Jump to content

cliff.b

TSSC Member
  • Posts

    1,475
  • Joined

  • Last visited

  • Days Won

    5

Posts posted by cliff.b

  1. 1 hour ago, Peter Truman said:

    If I remember correctly some cars in the 60's had an air filter inlet trumpet which was and recommended to be rotated to different positions for summer and winter to optimise the combustion air temperature.

    I remember cold foggy nights driving home across the York moors and the car ran beautifully with the dense air.

    Yes, despite not getting very warm my Spit was running beautifully on Sunday in the cold 5C air. Certainly seemed to be pulling well.

  2. 5 minutes ago, Steve P said:

    And remember the position of the needle on the gauge can be altered with the variation in resistance from the senders offered today.

    I did some tests on my Herald when I put a new engine in it. The car has an ally rad as well.

    I bought 3 senders of the same part number from different suppliers and measured them cold, they varied from 550 ohms to 760 ohms, I fitted the lower one and it gives a hot reading on the gauge of just under half and never goes above half. The others gave a higher needle on the gauge, the heater is toasty btw so no issues.

    Steve

    Yes, when I got the car the sender was faulty and the one I replaced it with, although sold as the correct part, read high. I then sourced another one which usually shows just under 1/2 and which I validated as correct with a thermometer, as described in the other post I have just made. 

    It's only differences to usual readings that matter, I suppose. 

  3. 2 minutes ago, johny said:

    And dont forget temp gauge isnt linear, far from it, so 1/4 could be 75º and half 85º for example. Could be worth having a visual check of the thermostat....

    Last summer I ran it on the drive with the rad cap off and digital thermometer poked in there. As it warmed up I saw the coolant flow increase when the thermostat opened and at that point, the thermometer read 84C and the temp gauge in the dash read midway between 1/4 & 1/2.

    When I next take her out it will probably be warmer do I will see what happens & investigate further if anything seems abnormal. 

  4. 7 minutes ago, Pete Lewis said:

    most of the 1500 spitty spec a 88c stat for uk/euro 

    if yours is barely moving the gauge it suggests to thermostat is stuffed 

    an 82c  will  show as a reduced   gauge reading 

    Pete

    Well the gauge was reading just over 1/4 yesterday but the heater was hot. Am I correct in thinking you still get flow to the heater before the thermostat opens?

  5. 2 hours ago, johny said:

    However do also check that the viscous fan, if fitted, can spin freely...

    Fan not viscous, and also I think it might have an older style pump. It needs maximum adjustment to stop the fan belt slipping which I think is due to the pump pulley being smaller. Which would make the pump and fan turn faster, I suppose. Maybe this is a contributory factor 🤔

    Anyway, I don't intend to make a habit of driving around in these temperatures regularly so it is more a matter of interest than an issue to sort out lol

  6. 17 minutes ago, Iain T said:

     

     

    17 minutes ago, Iain T said:

    What temperature thermostat is fitted? Low temperature summer thermostats are no good for cold winters. At mid 70s most thermostats are still closed so there will be no flow through the radiator. 

    Iain 

    I've got an 82C thermostat fitted and I think a 1500 Spit is supposed to be 88C, but assumed that was to let it run hotter for emission control purposes. 

  7. 10 minutes ago, Stratton Jimmer said:

    My old Landrover was capable of over cooling and I had a radiator blind fitted but the thermostat was the key thing really. During the very bitter winter of 81/2 I never had to use the blind as the thermostat was doing what it should.

    Yes, I suspect the thermostat was barely opening which will restrict the flow so the coolant will take longer to pass through the rad and return to the engine even colder, keeping the engine cooler etc etc lol

  8. 6 minutes ago, Iain T said:

    I took my Vitesse out last week and on the move the water temp read mid to high 70C. Warmed up in traffic but then I don't have a crank driven fan only an electric. It seems if your engine and cooling system are in good condition getting temperatures up to optimum in cold weather is an issue but I wouldn't get too worried about it. If we used our cars every day in very cold weather then perhaps. 

