Upon recent inspection of my spark plugs I found that on some of them the porcelain is slightly cracked. I know this is most likely a heat issue just curious what you guys are running and if you have ever seen or heard of this before.

The plugs I was running were NGK iridium IX which I thought was a pretty good plug .

I am running an MSD ignition coils with MSD super conductor plug wires. I called MSD tech support to see what they recommend and they impression I got from them is that don't want to endorse anything and that the coils will fire a cheap $1.49 copper plug just as well as a top of the line plug and they more less said copper plugs . They did say if I was running the ignition box ( which I am not) that I needed to run copper plugs ) . I have the 4.6 engine and those back plugs are bear to get at as you all know and I don't want to change copper plugs every 10,000 miles. I would like to get something that a put in once and forget about for long time so platinum or iridium are ideal although I have heard there are some E3 copper plugs that can go up to 100,000 miles.

Just an FYI the plugs are all out and did not break cracks are not that bad. I put my old plugs in that came out last year when I put the NGKs in. NGKs had 18,000 miles on them the old plugs which were platinum tipped did look ok but had close to 100,000 miles on the them ( I always hang on to my old parts ).
The old plugs were I believe motorcraft but did not have the MSD coils and plug wires.

Thanks for your insight guys .

 

I have the E3 plugs. Great plugs as I have put them thru some brutal tuning parameters and they show no problems.

 

What are those rated at for mileage? How many miles do you have on them?

 

Don't recall if I ever saw a mileage rating. I have about 10k miles on them and a stock ignition. I like to replace the plugs every 30=40k miles any way.

 

I don't know why anyone runs anything but Motorcraft in the modular engines. That is what the engines like best and are the most trouble free.

 

The only way I've seen a plug crack is from the install or removal. No other way IMO.

E3's have been tested on this site and eventually failed. BUT, those were in the 5.4L 3 valves. Personally, I haven't heard of anyone using them in a 2 valve until now.

Absolute worst plugs are the Bosch and Autolite for the two valve. They can't always handle the heat range. The Autolite heats up turns colors and misfires. The Bosch heats up and falls apart inside the cylinder. Stay away from those.

The best for the two valves IMO, in order -

*Denso Iridium fine wire
*Motorcraft
*NGK

 

I've been a repair or R and D tech most of my working carreer so experimenting is in my blood.

 

How long are those Denso's good for mileage wise? When I was last looking at plugs and bough my NGKs I rember I chose the NGKs over the Denso's because I thought the Densos were only a 30,000 mile plug and the NGKs were 100,000 + miles .

And yes my concern is the heat with this engine so thank you the Bosch is was on my radar for consideration along with autolight are off the list.

I would love to stick with Irdium but a good platinum would be just fine so Motorcraft sounds good to . It is possible but unlikely these weren't properly torqued . I called NGK to ask them about the issue and they said they need to be 7.2 -14.4 .

 

Couldn't pay me enough to be a tech. Customers can be a brainless hell, usually. I've done plenty of experimenting tho.

Fuel mileage changed for the better going with Denso's over Motorcraft. Not a whole lot. Just city mileage tho.

W/Motorcrafts -- 14City/16HW
W/Denso's ------ 16City/16HW

 

Did more repair in the military than dealerships and the rest R and D. Very little customer interface. Their cars spoke volumes on abuse. R and D=lot of free parts to.

 

In general, all plugs should be changed @ 60,000-65,000 miles

For your heads, the best spec is 28' lbs. DO NOT torque to factory spec with these aluminum heads and DO NOT use anti-sieze. Torque dry. Or there's a good chance you'll end up joining the blown plug club.

Don't worry, -heads have been test to 100' lbs with NO issues. The plugs porcelain seal will hold up as well. Just keep it at 28' lbs.

 

Here are the Denso's offered for my engine .

http://www.jegs.com/i/Denso/313/5325/10002/-1

Would this be considered a fine wire ?

 

Best way to run plugs in with THESE heads is with a section of 3/8 air hose. That will keep you from taking out the first few threads starting them with a plug socket. It's easy to do incorrectly with the angle involved. Even with a good plug socket you can be off enough to chew on the first couple. After all, there's just 4 threads total keeping the plugs in the heads. Sucks, but that's all there is.

 

Yes, but don't pay that for them lol. Try Rock Auto. Think I paid a little over $30 for a box of four.

 

Yeah that was just the best link I found.

Thanks