Have I got trouble at the Mill.
Discussion
Pics are a bit over exposed Alun , something like this that relies on shades it really matters, nothing untoward with deposits AFAIC that top pic look greyish from what I can make out so good 
no evidence of oil use also backed up by saturdays run out e.g no smoke when your on it
no evidence of oil use also backed up by saturdays run out e.g no smoke when your on it Edited by Sardonicus on Wednesday 18th April 22:37
Yeah crappy iPad camera and I zoomed in thinking it might help
There about the same colour as my hair,,, freaking grey white.
I can’t find a colour chart that shows this colour but the odd one that’s closest in colour suggests normal operation although I’d expect them to be slightly browner. Deposits will be a bit of burnt oil I’d suppose and nothing to worry about.
Blasted back from Peters not stopping and with nice engine temps ran constantly at 3/4000 revs and oddly for me feeling the power at every opportunity,,, used a full tank overall that day, should have cost 28 quid
That’s the thing, whatever revs you run it settles and leans off to a bare minimum of fuel used is how it seems.
Crisp Like.
I’m thinking of going to 7’s again just to see if I notice much difference.
There about the same colour as my hair,,, freaking grey white.
I can’t find a colour chart that shows this colour but the odd one that’s closest in colour suggests normal operation although I’d expect them to be slightly browner. Deposits will be a bit of burnt oil I’d suppose and nothing to worry about.
Blasted back from Peters not stopping and with nice engine temps ran constantly at 3/4000 revs and oddly for me feeling the power at every opportunity,,, used a full tank overall that day, should have cost 28 quid
That’s the thing, whatever revs you run it settles and leans off to a bare minimum of fuel used is how it seems.
Crisp Like.
I’m thinking of going to 7’s again just to see if I notice much difference.
The thing is Alun, since they took the lovely lead out of our petrol, the old 'Tan Brown' rule simply doesn't apply any more, if you're still using the 'Tan Brown' rule as your reference for the correct plug colour....... it's time to move on.
For those of us brought up on the old plug colour rules, and that's very much me included, its really hard to see a white/grey ground strap and not think 'FEK,,,LEAN!
, the thing is this is simply not the case with modern unleaded fuels. Your base rings are black with light soot, these days if you see this combined with a white/grey ground strap you can be confident all is as it should be.
Its hard to see in your photos as phone cameras aren't always the best, but if you're being super detailed in your analysis... which is more about ignition timing and so heat than it is about mixture reading, you need to look for the color change in the ground strap. Its all about where the colour changes from white to a light grey, more timing will make the colour change point get closer to the base ring, the more you retard your timing the closer this change point will move toward the tip of the ground strap.
What you're aiming for is the color change point to be positioned on the curved bend area of the ground strap, in my opinion however this is where things get a bit too geeky to be genuinely something to measure or worry about. Its hard to see for sure but the red line below seems to be where your colour change point exists, with the green line being the ideal curved bend area of the ground strap. This would seem to suggest your ignition timing is a fraction over advanced but a rolling road is the proper tool to establish this not a spark plug, so you really need to to trust that your engine mapper has already found best torque on the dyno when fine tuning your ignition timing under various engine speeds and load scenarios.
TBH Alun, in relation to AFR your plugs look perfect to me, absolutely nout to worry about mate.
I'd say looking at those plugs your engine is running the perfect AFRs and are demonstrating as clean a burn as you could ever expect to achieve on a Rover V8 ,the ignition timing element I can't really see but using plugs to analyse mixtures and ignition timing became old hat when we got wide band labmda sensors with distrubutorless ignition and laptops to view it all in real time.
If you're still worried.... simply find someone running the 14CUX and distributor set at 10-12 degrees with those highly inappropriate shrouded electrode NGK B7ECS fitted.....
For those guys seeing the above is not uncommon
, then there's something to worry about, but not yours mate 
For reference here's a plug from 'Ol Gasbag' showing the clean burning nature of LPG on the perfect tune, this plug is essentially providing a window into my combustion chambers which will be equally as clean.
