Spark Plug questions

[futat2]

once the dragsters get started and heat up, i don't believe the plugs matter anymore.

*Edit, found info;* 
Dual magnetos supply 44 amps to each spark plug.  This is the output of an arc welder in each cylinder.

Spark plug electrodes are totally consumed during a pass.  After 1/2 way, the engine is dieseling from compression plus the glow of exhaust valves at 1400 degrees F.  The engine can only be shut down by cutting the fuel flow.

 

[crash712us]

$300 I'll quit my job and change plugs for a living. By 68 chargers plugs where harder to change. All kidding aside, someone needs to put together a well detailed how to on this. Anyone could do this, with some simple tools.

 

[SoCalSHO]

I think the hard part is removing the hoses/tubes and wires in the back. Or I would have attempted it my self. I have the torque wrench, just need to know what other things I would need to make it easier.

 

[IHeartGroceries]

I just ordered some plugs. I don't mind documenting the procedure with some photos, and formulating a brief how-to. Surprised one doesn't exist already, though...

But when will I find the time? That's the mirron dorrah question.

Sent from my SM-N900V using Tapatalk

 

[JMR76]

They are easy compared to other vehicles.  I was driving my father nuts doing them without any extra light. 

 

[crash712us]

Glad iHeart stepped up to the plate. It is a simple job no hose have to removed, there only one plug that is a little difficult to get at. But the front 3 are a breeze. Just do them one at a time, unplug coil, remove bolt, remove coil, remove plug and reassemble. The hard one you have to remove nut from the crossover tube on top of engine and lift of stud push out of the a little bit to you can get at back driver side plug. But I know everything sounds go on paper so photo tutorial should put apprehensions to rests.

 

[panther427]

This is part of the reason the often drop a cylinder part way down the track

 

[mjhpadi]

Just a little FYI, having worked on a Funny Car team  years ago, and also being able to hang out in the Force pits a bit I have seen a ton of spark plugs from both the older fuel engines and the new ones.  The plugs don't always get completely eaten up on each pass, but the do get changed.  I believe that the strain put on the plugs pretty much destroys the plug in the pass if the electrodes are not eaten completely up.  Again, I've seen a lot of plugs and most of them are not completely destroyed during a run, but are really in bad shape, they are subjected to a lot from a fuel engine. And with the cost of a plug, it just hasn't made sense to risk re-using spark plugs when so much depends on the engine working at peak on each run.

 

[DJE624]

I'm going to get my plugs done tomorrow.  They are charging about $200.  I'll report what the gaps were from the factory. 

 

[TSS]

I'm going to get my plugs done tomorrow.  They are charging about $200.  I'll report what the gaps were from the factory. 

IIRC, that is about what I paid at the dealer. 

 

[DJE624]

I'm going to get my plugs done tomorrow.  They are charging about $200.  I'll report what the gaps were from the factory. 

IIRC, that is about what I paid at the dealer. 

Thanks for the confirmation.  I think these guys are much better than my dealer for non-warranty work.  I am going to try getting better pricing from them as we get to know each other better.  They are the guys who are going to do my down pipes and T Stat.  I was going to do it all at once but since I have the plugs, I'll get that out of the way.  And, at -8 today, I don't think I need a cooler T Stat right now. 

 

[mjhpadi]

These plugs can't be as hard as the ones on the Triton 5.4...I had to remove the fuel rail on the driver's side to get at those plugs. And the rear one on the passenger side requires a wobble extension and them you have to watch that you don't get it wedged between the firewall and the head.  The were very hard to change, it took almost 5 hours.  And the first time I changed them, I ended up with a fuel leak when I reinstalled the fuel rail.

 

[Kolk1]

 

[REDSHOCGO]

Hmm wondering if I should change mine. I have 49000 miles on the car so pro ally time to change it as I don't think the previous owner did

 

[DJE624]

I'm changing mine tomorrow with just 7200.  But, I wanted to have my gaps set at 30 so, another $30 to put in SP534's was worth getting new. I will be very interested to see what shape the existing ones are in and what the gaps are.

 

[BiGMaC]

This is impressive!... these aren't funny-cars and we are definitely eating electrodes fast!

 

[mjhpadi]

Dave, hope you get the old ones and get some photos of them.

 

[SHOdded]

x2 on the photos, Dave.  Also keep 'em sorted by cylinder, just in case.

 

[QuickSilver]

I'm changing mine tomorrow with just 7200.  But, I wanted to have my gaps set at 30 so, another $30 to put in SP534's was worth getting new. I will be very interested to see what shape the existing ones are in and what the gaps are.

Im with you DJE, i have a new set of plugs here and tho I only have 69XX miles, I want em all gap set. Next time Im underhood, Ill screw em in but certainly by 10K miles...

 

[DJE624]

All Right!  Got the plugs swapped.  After a $20 coupon the installation was $140!  Can't beat it.  All of my existing plugs were at 34-35.  They looked pretty good.  Not too rich, not too lean.  The guy put them under a microscope.  Not exactly sure what he told me but it was to check if there was any boiling, like running too hot.  All of the SP534's came gapped at 30.  So it was a great report and a great job done.  They also checked all of my upper hot pipe joints to make sure there were no leaks.  There wasn't any. (I'll have them check the lower joints when they do the down pipes.) Didn't think there were any, just wanted to check.  Pictures of old plugs with 7200 on them coming as soon as photobucket comes back on line.