Increasing plug gap fixed my issues!

[VadersV6]

When i first got the car, it would idle worth a crap. Died all the time and ran terrible. I fixed just about everything you can imagine. The idle was far better than it was, but it would still idle very rough after it warmed up and was never smooth by any measure. I also had an intake popping issue from day 1. You name it, and Ive probably fixed or replaced or adjusted it.
Yesterday for kicks, I did the unthinkable, and gapped my plugs to .040.
My engine idles like a stock Honda now. Smooth as silk. While driving, it accelerates sooo smoothly and my wife even asked me if I had done something to make the car faster. I was barely giving it any gas at all...just cruising. But it was so much smoother that it felt "faster" to her, and even to me. The WOT popping is practically gone.
Ive used platinum, copper, and the ones that have been in it for 9 months or so are autolite double platinum's. Ive had them gapped at .030. Ive tried from .025 to .035 between all the different plugs. It always ran the same.
Im almost tempted to open the gap even more and see what happens. I thought for sure I would be getting spark blowout, but I'm not. Im astounded with how damn smooth this engine idles and runs now.
It might be worth it for some of you guys to go against the grain and do a little experiment, and see if this helps you at all too. It may not work as well with a higher resistance plug like a regular copper one. These double platinums have less than half the resistance of the copper ones I had before.

 

[Roger]

Platinum runs hotter than copper & will cause more knock retard. I have a set of iridiums I haven't put in yet & am interested in how they'll work.

 

[karst#9]

Plug gap

You must be running low boost because at higher boost levels above 23 PSI I've tried different kinds of plugs and 40 gap will not work.

 

[bruce]

When i first got the car, it would idle worth a crap. Died all the time and ran terrible. I fixed just about everything you can imagine. The idle was far better than it was, but it would still idle very rough after it warmed up and was never smooth by any measure. I also had an intake popping issue from day 1. You name it, and Ive probably fixed or replaced or adjusted it.
Yesterday for kicks, I did the unthinkable, and gapped my plugs to .040.
My engine idles like a stock Honda now. Smooth as silk. While driving, it accelerates sooo smoothly and my wife even asked me if I had done something to make the car faster. I was barely giving it any gas at all...just cruising. But it was so much smoother that it felt "faster" to her, and even to me. The WOT popping is practically gone.
Ive used platinum, copper, and the ones that have been in it for 9 months or so are autolite double platinum's. Ive had them gapped at .030. Ive tried from .025 to .035 between all the different plugs. It always ran the same.
Im almost tempted to open the gap even more and see what happens. I thought for sure I would be getting spark blowout, but I'm not. Im astounded with how damn smooth this engine idles and runs now.
It might be worth it for some of you guys to go against the grain and do a little experiment, and see if this helps you at all too. It may not work as well with a higher resistance plug like a regular copper one. These double platinums have less than half the resistance of the copper ones I had before.

Increasing the plug gap increases the intial firing voltage at the plug. The larger the gap the higher the voltage has to be to fire the plug.

Dunno about *blow out*, but what can happen is that as you raise the min firing voltage you can reduce the reserve firing voltage to a level low enough that the ionization path is poor enough that the spark guality gets so bad as to not cascade the reaction in the chamber properly.

Also, as you increase the gap you increase the intial flame kernel, and that in effect is like increasing the timing, and can lead to detonation. As you get past .045, and more you can effectively adding 2-3d timing, BTDT.

Experimentation is a good thing, just tossing some of what I've found to be true out there.

BTW, using an ohm meter across the center electrode can be interesting in and off itself.....

 

[VadersV6]

This morning the car pulled harder than it ever has. Somehow it hooked and pulled like a damn jet. Now Im gunna spend the next year chasing that feeling, and god knows the car will never run that strong again.
Right now Im running about 18psi with 25 degrees timing. This is without alky and 91 pump gas. Im getting very little KR, if any, and these plugs are the stock heat range believe it or not. I run 22-23psi with the ALKY running.
But what bugs me is the popcorn sound. It sounds EXACTLY like detonation on all 6 cylinders, but as if its outside the motor. Like the marbles, but outside...like its popping through the intake tube. Its the same frequency and pattern as the sound of detonation, but ALOT louder. My knock sensor works, and this popcorn sound has no impact on the behavior of the knock sensor and KR. I can have major popcorn sound, but no KR. It seems totally independant. Its been killing me for a long time to figure out what this is. With the Alky running and everything tuned right, that sound is still there.
Ive heard of plenty of people who have had this, but no one ever really figured out what it is.

