2000 Nissan Altima: Blown Head Gasket -- Update

[The_Eric]

Originally Posted By: dishdude

Of course the rotor position affects ignition timing. If you jambed it on 90 or 180 degrees out of position, it would be the same as switching plug wires around.


And swapping plug wires doesn't effect WHEN the spark occurs. It effects WHERE it goes. Same with an out of place rotor.

Originally Posted By: The_Eric

The rotor's sole job is spark transfer. When a spark occurs, timing has been figured out.


Think about that... You and phishin are saying that saying that changing the position of the rotor will somehow alter WHEN the spark occurs. How can it when it has no play in producing the spark?

 

[1kickbuttranger]

The Eric and yonyon are correct about timing. But yes, if the rotor spun enough to send the spark to another cylinder at the wronng time during the cycles, it could create problems.

 

[yonyon]

Problems? Oh, come on, what's the worst that happens? You burn a few valves or bend a connecting rod? Minor nuisances, is all that sort of thing would be....

 

[antonmnster]

I think we need to see an engine autopsy!

 

[Phishin]

Originally Posted By: The_Eric

And swapping plug wires doesn't effect WHEN the spark occurs. It effects WHERE it goes. Same with an out of place rotor.

Think about that... You and phishin are saying that saying that changing the position of the rotor will somehow alter WHEN the spark occurs. How can it when it has no play in producing the spark?


I wish I could let this go, but I can't. You and yonyon are irritating the tar out of me. Perhaps, we are just using different definitions of what TIMING really is....

To me, timing is the relationship between where the piston in the cylinder when the spark occurs. That is timing to me, and all my friends.

When people "set their timing" they are doing what I just defined....they are defining when the spark fires in relationship to piston position in the cylinder.

If someone sets their timing at "0", that means that the spark plug fires at TDC. If they set their timing 5 degrees retarded, that means the plug fires 5 degrees of crank rotation before TDC. 5 degrees advanced timing, means the plug fires 5 degrees of crank rotation after TDC.

Of course the computer is advancing and retarding the timing in electronically controlled ignitions. And what that means is, the car is causing the plug to fire at a specific position that the piston is at in the cylinder.

So, if the rotor is twisted on the dizzy shaft OR the distributor cap rotates in either direction, the spatial relationship of the piston in the cylinder WHEN THE SPARK PLUG fires will change. Thus, a twisted rotor or a rotated distributor cap, effects timing.

Before you start to argue with me, OF COURSE, the computer will make an attempt to correct the change in timing that occurred because the rotor twisted or the cap rotated. Of course!!! But to say that the orientation of the rotor or the cap in relationship to eachother DOES NOT effect timing is RIDICULOUS.

Why would rotors be keyed then? Why not just shove them onto the dizzy shaft whatever way you want? Why do all newer distributor caps only go on one way? And why do older vehicles (like my old chevy 350) do people SET THE IGNITION TIMING by adjusting the orientation of distributor cap in relationship to the rotor (which is held constant by being keyed)?

So, basically it comes down to either 3 things:
1.) We are using different definitions for the term "timing" and I obviously can't figure out what way you are using the term.
2.) You successfully trolled the snot out of me.
3.) You have no idea what you are talking about or are misinformed, despite your profile saying you are a mechanic.

I am not trying to start a e-fight. But I'm just a lowly PhD chemist who tinkers with his vehicles. And I drive POS vehicles because I hard time finding that six-figure job again when I got out of prison. So, I'm educated and schooled. And I can't believe, with all the crazy knowledge I have stuck in my head, that I somehow missed the boat completely when it comes to ignition timing.

 

[OVERKILL]

Originally Posted By: Phishin
Originally Posted By: The_Eric

And swapping plug wires doesn't effect WHEN the spark occurs. It effects WHERE it goes. Same with an out of place rotor.

