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Spark Plug read please

Keeper

Keeper

Active Member
I know this is a touchy subject around here....lol

But I am in the process of doing some changes and was curious what folks thought about these plugs.

These are AC Delco #2's gapped to .45 using HEI distrib with stock coil, nothing fancy. 882 heads if anyone is curious.

Here is a shot of all 8. 1 cylinder being the upper left.

15%20aug%202014%20003.JPG_595.jpg


As you can see they are all the same color, with no visible oil. Threads are a bit dark due to the anti seize, it wipes off and they are clean under.

Some close ups:

15%20aug%202014%20004.JPG_595.jpg


15%20aug%202014%20006.JPG_595.jpg


I am pretty sure I am running a bit rich, but with the upcoming carb change I am not planning on tweaking this carb. I am in the process of rebuilding a Holley 390 to replace the 600.

Is this plug a bit cold for my engine? Everything I see seems to suggest that it might be, but I would like some expert opinions.

I do understand that these were not run strictly for a plug test and that they may be tainted. But I thought I would ask anyway.

You know we need some more drama around here....hahahahahaha.
 
This is going to be a long one. I wish I could say that under different circumstances. Back to the real question.
Those plugs do have some color, but not fouled. I would guess on the rich side, even if a lot of low speed running and idling are the case. They look orange to me. Are you adding an octane booster? I cannot think of the name, but one of them does that. No known issues. If you are turning a lot of cruise rpm the heat range may be close enough. If you idle and cruise at 2K or less, I would not be afraid to try a step hotter.
On tuning the rich/lean by reading the plugs, it is much more involved than what is available here. With today's gasoline, they say plug readings are difficult to get. After following the proper procedures, readers look for a color or carbon ring around the taper of the insulator. The rings location on the porcelain is used determine where you are on the a/f ratio.
I do not think you need to get that deep into your adjustments. With no choke issues, timing right, both float levels right, I would put in one size smaller primary jet and use the same plug to see where I am going. Even simpler, you could put in one step hotter plug and not touch the carb, unless some of the previous listings are not right. One change at a time!!! Let us know what and how you are doing. I need an ego boost.
 
Thanks.

No Octane boost, I try to only run the 94 Octane up here as it has no ethanol, but probably has other crap in it.

My cruise at 65-70 is right around 1800RPM, but most trips are across town to local cruises.

I was planning on putting them back in and running them with the new carb, that I should have done today, but I am holding off on swapping that, as I am swapping the rocker arms first to get away from the super noisy "roller tipped" rocker arms.

Carb will most likely be swapped next week, once I make sure the rockers are happy. One at a time!
 
Put old plugs back in until you get ready for the new carb and rockers and after all adjustments are made. then put new plugs in and read at some future point in time. No need to foul the new plugs before you are finished with changing things around. I personally would wait on the rockers until I got the A/F ratio adjusted. One change at a time until you have what you are looking for---that way you know what FIXED the problem and what caused it. IMHO which aint much these days.
 
True. I am more curious then worried. I have had plans for the rocker and carb change for a while, just never had the time to do them.

As for the plugs, again, more curious as I know things will change with the carb swap.

These rockers are just to damn noisy. I do not have guide plates and screw in studs for the rockers, Comp Cams said since I have the 882's with the small slot I really don't need them, but I would rather be safe them have a stud pull out due to me being stupid/lazy/cheap.
 
Do it right the first time for you will never have the time to do it again/ and be satisfied with it.
 
When a plug gets that much run time on it, it gets pretty tough to look at it and get any real sense of what is happening. Sure, if one hole happened to be eating water, you would have one plug that would look really clean. If one hole had a broken oil ring, it would be wet with oil. But with so many miles, trying to fine-tune with a plug reading is just impossible.

Your plugs are all dry and uniform in color, so there is no apparent engine damage. Beyond that, they are too far gone to be read for tuning purposes.

When you get ready for a new set of plugs, go find a lonely, long, straight stretch of road. Swap in the new plugs, start the motor and as soon as it has oil pressure, stand on it and let it eat for a mile, or two. Stick the trans in neutral and cut the ignition. Now, take those new plugs back out and look at them. But don't trick yourself into believing the end of the plug is all you are looking at. What we are looking for is evidence of how much heat the plug is seeing, so the outer part of the shell and the ground strap are what you want to focus on, first.

