Spark Plug Questions

[OriginHacker21]

Wow - awesome information here... I'm also reading that article explaining how the whole system works - definitely a better understanding on how all this works.

OK - so from what it sounds like - Bosch's Platinum +4s should work OK in my DIS application but won't last as long or as well as double platinum plugs which should have gone in there the first time. Because of this - I won't have a problem taking them out at 50k or longer if I feel like it. $30 for spark plugs isn't much anyway.

Car idled perfectly and recently backed out of parent's garage just fine. Tomorrow I'll do some driving and will report here if any problems arise.

Thanks for the information - really great stuff here.

 

[gedcruise]

If you have a vehicle in which changing the plugs is a real chore, like my Aerostar, it is a real good idea to use double plats that others have had good results with.
On something like one of my Hondas, on which plug changing is really easy, I would probably be more inclined to experiment.
If the thing has run a good many miles on the OEM plugs, and if the plugs are hard to get to, it might not be a bad idea to dance with the one that brung ya.

 

[OriginHacker21]

Well, did a 20 mile drive this morning. I was really easy on the engine the first 10 miles - keeping an ear out for misfires or what not. Engine sounded very smooth.

Last 10 miles I did some stress tests and a few 0-60mph runs (the second run I floored the gas). The engine doesn't feel any slower - maybe just a weeeee tad slower (but that could have been the wind - uphill etc...). I was still able to chirp the tires on start-off in 1st and a little on second.

So there can't be that much HP loss.

One thing I do notice that my passenger also noticed - the engine was a lot quieter in the high RPM range. At 3,000 rpms the engine purrs and at 4-5-6 - the engine was much quieter.

So thats my observation. Because this car isn't my future Corvette - I'm not too worried about performance as most miles are highway anyway. I think I'll stick with these plugs for possibly 50,000 miles then switch to double plats. I'll do more research (calling mechanics I know) into the effects of not using double plats in a vehicle that wants them.

gedcruise - the spark plugs are about as easy to change as changing the oil. The only thing is - requires a huge array of wrench sizes and - I couldn't get a metal bar above the housing off so I just bent it upwards a little to get the spark plug top out. I could probably do it again in 10 minutes or less.

 

[OriginHacker21]

OK - ordered some Autolite double platinum plugs. They'll be here on Tuesday.

Should I keep the Platinum +4s in or take them out and put the Autolite double plats in?

 

[The Critic]

Depends if you can still get your money back for the Platinum+4 plugs...

 

[OriginHacker21]

I am pretty sure I cannot since they are in the vehicle.

Either way - took your advice TheCritic & gedcruise - got some Autolite Double Platinum ordered that came in today. I was able to install them in about 15 minutes - everything looked nice and was very easy thanks to previous install. (Did all the anti-seize and boot protectant stuff).

Car started up very nicely - was a little louder at 3k rpm but also felt more powerful all around - definitely smoother than the original spark plugs.

*** On the Autolite box it says "Specifically designed for engines with OE/DIS that fire the spark in both directions." = Exactly what my engine has. And Made in the USA!

I can sleep tonight!

Thanks again all.

 

[ewetho]

Read an article on Nascar and couple other places that Bosch and Autolite specifically admitted single platinum plugs are not compatible with waste spark ignition so do not even bother trying.

Great discussion thread on DodgeForum here
http://www.dodgeforum.com/m_199034/tm.htm

Beat the horse dead we did.

 

[m2200b]

Since you have +4 in, I'd go 30K or year in your case and then put in the Autolites. Actually taking them out every 30K or once a year makes it easier to do and less likely to strip. You do get info on the head health by pulling the plugs although you'd get some info like coolant leaks with a UOA and a fair amount of info with the CEL.