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cherry82482
03-13-2008, 12:49 PM
I was just wondering the difference between a marine spark plug VS Automotive spark plug? Is the difference in heat ranges? OR ?????

MR43LTS VS CR43LTS

mrfixxall
03-13-2008, 01:14 PM
I was just wondering the difference between a marine spark plug VS Automotive spark plug? Is the difference in heat ranges? OR ?????

MR43LTS VS CR43LTS

now a days most marine sparkplugs are nickel coated so they dont seize in the spark plug hole,,other then that their the same heat range..

mjw930
03-13-2008, 01:24 PM
It's my understanding the the M series (Marine) has a SS or coated base vs. the normal steel for corrosion resistance. From a performance standpoint the 2 plugs you mentioned are identical

MR43LTS = Marine, Resistor, 14mm Threads, #3 heat range, Long Reach, Tapered base with extended tip

CR43LTS = Commercial, Resistor, 14mm Threads, #3 heat range, Long Reach, Tapered base with extended tip

mjw930
03-13-2008, 01:45 PM
You might also look into the Champion Marine plug for your application. They have a SS body and supposedly a better noise suppression technology.

BUIZILLA
03-13-2008, 03:28 PM
CR43LTS = Copper core, Resistor, 14mm Threads, #3 heat range, Long Reach, Tapered base with extended tipyuppers

RedDog
03-13-2008, 04:50 PM
I used R43T, R43TS and MR43TS in my former 454 and current stock Merc 502 Mag MPI.

what application would use the "L" long reach plug? I'd hate to bounce a piston off of a plug that was too long :hangum:

Jamesbon
03-13-2008, 09:47 PM
I needed the 8 of the following plugs today and looked at the following AC, Champion and NGK plugs for my 99 7.4L Mag MPI (385HP);

AC MR43T
Champion RV15YC4
NGK BR6FS

At first glance, only the AC seemed to have a "stainless" look to it. Additionally, they're what I removed yesterday and were free of rust... I went with them.

FWIW...

If you "Google" the above part numbers, only the AC MR43T
seems to be referenced in most marine applications.

The Napa guy says "MR" is for marine and is "stainless" or "stainless" coated. At 19 bucks for 9 of'em, you can't go wrong. (The ninth is for the one I usually break when doing this :smash: )

mjw930
03-13-2008, 10:05 PM
Originally Posted by mjw930 http://www.donzi.net/forums/fusion/buttons/viewpost.gif (http://www.donzi.net/forums/showthread.php?p=441914#post441914)
CR43LTS = Copper core, Resistor, 14mm Threads, #3 heat range, Long Reach, Tapered base with extended tipyuppers

It only means Copper Core when the "C" is a suffix. As a prefix it means Commercial ;)

BUT, based on a google search there is no such part as CR43LTS, it's simply R43LTS so I can see the confusion.

http://www.acdelco.com/parts/sparkplugs/identification.jsp

mjw930
03-13-2008, 10:21 PM
Here's the MR43TLS

http://198.208.187.182/servlet/com.entigo.acdelcocatalog.servlet.ProcessImageServ let?languagecd=EN&countrycd=US&user=InternetUser&mfgname=&prodlinecd=&acpartnbr=MR43LTS

And here's the MR43T

http://198.208.187.182/servlet/com.entigo.acdelcocatalog.servlet.ProcessImageServ let?languagecd=EN&countrycd=US&user=InternetUser&mfgname=&prodlinecd=&acpartnbr=MR43T

According to the AC Delco site the LTS plug fits a number of Ford products, OMC Cobra's and the 6.2LX as well as most Vortec heads.

mikev
03-14-2008, 11:57 AM
the NGK is stainless as well i have used them because you can get them at the auto parts store next day for alot cheaper.

BigGrizzly
03-14-2008, 02:21 PM
It is all about heat range and engine. Most plugs now have the anti corrosive materials on the out sides because of the aluminum heads on the engines. As for the reach and the extended tip it is combustion chamber design that dictates that. My suggestion is if your plug works then use it! I have always liked coper cores. You will find that those two plugs the commercial and the marine are actually the same plug inside. I had a chart from NGK which which were the same plug with different nomenclature not a replacement but the same plug with a different number, if I can just find it.

fasttrucker
03-17-2008, 12:22 PM
Powerbaot mag. april 2208."Iridium or platinum-type spark plugs can increase cylinder pressure,in turn increasing horsepower".Has anybody tryed DENSO iridium spark plugs? 5300 series starting at $11.99...CARQUEST ad.