    Iain 

    I have carried out some rudimentary calibration of my gauge in the past and based on that, I would say my car was also reporting mid to high 70C and the rad felt a lot cooler than that. But I don't plan to go out in those sorts of temperatures on a regular basis. I even felt the need to keep the hood up 😱

  9. Took my Spitfire out for the first time in a few weeks yesterday, intending to give it a thorough warm up. However, even after 25 miles, some of which was at speed up the A1, the temp gauge barely went above the 1/4 mark. And when I got home the rad wasn't very hot at all.

    So I suppose since last Winter I cleaned out all the partially blocked water galleries in the head when changing the gasket, flushed the rad which happens to be a full width one, raised the bonnet about 5mm as it was hitting the bumper when opening, but that will have made the above bumper gap slightly bigger, fitted a smaller number plate as only 6 digits and it sits right in the airflow.

    Anyway, after all this it never ran hotter than 1/2 on the gauge, even in nearly 40C temperatures, but yesterday being only 5C and the heater on appears to now make it "overcooled". Maybe I should block some of the rad off if I go out when it's that cold again 🤔

  10. 7 minutes ago, SpitfireGeorge said:

    Hi Guys,

    When tuning experts discuss distributors they mention changing tbe bob weights and springs. I have never seen any advertised for sale. Anybody know who sells them?

    Cheers,

    Brett

     

    As far as I am aware it is the springs that can be changed, not the weights and also the stop that limits maximum advance could be modified. Moss were selling a pack of various springs a couple of years ago and may still do so.

  11. 1 hour ago, johny said:

    I wonder if getting the absolute weakest mixture that will still allow the engine to run satisfactorily even makes much difference to fuel economy because perhaps theres a drop in power which you have to make up for by opening the throttle more anyway... 

    If it does make a difference I suspect it is only when "cruising" at moderate speed. Prior to my recent problems I unusually used almost an entire tank in a day driving mostly in the 55 to 65mph range with as little throttle as possible and covered 225 miles on the tank. Worked out about 35mpg which is better than usual and I think not too bad for a non overdrive car. Will be interesting to see if that improves now I have spent some time setting the car up, although I rarely get to go through an entire tank without some (ok, more than some) "enthusiastic driving" lol

    • Haha 1
  12. 12 minutes ago, johny said:

    yes in my experience the car lets you know when youve adjusted the carbs too lean as it bogs down. I know that in theory you can do damage to an engine running too weak but think thats only likely to happen with air leaks and if purely jet setting youre going to know about it...

    That's exactly what I was experiencing I suppose when the original fault I described was occurring. And as the jet tube on the rear carb had worked loose and risen, it made that carb run very weak. Before I found the cause I put my Colourtune on no4 and could see the actual spark and just a very slight flame which confused me at the time but made sense in the end.

  13. 31 minutes ago, Pete Lewis said:

    the 1500 is designed to run on the leaner side of whatever, hence they use a 88c thermostat etc  as the car is in the beginning's of the  emission control era.

    i would expect on a fast cruise the colour  will be lighter .

    think you need to stop checking and do more driving  Ha !

    finding just what needle and spring is fitted will be a good call .

    Pete

     

    Yes, now I know what to look for I will check it all out at some point 👍

  14. 44 minutes ago, Steve P said:

    That depends if you have the optimum needles and springs and then setup properly.

    Steve

    Yes, which ties in with the other things discussed. Probably need to look at the carbs in detail at some point and see what is actually in them. 

  15. 18 minutes ago, Pete Lewis said:

    a worn jet would be richer  as the hole bore becomes larger , adjusting does compensate a bit the start of all needles is the same diameter 

    so winding the jet upwards when the bore is worn makes up for the problem in way generally to be quite workable but not utopia .

    biased needles wear the jet as they rub the side of the jet bore hole 

    if you have a depth gauge use it to measure the height of the jet in the carb throat get both the same and adjust from there for best running idle 

    if you have lifting pins    just touchy feely contact with the air piston and lift a couple of mm  

    if it faulters a few rpm its lean    if it raises the idle a few rpm its rich   if nowt happens its about right 

    you are looking/listening for a hint of change nothing radical 

    never do this with the cleaners off  thats just a waste of time 

     

    Pete

     

    I can set the mixture ok at tickover but find if I then stop at a layby during a journey and check the plugs they usually look light greyish or even white if I have been driving fast. Other people have said similar here.

