Jump to content

steve redway

TR Register Members
  • Content Count

    81
  • Joined

  • Last visited

Community Reputation

1 Neutral

About steve redway

Recent Profile Visitors

317 profile views
  1. I finally ran a ColourTune on the TR7 confirming that my initial lifting pin set up was more or less on the nail. Now need to run it before another tweaking. Referring to the Gunston ColoutTune, what a load of **** that is now. Its been through too many cost down exercises I am afraid and whilst it still does the job it is a very frail price of kit now and quite difficult to use on a TR7 cross flow head. Indeed I broke my new one on the first use! However the Gunston LT-77043 (The Laser version) 6 piece compression tester kit , well that is a quality price of kit that'll should last a bit longer than the ColourTune and I highly recommend it. Cylinder pressure readings were between 120 to 135lb/sq " which I think is par for the course on the slant 4 cylinder 2 litre engine, so no issues there.
  2. David, I am interested please PM me at steveredway@aol.com
  3. The engine is now fully assembled and it has been able to set the tick over at 750rpm with timing set at 10 degree BTDC at 800rpm. Job done. Just to complete this exercise here is the conclusion as we used to call it in our secondary school science experiments. Just to remind us. this all came about as the car would not run below 1100 rpm. Pushing on the front carb throttle arm reduced the tick over to an acceptable level so I concluded that the butterfly spindles were worn. Stripping and replacing the spindles and butterflies resulted in an un-adjustable 1500-1800rpm tick over, even though the front carb butterfly was worn to an unacceptable level. Further work on the water pump saw the manifold and associated gaskets removed and replaced. So why wouldn't it run at a factory recommended 750rpm? The first issue was that fitting replacement butterflies and spindle in worn 40 year old HS6s is not necessarily a recipe for success. To gain minimum light leakage through the throats with the butterflies closed means that a mix of old and new parts was necessary. However I would not compromise on the front carb and a new spindle was fitted here. Note that it is impossible (certainly in my situation) to get a completely light free throat butterfly join. The second issue is the carb to head path and the propensity of leaking gaskets. Whilst the Carb Flexible Mounting Rubbers TKC1338 are renown for leakage, in this case it was essential that the paper SU gaskets Pt No 159871 either side of Carb plate Pt No TKC1718 were greased and not left dry. Also use blue Hylomar on the Carb Flexible Mounting Rubbers TKC1338 and the manifold. This solved air seepage at these points. Thirdly it is essential that the timing is spot on. Finally with the carb jet position two full turns down on the car should start and run. Once the mixture was set based upon the piston lifting pin technique (and on the rear cab it was nearer three turn down) then the tick over becomes very manageable and after a bit of balancing, 750rpm was achievable in a relatively stable manner.Note that the final tuning of the HS6s is quite a delicate process with small adjustment being necessary to mixture and slow running. I am going to run a Colour tune test and check cylinder compression values later.
  4. Nope, do it by ear. Not very sophisticated here
  5. Finally some progress. I ended up using a mix of old and new parts. New spindle at the front and old butterfly, plus old spindle and new butterfly at the rear. Dont ask me why, it just seemed to give me best fit. Both still showed slithers of light at different points. I filled the throats with oil and over a period of time none came through. Doing this with petrol of course caused it to drain through very slowly as expected. The gaskets between carbs, link plate and carb flexible mounting rubbers were greased this time and the mixture nuts on each carb set at 2 turns down from max up. The engine fired OK and ran roughly hunting rhythmically between 1000 and 500rpm. The throttle screws were now doing something and both carbs sort of balanced, not easy as the revs were all over the place. The 2 turns down turned out to be quite weak and once a richer mixture was tweaked in on both carbs the engine ran as if it was on all four at a more settled and stable 1000rpm. Tomorrow I will set the timing at 10 DBTDC with the advance tube disconnected and do a another tweak on the carbs to see if I can get it to run at 800rpm. Then put all the emission control pipes, vacuum feed and finally the air filter back on.
