nicrguy1966 Posted August 16, 2023 Author Report Share Posted August 16, 2023 29 minutes ago, Paul H said: Pretty sure mine is 19 / 20 btc in my mk 2 Vitesse Paul Great! I can cross out my to-do list and just consider this normal for today's conditions! I've got my weekend back! Thanks! Link to comment Share on other sites More sharing options...
Nigel Clark Posted August 16, 2023 Report Share Posted August 16, 2023 1 hour ago, nicrguy1966 said: So what is the general opinion on the correct timing for our cars with modern fuel? My GT6 is perfectly happy with strobe timing at 800rpm tickover set to 12 deg BTDC. That applies to both the standard 2 litre engine and the tweaked 2.5 litre fitted currently. I normally run it on 99 octane Tesco Momentum, or Shell V-Power if I'm feeling especially wealthy! Nigel Link to comment Share on other sites More sharing options...
nicrguy1966 Posted August 16, 2023 Author Report Share Posted August 16, 2023 Can the "correct" setting be as different as 12 degrees and 20 degrees? Link to comment Share on other sites More sharing options...
johny Posted August 16, 2023 Report Share Posted August 16, 2023 Something is wrong if you have to advance more than the manual setting to get good running... Link to comment Share on other sites More sharing options...
JohnD Posted August 16, 2023 Report Share Posted August 16, 2023 Nice guy, My thanks to Pete for taking up my sermon! Yes, in the situation you describe, very much worth checking where TDC really is, with a piston stop and a degree wheel on the crank. But if you can move the outer ( "inertia ring") part of the crank pulley on the hub, then clearly the rubber joint that does the damping has failed. If you are in any doubt, send it to me, and I will check it on my test rig. John Link to comment Share on other sites More sharing options...
nicrguy1966 Posted August 17, 2023 Author Report Share Posted August 17, 2023 3 hours ago, JohnD said: Nice guy, My thanks to Pete for taking up my sermon! Yes, in the situation you describe, very much worth checking where TDC really is, with a piston stop and a degree wheel on the crank. But if you can move the outer ( "inertia ring") part of the crank pulley on the hub, then clearly the rubber joint that does the damping has failed. If you are in any doubt, send it to me, and I will check it on my test rig. John I'll be taking a close look at the pulley this weekend, and also trying to set the crank to TDC to see what the timing marks say. Hopefully I'll be able to find TDC (or near enough) by feeling the position of the piston through the sparkplug hole (using a screwdriver as I don't have a piston stop), but otherwise I may have to remove the timing chain cover (which I really would prefer to avoid!). I'll report back when I've done this. Link to comment Share on other sites More sharing options...
Pete Lewis Posted August 17, 2023 Report Share Posted August 17, 2023 simple piston stop is rework an old spark plug by fitting a bolt in place of the electrode so it just obstructs/contacts the piston on full stroke no need to tamper with the timing cover or chain/gears ....wont help if you do a drop test with a probe mind you dont trap it and loose it in the cylinder there should be timing marks on the flywheel rim which you cant see as the clutch hsg. covers it (without a hole saw) so that wont help unless the engines ...out Pete Link to comment Share on other sites More sharing options...
johny Posted August 17, 2023 Report Share Posted August 17, 2023 You can also get a pretty good indication of TDC from the camshaft position as shown by the rockers but of course this needs the cover off and assumes that the valve timing was set correct initially😁 Link to comment Share on other sites More sharing options...
nicrguy1966 Posted August 17, 2023 Author Report Share Posted August 17, 2023 49 minutes ago, Pete Lewis said: simple piston stop is rework an old spark plug by fitting a bolt in place of the electrode so it just obstructs/contacts the piston on full stroke no need to tamper with the timing cover or chain/gears ....wont help if you do a drop test with a probe mind you dont trap it and loose it in the cylinder there should be timing marks on the flywheel rim which you cant see as the clutch hsg. covers it (without a hole saw) so that wont help unless the engines ...out Pete I have plenty of old sparkplugs, they seem to breed! Link to comment Share on other sites More sharing options...
