How does this look?

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DARTLARRY

DARTLARRY

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I have been tuning this thing of and on this weekend, all 8 plugs look like this. I am not an expert on reading plugs, I was hoping someone could give a clue from looking at this.
 
It is new, with less than 20miles on it. I too thought it may be lean, but like I said I am not sure.
 
What are you using for fuel? Are you putting any additives to your fuel? What spark plug and heat range?

I doubt it’s lean but it’s hard to say without getting a better look at it.

Do yourself a HUGE favor (who deserves a favor more than you???) and get on Amazon and buy yourself a Dr. Mom otoscope. It should be less than 20 bucks.

With that tool you can see fine details and the fuel ring at the bottom of the porcelain.
 
DARTLARRY said:
93 octane no additives, NGK heat range 5, for a 5.9 magnum.
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That plug looks like it’s got more than plenty timing on it. I’d fix that first.

It’s a touch rich at idle and probably transition and cruise. Can’t see WOT.

Are you running a vacuum advance and what is your timing now?
 
DARTLARRY said:
In at 2600, EQ heads with 2.02 valves installed.
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That is in way, Way WAY TOO SOON.

That head only needs 30, maybe 32 total and it doesn’t need anywhere near that at peak torque. Probably 24 at peak torque. Maybe a skosh less.

Unless you have compression less than 9:1 and a huge cam that curve is killing power.

Peak torque is about 1500 RPM less than peak power. So if you are making max power at 6,000 that means peak torque should be no higher than 4500 and it probably first peaks another 500 RPM lower than that.

You need to slow the curve down and get the timing in line with what the engine wants.
 
Easy to say, hard to explain and give specific info.

To me it looks a hair lean. Not something I’d worry a whole lot about. I don’t see the timing mark left behind on the electrode ground.

What carb and jets, etc….

FWIW, I think it’s going pretty good for you so far.
 
it wants more than 22 degrees at idle, more like 26 or 28. I have run as high as 40 degrees total with no pinging. I do agree on the curve needing slowed down, I can add stiffer springs. Carb is an Edelbrock AVS, heavier springs is the only change from stock.
 
DARTLARRY said:
it wants more than 22 degrees at idle, more like 26 or 28. I have run as high as 40 degrees total with no pinging. I do agree on the curve needing slowed down, I can add stiffer springs. Carb is an Edelbrock AVS, heavier springs is the only change from stock.
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Then you have more cam timing than your compression wants.

In that case, you need to band aide it with vacuum advance and hook it to manifold vacuum so it will pull some timing at idle.

What you can’t do is mechanically cram a bunch of initial into it. If you do that you might as well lock it out and you still haven’t given the engine what it wants.

How much compression do you have and what is your seat to seat timing?
 
My next step was to use manifold vacuum to give the engine what it wants. The bottom end is stock 5.9 magnum, with advertised 9:1 compression. Not sure what seat to seat timing is.
 
DARTLARRY said:
My next step was to use manifold vacuum to give the engine what it wants. The bottom end is stock 5.9 magnum, with advertised 9:1 compression. Not sure what seat to seat timing is.
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What cam specs do you have? It makes it easier to try and see what your curve should look like if you know your CR and cam numbers.

I’ve said this before but this kind of work is quicker if you have a distributor machine. It’s even easier and quicker if you can get the engine on a dyno. That’s probably not an option now but it’s something to consider.

It takes more time and work doing it in the car but the best possible scenario is to start with the closest curve you can get for your first test.

Something to consider when using MV to clean up the idle is you can quickly get to the point where you have to delay the start of your mechanical advance by a good margin.

For example, if you need 40 at idle (with MV) and you decide that without the MV you want 20 initial you have to control the advance mechanically to keep the timing where it needs to be.

Let’s say you have 20 initial (no MV) at 1000 RPM. And at 1500 you’ve added another 3 degrees (unless the curve is horribly slow) and by 3000 if you have the curve all in with 35 total you already have more timing at that point than it wants.

Now add the MVA to it. You’ll have 40 degrees at 1000 but what does that give you at 2500???

So when you are thinking about doing this you may want to consider the timing as two separate curved. One mechanical and the other mechanical and MVA and what the curve will look like in both scenarios.

And what you may have to do to get both curves to be happy. The one curve for part throttle and high MV situations and the other when you are at WOT situations without MVA.

The biggest thing IMO is getting the curve correct for not using MVA and then just hooking the MVA up.

But…that means you can’t just drop 40 initial and put MVA on top of it.
 
I just checked it, TDC is good. I was thinking the same as you. I stopped worrying about the numbers on this engine, only using them for reference. I set initial to max RPM, and max vacuum, then back it off to where it doesn't kick back. I find my overall by driving up an incline in first gear, with the RPMs up, If it pings, I back it off. I welded the plates in the distributor to limit the distance between the two, and removed the large spring. I have not recorded the actual curve I have yet.
 
DARTLARRY said:
I just checked it, TDC is good. I was thinking the same as you. I stopped worrying about the numbers on this engine, only using them for reference. I set initial to max RPM, and max vacuum, then back it off to where it doesn't kick back. I find my overall by driving up an incline in first gear, with the RPMs up, If it pings, I back it off. I welded the plates in the distributor to limit the distance between the two, and removed the large spring. I have not recorded the actual curve I have yet.
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At this point your plan sounds the best. Keep at it until it’s happy. That’s what it wants.
 
DARTLARRY said:
I set initial to max RPM, and max vacuum, then back it off to where it doesn't kick back.
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That's why it seems to 'want' so much advance. In neutral it will be happy with a a lean burn and additional time to make the most with that lean burn.
DARTLARRY said:
I find my overall by driving up an incline in first gear, with the RPMs up, If it pings, I back it off.
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First gear is generally a fairly light load. Obviously an incline helps increase that load but it is not equivalent of a heat soaked engine going up a mountain in 3rd gear - which is the scenario a street car needs to handle.
DARTLARRY said:
I welded the plates in the distributor to limit the distance between the two, and removed the large spring.
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The long looped spring is the not very secret sauce for mid to high rpm performance.
DARTLARRY said:
I have not recorded the actual curve I have yet.
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There's been some 5.9 magnum engine timing info posted if you search.
 
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