Hey fellas, trying to tune in a new engine. Looking for opinions on the plug pics. I'm not a plug reading expert, so maybe someone can tell me if these plugs could take more timing. Thanks

Engine; 10:1 Teksid 4.6 2V, TFS heads
13* Timing up top. 11.4-11.5 AFR gas scale
E85 fuel, but was only 73% Ethanol due to some 93 mixed in.
118* IAT temp at 7k rpm @18 psi
NGK BR7EF plugs

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Looks pretty good to me. E85 makes reading plugs difficult because they won't tell you much about your fuel. But your timing looks good there.

 

Yea I thought they looked pretty good. Crazy thing is I built my timing map super conservative, and the plugs look like this right off the bat. Those plugs do have quite a bit of idle and part throttle on them.

I read that looking for color on the base ring is how you read the fuel with Alcohol? I have a full turn of color on them. Is the chart down below about right for target AFRs?

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Here's another one but they are not the same, I found from this site.

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This one

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To see the base ring with e85 you need a fresh plug with a clean pass.
Ive made multiple passes on the same plug at the track with just pit drive back time without to much effect. But any street driving will start throwing the readings off. Especially the fact that timing is higher and light cruise so it effects timing readings on the plug.

It looks pretty good. Id say it could use a bit less timing. But, fresh plug and some track passes to verify what it wants would be the proof.
Looks like have some anti seize on the thread. Keep it to an absolute minimum. Like a itty bitty sckoch every once in awhile.

 

To me they look good. Plug reading is definitely an art. All my plugs look about the same for each cylinder, however some have a very definitive timing mark at the bend of the strap, and some it's kind of hard to see it at all.
So why no or very little anti seize? Makes it hard to see the soot on the top threads?

 

anti seize is well know to cause resistance so the plug doesnt ground to the head well. Shitty ground , shitty spark.

 

Ahh, gotcha. Didn't know that. Thank you...What about the copper anti seize?

 

dont know. Just keep it to a minimum. On iron heads i dont use it. On aluminum it use a dab. I stays on the threads in the head for quite awhile.

 

Alright cool, thanks. Going to wipe the plugs clean next time I have them out. There's more than a liberal amount on them lmao. Thanks again

 

That chart is for drag racers. A modern, high performance 4 valve engine will often make best power NA at 0.9, Idle at 1.0 and make best economy at 1.2.

 

Always shoot for peak rich power on the fuel used first. IMO you don't want a conservative street car to have a timing mark on the bend and you don't want a heat line past the 1st thread. (impossible to see on your plugs. Clean all the sanitize off IMO... esp to read a plug.

You want about half way down the strap. Pull 2* out of it and get another read IMO. MAy be down on power but you can likely add a lb of boost when you drop 2* and make it all back and then some.

Can also step up to a 8 heat range plug. You'll need resisted plug boots. They screw on super easy. Then you have 8-9-10 heat range plugs to work with dirt cheap. E85 won't foul out the plugs, so a hot plug isn't needed. I daily drove on 8's forever. Zero fouling issues. No reason for a hotter plug.

After that's "safe" i'd slowly lean it out and watch MPH or power output on the dyno. You aren't giving up much power ruining it 10.8-11.0. and you may save cylinders, as some usually run leaner than others.

 

We should always talk lambda.

For example 10.8 - 11.0 is cruise mixture on E85 (9.8 is stoich). (Yeah, I know what you meant. We should stop doing it.)

 

The sensor doesn't care what fuel you run... If it's a gas scale sensor it will read on a gas scale. Most sensors do this, so that's what I use. My sensor doesn't display lambda. I'm not aware of any that do.

 

You got your math wrong. 9.76 e85 afr is 1.0 lambda or 14.7 gasoline.
10.8 e85 afr is 1.1 lambda or 16.2 gas afr which is for most engines a lean misfire.
9.27 e85 afr is a nice lean cruise afr.
WOt boost would be in the 7.8 range.

I only play with lambda or gas afr just cuz I dont need a third in the mix to be converting in my head all the time.
Innovate sensors will show lambda, gas, e85 or any scaled stoich you want to use.

 

What math? I said 9.8 was stoich, you said 9.76 is stoich.???

"Most engines". Not sure what sort of engines you work on but best cruise economy on a mild cam, EFI happens at about 1.2 which is even leaner than the 1.1 I suggested. For the DIY tuner 1.0 to 1.1 works fine. The more modified the engine, the richer the cruise will need to be. OTOH if it has a 3 way cat and no air-pump, it will need to be 1.0. For the last 50 years, the vast majority of cars came from the factory running 1.0 at cruise and would be more economical if they were leaner.

16:1 is what engines used to run before cats appeared. Things like Chrysler ELB (carburettor) were even leaner (17 - 18:1). Engines need a lot of spark advance to cruise that lean.

 

I got ya.
10.8 is super lean on e85 though. Ive never been able to get any motor on e85 to cruise that lean without some type of surge , even with a bunch of timing. On carbs thats even harder to have the transition circuit that lean and still get the accel pumps to cover the afr change. Gasoline, not so tuff.

 

I think you will want the timing mark "strap" farther from the threads. I would pull 2* of timing and see if it moves as was mentioned already.

For fuel, leaner isn't meaner. You need more fuel in there than necessary so oxygen molecules can rapidly find partners during the critical rod angle ratios (much after TDC approaching 45* to 90*~). I think gasoline scale 10.8:1 is desirable for majority of LSx applications after say 12 to 15psi, at least in my experience

 

Yes. That is the anti seize to use as it is conductive.