John McCormack Posted August 8, 2020 Report Share Posted August 8, 2020 After a few days of rain it was dry today so I took the TR6 for a run. Towards the end of a very enjoyable 45 minute drive (over the ANZAC, Sydney Harbour and Gladesville Bridges) and quite near my place I pulled up behind a Healey 100/4. We stopped for a chat, not too many Brit cars in our area. I had the car idling for maybe 5-10 minutes. Of course the plugs had fouled up so I tried an Italian tune. This did clear them but living in a built up area the opportunity wasn't there for a really good blast. I ended up pulling the plugs and wire brushing them, checked the gaps and a test drive showed all is good. I only use BP 98 octane, regarded here as the best for our cars. Fuel consumption seems normal for a PI living near a major city, about 15-18 mpg around town and 25 mpg on a trip. Do other PI owners have the same problem? I'd like to know what plugs PI owners are using and what gap they are setting them too. The book says 25 thou which seems small to me, the TR2 is 32 thou. Quote Link to post Share on other sites
Yarm 783 Posted August 8, 2020 Report Share Posted August 8, 2020 Yes, I am afraid so. I try to avoid leaving the car at tickover, use choke only to start the car (pushing it almost immediately and try to use the car over distances that get everything, including the plugs, up to temperature. But every now and again the plugs will need drawing and cleaning. Quote Link to post Share on other sites
cp25616 Posted August 8, 2020 Report Share Posted August 8, 2020 John I would try a hotter running plug. Sounds like your PI is running ok from the figures you have supplied and I don't know which brand of plugs you are using but I find the NGK BP6ES to be fine for me so just as an exercise try using NGK BP5ES or BPR5ES if you need a resistor plug. These run hotter than the 6ES and might, just might, help with your "city fouling" of your plugs. Its certainly a cheap starting point in your quest. Alan G Quote Link to post Share on other sites
John McCormack Posted August 8, 2020 Author Report Share Posted August 8, 2020 22 minutes ago, cp25616 said: John I would try a hotter running plug. Sounds like your PI is running ok from the figures you have supplied and I don't know which brand of plugs you are using but I find the NGK BP6ES to be fine for me so just as an exercise try using NGK BP5ES or BPR5ES if you need a resistor plug. These run hotter than the 6ES and might, just might, help with your "city fouling" of your plugs. Its certainly a cheap starting point in your quest. Alan G The car has electronic ignition (Lumenition) and the ballast resistor has been disconnected. I currently have Champion N12YC plugs. They have performed very well but I'm thinking a slightly hotter plug might be better. I have a set of RN14YC but as the resistor has been disconnected they wouldn't be suitable. Quote Link to post Share on other sites
RobH Posted August 8, 2020 Report Share Posted August 8, 2020 6 minutes ago, John McCormack said: I have a set of RN14YC but as the resistor has been disconnected they wouldn't be suitable. Why? The plug resistance is only there in the HT side to reduce interference with radios. If you have silicone plug leads they do exactly the same thing. There is no comparability between that and the ballast resistor in the LT side of the coil which prevents a low-voltage coil from overheating. Quote Link to post Share on other sites
John McCormack Posted August 8, 2020 Author Report Share Posted August 8, 2020 26 minutes ago, RobH said: Why? The plug resistance is only there in the HT side to reduce interference with radios. If you have silicone plug leads they do exactly the same thing. There is no comparability between that and the ballast resistor in the LT side of the coil which prevents a low-voltage coil from overheating. Thanks Rob. I am a numpty on anything electronic. The 14 plugs are hotter so using them should reduce fouling? Quote Link to post Share on other sites
astontr6 Posted August 8, 2020 Report Share Posted August 8, 2020 1 hour ago, cp25616 said: John I would try a hotter running plug. Sounds like your PI is running ok from the figures you have supplied and I don't know which brand of plugs you are using but I find the NGK BP6ES to be fine for me so just as an exercise try using NGK BP5ES or BPR5ES if you need a resistor plug. These run hotter than the 6ES and might, just might, help with your "city fouling" of your plugs. Its certainly a cheap starting point in your quest. Alan G I keep away from resistor plugs as they cut down the intensity of the spark. Lessons learnt from my motor cycle days! The plug that i use is NGK BP5ES on all cylinders. Your problem could also be that your M/U is running too rich? R type plugs are not required if using suppressed HT leads as most cars are? Bruce. Quote Link to post Share on other sites
Mike C Posted August 8, 2020 Report Share Posted August 8, 2020 Used to have this problem with BP5ES and BP6ES plugs. Never had it since I switched to NGK BUR6ET triple electrode plugs. Quote Link to post Share on other sites
RobH Posted August 8, 2020 Report Share Posted August 8, 2020 (edited) 1 hour ago, John McCormack said: The 14 plugs are hotter so using them should reduce fouling? It's certainly worth a try, they can do no harm (except perhaps to introduce running-on if they are too hot). Bruce is right that you don't need both resistive plugs and suppressed leads but it wouldn't hurt for the purpose of an experiment to see whether they cure the fouling. For the record, resistor plugs do not materially reduce spark intensity any more than do resistive leads. All they do is slow down the very front edge of the discharge to reduce radio-frequency noise. Using suppressed plugs and leads together might give some effect if the ignition system is very marginal. Edited August 8, 2020 by RobH Quote Link to post Share on other sites
