How do my spark plugs look?

[My1GLaser]

I am kind of familiar with the Haynes manual color spark plug pics. I don't see any of the problems listed. I am interested if you can tell how my tune looks from looking at my plugs. I have never learned how to read plugs. Some people can look at them and tell if your timing is good, etc. If you see an issue then please chime in!

It seems like plug 1 is a little different than the rest in both electrode color and the black soot that is on the end of the plug body. What is that weird design? Does it mean anything?

60% E-85, 12:1 AFR, BR8ES, 35 psi (53-54 lb/min), JMF Race SMIM

 

[GIRman67]

Call me crazy and it may be the angle of the pictures. Why does the gap look so tiny? It looks like it got smashed

 

[little-razcal]

The correct way to read the plugs is to put them in right before a pass or third gear pull, then shut it off immediately at the top end. (Leave the car in gear and let the ECU cut fuel while your coasting, to let the engine and turbo circulate the oil a bit through before you shut it down) Pull the plugs, then post your results. This is the only way you will ever be able to accurately read plugs. This method of reading plugs is more helpful to a distributed V8 with a big carb when dialing In the jetting and timing. It can however be useful for us if done correctly.

 

[My1GLaser]

Oh crap! Well at least I posted in the newbie section! I doubt I will be able to do that method correctly for a while...

So the pics of these plugs don't really tell you anything then?

The gap is .018" cause it blows out if it is larger.

 

[Metal Health]

Appears to be normal, the high oct is the white, an should have little tan which it does. Wideban is a more reliable way to read a tune : )

 

[My1GLaser]

I can't 100% trust my WB, since my flex section is leaking a good amount. My AFR isn't as stable as it should be and varies from 11.7 to 12.7.

Nothing looks a little odd in the first pic? I could just be nit-picking, and am a curious if all 4 cyls are running the same. I read that a SMIM can sometimes make one cyl run leaner than the rest. Plug #1 looks different, but I could be over-thinking. Thanks for the replies so far!

 

[mondale]

To be fair your plugs could look all ok and one or more of them could be fouled. E85 can be very tricky when trying to look at a plug and judge the engine's current performance from it.

Source cited - Shane @ DB performance

 

[funcar]

Plugs look ok, but a af gauge is where its at.
Off topic but I was reading a while ago and a lot of the old school turbo guys would tune based off hotside wheel. They have the same carbon and fuel build up like plugs, but not so easy to access. I thought it was interesting.

 

[bastarddsm]

Start over with new plugs. Looks like there's a lot of ash on them. You should go up one heat range, too. Possibly give it just a little more timing. Also it's way fat at idle/low load.

Mine look like new plugs even after a bunch of passes. Only they have the cad burned off the ground and stuff.

Use a cut off wheel and cut one open so we can see the very bottom of the pocelin. Thats where WOT shows AFR.

 

[Mark L]

I have never tuned by spark plug reading. How close do you need to be to the hairy edge on timing? I don't know how useful it is when we have knock sensors and widebands. I look at plugs just to make sure the engine is healthy, making sure all the plugs look similar.

 

[My1GLaser]

Thanks for the info. When you say go up one heat range do you mean hotter? As in 7s? I'm running 35-38 psi and 22-23* timing. I have been getting consistent 58-60 lb/min airflow on my new hotside!Yeah it does seem to go really rich before 3k. I need to get that taken care of & recalibrate my WB.

I'm concerned with cyl 1 appearing to run leaner than the rest based on the plug color. Without 4 EGT gauges or something, I don't know how else to determine individual cyl AFR. The WB just gets the combined AFRs, so I'm hoping that looking at the individual plugs will shed some light.

Glad the thread came back around cause I recently had a suspicion about something. I had an issue with pushing coolant about 9 months ago. It pushed between cyl 1&2 on the front coolant passage near head stud 6. The head was warped .002. I got the head decked, hand lapped head and block (block was decked when I rebuilt the motor) installed Fel-pro Permatorque and L19s at 105 ft/lbs with moly lube.

It was running fine until I started turning up the boost again. I spiked to 43 psi and peaked at 60 lb/min this weekend and it pushed coolant again. I assume the same place, since stud 6 was looser than the rest. (I checked them a couple months ago after 4-5 heat cycles and they were fine) I just retorqued them and I'll see if the head warped again and it keeps pushing coolant. (I turned the boost down )

It wasn't knocking, but I had a couple degrees of knock the night before so I know the sensor is working. Plugs look the same as the pics again (no metallic flakes) so I don't think there was detonation. I think cyl 1 is leaner due to SMIM airflow design and inj 1 being the last to get fuel from a single Wally 255HP with 80 psi fuel pressure. Its rewired and I have a Boost a Pump at 15V, but I need another pump ASAP. Maybe the heat/pressure from it being leaner lifted the head again? I didn't think L19s would allow that!!!

 

[Mark L]

I would also pull your injectors to see if you have gunk build up. This can be a source of unbalanced fueling in the cylinders. I've hear of lots of clogged injector complaints when running E85 too.

 

[bastarddsm]

yeah I'd run 7's I run 8's in my car, but I'm running more boost/more flow, and my tune is on the ragged edge.

What intake is on your car? The only one I know of that has really poor air distribution is the old school magnus.

Mark L - I don't know how much I'd trust the knock sensor anyway, that was designed/tuned for lots different than what we are running. Even the E85 has a way different knock signature than 93 so it probably isn't even listening to the right stuff.

I tune my car by power, and check the plugs to make sure it's not knocking.

Oh jeeze I just saw your on a single wally. Your waaay outa fuel. A second inline 255 in series with your intank will get you 550whp, I made 600 on it but it was waaay lean.

 

[My1GLaser]

yeah I'd run 7's I run 8's in my car, but I'm running more boost/more flow, and my tune is on the ragged edge.

What intake is on your car? The only one I know of that has really poor air distribution is the old school magnus.

I tune my car by power, and check the plugs to make sure it's not knocking.

Oh jeeze I just saw your on a single wally. Your waaay outa fuel. A second inline 255 in series with your intank will get you 550whp, I made 600 on it but it was waaay lean.

I have a JMF race SMIM.

What do you look for on the plugs to make sure its not knocking?

I have a Kenne Bell Boost-A-Pump at 15v to keep the pump consistent and running smoother. I'm only running 60% E-85 & 1150s at about 80% IDC. I only went leaner than my AFR tables when I was running 43 psi base FP a few months ago, or when I recently hit 43 psi boost. When I am running 37psi base FP & 35-37 psi boost, I run a consistent 11.8-12.2 AFR with some rich and lean spikes thru the pull. I just recalibrated my WB so I'll see what it reads now. I think cyl 1 is a little fuel starved. I am going to increase DT on that inj for now, but I'm sure the effect will be negligible. I will keep the boost around 33-34 psi until I get an inline pump or a Wally 400.

 

[bastarddsm]

The JMF should be pretty good about even distribution.

On the plugs det will show up as little black specks, looks like pepper on the plugs.

I think even with E60 and 34psi your out a fuel on 1-255. I was running 47psi base, and at 25 it was on the edge with a poor flowing setup.

 

[DSM1G90]

Put them back in and happy driving - they look fine.