The above also demonstrates why my oil stays a beautiful golden brown colour between my 5,000 mile oil changes, and why my low carbon producing 'Ol Gasbag' is massively less polluting than any petrol powered TVR.
Of course the following very common super sooty NGK B7ECS is the same window on what's really going on inside this TVR's engine, the valves and combustion chambers on this 14CUX TVR will be coked up to hell
The above plug is also a perfect illustration why the emissions driven retarded timing setting of 10-12 degrees is far from ideal, especially when trying to run No7 heat range plugs, this plug is clearly only just starting to reach it's self cleaning temp right at the very tip of the earth electrode.
If this TVR owner simply switched to a hotter running No6 heat range extended electrode plug and ran a full manifold vacuum signal to his vac advance capsule to give 18 degrees of timing at idle the plugs would come out lovely and clean, more importantly the car would drive soooooo much better...... and all for the cost of a set of BPR6ES or better still and for only a little more money, a set of BPR6EIX Iridiums
For those of us brought up on the old plug colour rules, and that's very much me included, its really hard to see a white/grey ground strap and not think 'FEK,,,LEAN!
, the thing is this is simply not the case with modern unleaded fuels. Your base rings are black with light soot, these days if you see this combined with a white/grey ground strap you can be confident all is as it should be.Its hard to see in your photos as phone cameras aren't always the best, but if you're being super detailed in your analysis... which is more about ignition timing and so heat than it is about mixture reading, you need to look for the color change in the ground strap. Its all about where the colour changes from white to a light grey, more timing will make the colour change point get closer to the base ring, the more you retard your timing the closer this change point will move toward the tip of the ground strap.
What you're aiming for is the color change point to be positioned on the curved bend area of the ground strap, in my opinion however this is where things get a bit too geeky to be genuinely something to measure or worry about. Its hard to see for sure but the red line below seems to be where your colour change point exists, with the green line being the ideal curved bend area of the ground strap. This would seem to suggest your ignition timing is a fraction over advanced but a rolling road is the proper tool to establish this not a spark plug, so you really need to to trust that your engine mapper has already found best torque on the dyno when fine tuning your ignition timing under various engine speeds and load scenarios.
TBH Alun, in relation to AFR your plugs look perfect to me, absolutely nout to worry about mate.
I'd say looking at those plugs your engine is running the perfect AFRs and are demonstrating as clean a burn as you could ever expect to achieve on a Rover V8 ,the ignition timing element I can't really see but using plugs to analyse mixtures and ignition timing became old hat when we got wide band labmda sensors with distrubutorless ignition and laptops to view it all in real time.
If you're still worried.... simply find someone running the 14CUX and distributor set at 10-12 degrees with those highly inappropriate shrouded electrode NGK B7ECS fitted.....
For those guys seeing the above is not uncommon
, then there's something to worry about, but not yours mate For reference here's a plug from 'Ol Gasbag' showing the clean burning nature of LPG on the perfect tune, this plug is essentially providing a window into my combustion chambers which will be equally as clean.
The above also demonstrates why my oil stays a beautiful golden brown colour between my 5,000 mile oil changes, and why my low carbon producing 'Ol Gasbag' is massively less polluting than any petrol powered TVR.
Of course the following very common super sooty NGK B7ECS is the same window on what's really going on inside this TVR's engine, the valves and combustion chambers on this 14CUX TVR will be coked up to hell
The above plug is also a perfect illustration why the emissions driven retarded timing setting of 10-12 degrees is far from ideal, especially when trying to run No7 heat range plugs, this plug is clearly only just starting to reach it's self cleaning temp right at the very tip of the earth electrode.
If this TVR owner simply switched to a hotter running No6 heat range extended electrode plug and ran a full manifold vacuum signal to his vac advance capsule to give 18 degrees of timing at idle the plugs would come out lovely and clean, more importantly the car would drive soooooo much better...... and all for the cost of a set of BPR6ES or better still and for only a little more money, a set of BPR6EIX Iridiums
Edited by ChimpOnGas on Thursday 19th April 08:20
It’s the timing I’m slightly concerned about.