Think about that... You and phishin are saying that saying that changing the position of the rotor will somehow alter WHEN the spark occurs. How can it when it has no play in producing the spark?


I wish I could let this go, but I can't. You and yonyon are irritating the tar out of me. Perhaps, we are just using different definitions of what TIMING really is....

To me, timing is the relationship between where the piston in the cylinder when the spark occurs. That is timing to me, and all my friends.

When people "set their timing" they are doing what I just defined....they are defining when the spark fires in relationship to piston position in the cylinder.

If someone sets their timing at "0", that means that the spark plug fires at TDC. If they set their timing 5 degrees retarded, that means the plug fires 5 degrees of crank rotation before TDC. 5 degrees advanced timing, means the plug fires 5 degrees of crank rotation after TDC.

Of course the computer is advancing and retarding the timing in electronically controlled ignitions. And what that means is, the car is causing the plug to fire at a specific position that the piston is at in the cylinder.

So, if the rotor is twisted on the dizzy shaft OR the distributor cap rotates in either direction, the spatial relationship of the piston in the cylinder WHEN THE SPARK PLUG fires will change. Thus, a twisted rotor or a rotated distributor cap, effects timing.

Before you start to argue with me, OF COURSE, the computer will make an attempt to correct the change in timing that occurred because the rotor twisted or the cap rotated. Of course!!! But to say that the orientation of the rotor or the cap in relationship to eachother DOES NOT effect timing is RIDICULOUS.

Why would rotors be keyed then? Why not just shove them onto the dizzy shaft whatever way you want? Why do all newer distributor caps only go on one way? And why do older vehicles (like my old chevy 350) do people SET THE IGNITION TIMING by adjusting the orientation of distributor cap in relationship to the rotor (which is held constant by being keyed)?

So, basically it comes down to either 3 things:
1.) We are using different definitions for the term "timing" and I obviously can't figure out what way you are using the term.
2.) You successfully trolled the snot out of me.
3.) You have no idea what you are talking about or are misinformed, despite your profile saying you are a mechanic.

I am not trying to start a e-fight. But I'm just a lowly PhD chemist who tinkers with his vehicles. And I drive POS vehicles because I hard time finding that six-figure job again when I got out of prison. So, I'm educated and schooled. And I can't believe, with all the crazy knowledge I have stuck in my head, that I somehow missed the boat completely when it comes to ignition timing.


FWIW, your definition of ignition timing is in-line with my own.

 

[yonyon]

Maybe we are having some sort of weird communication problem. Okay, lets consider a nice simple system: a basic 4-cyl engine engine with electronic ignition and with advance disabled.

The distrubutor shaft turns in sync with the camshaft. As the distributor shaft turns it triggers the magnetic pickup. The ignition control module (or igniter) responds by cutting the Battery Negative to the coil and initiates the spark event. This occurs at the same moment in Time regardless of where the rotor is pointed or whether or not a rotor is even present. For this reason I do not consider a change in rotor position to be a change in ignition timing. The pickup does not give a flying bleep about the rotor.

If you rotate the distributor base, you change the position of the magnetic pickup and can change the ignition timing (when the spark event happens relative to camshaft position) in infinitely fine resolution. This is setting timing. We can agree on this.

If you move the rotor relative to the distributor just a few degrees this will not change the time of the ignition event. The spark event will happen at exactly the same moment in time and the same camshaft position regardless of rotor position.

Here's where it gets a little hairy: The spark will go to the cylinder corresponding to where the rotor is pointed. If your rotor is more than 45 degrees out of position (really, 30 degrees could do it) the spark will go to the wrong cylinder.

The cylinder is getting the wrong spark event and as such is experiencing that spark event at 180 degrees, 360 degrees or 540 degrees of crankshaft rotation out of time. This is exactly one stroke or a multiple of one strokes out of time. You consider this a timing change. I consider this a crossfire or misdirection of spark energy.

Is there some way you disagree with this?