Nigel Triumph Posted August 8, 2020 Report Share Posted August 8, 2020 58 minutes ago, Mike C said: Used to have this problem with BP5ES and BP6ES plugs. Never had it since I switched to NGK BUR6ET triple electrode plugs. +1 I've used only multi electrode plugs in my Triumphs for years, TR6 on Lucas PI and a GT6 on carbs. NGK BUR6ET or Bosch WR78 plugs seem more resistant to fouling plus give smoother idling and crisper pick up. Nigel Quote Link to post Share on other sites
astontr6 Posted August 8, 2020 Report Share Posted August 8, 2020 18 minutes ago, Nigel Triumph said: +1 I've used only multi electrode plugs in my Triumphs for years, TR6 on Lucas PI and a GT6 on carbs. NGK BUR6ET or Bosch WR78 plugs seem more resistant to fouling plus give smoother idling and crisper pick up. Nigel Hi Nigel, Which type do you prefer Bosch or NGK? Bruce. Quote Link to post Share on other sites
Nigel Triumph Posted August 8, 2020 Report Share Posted August 8, 2020 Hi Bruce, I can't discern any difference between Bosch or NGK multi electrode plugs, both are better than single electrode. Some say that once an NGK plug has been sooted up it will never completely recover even after cleaning, and will forever be prone to misfiring and fouling again. I believe this is thought to apply to single electrode NGKs. Can't say I've experienced this problem; no such concerns have been expressed about Bosch. May be hearsay? So to summarize, I would recommend Bosch and NGK multi electrode plugs. Nigel Quote Link to post Share on other sites
barkerwilliams Posted August 8, 2020 Report Share Posted August 8, 2020 On my Pi I use BP6ES for plugs 1-4 and BP5ES for plugs 5-6 (bulkhead end) 5&6 always were the sootiest, furthest from the air intake I assumed. And since using the hotter plug in 5&6 all plugs are typically evenly brown'ish. As 1-4 looked ok fitting the hotter plug in those would not have been good. No reason not to mix plug heat rating. Alan Quote Link to post Share on other sites
Kevo_6 Posted August 8, 2020 Report Share Posted August 8, 2020 7 minutes ago, barkerwilliams said: On my Pi I use BP6ES for plugs 1-4 and BP5ES for plugs 5-6 (bulkhead end) 5&6 always were the sootiest, furthest from the air intake I assumed. And since using the hotter plug in 5&6 all plugs are typically evenly brown'ish. As 1-4 looked ok fitting the hotter plug in those would not have been good. No reason not to mix plug heat rating. Alan I have done the same and I’ve had no plug fouling since. Quote Link to post Share on other sites
tr6tuga Posted August 8, 2020 Report Share Posted August 8, 2020 Regardless of plug choice , the most important is to have very fine tunning of buterflies, at idle and at 1400-1500 rpm wich is a time consuming and trial error . Quote Link to post Share on other sites
John McCormack Posted August 9, 2020 Author Report Share Posted August 9, 2020 (edited) Raining again today. I put the RN14YC plugs in and it starts and drove for a few hundred metres without issue. The rain was getting heavier so I didn't want to go further. After cleaning the old plugs yesterday I took the car for a couple of km drive and today they were brown with three (3, 4 and 6) slightly darker but still brown. Overall the mixture looks pretty well setup. I like the idea of the BUR6ET but they cost a bit. Edited August 9, 2020 by John McCormack Quote Link to post Share on other sites
Nigel Triumph Posted August 9, 2020 Report Share Posted August 9, 2020 Multi electrode plugs are a little more expensive but will last 20-40k miles according to modern car service schedules. That makes them much cheaper on a per mile basis... If you cover enough miles. Nigel Quote Link to post Share on other sites
Schnippel Posted August 9, 2020 Report Share Posted August 9, 2020 Hello We build Bosch WR 78 into every TR 6 machine. I drove a service life of over 60,000 km myself. Insensitive to fatty mixtures. Hand on it for PI'S the best spark plugs! But the voltage supply for the spark plug must also be top-notch. I think that explains itself. Ralf Quote Link to post Share on other sites
Waldi Posted August 9, 2020 Report Share Posted August 9, 2020 Hallo Ralph, good to hear. If you say voltage supply must be top notch, what HT leads and coil do you use/prefer? Thanks, Waldi Quote Link to post Share on other sites
michaeldavis39 Posted August 9, 2020 Report Share Posted August 9, 2020 Just ordered the Bosch WR78, £24.78 including 2nd class delivery from Green Spark Plug Company- that is not expensive- is it??? To me it isnt. Michael Quote Link to post Share on other sites
Mike C Posted August 9, 2020 Report Share Posted August 9, 2020 3 hours ago, michaeldavis39 said: Just ordered the Bosch WR78, £24.78 including 2nd class delivery from Green Spark Plug Company- that is not expensive- is it??? To me it isnt. Michael That's a very good price. About half of what my last set of BUR6ET's cost in Australia. Quote Link to post Share on other sites
michaeldavis39 Posted August 9, 2020 Report Share Posted August 9, 2020 I like a bargain Mike, though I didn't know it was. Now need to find some decent HT plug leads- any recommendations?? Michael Quote Link to post Share on other sites
RobH Posted August 9, 2020 Report Share Posted August 9, 2020 The WR78 is a resistor-type suppressed plug so copper cored leads are best. Quote Link to post Share on other sites
michaeldavis39 Posted August 9, 2020 Report Share Posted August 9, 2020 Thanks for that Rob- any recommendations as to manufacturer or suppliers? Michael Quote Link to post Share on other sites
RobH Posted August 9, 2020 Report Share Posted August 9, 2020 DIY. Copper cored wire is cheap and the push-fit ends are readily available. It's very simple to make up your own. https://www.gsparkplug.com/ignition/ignition-lead Quote Link to post Share on other sites
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.