Big Blue's Transformation

[grumpin]

They are in firing order, but who knows which cylinder is showing first on the screen as he didn't put a pickup on #1, just the coil wire.

This was just the one screengrab he sent me, but others that we looked at were a bit different in that the one cylinder was wonky and the other seven cylinders were all alike. And since the ECU was playing with the AFR during all of this he suggested I not worry about the cylinders that appear to be lean. Instead go figure out what is wrong with that one cylinder. And obviously it is the plug, the wire, or the cap.

But the plug seems the most likely given the conversation starting back here when I told y'all that I'd put Autolite 24's in. For instance, Jim said "You've been warned about Autolites!" (In my defense they are what Scotty recommended.)

It makes sense to start by pulling the plugs, but I don't want to put them back as I want to put new plugs in. So let's (all) go back over the "which plug" bit. This engine is basically a stock '96 460 but with a bit more compression and cam. Plus headers. And it is running a stock ignition system. So is that enough to suggest a non-stock plug?

Rock Auto says that these are stock copper plugs for that engine: Autolite 25; Champion 18 or 4018; NGK 6630 (UR4); & probably Motorcraft ASF42 since the ASF42P is the stock platinum plug. Any favorites there? Any reason to go to a platinum plug? (I know you've had trouble with them, Bill, but in what application?)

I like NGK, a lot of that comes from riding 2 cycle dirt bikes, Husky's, and they did better to me with NGK.

Champion aircraft spark plugs are great, not a fan of Champion auto spark plugs.

I’d probably go with copper on your engine, maybe platinum if it showed necessary.

My Xterra calls for double platinum I believe, it will eat up anything less.

[Gary Lewis]

I like NGK, a lot of that comes from riding 2 cycle dirt bikes, Husky's, and they did better to me with NGK.

Champion aircraft spark plugs are great, not a fan of Champion auto spark plugs.

I’d probably go with copper on your engine, maybe platinum if it showed necessary.

My Xterra calls for double platinum I believe, it will eat up anything less.

Thanks, Dane. It doesn't look like the engine is hard on plugs as these have maybe 5000 miles on them.

I don't see anything that raises my eyebrows. Yes, they are light, but one side of each plug is lighter than the other. Maybe they are too hot?

Here's what I'm calling Side 1, with them laying as they would be in the engine, meaning #1 on the lower left and #8 on the upper right:

And here's the flip side, still as they'd be on the engine:

[ArdWrknTrk]

I like NGK, a lot of that comes from riding 2 cycle dirt bikes, Husky's, and they did better to me with NGK.

Champion aircraft spark plugs are great, not a fan of Champion auto spark plugs.

I’d probably go with copper on your engine, maybe platinum if it showed necessary.

My Xterra calls for double platinum I believe, it will eat up anything less.

Honestly I've always felt that Champions were only for Briggs & Stratton lawn equipment

I had some issues with Autolite a decade back and now use NGK V-power copper plugs UR-4. (6630?) in my truck.

Gary's plugs look fine!

[Gary Lewis]

Honestly I've always felt that Champions were only for Briggs & Stratton lawn equipment

I had some issues with Autolite a decade back and now use NGK V-power copper plugs UR-4. (6630?) in my truck.

Gary's plugs look fine!

Thanks, Jim.

Seems to me that the temp is about right. These are 24's and the stock one would be a 25. This Autolite site says:

Autolite indicates the heat range with the last digit of the part number. For example, 3923 has a heat range of 3. The higher the number, the hotter the plug. The lower the number, the colder the plug.

For instance, starting with part # 24 (heat range 4), if you want a colder plug you would use part # 23 (heat range 3), for a hotter plug you would use part # 25 (heat range 5).

So I have one notch colder plug. Stock NGKs would be NGK 6630 (UR4), but this NGK site says hotter is a smaller number. So now I'm trying to figure out which of the numbers needs to be bigger. I'm guessing the "4" in UR4 needs to be 5. Anyone know?

[ArdWrknTrk]

Thanks, Jim.