  6. Hi Dave, I guess that is exactly how the discs on both carbs have been set up as there is a fair bit of "adjustment" room within the spindle slot. My view is that on this pair of HS6s it is not possible to loose light completely down the throat with the butterflies closed. So one more try. I will take them apart again and replace the old spindles and old butterflies together and see what the result is. Regarding the three throttle return springs. My car too has only ever had one, but both Rimmers and "Original TR7" by Bill Piggott state that three were fitted/required. There are three holes on the Bracket-throttle spring which I always assumed were for different spring tensions. Not for the ends of three separate springs? Definitely one for the Anoraks Dave.
  7. Here's an odd one. The parts manual and other sources call for three throttle return springs Pt No 159463. My car has just one connected to the Throttle Lever/Link Rod - UKC6848 and the other end to the Bracket - Throttle Spring - UKC6168 which has three holes in it, for I presume three springs. The question is where do the other two springs attach to on the carbs and why has my car only one. One for the Anoraks I fear?
  8. Rob i now have the new spindles and new butterflies as good as it gets and am wondering about this slot business. Visually the spindle slot looks perfect. Burlen ship a lot of these kits and have a very good name, hence I would hardly expect these to be an issue with their machining of the spindle slot, but I do understand where you are coming from. Also on viewing the old butterflies the original shamfer is quite a rough affair, almost a punched edge (at an angle of course). These have been in the car for as long as we have had it without issue (that is until recently). So what I am getting at here is "expectations", or is it not reasonable to expect to see a slither of light occasionally? Maybe someone can do the same test: shine a light down the throat and see absolutely nothing or (on a good running carb) see a slither of light. Maybe there is a secret I am unaware of in fitting HS6 butterflies? Incidentally I dont want to end up having to use the old spindles as there was a fair amount of wear to them and this alone could well cause leakage
  9. ntc, Not so daft. Difficult to tell as they have an overrun poppet valve in them, so it's impossible to tell. Have tried old and new butterflies, neither seal and both emit light around the edges
  10. Well, I dont now whats wrong. I have taken the spindles and butterflies our cleaned carefully the throats and even reverted to using the old butterflies and still however I tweak them, I can see light around the edges. They just won't seal.
  11. I have been talking with Burlen. The numbers refer to the poppet valve, nothing else. He agreed that you should see no light through the throat and that air must be getting around/though the butterfly. So back to basics and take it apart yet again to see if it is at all possible to get t to sit better. I dont remember having this problem with butterflies before? Just whack em in and off you go.
  12. The carbs are the right way up, you can just see the top of the float bowls and emission outlets with the tyre valve caps on. If they were put in the other way then the chamfer on the butterfly would be the wrong way round? Now three more pictures. Pic 1 and 2 shows the markings on the butterfly. The new one in the carb is marked 15 and the old one taken out 22,5. Whats that all about then? Pic 3 shows the butterfly held open and a hole the air filter side of the carb. This hole is "plugged" by the back screw of the dash pot. It is the same on both carbs. What if it drew air in? Any comment
  13. So here are the two carbs with light source down the front. As you can see on both front and rear there are slivers of light where the butterflies do not 100% meet the carb throat. Is this tiny amount enough to cause the problem? If so, i spent a long time trying to get it this good. I realise that the edges of the butterflies are chamfered, maybe they are in the wrong way round? Over to you for comments please
  14. OK Rob, have todays clue to chase. Standby for images Many thanks for everyone's assistance incidentally, you are all a great help :o)
  15. Hi Dave I tend to agree regarding the Waxstats, I dont think they are the cause of this fault. It's not a mixture or rough running issue it's just air getting past the butterflies and pushing the revs up. As I said to Rob I'll have 'em off again and take a pictures through the throats for your comments.
×
×
  • Create New...

Important Information

Please familiarise yourself with our Terms and Conditions. By using this site, you agree to the following: Terms of Use.