It’s got in the region of 350 ft of torque so I’d say maxed out on advancing the ignition on a 4.6
I very much like the effects the iridium tipped plugs have but is the 6 grade a step to far.
I need to go over to Powers to steal Dom’s head porting knowledge, a bit like some very nice things I’ve heard about Lloyd’s recently Dom is really very supportive of this sort of thing and has offered to show me what to do which I think is diamond of him.
So I think I’ll remove a few plugs over there and let Jason assess them.
These plugs by the way have been subjected to almost daily use throughout this horrendously wet winter. Short journeys of like 3 miles from stone cold etc and they have done over 10,000 miles so far without a missed beat.
It’s just my head can’t get round this colour thing.
I see exactly what your saying about modern cars plug colour and mine seems to show that same colour.
Bit like my old Jag ones on lpg now I come to think about it.
Thanks for the responses guys
It’s got in the region of 350 ft of torque so I’d say maxed out on advancing the ignition on a 4.6
I very much like the effects the iridium tipped plugs have but is the 6 grade a step to far.
I need to go over to Powers to steal Dom’s head porting knowledge, a bit like some very nice things I’ve heard about Lloyd’s recently Dom is really very supportive of this sort of thing and has offered to show me what to do which I think is diamond of him.
So I think I’ll remove a few plugs over there and let Jason assess them.
These plugs by the way have been subjected to almost daily use throughout this horrendously wet winter. Short journeys of like 3 miles from stone cold etc and they have done over 10,000 miles so far without a missed beat.
It’s just my head can’t get round this colour thing.
I see exactly what your saying about modern cars plug colour and mine seems to show that same colour.
Bit like my old Jag ones on lpg now I come to think about it.
Thanks for the responses guys
Alun, I think 100 miles of motorway may be what you are seeing. My AFR gauge shows well lean (15-18) when cruising in motorway conditions off throttle, ie not arsed with the stop start queue in the German lane, but instead just cruising steadily along in the first two lanes going just as quickly. AFR only really matters when you are giving it wellie.
My car is running fine on iridiot 6s. And a turbo car, if anything, should be on a colder plug than an NA car. My Saab, for example, is on 9s.
My car is running fine on iridiot 6s. And a turbo car, if anything, should be on a colder plug than an NA car. My Saab, for example, is on 9s.
like Dave mention's you wont see biscuit/rich tea brown nowadays on plugs I was schooled in the black art of reading plugs by some very talented old heads may Years ago.
The thing is that was back in the good old leaded fuel days, very little of that knowledge actually translates these days with modern fuels.
TBH tuning by plug colour is fundamentally flawed anyway, the colour you see is only ever a reflection of how the car was driven immediately before the plugs are removed, and inevitably that's always after a short period at idle.
The thing is that was back in the good old leaded fuel days, very little of that knowledge actually translates these days with modern fuels.
TBH tuning by plug colour is fundamentally flawed anyway, the colour you see is only ever a reflection of how the car was driven immediately before the plugs are removed, and inevitably that's always after a short period at idle.
ChimpOnGas said:
I was schooled in the black art of reading plugs by some very talented old heads may Years ago.
The thing is that was back in the good old leaded fuel days, very little of that knowledge actually translates these days with modern fuels.
TBH tuning by plug colour is fundamentally flawed anyway, the colour you see is only ever a reflection of how the car was driven immediately before the plugs are removed, and inevitably that's always after a short period at idle.
If your plug chopping make it quick The thing is that was back in the good old leaded fuel days, very little of that knowledge actually translates these days with modern fuels.
TBH tuning by plug colour is fundamentally flawed anyway, the colour you see is only ever a reflection of how the car was driven immediately before the plugs are removed, and inevitably that's always after a short period at idle.
in my old 2 stroke off road days you at to be even quicker if you didnt want the result corrupted QBee said:
Alun, I think 100 miles of motorway may be what you are seeing. My AFR gauge shows well lean (15-18) when cruising in motorway conditions off throttle, ie not arsed with the stop start queue in the German lane, but instead just cruising steadily along in the first two lanes going just as quickly. AFR only really matters when you are giving it wellie.