Gully Posted August 17, 2023 Report Share Posted August 17, 2023 My GT6 Mk 3 is set at around 10 degrees advance - I've tweaked it by about a degree in 10 years of ownership! Tickover is set slightly higher than the manual at c. 1000rpm, as it's always had a tendency to occasionally die at junctions when down at c. 850. Pulls fine across the rev range. I use Super Unleaded, generally with a fuel additive (which includes octane boost as well as lead substitute and anti-ethanol properties). As many have outlined above - if it runs well when set 'by feel / ear', there can't be too much wrong; seems to point to the damper ring having slipped as per John D's research. Gully Link to comment Share on other sites More sharing options...
nicrguy1966 Posted August 17, 2023 Author Report Share Posted August 17, 2023 (edited) 7 minutes ago, Gully said: My GT6 Mk 3 is set at around 10 degrees advance - I've tweaked it by about a degree in 10 years of ownership! Tickover is set slightly higher than the manual at c. 1000rpm, as it's always had a tendency to occasionally die at junctions when down at c. 850. Pulls fine across the rev range. I use Super Unleaded, generally with a fuel additive (which includes octane boost as well as lead substitute and anti-ethanol properties). As many have outlined above - if it runs well when set 'by feel / ear', there can't be too much wrong; seems to point to the damper ring having slipped as per John D's research. Gully Maybe I need to invest in super unleaded then try again. Given the low mileage I do, it will not make much difference to the total cost of ownership. The difference between normal unleaded and super unleaded plus an additive could be huge. When set "by ear", mine ticks over quite happily at 600 rpm! Edited August 17, 2023 by nicrguy1966 Link to comment Share on other sites More sharing options...
johny Posted August 17, 2023 Report Share Posted August 17, 2023 (edited) 25 minutes ago, nicrguy1966 said: Maybe I need to invest in super unleaded then try again. Given the low mileage I do, it will not make much difference to the total cost of ownership. The difference between normal unleaded and super unleaded plus an additive could be huge. When set "by ear", mine ticks over quite happily at 600 rpm! What normally happens is that you set the correct timing and then find theres excessive pinking (the engine continues to rattle after reaching 2000rpm during full acceleration in 4th gear on the flat). This can be an indicator that the fuel octane is too low so its worth trying to raise it with a different fuel or additive. The alternative is to just retard the timing until the above criteria is achieved... Edited August 17, 2023 by johny Link to comment Share on other sites More sharing options...
Pete Lewis Posted August 17, 2023 Report Share Posted August 17, 2023 the cars were designed and spec'd to run om 100 octane of the day using 97/99ron E5 is as close as you can get to use the original settings ive used only sainsbugs 97 since 2003 on both the rorty Vit6 and the current 2000 with std timing and no problems 95 ** was back in the day for side valves and motor mowers of low compression why on earth would you crucify the performance by spending a £££s on Must Haves and then fill with low grade fueling ????? retard to make them run without pinking then wonder where the optimum performance has gone . just some rambling Pete Link to comment Share on other sites More sharing options...
nicrguy1966 Posted August 17, 2023 Author Report Share Posted August 17, 2023 1 hour ago, Pete Lewis said: the cars were designed and spec'd to run om 100 octane of the day using 97/99ron E5 is as close as you can get to use the original settings ive used only sainsbugs 97 since 2003 on both the rorty Vit6 and the current 2000 with std timing and no problems 95 ** was back in the day for side valves and motor mowers of low compression why on earth would you crucify the performance by spending a £££s on Must Haves and then fill with low grade fueling ????? retard to make them run without pinking then wonder where the optimum performance has gone . just some rambling Pete Unless the timing marks on my pulley are way off, retarding to stop pinking is the complete opposite of how my car is tuned! It's so far advanced it's making me nervous! Link to comment Share on other sites More sharing options...
Pete Lewis Posted August 17, 2023 Report Share Posted August 17, 2023 you need to get to the bottom of why the advance showing is so far away from the basic spec old fuel new fuel there is no reason things need to be as such and excessive advance is likely to crack up the pistons life . dooesnt matter where the dizzy gear is timed as you just rotate the dizzy to suit assuming the vac doesnt foul on the other parts and lack of lube on delco can be a disaster for spindle wear ,less so with lucas but any side float on the cam spindle will make points gaps very variable electronics can help overcome that . but a squirt of oil down the base plate keeps the top unlubricated bush nicely oiled as it often states "oil"on the base plate the vac unit just aids MPG if the spring inside has failed then static timing will always vary depends where it decides to stop. Pete Link to comment Share on other sites More sharing options...
