DVSA, a process has been identified whereby the keepers of vehicles qualifying as VHIs, who are under the law entitled to be exempt, will not be obliged to take what would legally be a voluntary MOT test just to escape possible enforcement based upon the DVLA record. • The DVLA record currently shows every pre-1960 vehicle as being exempt from the MOT. • The DVLA record will pick up, by reference to the date of first registration, when any vehicle which might qualify (i.e. not an HGV or a bus or coach in commercial use) becomes over 40 years old. • The record will then show that vehicle as MOT exempt. • If at the time of next licence renewal a declaration as a VHI is not made, the requirement for an MOT will reappear on the DVLA record. • The DVLA record is and will continue to be updated bi-monthly to the police. • The police will therefore treat every vehicle over forty years old as MOT exempt unless and until the record shows it is NOT exempt. If you read the 3rd bullet point the agreed approach is that if you do not declare whilst taxing, your record with the DVLA will be changed to show your car is not exempt and hence MOT is required. Mike
  22. Hi Dave, That is what I was expecting but no, the web page doesn’t ask you if you have a current MOT, it automatically checks it and just jumps through if you have an MOT. So you can’t apply for exemeption. It only asks you about exemption if you don’t have an MOT. But of course you will have an MOT because you haven’t applied for exemption yet. and because you have an MOT you can’t get exemption. I’m beginning to pull my hair out !
  23. Yes that’s exactly the point .... it looks like if you have an MOT you can’t apply to be MOT exempt, if your not MOT exempt you have to have an MOT and so it goes on. Mike
  24. As far as I could see there was no tick box. Unless I missed it.... but I was specifically looking for something whilst going through the screens. Guess I’ll jusr have to look again next year. Mike
  25. I intend to keep my GT6 MOT’d but it might be useful once in a while to use the fact that it’s MOT exempt. I went to Laon on a scenic car trip last month where the trip was just before MOT due. So end up with dilemma of whether to get MOT before trip or after trip .... a little extra leaway because of exemption would be useful. But looks like I’ll never actually get the opportunity to apply for exemption. To answer Shaun, it can’t be exempt already because you have to apply for exemption through the taxing process. Think I read through club triumph magazine that you are assumed exempt by being old enough (the car not the person) but would have to declare exempt at the next opportunity if you choose to use your car without MOT. Personally I don’t like that approach because if you get turned down when declaring for whatever reason you have already broken tne law. It’s all a bit catch 22.
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