    I usually then richen a little thinking it is better to be rich at low speed than weak at high speed. 

    Was wondering if this is indeed normal or if perhaps could be due to worn jets or something. It's not a problem, but I assumed the mixture should stay roughly right throughout the rev range once set.

  16. 1 hour ago, Pete Lewis said:

    any wax plug goes out of spec after some years  thermostats are the same 

    they are easy to change  so a  wax stat with the 2p mod will remain reliable , ie there is nothing left to fail

    only if the needle has worn the jet orifice.

    pete

    Yes, I suppose so. As a matter of interest, what would be the symptoms of a worn jet orifice? I'm assuming not maintaining correct mixture through the rev range but would it make it too weak or too rich at higher revs?

  17. 27 minutes ago, Pete Lewis said:

    not really   a 2p mod to waxstats is fine   but if its bent  then its where from here ???

    the rods/levers in the kit sold by the many as a replacement are pretty hopeless

     

     

    It's not bent, it's just that the jet pipe came loose. Maybe I have fixed it and it will be fine.

    If I do need to replace it though a new Waxstat jet would be easier and presumably certain to work ok. Are all the problems with them just because they are old or did they always cause issues?

  18. 13 minutes ago, Josef said:

    You can get an idea of manufacture date of your car (and engine) by comparing the commission number with other examples. An original engine is usually close ish in number to the commission number, within a few thousand or so.

    Just checked and my commission number is well in the middle of other 78 cars so that would be right. The engine number has a prefix of DM and a suffix of ESS which I believe means it was a factory exchange unit. 

  19. 7 minutes ago, Pete Lewis said:

    if you buy the silly priced wax stat conversion i can assure you half of it wont fit the linkage will jam and you will be worse off than when you started all this  

    Pete

    Is there a better solution, other than replacement Waxstat jets?

  20. Ok, spanners out, air box off and another go at it all. Looked at the rear carb and the jet was above the bridge again by a couple of mm. I was at a loss to understand how this could be but took the jet out, measured it and it was longer than it was yesterday lol. Pulled the jet tube gently and it came away from the rest of the jet, which explains everything. Reseated it, squeezed gently in a vice and now jet is 4mm shorter. Feels tight so refitted, adjusted and then went through all the idle/fast idle/choke adjustments, some of which were way out. By eye, the pistons in each carb appear to rise together now, the tickover is perfect and running well on the road. 

    Maybe it's time to bin these old waxstat jets and get some new replacements.

    Incidentally, the tag on the carb says FZX1258 so if what I have read is correct, either the carbs or the entire engine would appear to be from an earlier car. Unless mine was made in 77 and hung around for a while before being registered.

  21. 10 minutes ago, Iain T said:

    Having tried 3 weights in my Stromberg carbs it makes a big difference! It alters the rise of the air piston(valve) which has a large effect on the fuel mixture. 

    Generally the lighter spring is a weaker mixture but then there are the needle taper and damper oil effects to consider. I found choosing the correct needle/spring is paramount and damper oil changes acceleration mixture. 

    Take a peek at my topic Vitesse needle the story in this section. All fun and games and I've not yet posted my latest and greatest! 

    Iain 

    That's interesting. I will dig it out and have a read. I noticed yesterday when adjusting with the filters removed, although I got both pistons to start rising simultaneously, one then moved more slowly than the other. Need to check again that there is no binding or suppose it could be due to an air leak 🤔

    Was initially wondering if due to differences between the carbs but that is probably a long shot. Work checking out now I have a better idea what to look for though.

  22. 49 minutes ago, Josef said:

    I think springs were originally colour coded. But I’m not certain. 

    Looking at what is available to buy online, both types say they are Red and 4.5oz but the earlier ones are long and thin and the later ones are half the length but much fatter. Not sure what, if any, affect that has on how they perform.

  23. 22 minutes ago, Josef said:

    The needles are marked. In tiny letters! So you should be able to check if you have them out again.

    Any idea if the springs have any identification marks on them? The comments I read about the different needles in later Spits also said the springs were different. Looking at my carbs, there are some slight differences and I'm not 100% convinced I have a matching pair.

×
×
  • Create New...