 

[bruce]

This morning the car pulled harder than it ever has. Somehow it hooked and pulled like a damn jet. Now Im gunna spend the next year chasing that feeling, and god knows the car will never run that strong again.
Right now Im running about 18psi with 25 degrees timing. This is without alky and 91 pump gas. Im getting very little KR, if any, and these plugs are the stock heat range believe it or not. I run 22-23psi with the ALKY running.
But what bugs me is the popcorn sound. It sounds EXACTLY like detonation on all 6 cylinders, but as if its outside the motor. Like the marbles, but outside...like its popping through the intake tube. Its the same frequency and pattern as the sound of detonation, but ALOT louder. My knock sensor works, and this popcorn sound has no impact on the behavior of the knock sensor and KR. I can have major popcorn sound, but no KR. It seems totally independant. Its been killing me for a long time to figure out what this is. With the Alky running and everything tuned right, that sound is still there.
Ive heard of plenty of people who have had this, but no one ever really figured out what it is.

A knock sensor listens for detonation. And detonation only.....

Preignition, is just as distructive as detonation and the kncok sensor it completely and totally deaf in hearing pre-ignition.

Look at the plugs, and be SUREEEEEEEEEEEEEEEEEE there are no little black, gray, or silver specks on them, they're just slightly larger then microscopic!!.

While you might have hit a good batch of gasoline, something else is going on, be very, very careful about 25d on pump gas....

You don't want to be figuring out the noise by taking the heads off, and seeing the perimeters of the piston domes, are missing.

 

[Pronto]

Popcorn sounds think of your pistons being shot with a million little bbs.

 

[VadersV6]

Yeah its been there all along. And its even there, with the same intensity, with Alky spraying at 10 and O2's in the 850's. I figured, if its detonation, how in the world could it be making the same amount of noise with alky spraying? I will hit the primer button with the engine idling, and it will bog down and stall. So I know its spraying, and the level drops at a normal rate.
As far as pre-ignition goes, whats the difference? Pre-ignition, pinging, detonation, knock are one and the same as far as Ive always thought. How could the knock sensor be deaf to "pre-ignition"? This is the first time Ive ever heard of there being a difference between the 2. I just always thought its the same thing...such different levels of intensity. Are you just saying that with too much advance, the combustion is happening with full intensity too early as a result of the plug firing, as opposed to detonation being a milder form of pre-ignition brought on by glow points in the chamber and low octane?...firing from dieseling as opposed to the spark? How in the world could they have made a knock sensor that is deaf to the most destructive form of detonation?
Ive always read plugs to see whats really going on in any motor, and I saw no signs of detonation on the porcelain. No specks anywhere. Ive always been able to see signs of it without the use of a microscope, cause the bits of metal tend to clump together.
Only thing I saw was a rich condition on the flat ring where the ground electrode is welded. (the true place to read a plug). Although #6 looked MUCH leaner than the other cylinders. Weird because #5 looked just as rich as the others. Its supposed to be the back 2 cylinders that run lean. Not just 1.
Now Ive heard detonation a million times, and this never struck me as detonation. Its LOUD! Any detonation that loud would have to have killed my motor by now. The thing pulls like gangbusters too. Ive put over 20,000 miles on my car in the past year, and have jumped on it many many times. Good thing I never stay in it for more than 2nd gear and a little bit of 3rd.
If this is indeed some violent loud form of detonation, Im absolutely shocked my motor runs fine and the compression is good (at least it was 9 months ago, lol).
Jesus Christ you guys have me worried. I'm going to pull as much timing out as I can and see what happens. I think the lowest I can get it is 19 degrees? The extender chip supposedly comes with 2 degrees additional advance, but they're not making it clear if thats 2 more degrees than their advertised 23 degrees, (25) or if the 23 degrees is the number WITH that additional 2 degrees. So if I take the parameter down to 0, what will the timing be? Will it be 19 degrees, or 21?

 

[bruce]

As far as pre-ignition goes, whats the difference? Pre-ignition, pinging, detonation, knock are one and the same as far as Ive always thought.

