[Blued and Painted]

I've seen plugs come out of the box like that.

[JSPONT]

Had a problem like that with the last motor. I bought a scope camera from Harbor freight, went down the spark plug hole and looked at the piston and head. I my case I had a broken piston piece that closed the gap on the plug. It is worth checking it out for the $ 50 I spent with the coupon.

[unruhjonny]

you can get bore scopes super cheap these days...
some of them work with your smartphone (making the smartphone the screen).

[steve25]

Is the car kept/ stored on your property where otters have access to it?
A friend two years ago who stores with others at a big garage had a strange sound coming from under the Hood one day while driving only, and went nuts trying to figure out what was going on only to find that a buddy that stored at that same garage had cable tied a Harmonica to the radiator support in the nose of the car. Lol!!!!

[AdamIsAdam]

Originally Posted by steve25

Is the car kept/ stored on your property where otters have access to it?
A friend two years ago who stores with others at a big garage had a strange sound coming from under the Hood one day while driving only, and went nuts trying to figure out what was going on only to find that a buddy that stored at that same garage had cable tied a Harmonica to the radiator support in the nose of the car. Lol!!!!

That's hysterical! Ingenious. Downright evil!

[steve25]

I know , I still to this day near wet myself when I think about it!!!

[track73]

On our crate motor stock car, a crew member took off the air box and unbeknown to us a few small pebbles fell into the intake. During hot laps the driver noticed a miss. We checked the headers and found the coolest one. We checked the sparkplug and the electrode was grouned out. Regapped the plug and won the feature race.

[HWYSTR455]

Stuff falling into the cyls is fairly unlikely, especially the whole bank. If that much 'stuff' fell off the carb, like as in carb parts, I doubt it would run at all. Like what kind of parts would distribute among all cyls on one side?

Valves move pretty fast, would think that they would be damaged from foreign debris.

I'd have to guess that the plugs were either installed that way, or carbon chunks did it. Maybe that side leaned out, loosened some carbon in the chamber, and made contact with the electrodes. That could happen and not cause perm damage to valve, etc.

.

[ambmech1]

Originally Posted by HWYSTR455

Stuff falling into the cyls is fairly unlikely, especially the whole bank. If that much 'stuff' fell off the carb, like as in carb parts, I doubt it would run at all. Like what kind of parts would distribute among all cyls on one side?

Valves move pretty fast, would think that they would be damaged from foreign debris.

I'd have to guess that the plugs were either installed that way, or carbon chunks did it. Maybe that side leaned out, loosened some carbon in the chamber, and made contact with the electrodes. That could happen and not cause perm damage to valve, etc.

.

Thanks, it wasn't one bank. It was both sides but 1 plane of the intake manifold. That's why I keep thinking a mixture problem. Plugs have been in for over 2 years. Maybe 7500 miles. Car ran great up until this problem. Once I replaced the plugs the car ran great again. Still pulls hard and idles fine. I've got maybe 10 miles on these plugs then I put it away for the winter. No mechanical damage to the end of the plug.
Baffling.

[harley3296]

You're having detonation issues, the detonation cracked piston rings and Bends spark plug electrodes. What kind of heads do you have ? What is the compression ratio and what's the exact configuration of your cam. I've had a spark plug bend on me once but then the engine blew up as well after that, meaning some of the piston rings cracked

[ambmech1]

This is what I was afraid of. The heads are 13s and the cam is:

[harley3296]

Just run 94 octane if you can, do a compression test and a leak down test to monitor your combustion Chamber and rings. .. add a little octane booster to be on the safe side and don't run too much spark Advance somewhere around 32 to 34. Don't run any vacuum advance, pull that vacuum hose off and cap it. Just run strictly mechanical.

[70 bird]

You might have sucked up a mouse or rats nest, enough crap to bend a ground strap but not enough to damage the engine.

[alloy indian]

You'd be surprised what can take place in an engine when spinning at high RPMs. I had my blower motor lean out at the top of third gear one night. It melted just one piston but pieces of that melted piston was in bedded in every piston on the right bank of the engine. That manifold is divided side to side with a ramp in the center. So at 6500 RPM pieces of that one piston made it's way into three other cylinders! The valves were untouched it must be some weird reversions going on for that to happen with boost pushing back at it. You may have had something fall into that side of the manifold and at certain Rpm's reversion did the rest. If it wasn't metal you would never hear it.

[Keith Seymore]

Check to make sure the center electrodes are not broken.

We had a Champion plug one time that would gradually lose the gap and cause a miss. After a couple iterations we finally replaced it and set it in the "broken parts display".

I was messing around with it one day and noticed you could push the electrode down (as if you were gapping it) and it would stay there for a little while, gradually working it's way back up until it hit the side electrode. It was like it had a little spring inside there.

I still have it. I was tempted to cut it up to see what was going on with it but decided I'd rather have it as a discussion piece.

K

[92GTA]

Originally Posted by Keith Seymore

I was messing around with it one day and noticed you could push the electrode down (as if you were gapping it) and it would stay there for a little while, gradually working it's way back up until it hit the side electrode. It was like it had a little spring inside there.

That's one the craziest things I've every heard, wow

[STEELCITYFIREBIRD]

Any updates?





http://race-1.com/p-26201-what-shoul...ug-gap-be.html

[ambmech1]

Nothing yet. Weather is still not conducive to enjoying classic cars. Hopefully in the next few weeks I can get back to it. It's 18* with 30 mph winds at the moment. Hi of 16* tomorrow.

[STEELCITYFIREBIRD]

I feel it here too!

This one has me wondering. Saw the link I provided and your issue came to mind.