Seems to me that the temp is about right. These are 24's and the stock one would be a 25. This Autolite site says:

Autolite indicates the heat range with the last digit of the part number. For example, 3923 has a heat range of 3. The higher the number, the hotter the plug. The lower the number, the colder the plug.

For instance, starting with part # 24 (heat range 4), if you want a colder plug you would use part # 23 (heat range 3), for a hotter plug you would use part # 25 (heat range 5).

So I have one notch colder plug. Stock NGKs would be NGK 6630 (UR4), but this NGK site says hotter is a smaller number. So now I'm trying to figure out which of the numbers needs to be bigger. I'm guessing the "4" in UR4 needs to be 5. Anyone know?

NGK is the reverse.

Lower number indicates a hotter plug.

There are UR5, UR6 etc, but that is their old nomenclature.

The newer numbers (6630) don't seem to have any rhyme or reason.

A UR5 is 2771

[Gary Lewis]

NGK is the reverse.

Lower number indicates a hotter plug.

There are UR5, UR6 etc, but that is their old nomenclature.

The newer numbers (6630) don't seem to have any rhyme or reason.

A UR5 is 2771

I got lost. So if I want a colder plug than a 6630 (UR4) then what do I look for?

I tried to get the robot at NGK to tell me that, but he wouldn't go there and tried to refer me to a human - on July 4th.

[ArdWrknTrk]

I got lost. So if I want a colder plug than a 6630 (UR4) then what do I look for?

I tried to get the robot at NGK to tell me that, but he wouldn't go there and tried to refer me to a human - on July 4th.

5 is colder than 4

Its number is 2771.

Although, I don't know that E7TE head castings are the same as my carbureted engine, if NGK UR4 are what you use stock then UR5 would be one step colder.

UR6=7773 is colder still.... etc

[Gary Lewis]

5 is colder than 4

Its number is 2771.

Although, I don't know that E7TE head castings are the same as my carbureted engine, if NGK UR4 are what you use stock then UR5 would be one step colder.

UR6=7773 is colder still.... etc

Yes, I got the "5 is colder" bit. But got lost elsewhere. However, I think I understand, so let me see:

• 6630 UR4 is stock

• 2771 UR5 is one step colder

• 7773 UR6 is two steps colder than the UR4

Right? If so I'll check with Skiatook Auto Parts tomorrow and see if he has them. Thanks!

Meanwhile I've been texting with my nephew. He also liked the plug pics. And he said "I sure like NGK best. Pretty much never have an early failure with them."

But that leaves plug wires and the cap to check as there is some problem with the ignition on one cylinder.

 

[ArdWrknTrk]

Yes, I got the "5 is colder" bit. But got lost elsewhere. However, I think I understand, so let me see:

• 6630 UR4 is stock

• 2771 UR5 is one step colder

• 7773 UR6 is two steps colder than the UR4

Right? If so I'll check with Skiatook Auto Parts tomorrow and see if he has them. Thanks!

Meanwhile I've been texting with my nephew. He also liked the plug pics. And he said "I sure like NGK best. Pretty much never have an early failure with them."

But that leaves plug wires and the cap to check as there is some problem with the ignition on one cylinder.

Yes, those are the correct numbers. (and they have me confused too!)

I'm used to the much older numbering system (ex. BPR6ES) from my younger days tuning motorcycles.

However I'm in agreement with your nephew. Ive never had problems with NGK's.

So I guess it's time to get out the IR thermometer and check some header primary temps to find the cold cylinder and then swap plug wires.

BTW, what plug wires do you use?

 

[Gary Lewis]

Yes, those are the correct numbers. (and they have me confused too!)

I'm used to the much older numbering system (ex. BPR6ES) from my younger days tuning motorcycles.

However I'm in agreement with your nephew. Ive never had problems with NGK's.

So I guess it's time to get out the IR thermometer and check some header primary temps to find the cold cylinder and then swap plug wires.

BTW, what plug wires do you use?

I'm going to put my DVOM on the wires and see if there is anything obvious. And check the cap. Then after I get new plugs and install them I'll use my ignition scope and see if the problem is still there and which cylinder it is.

If it is still there and I know which cylinder I'll swap a plug wire with used ones I have. But I got these from Scotty and don't remember what brand they are.