It's completely different! !....

While detonation can at times lead to pre-ignition, pre-ignition, *CAN* be more damaging then detonation. Both are abnormal combustion events.

While some like to lump the two together they're not the *same thing*

Here's a short text about them.
There are entire books on combustion, and the combustion process, but here's an easy read..

http://www.contactmagazine.com/Issue54/EngineBasics.html

 

[VadersV6]

So many years working on engines, and just when you think you understand most things about an engine, you find that something you always "knew" turns out to be wrong. Ive always thought of detonation as pre-ignition...the gas becomes unstable, and some hot spot in the chamber induces combustion before the plug fires....or too much advance with a fast burn chamber and the pressure spikes far too quickly before the piston has even reached TDC.
Detonation occurs AFTER the plug fires and combustion has been initiated normally...after being so sure about so many things engine related (not with everything, but alot about engines), its pretty embarrasing to admit that I never knew of the gas at the end of the chamber which ignites abnormally, and causes 2 simultaneous combustion events to occur which collide.
Well anyway, according to this, pre-ignition likes to start at BDC. he's saying that you dont/cant even hear this happening, and it will destroy your motor before you can blink. Electrodes melted out, holes in pistons, etc. There is no warning at all. When combustion happens that early and the motor is working against the expanding gases, you will obviously make NO power. My car pulls strong.
Here's the thing. My electrodes look beautiful. pre-ignition will melt them in a heartbeat. Long term detonation (not even a big deal according to this guy) will break up the tiny particles of the piston and will gradually embed themselves in the porcelain. I dont have either. No specks. The plugs look fine everywhere. The center electrode and ground electrodes look great after 8 -9 months. I checked the gap before opening them up, and no gap erosion had occured whatsoever.
You cant hear pre-ignition according to this guy. Whatever is happening to my motor, its LOUD, and it will stay there as long as Im in boost. Even if Im as low as 10psi, the sound is there. With Alky spraying, its there. Imagine if they made an automatic BB gun that shot 40 BB's a second. Open fire on a plywood board. Shut the sound of the BB gun firing out of your mind, and just imagine the sound of the BB's pelting the board. This is what it sounds like. Not like the classic tink tink tink of marbles inside a motor..a sound that is greatly muffled by the block. This sounds like a crackling spraying noise. Like a few crank degrees of every combustion event is bleeding into the intake tube. Maybe its coming out of the exhaust, but the sound just doesnt come from there.
Im going to pull all the timing I can out of the chip. Im going to richen it up, and drop boost even more. but I doubt the sound is going to go away.
Thanks for your help, and that link. I bookmarked it cause its a good one.

 

[bruce]

So many years working on engines, and just when you think you understand most things about an engine, you find that something you always "knew" turns out to be wrong. Ive always thought of detonation as pre-ignition...the gas becomes unstable, and some hot spot in the chamber induces combustion before the plug fires....or too much advance with a fast burn chamber and the pressure spikes far too quickly before the piston has even reached TDC.
Detonation occurs AFTER the plug fires and combustion has been initiated normally...after being so sure about so many things engine related (not with everything, but alot about engines), its pretty embarrasing to admit that I never knew of the gas at the end of the chamber which ignites abnormally, and causes 2 simultaneous combustion events to occur which collide.
Well anyway, according to this, pre-ignition likes to start at BDC. he's saying that you dont/cant even hear this happening, and it will destroy your motor before you can blink. Electrodes melted out, holes in pistons, etc. There is no warning at all. When combustion happens that early and the motor is working against the expanding gases, you will obviously make NO power. My car pulls strong.
Here's the thing. My electrodes look beautiful. pre-ignition will melt them in a heartbeat. Long term detonation (not even a big deal according to this guy) will break up the tiny particles of the piston and will gradually embed themselves in the porcelain. I dont have either. No specks. The plugs look fine everywhere. The center electrode and ground electrodes look great after 8 -9 months. I checked the gap before opening them up, and no gap erosion had occured whatsoever.
You cant hear pre-ignition according to this guy. Whatever is happening to my motor, its LOUD, and it will stay there as long as Im in boost. Even if Im as low as 10psi, the sound is there. With Alky spraying, its there. Imagine if they made an automatic BB gun that shot 40 BB's a second. Open fire on a plywood board. Shut the sound of the BB gun firing out of your mind, and just imagine the sound of the BB's pelting the board. This is what it sounds like. Not like the classic tink tink tink of marbles inside a motor..a sound that is greatly muffled by the block. This sounds like a crackling spraying noise. Like a few crank degrees of every combustion event is bleeding into the intake tube. Maybe its coming out of the exhaust, but the sound just doesnt come from there.
Im going to pull all the timing I can out of the chip. Im going to richen it up, and drop boost even more. but I doubt the sound is going to go away.
Thanks for your help, and that link. I bookmarked it cause its a good one.

