spark plug reading your opinions on my plug - guess it´s too hot

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lilredridinghoo

lilredridinghoo

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hi fellows, after driving the 5.2 Magnum SBM in my Barracuda for a while now i cld manage to install an AFR Reading Gauge

AFR is reading between 12,4 and 14,2 as an average overall (has a short lean spot when accelerating 1/100 of a second will jump to 16-17 AFR and the go back to 11 AFR - which i guess can be adjusted by fine tunning the pump squirt)

but my questions are going to spark plug reading

after some test drives i pulled the plug and looks pretty good - beside the 3 little spots on the porcelain(unfort. only 2 visible in the pic)
refering to that spark plug reading sheet it cld. be a indication for a too hot spark plug.

(ignition is set at 18° initial at idle and 34° total all out (limiter plate 16° advance); all out is reached at 2400 RPM; no vacuum hooked up; rev-n-nator ignition box; no piniging or knocking; spark plugs are NGK FR5-1 which is the standard plug for Magnum engines)

24.08.png


Pump Gas Plug Reading.jpg
 
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If you have a Chiltons manual, look inside the back cover. There's an illustrated and more complete plug diagnosis chart in there.
 
How many miles on that plug? It doesn't look nearly coloured enough to start reading yet. Still very white. Unless that's the lean/hot problem. Try to get a bigger/better picture as well. Reading with modern gas is much more difficult. Try to see if you can get a magnifying glass to look down and check all the porcelain.
 
CudaChick1968 said:
If you have a Chiltons manual, look inside the back cover. There's an illustrated and more complete plug diagnosis chart in there.
Click to expand...
Absolutely agreed ,Mistress of Metal" (gawd,I love that name,Leanna....) Are you running a MSD box,or something similar?
 
And what formula of fuel ,are you running?.(and plug number..if possible..)
 
PLugs are NGK FR5-1
Ignition is a standard Mopar dizzy with a limiter plate - MSD Blaster 2 coil and a Rev-n-nator ECU

fuel is European 95 ROZ/RON which is 85 MOZ/MON so it should be 90 RON compared to USstandard
plugs are in for approx 200 miles now
 
lilredridinghoo said:
PLugs are NGK FR5-1
Ignition is a standard Mopar dizzy with a limiter plate - MSD Blaster 2 coil and a Rev-n-nator ECU

fuel is European 95 ROZ/RON which is 85 MOZ/MON so it should be 90 RON compared to USstandard
plugs are in for approx 200 miles now
Click to expand...

Best thing to do is some full throttle runs. Get her all the way up. Then shut it off, coast, and pull the plugs immediately. That usually gives the best reading. Obviously do this somewhere safe. Do this a few times. Compare results. This must be done under load. Sitting in the driveway revving it won't do it.

If they are THAT white, and the spotting. It does look like a lean/hot condition. Plugs are cheap. Go two heat ranges down. Full throttle runs. See how they look. Compare results.
 
Lustle said:
Best thing to do is some full throttle runs. Get her all the way up. Then shut it off, coast, and pull the plugs immediately. That usually gives the best reading. Obviously do this somewhere safe. Do this a few times. Compare results. This must be done under load. Sitting in the driveway revving it won't do it.

If they are THAT white, and the spotting. It does look like a lean/hot condition. Plugs are cheap. Go two heat ranges down. Full throttle runs. See how they look. Compare results.
Click to expand...

i pulled the plugs right after driving some miles on the road (approx 60-70 mph) and shut off the ignition rolling out on the parking lane - maybe i have to try to find a place to do some full throttle run (which is not easy in Germany)
 
lilredridinghoo said:
PLugs are NGK FR5-1
Ignition is a standard Mopar dizzy with a limiter plate - MSD Blaster 2 coil and a Rev-n-nator ECU

fuel is European 95 ROZ/RON which is 85 MOZ/MON so it should be 90 RON compared to USstandard
plugs are in for approx 200 miles now
Click to expand...
lilredridinghoo said:
hi fellows, after driving the 5.2 Magnum SBM in my Barracuda for a while now i cld manage to install an AFR Reading Gauge

AFR is reading between 12,4 and 14,2 as an average overall (has a short lean spot when accelerating 1/100 of a second will jump to 16-17 AFR and the go back to 11 AFR - which i guess can be adjusted by fine tunning the pump squirt)

but my questions are going to spark plug reading

after some test drives i pulled the plug and looks pretty good - beside the 3 little spots on the porcelain(unfort. only 2 visible in the pic)
refering to that spark plug reading sheet it cld. be a indication for a too hot spark plug.

(ignition is set at 18° initial at idle and 34° total all out (limiter plate 16° advance); all out is reached at 2400 RPM; no vacuum hooked up; rev-n-nator ignition box; no piniging or knocking; spark plugs are NGK FR5-1 which is the standard plug for Magnum engines)

View attachment 1714961164

View attachment 1714961163
Click to expand...
What are you gapping ,those plugs at? (picture looks ,wide gappish...) I don't normally recommend a colder plug, I would try one notch down, on heat range...
 
Abodybomber said:
What are you gapping ,those plugs at? (picture looks ,wide gappish...) I don't normally recommend a colder plug, I would try one notch down, on heat range...
Click to expand...

i have to confess i don´t really know the current gap.... guess it was 0.04 (which is about 1 mm as given by NGK)

here is a pic without that yellow mark
14101786_1202340343163925_996728052_n.jpg
 
if you dont know the gap how in the world did you set them? tell me not out of the box
 
Gap is very important for plugs. If I was you, I would get a new set at that heat range. And a new set at two heat ranges lower. Gap them properly (and accurately). Do full throttle runs (a few is good) with both sets. Compare what the sets look like. Whichever looks better. Go with them.

Plugs are cheap. Detonation (which is what those spots look like) is not.
 
modern gas burns very clean and plug reading is difficult.
Your a/f readings are good and that plug looks fine!
 
Plug charts date back to leaded gas. About all you can see now is black fouling, from way too rich, or clean plugs. Tip erosion can show if too hot,but may look similar if high miles on plug. Some information can be found by looking for black down in the well, but short runs makes them black too. If temperature range is correct, plugs self clean under highway cruise conditions.

Best use WBO2 as suggested above.
 
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