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Read my plugs for me...

MarPar

If it weighs, it pays
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Pulled my plugs out of the Dart last night, and this is what they look like...

DSC09358.JPG



225 slant 6, edelbrock 500 4bbl, unknown cam-but pretty lopey, and Autolite 65's for the plugs.

Vid of the motor running...



checked the gaps as I pulled them out and below is the list.

#1--.30 starting

#2--.28 starting

#3--.28 starting

#4--.30 starting

#5--.28 starting

#6--.28 starting

So it seems to me the motor to be running a little rich. I still need to fiddle with the carb a little bit, but she does run relatively well. My question is, should I gap them all to .28? .26? .30? The cam is what's throwing me off. Stock gap for a 225 /6 is .35, but obviously this is not a stock setup.

Bigger cam=smaller gap?

Should I change to hotter/cooler plugs?

Thank you Gents. {and I use that term very loosely lol}
 
One toward the right looks like it running slightly rich. What's up with The one on the left end, looks like it's oil-fouled ?
 
One toward the right looks like it running slightly rich. What's up with The one on the left end, looks like it's oil-fouled ?

None of them were wet when I pulled them out. then again, I havent run the car in 2 years.
 
I've just noticed this today, on my phone, but all pictures are to the right of my screen and I have to hold my phone sideways to see the right side of the pic and don't always see that far?

Anyway, it does look like the one on the left has some oil contamination. Maybe that cylinder isn't broke in fully or there's a valve seal that's not up to snuff. Not being a daily driver and getting a good long run every day, I wouldn't worry about them. Maybe get a set of NGK of the same heat range and just run her. .035 on the gap.

That SOB sounds great! Sounds like an eight cylinder with that cam:thumbsup:
 
That's a very cool Dart Mario! That S6 sounds pretty good to boot!
That one on the left looks like it has a seal of guide leaking. Maybe its from sitting those 2 years.
I would buy a new set and put some miles on it then read them...
 
I've just noticed this today, on my phone, but all pictures are to the right of my screen and I have to hold my phone sideways to see the right side of the pic and don't always see that far?

Anyway, it does look like the one on the left has some oil contamination. Maybe that cylinder isn't broke in fully or there's a valve seal that's not up to snuff. Not being a daily driver and getting a good long run every day, I wouldn't worry about them. Maybe get a set of NGK of the same heat range and just run her. .035 on the gap.

That SOB sounds great! Sounds like an eight cylinder with that cam:thumbsup:

Thanks Kid! That's what drew me to her in the first place!

You reckon .035 gap? the cam and the big carb wont affect it?
 
i'd say fuel distribution issue. without a picture of the intake and carb my guess would be to stagger the jetting.
 
That's a very cool Dart Mario! That S6 sounds pretty good to boot!
That one on the left looks like it has a seal of guide leaking. Maybe its from sitting those 2 years.
I would buy a new set and put some miles on it then read them...

Thanks Mike! She's a fun little ride!
 
Never heard a six cylinder idle like that, would never have know it wasn't a V-8 until you revved it up a bit. Must be a radical camshaft profile.
 
So I took another look at the plugs and y'all iz right. Look at the cardboard, it has an oil ring around #6.

DSC09367.JPG


So a valve guide? Can I replace it without ripping the top end apart?

I take it I have to replace the ignition box while im at it lol??

DSC09364.JPG
 
i use the ngk s on mine gapped them at .035 and run a msd coil.there all just a tad dark
i have the twin carb set up from clifford and a 268 cam . yours sounds lumpier than mine
i'm running twin 2 barrel webber that open all together at same time( not primary then secondary)
you might have crap in your gas tank and now in carb. because you said it was sitting.
check fuel filter . but also it might clean up after you drive it a bit , make sure the intake gasket it is not
leaking air, ( i check by spraying brake clear around it to see if idle picks up)
 
Pulled my plugs out of the Dart last night, and this is what they look like...

View attachment 526434


225 slant 6, edelbrock 500 4bbl, unknown cam-but pretty lopey, and Autolite 65's for the plugs.

