Spark plug question ???

[davids2toys]

While doing my valve cover gaskets, I notice how much easier the plugs looked like they would be to change without the valve covers installed.
I pulled a plug out, it is a Champion RF91C, it seems to be burning good...I have no idea how old they are, or if they are even the right plug.
I have a 428, with CJ heads, MSD box.
What would be the correct plugs for this engine...also, what should the gap be.
I did search but only found small block info!

[Naumoff]

David, Are those RF9YC? They are correct.

Motorcraft BF-32/ Resistor BSF-42C
Autolite 35 or 34/ Resistor 45 or 44
Champion F11YC or F-9YC /Resistor RF-11YC or RF9YC
Accel 378 /Resistor 675


Points distributor Gap 35
Electronic distributor Gap 44

If you are looking for performance you want to use non-resistor spark plugs. A resistor is exactly what the word implies. When the spark crosses the point of resistance some of the spark energy is lost. A resistor is like an electronic obstacle and could be the cause for a weak spark. Non-resistor spark plugs deliver a more powerful spark.

[davids2toys]

David, Are those RF9YC? They are correct.

Motorcraft BF-32/ Resistor BSF-42C
Autolite 35 or 34/ Resistor 45 or 44
Champion F11YC or F-9YC /Resistor RF-11YC or RF9YC
Accel 378 /Resistor 675


Points distributor Gap 35
Electronic distributor Gap 44

If you are looking for performance you want to use non-resistor spark plugs. A resistor is exactly what the word implies. When the spark crosses the point of resistance some of the spark energy is lost. A resistor is like an electronic obstacle and could be the cause for a weak spark. Non-resistor spark plugs deliver a more powerful spark.

I would like to replace the champions with autolites because I have heard they are much better...every thing cross referances back to a Autolite resister 45, there is no such thing as a 44, at least not any more. There are no straight champions either, just resister. Believe it or not, the difference in champion RF11yc and RF9yc is the thread, I thought it would be the heat range!!!
Autolite does make a non resister but it is a racing plug, I think the numbers started with AR
I ended up buying R45's, but not sure if I should put them in.
What do you think about the racing autolites?
The Champion RF9yc I took out looked like it was burning nice, I dont want to end up with a problem, especially because it looks like you need to remove the valve covers to get the plugs out!!
Also, would you know the torque on the plugs, and I will be using a tiny bit of anti-sieze, unless that is a no no to...lol.

[Naumoff]

Just guessing but it might be getting harder to find a variety of those pugs for the original CI heads. R45 should be fine.
I would run the racing plugs but that might just be me.
Here is a link to torque specs and aditional info.
http://www.autolite.com/pdf/TorqueSpecs.pdf

Installing Spark Plugs Without a Torque Wrench

14 and 18mm tapered seat plug – tighten 1/16 turn after finger tight;
14 and 18mm gasket seat plug– tighten 1/2 turn past finger tight;
12mm gasket seat plug – tighten 3/8 turn past finger tight;
10mm gasket seat plug – tighten 1/4 turn past finger tight.

NOTE:

Spark plugs should be installed with clean and dry threads to avoid overtorquing or stretching

the spark plug which can, and often does, result in engine damage


I have changed my plugs with the valve covers on but if you have them off it is easier. I use a swivel spark plug socket with a long extension. Same thing we use on big block 67 - 70 Mustangs and Cougars.

Racing plugs are colder.

I found this info on the web,

Keep in mind the insulator nose length is a determining factor in the heat range of a spark plug, the longer the insulator nose, the less heat is absorbed, and the further the heat must travel into the cylinder head water jackets. This means the plug has a higher internal temperature, and is said to be a hot plug. A hot spark plug maintains a higher internal operating temperature to burn off oil and carbon deposits, and has no relationship to spark quality or intensity.
Conversely, a cold spark plug has a shorter insulator nose and absorbs more combustion chamber heat. This heat travels a shorter distance, and allows the plug to operate at a lower internal temperature. A colder heat range is necessary when the engine is modified for performance, subjected to heavy loads, or is run at a high rpm for a significant period of time. Colder spark plugs remove heat quicker, reducing the chance of pre-ignition/detonation. Failure to use a cooler heat range in a modified application can lead to spark plug failure and severe engine damage


http://www.ngksparkplugs.com/techinf...000&country=US

[davids2toys]

Just guessing but it might be getting harder to find a variety of those pugs for the original CI heads. R45 should be fine.
I would run the racing plugs but that might just be me.
Here is a link to torque specs and aditional info.
http://www.autolite.com/pdf/TorqueSpecs.pdf

Installing Spark Plugs Without a Torque Wrench
14 and 18mm tapered seat plug – tighten 1/16 turn after finger tight;
14 and 18mm gasket seat plug– tighten 1/2 turn past finger tight;
12mm gasket seat plug – tighten 3/8 turn past finger tight;
10mm gasket seat plug – tighten 1/4 turn past finger tight.

NOTE:

Spark plugs should be installed with clean and dry threads to avoid overtorquing or stretching
the spark plug which can, and often does, result in engine damage


I have changed my plugs with the valve covers on but if you have them off it is easier. I use a swivel spark plug socket with a long extension. Same thing we use on big block 67 - 70 Mustangs and Cougars.

Racing plugs are colder.

