87 Waggy spark plug engine problem pictures!!

GregGA said:
Cruiser, I use Champion copper. Why do you like NGK? Thanks!
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Champs, FTW! My son tried another brand some years ago in his '95, and it was Mis-firing rather badly, immediately. I'd always read on this site to use Champ coppers, new every 30k. Well, he took my advice, and it was immediately fine! I wouldn't have believed it if I hadn't witnessed it myself! Although, I had a set of Autolite platinums in my '92 for 30k, pulled 'em and they looked great, so I put them back in for another 30k. Next time I pulled them, they looked like brand new, but with 60k on they, they got tossed. I tried them in my Subie, and at about 30k, the both electrodes were GONE! Go figure...
 
cruiser54 said:
What brand spark plugs are you using again?
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Currently, Autolite Single Platinum. I had used Bosch single platinum for 6 years with great results before.
 
Ecomike said:
Currently, Autolite Single Platinum. I had used Bosch single platinum for 6 years with great results before.
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You don't need Platinums. They require more voltage to fire than standard coppers as they are designed for extended interval changes. Your current messed up plugs look like the platinums that bit the dust after 10,000 miles on my propane powered truck. After 10K on the NGKs, the center electrode tips were square, the gap was the same as when installed, and there was no accumulation of that white crap. try them.
 
They did not have the ones you suggested. I got 3 ea of Champion Copper Plus 344 RC9YC AND Bosch copper Super Plus 7927, FR 8 DC+ (made in Mother Russia, LOL) to run some tests for now.
 
I installed the Bosch on Cyl #2, and the Champion on #1.
 
Bosch makes a triple electrode plug that works well in applications prone to fouling (overhead cam motors). I sure don't know if they make the small plugs or for that matter one in your heat range in that configuration. They are expensive though.
 
Since the noticeable missfires showed up once the ground electrodes where thick with scale, it makes me think I need a hotter plug that can keep the ground electrode clean. But the junk on the white ceramic insulator may be stealing electrons when the plug fires as well (thus needing a hotter plug), I suspect more ground electrode volume, 2, 3 or 4 ground electrodes designs may make the problem worse, keeping the ground electrode colder? And thus letting junk build up faster? I have some new pictures of the used plugs I cleaned and reused 300 miles ago, they had trace signs of black oil on them. But I am only using 1 quart oil every 1000-1200 miles (281,000 miles).
No signs of coolant leaking in any way shape or form.

I may need to go grab a low mileage engine's rocker arm parts and replace the worn ones on mine as they seem to wobble too much and sometimes side load the valve stems, and making the new intake valve seals leak a little on the intake stroke? If that does not work I need a hotter than stock spark plug for now, or new valve guides it seems.

I will pull these two plugs after 1 tank of gas, about 250 miles and see what they look like.

It also may be time to replace the fuel injector pig tails on these two cylinders. I have the new ones, the old ones are iffy on the good continuous contact!!!

8Mud said:
Bosch makes a triple electrode plug that works well in applications prone to fouling (overhead cam motors). I sure don't know if they make the small plugs or for that matter one in your heat range in that configuration. They are expensive though.
Click to expand...
 
Ecomike said:
Since the noticeable missfires showed up once the ground electrodes where thick with scale, it makes me think I need a hotter plug that can keep the ground electrode clean. But the junk on the white ceramic insulator may be stealing electrons when the plug fires as well (thus needing a hotter plug), I suspect more ground electrode volume, 2, 3 or 4 ground electrodes designs may make the problem worse, keeping the ground electrode colder? And thus letting junk build up faster? I have some new pictures of the used plugs I cleaned and reused 300 miles ago, they had trace signs of black oil on them. But I am only using 1 quart oil every 1000-1200 miles (281,000 miles).
No signs of coolant leaking in any way shape or form.

I may need to go grab a low mileage engine's rocker arm parts and replace the worn ones on mine as they seem to wobble too much and sometimes side load the valve stems, and making the new intake valve seals leak a little on the intake stroke? If that does not work I need a hotter than stock spark plug for now, or new valve guides it seems.

I will pull these two plugs after 1 tank of gas, about 250 miles and see what they look like.

It also may be time to replace the fuel injector pig tails on these two cylinders. I have the new ones, the old ones are iffy on the good continuous contact!!!
Click to expand...

At one time Bosch recommended the three pole plugs for old school overhead cam motors that tended to leak oil down into the cylinders past the valves. I'm not sure if the newer offerings are designed to be self cleaning or not, they have pretty much cured the oil bypass issues in newer overhead cam motors.

I used them in my old Jeep tornado motor (M 715), they seemed to last a lot longer before they fouled.

http://www.championsparkplugs.com/learning-center/article/225/heat-range-conversion-chart

The higher the number the hotter the plug with Champion.
 
Last edited:
Do you think the 2 extra ground electrodes and the vertical contact points make them more foul resistant? I made need to rethink those?
 
8Mud said:
At one time Bosch recommended the three pole plugs for old school overhead cam motors that tended to leak oil down into the cylinders past the valves. I'm not sure if the newer offerings are designed to be self cleaning or not, they have pretty much cured the oil bypass issues in newer overhead cam motors.

I used them in my old Jeep tornado motor (M 715), they seemed to last a lot longer before they fouled.

http://www.championsparkplugs.com/learning-center/article/225/heat-range-conversion-chart

The higher the number the hotter the plug with Champion.
Click to expand...

The Platinum Bosch plugs I was using were hotter (#8). The Autolite platinums were one step colder (9)!!! The Copper Bosch I just bought is the same heat range as the platimum Bosch was, and the new Champion Copper is the colder heat range same as the Autolite I am having trouble with on the #1 and #2 cylinders.
 
Top plug is #1, bottom is Cyl #2. Hard too see but even after, cleaning #2 with tooth pick tool it had a tick deposit on the insulator making it visibly thicker.

picture.php


picture.php
 
IIRC there is difference in the voltage needed to spark and fire a cylinder as the compression changes from wear or modifications. Any know the details on that?
 
Ecomike said:
IIRC there is difference in the voltage needed to spark and fire a cylinder as the compression changes from wear or modifications. Any know the details on that?
Click to expand...

Mostly rumor, reading and what some people call common knowledge (but is sometimes myth). The higher the compression the higher the voltage needed. Makes sense IMO, the denser the charge the more voltage you need to jump the gap.

Whole books have been write on this and the characteristics of ignition. I spent a lot time with an oscilloscope and studying it (back in the 70's), the end result was basic physics. if it works, no matter what the theory says, it works.
 
So based on that I wonder if the plugs fire too fast or early when compression is at the low end of OEM spec.
I wonder if that timing is significant and if it can be adjusted by changing the gap.

It may be more of an issue on rich mode WOT or lean Decel mode (which bypasses the closed loop mode).

I have been running this rig at heavier throttle and higher RPMs than I use to.

I may be talking myself into digging up a textbook on sparks and flame front propagation theory :-):party:


8Mud said:
Mostly rumor, reading and what some people call common knowledge (but is sometimes myth). The higher the compression the higher the voltage needed. Makes sense IMO, the denser the charge the more voltage you need to jump the gap.

Whole books have been write on this and the characteristics of ignition. I spent a lot time with an oscilloscope and studying it (back in the 70's), the end result was basic physics. if it works, no matter what the theory says, it works.
Click to expand...
 
Nice info find here!!!!! Confirms some of my thoughts and adds a few more.

http://www.briskusa.com/technical-info/spark-plug-diagnosis/

I can see how a dirty air filter, a slightly colder plug (like I was using), and lower compression than a new engine can all add up to rapid plug fouling picture #1
 
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