Vid of the motor running...



checked the gaps as I pulled them out and below is the list.

#1--.30 starting

#2--.28 starting

#3--.28 starting

#4--.30 starting

#5--.28 starting

#6--.28 starting

So it seems to me the motor to be running a little rich. I still need to fiddle with the carb a little bit, but she does run relatively well. My question is, should I gap them all to .28? .26? .30? The cam is what's throwing me off. Stock gap for a 225 /6 is .35, but obviously this is not a stock setup.

Bigger cam=smaller gap?

Should I change to hotter/cooler plugs?

Thank you Gents. {and I use that term very loosely lol}

Here's my take on what I see. #1(left on my screen) is the same as 4,5 and 6. It was probably the last cylinder on "intake" when the motor was shut off and never fired. Fuel leeched the carbon and left what appears to be oil. 2 and 3 appear as though they were in a lean enviroment probably because of the firing order. The other runners were getting a richer mixture. Not surprising with that size of carb, cam should make little difference. I would gap .035 hotter Motocraft or use iridium plugs which are not very sensitive to heat range and always fire a hot concentrated spark. You also don't have to worry about indexing the plugs which helps when intake and exhaust manifolds are on the same side of the head. I'd also add a bit more timing to the beast to get maximum fuel burn. Advance to "ping" then back off until it's gone. Most interesting engine you've got there!
 
i use the ngk s on mine gapped them at .035 and run a msd coil.there all just a tad dark
i have the twin carb set up from clifford and a 268 cam . yours sounds lumpier than mine
i'm running twin 2 barrel webber that open all together at same time( not primary then secondary)
you might have crap in your gas tank and now in carb. because you said it was sitting.
check fuel filter . but also it might clean up after you drive it a bit , make sure the intake gasket it is not
leaking air, ( i check by spraying brake clear around it to see if idle picks up)

thanks 67! I havent started it yet, so there may not be crap in the carb.

and thank you for the intake gasket tip!
 
Here's my take on what I see. #1(left on my screen) is the same as 4,5 and 6. It was probably the last cylinder on "intake" when the motor was shut off and never fired. Fuel leeched the carbon and left what appears to be oil. 2 and 3 appear as though they were in a lean enviroment probably because of the firing order. The other runners were getting a richer mixture. Not surprising with that size of carb, cam should make little difference. I would gap .035 hotter Motocraft or use iridium plugs which are not very sensitive to heat range and always fire a hot concentrated spark. You also don't have to worry about indexing the plugs which helps when intake and exhaust manifolds are on the same side of the head. I'd also add a bit more timing to the beast to get maximum fuel burn. Advance to "ping" then back off until it's gone. Most interesting engine you've got there!

Thank you for the very informative post Yatzee! I copied and pasted it to my 'Dart file' for further digestion.

Also, I didnt even think of the indexing of the plugs for motor! Im used to opposed cylinders, not inline ones :D

So a couple questions for you, @Yatzee, if you dont mind...

How does one determine the heat range of the plugs? I looked up a few sites and they were a bit confusing.

And what is the relationship of the heat range to performance? How does one affect the other?

:thankyou:
 
I don't think I have ever seen a 6 with a quad on it. Like Dibbons, I never would have guessed by the sound of the exhaust. :thumbsup:
 
Thanks Kid! That's what drew me to her in the first place!

You reckon .035 gap? the cam and the big carb wont affect it?

I think the .035 is unamanous. There are other good suggestions on here also.

When you get her fired up the next time, check the choke position and see how long it takes to open. When bone cold, it should be closed but not with a lot of tension. When started, see if it's open about a quarter inch and then opens fully within a few minutes. Being too tight and taking too long to open could cause the rich conditions.
 
Just for reference, 225 engine uses the N14Y as the stock plug, or Autolite 66 plug, which is hotter than what you have in with the autolite 65 plugs which are equivalent to RN12Y. Stock gap on your 225 should be .035.

Oh, and the carbon on the plugs is indicative of rich condition.
 
Last edited:
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