My car is running fine on iridiot 6s. And a turbo car, if anything, should be on a colder plug than an NA car. My Saab, for example, is on 9s.
15-18,, that’s very interesting and I’d have thought way to lean but what do I know. My car is running fine on iridiot 6s. And a turbo car, if anything, should be on a colder plug than an NA car. My Saab, for example, is on 9s.
It stumps me as my engine bay temps are generally way lower than they used to be but this leaned off nature which seems great for mpg should surely have the engine running very hot.
I’d read how the CUX dumps fuel into the mix as a way to control engine internal heat so without that going on wonder how it now does it.
Hang on,,,,,
Brain wave maybe?
When not under load the engine timing is also retarded I seem to think, this reduces combustion chamber heat as explosions are not required to be max power thus this timing retarding reducing heat allows you to lean off the mix.
Hmmm?
After market Ecu rock man
Classic Chim said:
QBee said:
Alun, I think 100 miles of motorway may be what you are seeing. My AFR gauge shows well lean (15-18) when cruising in motorway conditions off throttle, ie not arsed with the stop start queue in the German lane, but instead just cruising steadily along in the first two lanes going just as quickly. AFR only really matters when you are giving it wellie.
My car is running fine on iridiot 6s. And a turbo car, if anything, should be on a colder plug than an NA car. My Saab, for example, is on 9s.
15-18,, that’s very interesting and I’d have thought way to lean but what do I know. My car is running fine on iridiot 6s. And a turbo car, if anything, should be on a colder plug than an NA car. My Saab, for example, is on 9s.
It stumps me as my engine bay temps are generally way lower than they used to be but this leaned off nature which seems great for mpg should surely have the engine running very hot.
I’d read how the CUX dumps fuel into the mix as a way to control engine internal heat so without that going on wonder how it now does it.
Hang on,,,,,
Brain wave maybe?
When not under load the engine timing is also retarded I seem to think, this reduces combustion chamber heat as explosions are not required to be max power thus this timing retarding reducing heat allows you to lean off the mix.
Hmmm?
After market Ecu rock man
t loads of advance Alun to give that lean mix time to burn , hence the good MPG, its not detrimental to the engine as soon as you jump on the throttle its a whole new ball game so no chance of detonation/pinking etc you could say the joys of modern engine management 
Sardonicus said:
On cruise your running st loads of advance Alun to give that lean mix time to burn , hence the good MPG, its not detrimental to the engine as soon as you jump on the throttle its a whole new ball game so no chance of detonation/pinking etc you could say the joys of modern engine management
Arrrrh, so the opposite then. t loads of advance Alun to give that lean mix time to burn , hence the good MPG, its not detrimental to the engine as soon as you jump on the throttle its a whole new ball game so no chance of detonation/pinking etc you could say the joys of modern engine management I need to read more on this subject.
The reason your engine temps are so much lower Alun is a purely function of ignition timing, the standard setup with a distributor is designed to run at 10-12 degrees at idle to get the cats nice and hot quickly, and ultimately to lower emissions.
If you change that to 18 degrees you will invariably pollute more, but because that's the idle timing the engine actually wants your idle will become much smoother.... and because you're no longer passing still burning gas into the exhaust headers your under bonnet temps also fall dramatically.
If you crack the laptop out and check your idle timing I bet it will have been set somewhere between 15-20 degrees, it will also be slowly fluctuating above and below what I would guess will be 18 degrees as the ECU manages your target idle speed using ignition timing (scatter spark idle management).
TBH the MegaSquirt, MBE, Canems and Emerald systems we all run on our TVR's are massively old hat engine management technology compared with whats out there these days, but they are still a monumental step forward from the 14CUX and especially the distributor ignition Chimaeras and Griffiths were burdened with.
Switching to an after market engine management system was the best thing you ever did with your TVR, but I dont know why I'm telling you this as for sure you know this already... Jus enjoy the car and don't worry about your plugs being a bit on the white side, things aint what they used to be when it comes to reading plug colour for the reasons I've already explained.