 

[The_Eric]

phishin, I believe you're oversimplifying things. Yes, I suppose that altering the position of the rotor a few degrees would alter timing. But you said that your rotor was off 40-80 degrees. That's cross firing...

Remember that the rotor was only ever meant to direct the spark and doesn't affect when it's produced. Even the old mechanical systems varied when the spark was produced by means OTHER than moving the rotor.

Punisher and yonyon don't have things mixed up.

 

[OVERKILL]

Originally Posted By: yonyon
Maybe we are having some sort of weird communication problem. Okay, lets consider a nice simple system: a basic 4-cyl engine engine with electronic ignition and with advance disabled.

The distrubutor shaft turns in sync with the camshaft. As the distributor shaft turns it triggers the magnetic pickup. The ignition control module (or igniter) responds by cutting the Battery Negative to the coil and initiates the spark event. This occurs at the same moment in Time regardless of where the rotor is pointed or whether or not a rotor is even present. For this reason I do not consider a change in rotor position to be a change in ignition timing. The pickup does not give a flying bleep about the rotor.

If you rotate the distributor base, you change the position of the magnetic pickup and can change the ignition timing (when the spark event happens relative to camshaft position) in infinitely fine resolution. This is setting timing. We can agree on this.

If you move the rotor relative to the distributor just a few degrees this will not change the time of the ignition event. The spark event will happen at exactly the same moment in time and the same camshaft position regardless of rotor position.

Here's where it gets a little hairy: The spark will go to the cylinder corresponding to where the rotor is pointed. If your rotor is more than 45 degrees out of position (really, 30 degrees could do it) the spark will go to the wrong cylinder.

The cylinder is getting the wrong spark event and as such is experiencing that spark event at 180 degrees, 360 degrees or 540 degrees of crankshaft rotation out of time. This is exactly one stroke or a multiple of one strokes out of time. You consider this a timing change. I consider this a crossfire or misdirection of spark energy.

Is there some way you disagree with this?


I think the "wrong spark event" is where you guys are getting mixed up. It would be an extreme timing mismatch for that particular cylinder, which would also be called a crossfire in my books. And of course this could readily occur if the rotor moved enough on the shaft, IE, if the pin sheered and it rotated.

 

[yonyon]

The thing that sounds scariest to me is the scenario of it running properly, then during a WOT acceleration, having the rotor turn and give the individual cylinders the wrong spark effectively 540 degrees late. What would happen in that case?

 

[javacontour]

Is it running now?

 

[Phishin]

Originally Posted By: javacontour
Is it running now?


The new engine is in and running. I have to replace the exhaust manifold gaskets today. Thats it.

Oh......and I'm done talking about timing. Please. That just fires to show you what kind of info is in the net....even on a respected site like this.

Engine autopsy may begin in a few weeks. What should I do with the old engine? After I hoard all the components off it? Take it to scrap yard? What can I expect to get for it?

 

[Vikas]

I was thinking along the lines as Phishin has been posting. However, latest by yonyon clears my misconception. His explanation now makes sense especially once it got through my head that rotor is there just to pick up the spark and deliver to correct cylinder. Since it jumps anyway, it does not need to be perfectly aligned when the spark occurs. I do not think I had grasped the concept it the past and I have to thank yonyon for making it clear.

- Vikas

A PhD chemist coming out of prison? Man you must know your "chemistry" really well, huh???

 

[martinq]

.
Having rebuilt & set timing on many engines (ECU/distributor, ECU/no-dist, points/dist, etc) and having been fed-up with so many mechanics who don't understand mechanics, just have a few thing to set straight.

Originally Posted By: Phishin
To me, timing is the relationship between where the piston in the cylinder when the spark occurs. That is timing to me, and all my friends.

When people "set their timing" they are doing what I just defined....they are defining when the spark fires in relationship to piston position in the cylinder.

