Spark Plugs Recommendations: 454

[enigma960080]

Sent: 9/3/2007

I would like to know  every 454'ers opinion/experience (good,bad,indifferent) on the  different brands of Plugs you have used in your 454.  My old MOPARS always seemed to prefer Champion.  I have not replaced the plugs in my rig since I have owned it. Just want to know what everyone is sparking on.

[jazzin112]

Sent: 9/4/2007

Well, in the two 454's I have had, I've always been partial to AC plugs, I've tried Champions and NGK's but they just don't seem to work as well as the AC's.  Like you, however, I've always preferred Champions in my old MOPARS.  My Ford's however didn't seem to have a preference.

Jazzin112
'84 ElanDan 31RT  454 "Ol Snort"

[enigma960080]

Sent: 9/5/2007

What  flavor  AC  were you using?   Regular, RapidFire or Platinum?

[Lefty]

Sent: 9/5/2007

I have used the Rapidfire plugs, and didn't like them. They might be the hot ticket for an engine that burns perfectly clean, but I found that they foul out quickly due to the very small electrode if used in an engine that has some miles on it.
I like the regular old AC plugs, but my favorite plug is Nippondenso or NGK. I have used them in all kinds of engines and have always been happy with them.

[sharkfot]

Sent: 9/6/2007

AC--go one stage hotter than the factory spec!

[enigma960080]

Sent: 9/6/2007

I know  the plugs  in there  now have at least  11K miles on them.  Here in Commifornia, I/we have  to smog check every 2 years  everything  newer than 1975. I have a  year  before my time  comes  but I want  to start a  build-up of parts now so when the  crappy  weather  comes  I'll  have  something  to do....

[RV Mech Tech]

Phil - the type of plug you use in an engine depends on several factors - compression ratio, engine operating temps, camshaft profile (camshaft timing) intended use for that specific engine, combustion chamber and piston head shape, internal resistance of the plug itself in relation to the type of ignition system used,  are all things taken into consideration by the manufacture for the manufactures recommended spark plugs - the comments you and other members made about the Mopar engines running better on Champion plugs is what I experienced as well -why? the engines were designed a certain way and the plugs are designed that way as well - you can use different types of plugs in one type of engine but you will find that one or two brands and designs will work better than others - the older engines were  very similar in internal design for things like combustion chambers, piston design etc. but today's emission engines are very different- use the wrong type or heat range  in a new engine and your asking for trouble- for example- the combustion temperature and pressure will have an affect on the plugs ability to fire - with a lower compression ratio  the pressure between the center electrode and the side electrode will be lower ( with the piston at or near top dead center on the compression cycle)  than an engine with a lets say 10 or 11:1 compression ratio and a higher performance type of plug will work a lot better in the higher compression engine- also be carefull of the design of the plug-  Mopar engines usually use a 'projected core nose' type of plug where a G.M. engines on average will use a different core nose ( this is on account of the different heat range requirements) and using a projected nose plug in an engine not using that type of plug may  cause engine damage- what I usually do is find out the factory recommended plug for the intended application and then install them  and after a while pull the plugs and look at them for color and  other signs for operating conditions- the race car engine builders do this as the plug condition and color are definite indicators of how that cylinder is operating - this may also tell you if there is a problem (if any) in any of the cylinders - also keep in mind that  motorhome applications are in the 'severe duty' category and are different from auto or light duty truck application and a 454 in your motorhome may require a different heat range than another 454 in another RV application - you can also do a search on the plug manufactures websites for plug tech info as well as any high-performance car and truck sites -they will have info on selecting plugs for different vehicles  and by the way "AC"  stands for "Albert Champion"    (same company!)   Y!

[ClydesdaleKevin]

I used AC/Delco platinum plugs when I put new plugs in during the Georgia Renaissance Faire last year...along with the best wires with good thick heat resistant boots I could find.  Thankfully the heat shield were all still in place and in good condition...but that didn't stop the old plug wire boots from disintegrating.

I used the platinum because they don't have to be replaced as often and they hold thier gap a lot longer...more resistant to heat and erosion.  Mostly I did this because the front 2 plugs are a REAL pain in the arse to replace...very hard to get to the way my chassis sits over it.

Kev

[jkilbert]

All of the GM product I've owned seemed to prefer ac/delco plugs. When i had my 'burb i tried Accell, Splitfire, Champion and Motorcraft. i had the best performance and economy with the AC plugs. I was actively looking for better performance since I was towing a 32' Shasta at the time