Regarding cruise, I've done extensive testing of AFRs vs fuel economy and while running lean can deliver a fraction more economy we are talking a tiny benefit for what can sometimes be at the cost of the ultimate drivability I see as the minimum from a big capacity eight cylinder engine moving around an extremely light car. I once ran my AFRs to 17/18:1 on cruise but these days I keep things under a 16:1 cieling even at the lightest load cruise, Ignition timing is a different story all together but the only real way I could prove where peak torque lived was to put the car on the dyno.
This exercise proved even on 110Ron LPG the maximum advance never exceeds the 50 degrees ceiling the Canems system offers, the topography of my 3D ignition maps between the two fuels however is very different indeed with a lot more advance being used early on in the LPG table compared with my ideal petrol ignition calibration. TBH all this has less to do with the different octane levels of the two fuels and much more to do with how the two fuels burn and the speed of the flame fronts.
If you change that to 18 degrees you will invariably pollute more, but because that's the idle timing the engine actually wants your idle will become much smoother.... and because you're no longer passing still burning gas into the exhaust headers your under bonnet temps also fall dramatically.
If you crack the laptop out and check your idle timing I bet it will have been set somewhere between 15-20 degrees, it will also be slowly fluctuating above and below what I would guess will be 18 degrees as the ECU manages your target idle speed using ignition timing (scatter spark idle management).
TBH the MegaSquirt, MBE, Canems and Emerald systems we all run on our TVR's are massively old hat engine management technology compared with whats out there these days, but they are still a monumental step forward from the 14CUX and especially the distributor ignition Chimaeras and Griffiths were burdened with.
Switching to an after market engine management system was the best thing you ever did with your TVR, but I dont know why I'm telling you this as for sure you know this already... Jus enjoy the car and don't worry about your plugs being a bit on the white side, things aint what they used to be when it comes to reading plug colour for the reasons I've already explained.
Regarding cruise, I've done extensive testing of AFRs vs fuel economy and while running lean can deliver a fraction more economy we are talking a tiny benefit for what can sometimes be at the cost of the ultimate drivability I see as the minimum from a big capacity eight cylinder engine moving around an extremely light car. I once ran my AFRs to 17/18:1 on cruise but these days I keep things under a 16:1 cieling even at the lightest load cruise, Ignition timing is a different story all together but the only real way I could prove where peak torque lived was to put the car on the dyno.
This exercise proved even on 110Ron LPG the maximum advance never exceeds the 50 degrees ceiling the Canems system offers, the topography of my 3D ignition maps between the two fuels however is very different indeed with a lot more advance being used early on in the LPG table compared with my ideal petrol ignition calibration. TBH all this has less to do with the different octane levels of the two fuels and much more to do with how the two fuels burn and the speed of the flame fronts.
ChimpOnGas said:
TBH the MegaSquirt, MBE, Canems and Emerald systems we all run on our TVR's are massively old hat engine management technology compared with whats out there these days, but they are still a monumental step forward from the 14CUX and especially the distributor ignition Chimaeras and Griffiths were burdened with.
Certainly are even my old 2002 year BMW DME would run rings around many of these after-market ECU's e.g CANBUS ,full seq fuel and ign, knock contol, PWM variable valve timing control, variable intake volume etc etc it's only when you get into the Pectel league for example the scales change however I am not convinced our old RV8 would fully appreciate this higher tech in the same way I am not convinced with the GEMS system the better drive-abilty comes about due to full seq fuel rather than the so called better/finer control or quality unit , even though it is a fine bit of kit but so are most OE installed ECU's 
Edited by Sardonicus on Thursday 19th April 14:51
ChimpOnGas said:
The reason your engine temps are so much lower Alun is a purely function of ignition timing, the standard setup with a distributor is designed to run at 10-12 degrees at idle to get the cats nice and hot quickly, and ultimately to lower emissions.
If you change that to 18 degrees you will invariably pollute more, but because that's the idle timing the engine actually wants your idle will become much smoother.... and because you're no longer passing still burning gas into the exhaust headers your under bonnet temps also fall dramatically.
If you crack the laptop out and check your idle timing I bet it will have been set somewhere between 15-20 degrees, it will also be slowly fluctuating above and below what I would guess will be 18 degrees as the ECU manages your target idle speed using ignition timing (scatter spark idle management).
