ATTN: Jeff C ( Colder Spark Plugs)

[Todd Z]

I found this while searching the Exhaust sound clips that Steriffic had colder plugs in his ST..

I wounder if this will help you out

Stock : AGRF22P (AGRF22PG)

Colder : AGSF12PP

Todd Z

 

[Jeff C]

Lol, okay I'll take a look. I found some NGKs that I think will work with the help of a member of another site, but I'll look at these too.

 

[Larry Phillips]

What's the advantage of a colder plug?

 

[Todd Z]

A colder plug is just that. It keeps the combustion temps lower inside the cylider...

This is great for vehicles driven Long trips all the time and for racing applications , mainly supercharging and NOS....



Todd Z

 

[Tom Schindler]

Larry,



This information will help you understand what a colder plug will do.

The term "heat range" refers to the relative temperature of the core nose of a spark plug. The words "hot" or "cold," when used in referencing spark plugs, are often a source of confusion and misunderstanding, since normally a hot spark plug is used in a cold engine (low horsepower) and a cold plug in a hot engine (high horsepower). The terms actually refer to the heat rating or thermal characteristics of the plug; more specifically, the plug's ability to dissipate heat from its firing end into the engine cooling system. A cold plug transfers heat rapidly away from its firing end into the cooling system and is used to avoid core nose heat saturation where combustion chamber or cylinder head temperatures are relatively high. A hot spark plug has a much slower rate of heat transfer and is used to avoid fouling where combustion chamber or cylinder head temperatures are relatively low. The primary means of adjusting heat range are by varying the length of the core nose and the alloy material used in the electrodes. Hot plugs have a relatively long insulator nose with a long heat transfer path. Cold plugs have a much shorter insulator nose and thus, transfer heat more rapidly (see illustration; hot to cold - left to right). The heat range of a plug does not affect the power output of an engine. Rather, it allows the plug to function as designed for the duration of the racing event. In other words, once the correct heat range is found that prevents fouling and does not contribute to the pre-ignition or detonation, a change to a hotter or colder plug will not have a positive effect on engine performance.

http://www.edelbrock.com/automotive/sparkplugs.html

Colder Spark Plugs Help Prevent Detonation





Does your car or truck "ping" when you're going up a hill or accelerating aggressively? If you don't have other major problems, you may be able to stave off detonation with a simple spark plug swap.



"Most applications that are not burning oil and are subjected to poor quality gasoline can possibly benefit from going to a one-step-colder heat range spark plug, especially if the vehicle has a tendency to 'ping' under load or while climbing a hill," says Jacobs Electronics (Dept. ETD, 500 N. Baird St., Midland, TX 79701, 800-955-3345, www.jacobselectronics.com). "A colder spark plug actually dissipates heat from the firing tip faster than a hotter plug. This helps lower the temperature in the cylinder and reduces the amount of preignition in most cases."

http://www.enjoythedrive.com/content/?id=24197

Spark Plug Heat Range:



A spark plug's heat range has no relationship on the actual voltage transferred through the spark plug. Rather, the heat range is a measure of the spark plug's ability to remove heat from the combustion chamber. The heat range measurement is determined by several factors:



The length of the ceramic center insulator nose

The insulator nose's ability to absorb and transfer combustion heat

The material composition of the insulator

The material composition of the center electrode

The longer the insulator nose gives you a larger surface area exposed to combustion gasses and heat is dissipated slowly. This also means the firing end heats up more quickly. We are talking about exposed ceramic length, not extended tip length.



The insulator nose length is the distance from the firing tip of the insulator to the point where the insulator meets the metal shell. Since the insulator tip is the hottest part of the spark plug, the tip temperature is a primary factor in pre-ignition and fouling. No matter what the plugs are installed in, be it a lawnmower, a boat, your daily driver or your race car, the spark plug tip temperature must remain between 450°C to 850°C. If the tip temperature is lo

 

[Rodger Tellefson]

The link from this post from '03 should also help.

 

[Jeff C]

Larry, here is why I need the colder plugs.



[Broken External Image]:

 

[Tom Schindler]

Jeff,



Also, no platinum plugs.





Tom

 

[Larry Phillips]

Thanks guys! Jeff, looks pretty good, I figured that's what they were for. That's the NX stage 1 EFI kit isn't it? I was looking into that one. I haven't done it yet because of the high mileage on the engine.

 

[Jeff C]

Larry, yeah. Tom, I know, copper cores. Larry, that is the Ford EFI kit, but the fuel rail adapter that comes with it is wrong, so Wayne is working on something. Also hooked in is a dual purge kit, and a MSD digital RPM window switch to keep it "safe". I'll probably run it a few times on this engine and then hook up a "full" spray of 100-125 when I rebuild a 4.0 with forged internals, flathead pistons, and an EE Xcharger.

 

[Travis Munday]

"I"?



Where do you plan on buying your stuff? Doing a quick search at Summt, there are only dish pistons (not even forged), and no rods. Certainly not any cranks or OHC cams.



i'd love to see a built up SOHC 4.0, but I've always been under the impression that the reason why it hasn't been done is because there aren't any parts.

 

[Larry Phillips]

Sweeeet....

 

[Jeff C]

Tiger, supersixmotorsports.com



They have flathead pistons, heads, and cams, and I already got a price quote. I already have an engine stand and hoist so as soon as I can find a used 4.0 for around $400-500, I'll start working. I aim to have it done and installed by the end of summer '08. I have also located a company that builds transmissions for baja racing in Nevada, and it just so happens they do a 5r55e.

 

[Travis Munday]

Sweet.



That site seems familiar to me, but I don't remember them having SOHC stuff. I guess with the new Mustang having this motor, it's becoming more popular for aftermarket people.

 

[Tim Turner]

That sounds like an awesome project and a nice start already. Definetly want to hear/see more about that when it gets rolling.

 

[Larry Phillips]

That site seems familiar to me, but I don't remember them having SOHC stuff.

Yeah, they just uploaded a .pdf catalog of 4.0L SOHC parts since the new Mustang came out. That's where I'm looking to get my parts as well. Didn't know about the transmission shop though. What kinda info do you have on them Jeff? What kind of upgrades are they making?

 

[Jeff C]

Alright, well I spent about an hour going through the books at work. Those plugs, the AGSF12PP are double platinum (bad for me) but are colder than the stock AGRF22pg. The AGSF12 (what I would assume to be the number for a copper plug), my Ford dealer does not have and cannot find in inventory (I didn't tell them why I needed colder copper plugs ). I did discover that the AGSF12 heat range is the same as the TR6 heat range in the NGK brand, basically the coldest "non-racing" plug you can buy. Since I have already picked up copper TR6 NGK that fit the ST (gapped at .044" for best mix of street and track use) I am confident that this setup will help prevent detonation when spraying, while still allowing normal daily driving use.



I guess it's time to get working on all my switches and what not. I've decided to run a 50shot on the current motor that will be used at track only. When I finish with the new motor with forged flathead pistons, I will up it to a 100shot. I'm getting really excited about this whole project now. 400rwhp, here I come!







Oh, Larry, the transmission shop I was looking at www.powerdemon.com has close and will not re-open, per their site. Guess I'm going to have to find some other means of beefing up the transmission.

 

[Travis Munday]

Yeah, like getting a C6 and having a custom bellhousing made...