As I said, his is but one view!.
Pre-ignition can very. It's not always an instant kiss of death.
Not to mention you can have both occuring at the same time. Again, a K/S is looking for a particular range of sounds, and a given volume. *You* can add enough fuel to alter the acoustic signature of the enigne to where a K/S misses it.

Rich, may make it worse. This is where having an EGT, and WB *can* be so useful. Still they are not absolutes, but the more diagnostic *stuff* you can apply the more accurate your analysis will be.

Learning is an on going process.

 

[VadersV6]

Regardless of the possibility of pre-ignition instantly smoking your engine or not, the signs *will* show themselves on the plugs. Especially after 9 months of driving 70 miles every day, and jumping on it about 10 times a week. The plugs are pristine. They look like they have 1000 miles on them. Detonation/pre-ignition are both destructive, and the plugs are usually the weak link in a combustion chamber.

 

[HellOnWheels]

Have you checked for an exhaust leak?

 

[Quick6'n'-K.C.]

Sounds like its lean on pump gas and rich on alky, find the happy medium between the two and tune for no popcorn sounds...
BW

 

[Buzzard]

I would do a leak down test on the engine to see if you have blown a headgasket. I have seen a head gasket blow to the outside and you can hear a fluttering or popping noise under boost.

 

[Ttype6]

But what bugs me is the popcorn sound. It sounds EXACTLY like detonation on all 6 cylinders, but as if its outside the motor.

Head Gaskets. Empty your coolant overflow tank and make the motor pop real good. If this puts coolant in the tank,you have blown gaskets.The sound you describe sounds exactly like what I would describe what I heard just before my gaskets blew three times.

 

[bruce]

Regardless of the possibility of pre-ignition instantly smoking your engine or not, the signs *will* show themselves on the plugs. Especially after 9 months of driving 70 miles every day, and jumping on it about 10 times a week. The plugs are pristine. They look like they have 1000 miles on them. Detonation/pre-ignition are both destructive, and the plugs are usually the weak link in a combustion chamber.

Just forget I said anything.
Now you're starting to cross talk the conversation.

 

[Pronto]

When did this popping sound start?

 

[VadersV6]

When did this popping sound start?

Oh, about a year ago...driving 70 miles a day every day. Boosting every day. Thats why Im not sold on head gaskets. its possible, but to go a year, driving that much, and to show no other signs of a blown head gasket is no fluke.
I'll find some time to do that test with the overflow tank. The level in that tank does eventually drop down over the course of a few months, but who's to say thats not evaporation?
I'm 90% sure this sound is coming through my intake tube. It accompanies the suction sound through the air filter with the same intensity. That tube has always been a loud MF.
Last night I dropped boost down to 16 or so, and pulled as much timing out as I could. The sound is still there.
Someone said im lean on fuel and rich on alky. I'm not running alky right now. It doesnt matter what I run.

 

[HellOnWheels]

Oh, about a year ago...driving 70 miles a day every day. Boosting every day. Thats why Im not sold on head gaskets. its possible, but to go a year, driving that much, and to show no other signs of a blown head gasket is no fluke.
I'll find some time to do that test with the overflow tank. The level in that tank does eventually drop down over the course of a few months, but who's to say thats not evaporation?
I'm 90% sure this sound is coming through my intake tube. It accompanies the suction sound through the air filter with the same intensity. That tube has always been a loud MF.
Last night I dropped boost down to 16 or so, and pulled as much timing out as I could. The sound is still there.
Someone said im lean on fuel and rich on alky. I'm not running alky right now. It doesnt matter what I run.

Something somehow get into the intercooler and gets rattled around when boost goes up??

A loose a/c compressor will rattle if one/some of the mounting bolts have loosened up?

HOW