TBH the MegaSquirt, MBE, Canems and Emerald systems we all run on our TVR's are massively old hat engine management technology compared with whats out there these days, but they are still a monumental step forward from the 14CUX and especially the distributor ignition Chimaeras and Griffiths were burdened with.
Switching to an after market engine management system was the best thing you ever did with your TVR, but I dont know why I'm telling you this as for sure you know this already... Jus enjoy the car and don't worry about your plugs being a bit on the white side, things aint what they used to be when it comes to reading plug colour for the reasons I've already explained.
Regarding cruise, I've done extensive testing of AFRs vs fuel economy and while running lean can deliver a fraction more economy we are talking a tiny benefit for what can sometimes be at the cost of the ultimate drivability I see as the minimum from a big capacity eight cylinder engine moving around an extremely light car. I once ran my AFRs to 17/18:1 on cruise but these days I keep things under a 16:1 cieling even at the lightest load cruise, Ignition timing is a different story all together but the only real way I could prove where peak torque lived was to put the car on the dyno.
This exercise proved even on 110Ron LPG the maximum advance never exceeds the 50 degrees ceiling the Canems system offers, the topography of my 3D ignition maps between the two fuels however is very different indeed with a lot more advance being used early on in the LPG table compared with my ideal petrol ignition calibration. TBH all this has less to do with the different octane levels of the two fuels and much more to do with how the two fuels burn and the speed of the flame fronts.
My AFR is in the 15’s at cruise If you change that to 18 degrees you will invariably pollute more, but because that's the idle timing the engine actually wants your idle will become much smoother.... and because you're no longer passing still burning gas into the exhaust headers your under bonnet temps also fall dramatically.
If you crack the laptop out and check your idle timing I bet it will have been set somewhere between 15-20 degrees, it will also be slowly fluctuating above and below what I would guess will be 18 degrees as the ECU manages your target idle speed using ignition timing (scatter spark idle management).
TBH the MegaSquirt, MBE, Canems and Emerald systems we all run on our TVR's are massively old hat engine management technology compared with whats out there these days, but they are still a monumental step forward from the 14CUX and especially the distributor ignition Chimaeras and Griffiths were burdened with.
Switching to an after market engine management system was the best thing you ever did with your TVR, but I dont know why I'm telling you this as for sure you know this already... Jus enjoy the car and don't worry about your plugs being a bit on the white side, things aint what they used to be when it comes to reading plug colour for the reasons I've already explained.
Regarding cruise, I've done extensive testing of AFRs vs fuel economy and while running lean can deliver a fraction more economy we are talking a tiny benefit for what can sometimes be at the cost of the ultimate drivability I see as the minimum from a big capacity eight cylinder engine moving around an extremely light car. I once ran my AFRs to 17/18:1 on cruise but these days I keep things under a 16:1 cieling even at the lightest load cruise, Ignition timing is a different story all together but the only real way I could prove where peak torque lived was to put the car on the dyno.
This exercise proved even on 110Ron LPG the maximum advance never exceeds the 50 degrees ceiling the Canems system offers, the topography of my 3D ignition maps between the two fuels however is very different indeed with a lot more advance being used early on in the LPG table compared with my ideal petrol ignition calibration. TBH all this has less to do with the different octane levels of the two fuels and much more to do with how the two fuels burn and the speed of the flame fronts.
Watched Jason swap some injectors over on a Griff for the same as mine 4.0 speed six jobbies, same spray pattern just better flow so they work less.
He makes things look so easy.
Car was running a beaut on the newly installed Mbe.
I was hoping to use a small notebook/ tablet for my diagnostics but it’s not really man enough for the software so back to getting a lap top but it’s not really a priority at the mo as I’m so close to Powers if I suspect something I’d rather let them look at it until I’m more clued up.
I’d look but I wouldn’t adjust anything myself. Really I wanted a small screen so I could leave it plugged in but then I don’t like spending money
Very interesting how Jason mentioned AFR of high 15’s at cruise and your 16.1 Dave
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