Look at the plug shell. How many threads are showing heat? On a street driver, you will likely want heat showing on about 3 threads, but no more than 4 threads.

With a magnifying light, look down into the plug. Do you see any pepper spots, or shiny spots looking back at you? The area near the tip of the center electrode might be showing some black coloration, if you let it idle too long. The next bit of area will show coloration for part throttle, but it is deep inside the plug that you are wanting to look at, because if things are close, combustion chamber heat will have cleaned the other areas off. This coloration is the fuel ring, and depending on the fuel, and/or additives you are using in the fuel, it will vary in color. With so short a time, look closely at the shell, directly under the ground strap, which is where the ring will start to form. With pump gas, the ring will take on a dark-gray to charcoal appearance. If you see any pepper spotting on the shell, then you know that hole is trying to detonate. Take out a touch of timing, or add one step of main jet. If you see any shiny, metallic spots, get some timing out and some more fuel in, as it is trying to burn a piston.

Look at the ground strap. Where is the heat line on the electrode? Is it beyond the bend, near the plug shell, or is it out near the end? The line should be just back, beyond the bend and above the weld. If there is no line, then you need to knock some timing out of it. On a street driver, I would want the line to be slightly closer to the bend, than to the weld.

Those are the things that will tell you whether or not the motor is happy, with respect to A/F ratio and timing.

If the porcelain is showing color, but the ground strap is not, then you might want to consider a slightly hotter plug.

Inversely, if the porcelain is clean, but the ground strap is showing you a lot of color, then it is time for a slightly colder plug.

Remember, much more than a few seconds of idle time will wildly skew the ability to read the plug. And idle conditions are not what you are interested in, anyway.

Wow, replacing a set of roller-tip rockers? Aren't those things worth like 87 horsepower, or something? :giggle: Won't you, like, need a high-torque starter, to turn the engine with all that additional friction? You'll probably need a second radiator, to use as an oil cooler, too. Here, can I get you another glass of Kool-Aid? :roflmao:
 
Thanks Mike. I kind of figured they may be to far gone for a good reading, but I was more looking for an overall "Things look okay".

I do not get a chance for many full throttle blast around here, any sort of "Display of speed/power" labels you as a "Street racer" which comes with an immediate seizure of your car for 7 days, a license suspension for at least 7 days and up to a $10,000 fine. Caught doing 50km over the speed limit, you must be a street racer and you get the same treatment. We have had 80YO ladies charged under this, its a pretty screwed up law....I will stop now as I am about to get rather political....lol

HAHAHAHA The roller tips came due to them being on sale and the stock rockers having to be shipped in from the US at twice the cost. I recently picked up a set of Howard cams rocker arms, nice units and they are much less ticky them the rollers. I ran them last night to one of the local cruises, I am happy with them.
 
Screaming Metal said:
---Stamped steel rockers should only be used on engines with less than .600? of valve lift and at engine speeds below 6,500 rpm. Higher lifts or engine speeds require upgrading to some type of performance rocker (aluminum or steel)---
Click to expand...
What that fails to point out is the real reasoning behind the statement. An engine using .600 lift, and revving over 6.500 is going to require (wait for it) heavier valve spring loads, which get beyond the scope of a stamped steel rocker. It's not the lift, it's not the duration, and it's not the RPM level, it is only the additional valve spring loads that are required to control the valvetrain when those parameters come into play.
 
Yea Mike, everyone wants to overcam everything. Back in the dirttrack, we'd run about .750 to .800 lift. Have to have spring pressures upwards of 500 lbs to keep the lifters in touch with the cam lobes....running rev kits.
ProStock runs upwards of .900 lift....with big journal cams to stiffen things to stand all that spring pressure....

The 350 Horse 327's had good flowing heads, a pretty rad. solid lifter cam, a good intake manifold with a Holley carb. They had to spin that motor on up there to get that 350 horses; 8500 rpms were commonplace. They could reliably go to 9500-9800 with a little here and a little there.
Morale of the story, those motors spun to 4500 to 5000 as easily as the modern motors go to 2200 rpms.
These motors did it with stock rocker arms solid lifter cams w/.530 to .550 lift, CR at about 11.75 to 1 and you had to run premium....on a single 4bbl or a 2x4 setup or a 3x2 setup....
My, how things have changed.....
You would've been shot in your tracks for even thinking about putting E85 into such a beast....besides, it would've ran like shit anyway....
 
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