Spark plug opinions........

« **on:** September 21, 2011, 07:16:09 PM »

Right now I am running the Bosch platinum plus plugs. The HR9BPX. I decided to take a look at a couple tonight, seeing as I put em in about 3 or 4 years ago and haven't checked them since. They are a rust color almost brown, and the gap is at 45 to 46 now. If I remember right I gapped them at 40 to begin with, not sure cause it's been so long. Should I replace them??? Opinions are like assholes everyones got one, so let's hear it guys!!

« **Reply #1 on:** September 22, 2011, 12:58:36 PM »

IMHO, you are running the worst spark plug that is available for a domestic motor. As I said before, that IMHO only. I own an auto repair shop and I can't even begin to tell you about all the cars with engine misfire trouble codes that we have had come in because of these spark plugs. The problem is that alot of the Bosch platinum spark plugs lack an exposed center electrode (the little metal thingy that pertrudes from the pocelain) As far as in know, domestic motors were designed to run conventional style spark plugs up until the mid y2k's. Lately we have been seeing new cars with rather odd looking spark plugs. If you've had luck with them, then I'd say continue to run them. In a car, platinum spark plugs last about 60k However, I have no idea what would be the boat engine hour equivalent to that. My advice to you is to install the spark plugs that your engine calls for and gap them accordingly. If you have a powerful electronic ignition, it wouldn't hurt to gap the plugs a little wider. I'm a pretty by the book kinda person and that's why when it comes to something like spark plugs I stick with what the manufacturer recommends.

« **Reply #2 on:** September 22, 2011, 02:58:59 PM »

Quote from: 76NORDIC on September 21, 2011, 07:16:09 PM

Right now I am running the Bosch platinum plus plugs. The HR9BPX. I decided to take a look at a couple tonight, seeing as I put em in about 3 or 4 years ago and haven't checked them since. They are a rust color almost brown, and the gap is at 45 to 46 now. If I remember right I gapped them at 40 to begin with, not sure cause it's been so long. Should I replace them??? Opinions are like assholes everyones got one, so let's hear it guys!!

I use standard,, cheapy conventional spark plugs for normally aspirated recreational marine engines,, usually about 2 heat ranges colder than stock due to the difference between the way the engines are used in a boat from a conventional, low rpm street engine, and usually Autolites that can be purchased at your local parts store for under $2 each

For forced induction or race engines, I tend to use NGK plugs, as I had fine success running them in my own super charged and turbo charged engines in my old Schiada ski race boat.

As far as I know, the rare metal plugs were developed to meet increasing demands for lower maintenance vehicles, and do not offer any advantage for your boat engine.

« **Reply #3 on:** September 22, 2011, 03:43:27 PM »

I run the NGK's , and have never had a problem.

« **Reply #4 on:** September 22, 2011, 04:42:06 PM »

AUTOLITES in everything and my nos guy likes me to use them when i was drag racing but ngks are cheaper

« **Reply #5 on:** September 22, 2011, 05:13:39 PM »

Thanks guys

Am now leaving the spensive plugs and going to autolite. What range you guys using??? 460 Ferd

« **Reply #6 on:** September 22, 2011, 05:43:05 PM »

In my opinion your plugs indicate to me your engine is okay, plugs jus ran there course. i prefer Autolite or motorcraft plugs.....Never had good luck with Champion or NGK... Just my thoughts

« **Reply #7 on:** September 22, 2011, 06:24:18 PM »

WOW Shorty, your still alive

Thanks for your input also!!!

« **Reply #8 on:** September 22, 2011, 07:19:26 PM »

Quote from: 76NORDIC on September 22, 2011, 05:13:39 PM

Thanks guys Am now leaving the spensive plugs and going to autolite. What range you guys using??? 460 Ferd

I don't know the Ford numbers,, sorry. My suggestion is to look up the stock plug, and find a non resistor plug(unless you have a stereo in the boat) that is one or two heat ranges colder than stock, particularly if you do any sustained higher rpm running.

You can even check the cross reference to the plug you are running.

By the way,, my first street car, a 66 Mustang, I always ran one range colder than "stock" even though the engine was not internally modified. Stock engine with tube headers and a 4 speed trans, driver with a heavy foot.