I found this info on the web,

Keep in mind the insulator nose length is a determining factor in the heat range of a spark plug, the longer the insulator nose, the less heat is absorbed, and the further the heat must travel into the cylinder head water jackets. This means the plug has a higher internal temperature, and is said to be a hot plug. A hot spark plug maintains a higher internal operating temperature to burn off oil and carbon deposits, and has no relationship to spark quality or intensity.
Conversely, a cold spark plug has a shorter insulator nose and absorbs more combustion chamber heat. This heat travels a shorter distance, and allows the plug to operate at a lower internal temperature. A colder heat range is necessary when the engine is modified for performance, subjected to heavy loads, or is run at a high rpm for a significant period of time. Colder spark plugs remove heat quicker, reducing the chance of pre-ignition/detonation. Failure to use a cooler heat range in a modified application can lead to spark plug failure and severe engine damage


http://www.ngksparkplugs.com/techinf...000&country=US

Great info, thank you!!!
Do you know which size I have?

14 and 18mm gasket seat plug– tighten 1/2 turn past finger tight;
12mm gasket seat plug – tighten 3/8 turn past finger tight;
10mm gasket seat plug – tighten 1/4 turn past finger tight.

or how I can tell?
So which Autoliter racing plug would you run, knowing thay the RF9YC was burning good? Is there a downfall to using the racing plug!

[Naumoff]

Probably 7/8" close to 18mm

Accel 378 did you try to find them?

Your on the street and the plugs look fine at an idle so running a colder plug would be fine. which is what racing plugs will be.


I have aluminum heads so my car takes a different sparkplug.

[eliminator]

"NOTE:
Spark plugs should be installed with clean and dry threads to avoid overtorquing or stretching"

That is BS, if you have aluminum heads you better not install the spark plugs with dry threads, you better have some anti-seize on them. If not you will be stripping some threads when you attempt to remove them. Even on steel heads it's a problem. Now you don't have paint the anti-seize on, use sparingly, a little goes a long way.

Since spark plugs only require about 14-18 ft lbs of torque you can't stretch them. So another case of don't believe everything you read.

[rdorman]

I always anti-seize the threads on the plug and put dielectric grease in the boot. The plain jane Autolite is hard to beat in our old school V8s. Dirt cheap to.

[will butterworth]

that you thread into aluminum-bolt into alum. put tiny bit of antiseize on threads, now thats kinda my rule of thumb.Will-alabama

[Brent]

There is no doubt Rick, Will , and Rick are correct.
Always anti-seze plugs into aluminum heads. It only takes a small ammount. It does not need to look like the Exxon Valdeze sank on your cylinder heads.

Dissimilar metals with totally different expansion characteristics.

On other items like intake bolts, etc. I use the ARP thread lubricant before torqued to spec. unless it a application for a thread locker.

[davids2toys]

Probably 7/8" close to 18mm

Accel 378 did you try to find them?

Your on the street and the plugs look fine at an idle so running a colder plug would be fine. which is what racing plugs will be.


I have aluminum heads so my car takes a different sparkplug.

Never looked for the accel at all...I am installing the r45 autolites.
I got 2 plugs in last night with a 44 gap, and torqued them to 19 ft lbs. I hope to finish the job tonight and get the valve covers back on.
I have steel heads and did not use antisieze at all, I may pull them back out and put a tiny bit on. The metal that grips onto the plug inside the wire is a very very loose fit, but the wires look to be in perfect shape...should I be concerned

[Brent]

Yes, I would use a thread lubricant either way.

No, you do not need to use a torque wrench on spark plug...nice and snug is good.

No, a loose end on a plug wire is not acceptable. You can either crimp it through the boot or pull the boot back and crimp it. It should "snap" when pushed on and it should spin but not have up and down "slop" in the connection.

Good choice on the Autolites.......Champion plugs %$@#&%
always have and always will.

[Naumoff]

Never used anti-seize or thread lubricant on spark plugs in cast iron heads and never had a problem removing them.

Aluminum heads are a different story.


I would do as Brent said and pull back the boot and check the terminal.

[davids2toys]

Yes, I did use a very small amount of anti sieze.
They do snap into place, but by design I believe, they move a real lot where the boot meets the wire. They are all straight boots, no 45's or 90's
One of my wires was missing a section of robber outside insulator, about a 1/4"x 1/4"...I painted it with two coats of liqid electrical tape.
I torqued everything to 18 lbs.
I used halomar on the valve cover / only on the valve cover side, and a ribbon of RTV on the int mani/head split...also carefully sanded down the intake gasket that was sticking up!
I even made an attempted on torquing the VC to 3 lbs!!!

The valve covers came out real nice...5 coats high heat satin clear, also decided to paint the inside line in the 427 script, body color (red)with a coat of clear.
Thanks for all the great info and advice...Dave

[Naumoff]

Sounds good. We need pictures!

[Brent]

We need pics!

[davids2toys]

took it to a show last night, a few of the cobra guys commented favoably.
I took a few pictures, as soon as I download them, I will post.

[davids2toys]

Here is few

[davids2toys]

One of my wires was missing a section of robber outside insulator, about a 1/4"x 1/4"...I painted it with two coats of liqid electrical tape.

The wire is damaged because of the throttle linkage coming thru the footbox...is there a cure for this?

[scott h]

i would consider rerouting the wires, you can still have a nice look. one of my wires rubs against the footbox on the pass. side, i sleeved it with insulating sleeve used for brake and clutch lines, you could also use wire loom.