If someone sets their timing at "0", that means that the spark plug fires at TDC. If they set their timing 5 degrees retarded, that means the plug fires 5 degrees of crank rotation before TDC. 5 degrees advanced timing, means the plug fires 5 degrees of crank rotation after TDC.

Of course the computer is advancing and retarding the timing in electronically controlled ignitions. And what that means is, the car is causing the plug to fire at a specific position that the piston is at in the cylinder.

This is correct.



Originally Posted By: Phishin
So, if the rotor is twisted on the dizzy shaft OR the distributor cap rotates in either direction, the spatial relationship of the piston in the cylinder WHEN THE SPARK PLUG fires will change. Thus, a twisted rotor or a rotated distributor cap, effects timing.

This is correct IF the sensor used to measure/set timing is in the distributor. Otherwise, distributor position has no effect on timing (either the spark goes to the right cylinder or it doesn't).



Originally Posted By: Phishin
Why do all newer distributor caps only go on one way? And why do older vehicles (like my old chevy 350) do people SET THE IGNITION TIMING by adjusting the orientation of distributor cap in relationship to the rotor (which is held constant by being keyed)?

This is due to the sensor (or cam/points) in the distributor which sets the timing, not the relative position of the rotor-in-the-cap (within reason). The rotor needs to be lined up in the cap only enough for the spark to jump the (short) gap. If it's too far out of line it'll mis-fire/no-fire or fire the wrong cylinder.

 

[Phishin]

Originally Posted By: Vikas
A PhD chemist coming out of prison? Man you must know your "chemistry" really well, huh???


Since I brought it up, I'll explain. I used to be a biochemist at a large pharmaceutical company in Indianapolis...Eli Lilly. I was in drug discovery in the Neuroscience division of that company.

But my life spun out of control as the result of drugs and alcohol, and I had to serve time.

Now I work as a quality control chemist in a high-tech foundry that refines nearly all copper used in the, semi-conductor business. Computer chips, circuit boards, etc.

Been sober now almost 7 years....thanks to God and the fellowship of Alcoholics Anonymous.

 

[Vikas]

Congratulations for successfully coming out on the other side! Your story is inspirational and you should be extremely proud of yourself.

 

[shell_user]

Phishin, glad you are well and doing good things so I say GOD BLESS YOU and thanks for your wisdom here.

adam

 

[Phishin]

Thanks fellas. The words of encouragement are nice to hear. I guess I had to go to that place, to get to this one.

Regardless, the car is running great. There is a slight exhaust rattle somewhere and the flex pipe on the exhaust needs changed out...so my buddy has the car at his exhaust shop this morning to put the final touches on her. I wasn't gonna have my mechanic fix these problems. I think he was tired of looking at the car, and I was tired of him dragging his feet.

Should be as good as new by this evening. I'll post engine bay pics soon.

Driving it last night, it seemed to have a really firm shift going from 1st to 2nd. I don't remember it being that firm. Not really sure if it can be adjusted....but this is my wife's car, so I don't drive it much.

Final bill was $525 for the motor install. That included the oil change, 2 gallons of antifreeze, exhaust manifold gaskets, and new plugs.

I think that was pretty reasonable. So, I got just about $1600 in the engine swap as of now. I think the exhaust work will be about $200 at the most. I'm fairly happy with this result.

 

[artificialist]

Originally Posted By: Phishin
Originally Posted By: javacontour
Is it running now?


The new engine is in and running. I have to replace the exhaust manifold gaskets today. Thats it.

Oh......and I'm done talking about timing. Please. That just fires to show you what kind of info is in the net....even on a respected site like this.

Engine autopsy may begin in a few weeks. What should I do with the old engine? After I hoard all the components off it? Take it to scrap yard? What can I expect to get for it?

I am not sure what you would get for it....
However, you could probably make more by separating the aluminum parts from the iron and steel ones, rather than selling an entire junk engine an having someone else separate the iron and steel from the aluminum.