nicrguy1966 Posted August 17, 2023 Author Report Share Posted August 17, 2023 10 minutes ago, Pete Lewis said: you need to get to the bottom of why the advance showing is so far away from the basic spec old fuel new fuel there is no reason things need to be as such and excessive advance is likely to crack up the pistons life . dooesnt matter where the dizzy gear is timed as you just rotate the dizzy to suit assuming the vac doesnt foul on the other parts and lack of lube on delco can be a disaster for spindle wear ,less so with lucas but any side float on the cam spindle will make points gaps very variable electronics can help overcome that . but a squirt of oil down the base plate keeps the top unlubricated bush nicely oiled as it often states "oil"on the base plate the vac unit just aids MPG if the spring inside has failed then static timing will always vary depends where it decides to stop. Pete I'll try to find out if the timing marks are way off this weekend. Having had a little play with the dizzy (static), I'm fairly happy that nothing major is wrong with it. Also, when setting it with the strobe at idle, the timing was regular and stable, no variation. Electronic ignition should reduce the chance of "points gaps" changing and I detected no play in the spindle when checking that the rotor arm had some "spring" in it. I'll give it some revs to check the centrifugal advance is doing something this weekend (and give it some oil in all the right places too). I'm also treating it to a new rotor arm and cap. With all this love, it will think it's got a new owner! Based on all the feedback so far, I'm actually hoping the timing marks are off as then I'll know it's probably correctly tuned and there's nothing else to worry about. If the timing marks are in the correct place, I'll be scratching my head for what else to try. I'll post here once I've looked at the timing marks compared to where I think TDC is as soon as I've completed my investigation. Link to comment Share on other sites More sharing options...
johny Posted August 17, 2023 Report Share Posted August 17, 2023 Another possibility is that the crank pulley key isnt doing its job and the complete thing has moved but this would also show up when you test for TDC.... Link to comment Share on other sites More sharing options...
Pete Lewis Posted August 17, 2023 Report Share Posted August 17, 2023 is there or was there any problem before all this started to awaken the need to check the timing ??? nothing wrong with using ears to set the best running then back off a bit ,.............. many of us do that anyway . Pete Link to comment Share on other sites More sharing options...
nicrguy1966 Posted August 17, 2023 Author Report Share Posted August 17, 2023 5 minutes ago, Pete Lewis said: is there or was there any problem before all this started to awaken the need to check the timing ??? nothing wrong with using ears to set the best running then back off a bit ,.............. many of us do that anyway . Pete No significant problem, except that any time anyone (including me) tries to set the timing to the "correct" place, the car runs like a dog. On my last drive, it wouldn't start for the return trip until I did a roadside adjustment to the dizzy back to the "wrong" setting that the car actually needs to run smoothly. I'm also assuming that if it really is at 20 degrees BTDC, I losing power (but without a rolling road, I have no way to know for sure). Link to comment Share on other sites More sharing options...
nicrguy1966 Posted August 17, 2023 Author Report Share Posted August 17, 2023 16 hours ago, JohnD said: Nice guy, My thanks to Pete for taking up my sermon! Yes, in the situation you describe, very much worth checking where TDC really is, with a piston stop and a degree wheel on the crank. But if you can move the outer ( "inertia ring") part of the crank pulley on the hub, then clearly the rubber joint that does the damping has failed. If you are in any doubt, send it to me, and I will check it on my test rig. John John, I forgot to ask, when you say "send it to me", just out of curiosity, where are you? Link to comment Share on other sites More sharing options...
Colin Lindsay Posted August 17, 2023 Report Share Posted August 17, 2023 2 hours ago, Pete Lewis said: you need to get to the bottom of why the advance showing is so far away from the basic spec Are the sparkplug leads fitted to the cap correctly, or is each rotated incorrectly by one position round the cap? Link to comment Share on other sites More sharing options...
nicrguy1966 Posted August 17, 2023 Author Report Share Posted August 17, 2023 23 minutes ago, Colin Lindsay said: Are the sparkplug leads fitted to the cap correctly, or is each rotated incorrectly by one position round the cap? The strobe is triggered by the spark to plug 1, so I'm not sure what difference that would make, apart from the position of the distributor, but I'm open to suggestions. Link to comment Share on other sites More sharing options...
JohnD Posted August 17, 2023 Report Share Posted August 17, 2023 Nicr, Please PM me? And we may swap addresses. I'm in Northwest England, but with respect, I'd prefer not to publicise online where I live! John Link to comment Share on other sites More sharing options...
nicrguy1966 Posted August 17, 2023 Author Report Share Posted August 17, 2023 7 minutes ago, JohnD said: Nicr, Please PM me? And we may swap addresses. I'm in Northwest England, but with respect, I'd prefer not to publicise online where I live! John If you're in NW England you probably don't need to share it with me either as I'm in SE England! Thanks for the offer anyway! Link to comment Share on other sites More sharing options...
JohnD Posted August 17, 2023 Report Share Posted August 17, 2023 Believe it or not, the Post Office does provide an excellent service, even to those parts of the UK that do not speak 'Received English'. John Link to comment Share on other sites More sharing options...
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