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Bent Spark plug electrode

34K views 34 replies 13 participants last post by  Plowman  
#1 ·
So after running poorly at the track and limping home I got around to draining the oil and pulling the plugs. 3 or 4 (i really dont remember) of the plugs electrodes were bent off to one side and up against the point.

Question: What causes this? Wouldn't it have happened to all of them if they were too long and causing the piston to contact them? Could it be heat? This would explain why the car wouldnt start again.

Im a bit worried about the pistons now and I just completed this motor last winter.
 
Discussion starter · #3 ·
No i've been driving the car around on small errands and just to cruise around the city. Took it out to the track for a test and tune. Made 2 runs and the 2nd run it started smoking really bad and it sounded like something wasnt right, so i limped it home and there its sat for the past 2-3 weeks. The oil smells burnt, i haven't pulled and cut the oil filter yet im waiting until i get some more money to go buy oil, spark plugs, and filter. Little strapped for cash this month.

Im thinking i would have heard metal to metal a lot more if it was constantly hitting the electrodes. Im betting that i can throw some plugs back in and new oil and it should start and run fine. Ill have to borrow a compression tester and see where im at.
 
Discussion starter · #8 ·
somethings here we are missing, .. piston type?( cast forged) dome or FT, head type I ron/aluminum, and plug type, and plug reach,
Pistons are Hypers and dome. Heads are Iron, plugs are champion (i forgot the specs). I think they are long reach.

Ill have to go to autozone and borrow a compression tester see if maybe they have a scope?

Im not surprised i didnt hear anything wrong especially at WOT and with my helmet on and windows up.
I have a fuzzy picture of 1 of the plugs on my phone, ill try and get it uploaded here soon or later tonight ill take some better pix with the wifes camera.
 
Discussion starter · #10 ·


Uploaded with ImageShack.us

You're right Paul, I should hold off on mashing down the 'Go pedal' because of the funds situation. At the time I was going fast I had some extra money, it has since been used :p

It doesnt look like the plugs were contacted by the piston, it would show damage to the grounding electrode, they just look bent and dirty.
 
Discussion starter · #14 ·
I apologize i was wrong, they are Bosch platinum HR9APX
Here's a better picture of one of the other plugs that wasn't as bent as badly as the other.



Uploaded with ImageShack.us


After close inspection of them it doesnt look like they came in contact with anything, its most likely heat related. I straightened one out and with such a small amount of force i was able to tear up the electrode pretty easily, making me think if a piston taped them it would show on the electrode yah?

Ah crude these pictures are so small. Here's a link to a larger picture. http://img691.imageshack.us/img691/8613/picture17193.jpg
 
Discussion starter · #22 ·
My intake gasket, between where the block and intake meet by the firewall, had a hole develop and i was leaking oil down the bell housing and it was hitting the exhaust and burning off. Also one of my valve breathers had oil coming out and hitting the exhaust as well. The smoke was coming from the engine bay and not the exhaust.
 
Discussion starter · #26 ·
no mine dont look like that, im getting pretty optimistic that there's no damage, just the fact that i was only running on a few cylinders was why the car seemed to be running so poorly. Ill find out for sure in the coming weeks tho :yes:
 
Discussion starter · #29 ·
Update - Sorry its been so long I've been catching up and trying to pay off some debts so even something as simple as buying spark plugs/oil/filter/etc just had to wait because that money could go to paying things off. Anyway...

Changed the oil, filter, put in new plugs and fired it up. Runs pretty O.k. but it is smoking from drivers side air breather. I need to reset my timing again the the motor really only ran for maybe 5-10 minutes at around 900-1600 rpm maybe a little more when i bumped the throttle a few times but i doubt it went up past 2200rpm. Pistons and rings probably have some oil and garbage on them from when the plugs weren't working correctly so everything needs to burn off and re-seat? I'm not spitting oil anywhere and not noticing any excess smoke from the exhaust so I highly doubt there is ring or piston damage. (Think ill need to buy or borrow a compression tester to be sure)
Have some coolant leaks to deal with from plugging the bypass hose - didn't have enough ARP thread sealer to really do the job - need to purchase my half shroud still for the mechanical fan, rebuild/helicoil my carburetor because the metering plates aren't getting a very good seal onto the carb. The bolts don't go in very far and striped out some of the threads so I'm constantly re tightening/fighting leaks on the outside...can only imagine that fuel is by passing in the carb and just dumping into the intake...:eek:
Need to go through and do some minor valve lash adjustments-I noticed today that i could spin the push-rods when I had the valve covers off. Not really loose as a goose but with hardly any effort they spin.

I also need to buy new rear tires as my passenger side M/T E/T streets now has a huge wear patch like i came to a screeching halt...it just leaks air out of the tire pretty bad so...$500 later and ill have new rear tires. Thinking of getting a detroit locker or maybe air locker and ditching the spool, its not worth going through tires this fast anymore. Car probably wont see the road again until next spring.

At least it starts now though!! :yes: