dutchzcarguy Posted January 21, 2024 Share #193 Posted January 21, 2024 7 hours ago, chaseincats said: I have been using NGK Iridium BPR6EIX-11 plugs. Why? are you doing 30000km/miles a year? no? then you don't need those i think.. just put in 6 cheap but good original BPR6ES from NGK (Watch out for super cheap copy $^!#..) They are about 3 dollar a piece and are perfect for the L series engines.. Then take a look at those after at least an hour of driving. (Haven't read it all but guess you have a "normal 2753cc engine..) Place some pics of those plugs ! 😉 Link to comment https://www.classiczcars.com/topic/65119-tuning-with-an-airfuel-gauge/?page=17#findComment-661254 Share on other sites More sharing options...
chaseincats Posted January 21, 2024 Author Share #194 Posted January 21, 2024 (edited) 5 hours ago, jonbill said: I'd just go with cheap bpr6es. Does your engine burn some oil? It looks like there are deposits on the spark plugs. I believe it burns some oil, but whatever it burns it isn't enough to affect oil level over the course of a year. @dutchzcarguy@jonbill Understood on the spark plug material. Which heat rating though (bp5, bp6, bp7)? 2 hours ago, madkaw said: Those plugs show lean and or hot - I would be concerned if my plugs looked like that . I haven’t read your complete thread , but those do not look good Plug reading really isn't the way to go as long as you have an air/fuel gauge to see what the engine is actually doing. It's running at a 13.8-14.2 idle, 12.3 WOT, and 14.7 highway cruise. I will say, the other day I did catch it running VERY lean (in the 17s) so I pulled over and fiddled with it - not sure if that's when the plugs started looking like this or not though Edited January 21, 2024 by chaseincats 1 Link to comment https://www.classiczcars.com/topic/65119-tuning-with-an-airfuel-gauge/?page=17#findComment-661255 Share on other sites More sharing options...
madkaw Posted January 21, 2024 Share #195 Posted January 21, 2024 7 minutes ago, chaseincats said: I believe it burns some oil, but whatever it burns it isn't enough to affect oil level over the course of a year. @dutchzcarguy@jonbill Understood on the spark plug material. Which heat rating though (bp5, bp6, bp7)? Plug reading really isn't the way to go as long as you have an air/fuel gauge to see what the engine is actually doing. It's running at a 13.8-14.2 idle, 12.3 WOT, and 14.7 highway cruise. I will say, the other day I did catch it running VERY lean (in the 17s) so I pulled over and fiddled with it - not sure if that's when the plugs started looking like this or not though Plugs can verify what you think is a proper tune . I’ve been running programmable EFI for years - those plugs look bad . Something is not right . 17’s would be terrible for an engine that doesn’t have full spark control. I run my engines lean - even my stroker and 15.5-16 is a lean burn for these old engineered engines . I appreciate your effort to make these old Bosch systems tunable - but without any load readings( I assume you use standard dizzy) you are guessing . i would recommend a 123 dizzy if you don’t already run one . 3 Link to comment https://www.classiczcars.com/topic/65119-tuning-with-an-airfuel-gauge/?page=17#findComment-661257 Share on other sites More sharing options...
chaseincats Posted January 21, 2024 Author Share #196 Posted January 21, 2024 11 minutes ago, madkaw said: Plugs can verify what you think is a proper tune . I’ve been running programmable EFI for years - those plugs look bad . Something is not right . 17’s would be terrible for an engine that doesn’t have full spark control. I run my engines lean - even my stroker and 15.5-16 is a lean burn for these old engineered engines . I appreciate your effort to make these old Bosch systems tunable - but without any load readings( I assume you use standard dizzy) you are guessing . i would recommend a 123 dizzy if you don’t already run one . The air/fuel gauge connected to the o2 sensor that was installed gives you load readings that I listed above though. Link to comment https://www.classiczcars.com/topic/65119-tuning-with-an-airfuel-gauge/?page=17#findComment-661258 Share on other sites More sharing options...
madkaw Posted January 21, 2024 Share #197 Posted January 21, 2024 What KPA is cruise running ? Link to comment https://www.classiczcars.com/topic/65119-tuning-with-an-airfuel-gauge/?page=17#findComment-661261 Share on other sites More sharing options...
chaseincats Posted January 21, 2024 Author Share #198 Posted January 21, 2024 1 hour ago, madkaw said: What KPA is cruise running ? Sorry if this is a dumb question, but what does KPA stand for? Link to comment https://www.classiczcars.com/topic/65119-tuning-with-an-airfuel-gauge/?page=17#findComment-661263 Share on other sites More sharing options...
Patcon Posted January 21, 2024 Share #199 Posted January 21, 2024 I believe it is Kilo pascals... Link to comment https://www.classiczcars.com/topic/65119-tuning-with-an-airfuel-gauge/?page=17#findComment-661264 Share on other sites More sharing options...
chaseincats Posted January 21, 2024 Author Share #200 Posted January 21, 2024 8 minutes ago, Patcon said: I believe it is Kilo pascals... Never heard of that let alone it being used as a metric for engines. @madkaw Link to comment https://www.classiczcars.com/topic/65119-tuning-with-an-airfuel-gauge/?page=17#findComment-661265 Share on other sites More sharing options...
AK260 Posted January 21, 2024 Share #201 Posted January 21, 2024 Never heard of that let alone it being used as a metric for engines. [mention=6833]madkaw[/mention]Often used when talking about MAP (manifold absolute pressure)As been said already, what I see on your plugs is Lean, very hot burn and some detonation marks (although that could just be the photo quality). Link to comment https://www.classiczcars.com/topic/65119-tuning-with-an-airfuel-gauge/?page=17#findComment-661266 Share on other sites More sharing options...
jonbill Posted January 21, 2024 Share #202 Posted January 21, 2024 100kpa is about 15psi is about 1 bar is about atmospheric pressure. 1 1 Link to comment https://www.classiczcars.com/topic/65119-tuning-with-an-airfuel-gauge/?page=17#findComment-661270 Share on other sites More sharing options...
madkaw Posted January 22, 2024 Share #203 Posted January 22, 2024 As said above - using MAP density tuning - KPA would be your measurement for load. Tuning for cruise would be difficult not knowing how the engine is loading . Loading can change a lot just climbing a slight grade though you aren’t putting much throttle to the engine . The OEM injection biases everything to the rich side to be safe . Those plugs took a while to look like that and most of the time we spend in cruise . That’s why the 123 ignition is a nice supplement to help keep the engine safe while tuning since it does have MAP sensor 1 Link to comment https://www.classiczcars.com/topic/65119-tuning-with-an-airfuel-gauge/?page=17#findComment-661272 Share on other sites More sharing options...
chaseincats Posted January 22, 2024 Author Share #204 Posted January 22, 2024 5 minutes ago, madkaw said: As said above - using MAP density tuning - KPA would be your measurement for load. Tuning for cruise would be difficult not knowing how the engine is loading . Loading can change a lot just climbing a slight grade though you aren’t putting much throttle to the engine . The OEM injection biases everything to the rich side to be safe . Those plugs took a while to look like that and most of the time we spend in cruise . That’s why the 123 ignition is a nice supplement to help keep the engine safe while tuning since it does have MAP sensor is that something you just pop in or does it require a lot of supplementary tuning? Link to comment https://www.classiczcars.com/topic/65119-tuning-with-an-airfuel-gauge/?page=17#findComment-661273 Share on other sites More sharing options...
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