« **Reply #9 on:** September 22, 2011, 09:04:00 PM »

Quote from: 76NORDIC on September 22, 2011, 05:13:39 PM

Thanks guys Am now leaving the spensive plugs and going to autolite. What range you guys using??? 460 Ferd

How old is your engine? Tomorrow when I get in to work I'll jump on my computer real quick and I'll get you some part #'s A colder plug is gonna richen your mixture up a bit, but if you want I can get you #'s for colder plugs as well.

« **Reply #10 on:** September 22, 2011, 09:06:42 PM »

Trying to remember

but do know it is early 70's Thanks for the info

« **Reply #11 on:** September 22, 2011, 09:17:16 PM »

mark just cross reference the plugs u have to a different plug or use the same again, they worked well for you

« **Reply #12 on:** September 22, 2011, 10:18:52 PM »

Quote from: N2GLOCK on September 22, 2011, 09:04:00 PM

How old is your engine? Tomorrow when I get in to work I'll jump on my computer real quick and I'll get you some part #'s A colder plug is gonna richen your mixture up a bit, but if you want I can get you #'s for colder plugs as well.

A colder plug does not change the fuel mixture

« **Reply #13 on:** September 22, 2011, 11:41:17 PM »

Bosch platinums suck...throw them
away. Run a conventional plug. NGK and Autolite make the best plugs on the planet. Stay away from Champion.

« **Reply #14 on:** September 22, 2011, 11:46:28 PM »

Quote from: obnoxious001 on September 22, 2011, 10:18:52 PM

A colder plug does not change the fuel mixture

Correct. A "hotter" plug simply has more exposed center electrode...more exposed protrution into a cylinder means that protrution will be exposed to more heat and therefor, retain more heat...eventually leading to preignition in some cases. Run the coldest plug you get away with without fouling it, and adjust your mixture for the right color. Reading plugs is a skill I've not yet mastered...few have. You can tell a lot if you know what to look for. Color is rough indicator, ground strap heat line is another, and how far the color extends down the insulator is another. I generally err on
The fat side, because I'd rather be 2/10 slower than a set of pistons broker.

« **Reply #15 on:** September 23, 2011, 12:39:56 AM »

I run Autolite 26's. Cheap, never seen one foul, and to be honest, gonna run the same on the blown, injected, E85 motor.

Ray

« **Reply #16 on:** September 23, 2011, 02:54:32 AM »

I run Autolite 25 in my 460 Ford.

« **Reply #17 on:** September 23, 2011, 08:41:08 AM »

The most common part #'s for BBF 4bbl motors from the 70's are as follows:
Autolite #25
Motorcraft ASF42C or SP450
NGK 6630

All call for to be gapped at .044

« **Reply #18 on:** September 23, 2011, 08:44:41 AM »

Quote from: lbhsbz on September 22, 2011, 11:46:28 PM

Correct. A "hotter" plug simply has more exposed center electrode...more exposed protrution into a cylinder means that protrution will be exposed to more heat and therefor, retain more heat...eventually leading to preignition in some cases. Run the coldest plug you get away with without fouling it, and adjust your mixture for the right color. Reading plugs is a skill I've not yet mastered...few have. You can tell a lot if you know what to look for. Color is rough indicator, ground strap heat line is another, and how far the color extends down the insulator is another. I generally err on
The fat side, because I'd rather be 2/10 slower than a set of pistons broker.

So if a colder plug does not change the mixture why did you say "Run the coldest plug you can get away with without fouling it, and adjust your mixture for the right color" That statement right there from you tells me that a colder plug will make the mixture richer. Isn't that in itself, changing the mixture?

« **Reply #19 on:** September 23, 2011, 09:04:54 AM »

Thanks guys for the info. Definately won't be buying the spensive stuff anymore

« **Reply #20 on:** September 23, 2011, 09:07:14 AM »

No, it won't change the mixture...it may slightly change the mixture requirement, but not the mixture. you could screw a pipe plug in where the plug is supposed to be and the same mixture would be be drawn into the cylinder.

A colder plug will have less chance of pre-ignition...and can also run a little less conservative tune.

« **Reply #21 on:** September 23, 2011, 06:27:38 PM »

Quote from: 76NORDIC on September 23, 2011, 09:04:54 AM

Thanks guys for the info. Definately won't be buying the spensive stuff anymore

Mark , You and I machined/built that 460 3 or 4 seasons ago and you been running the same plugs all this time?... Geez By a set of spark plugs bro

76NORDIC

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SS-201

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