Read my plugs for me...

[Glenwood]

Cool /6!
Interesting article on spark plug heat ranges
https://www.ngksparkplugs.com/about-ngk/tech-talk/spark-plug-basics

 

[metaldad]

sooooooooooooooo........... you're finally playing with the dart
can the gtx be far behind?

 

[RJRENTON]

Gentlemen,
My opinion re spark plug question....as the cam "seems" a little radical (it would be nice to know degrees, lift and how its installed--on center or advanced or retarded) as well as compression ratio. IF the cam has a lot of overlap or its installed retarded (to help on the top end), the cylinders will see a lot of residual exhaust retention thereby running cooler due to the retained gases. The engine will need a warmer plug, like Champion N12Y (OR N11Y) gapped at 0.035" (nominal). In factory engines with equipped with EGR, to control NOx, the plugs were usually hotter than those without EGR. The static timing should be around 5 degrees BTC and fully advanced (32 degrees total) by 2800-3000 RPM. its also unusual to have carb iinstalled the way you have. On an inline engine, USUALLY, the carb's primary bores are parallel (or axially) to the cylinder bores, to promote more even fuel distribution. It also appears that the carb is jetted slightly rich. Are you using the PCV system? Most of the after market carbs use PCV which helps the idle mixture.
These are just my comments & opinions....I'm sure others will agree/disagree.
Bob Renton

 

[MarPar]

Being too tight and taking too long to open could cause the rich conditions.

I will check the choke, Kid, thank you

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.

Thank you! My roadblock is understanding the 'hotness' of a plug vs not. Does a wider gap=cooler spark, or does the plug itself dictate how 'hot' it is? and wth is it with the resistors??

sooooooooooooooo........... you're finally playing with the dart...can the gtx be far behind?

oh, the GTX has been uncovered and ogled already...I finally took the Newport's interior out from the garage into the basement.

Gentlemen,
My opinion re spark plug question....as the cam "seems" a little radical (it would be nice to know degrees, lift and how its installed--on center or advanced or retarded) as well as compression ratio. IF the cam has a lot of overlap or its installed retarded (to help on the top end), the cylinders will see a lot of residual exhaust retention thereby running cooler due to the retained gases. The engine will need a warmer plug, like Champion N12Y (OR N11Y) gapped at 0.035" (nominal). In factory engines with equipped with EGR, to control NOx, the plugs were usually hotter than those without EGR. The static timing should be around 5 degrees BTC and fully advanced (32 degrees total) by 2800-3000 RPM. its also unusual to have carb iinstalled the way you have. On an inline engine, USUALLY, the carb's primary bores are parallel (or axially) to the cylinder bores, to promote more even fuel distribution. It also appears that the carb is jetted slightly rich. Are you using the PCV system? Most of the after market carbs use PCV which helps the idle mixture.
These are just my comments & opinions....I'm sure others will agree/disagree.
Bob Renton

Thank you Bob! I very much appreciate it!!




This forum is F***n great!! Thank you all for your knowledge and insight!!!

 

[idrivemopar]

The plug dictates heat range. Wider gap means weaker spark so less effective combustion of the gasses in the cylinder.

Not sure what you mean about resistors, they were added to reduce/eliminate rf interference in the electrical system of cars caused by the spark. If you think about it, its the same reason why you hear static from lightning on AM radio, spark plugs make tiny lightning bolts, and the resistor suppresses that noise from bleeding into the rest of the circuits.

 

[lewtot184]

i don't see oil on the plugs. looks dry to me; just fuel carbon. i'd try a 68x52 metering rod on the driver side first. this is probably a distribution issue due to the way the carb sits. the old hyper-paks had the carb sitting sideways which I think would have better fuel distribution with that type of manifold.

I was looking in the old engine manuals and it shows having to put dams in those 4bbl intake plenums for distribution issues. I think i'd try getting the idle and cruise cleaned up first by jet staggering and then look a WOT jetting before going the dams route.

 

[64BEL]

Sounds great, Mar!

 

[Darter6]

One of the biggest draw backs of the Slant 6 Engine was the poor fuel distribution. I raced Slants for years.There are things you can do. The number 1 and 6 plugs run 1 to 2 heat range hotter than 2,3,4,5. Yes N14 Y is the standard plug for the Tube Type Head.You may try the Autolites because they have a better selection of heat ranges.(as mentioned above)
With Mopar electronic ignition try a .040 gap.
Some say the position of the carb makes a difference.In theory it makes sense. I found no difference (see photos)
Remember this is not a V8 and not all things work the same with the Slant.I have ,along with other racers that Slants don't seem to like allot of timing.Most find that 30* total to be the max.We exclude the vacuum advance for the track.For me 23* total ran the best. Yours may vary. Just a few thoughts. Have fun !

 

[HEMI-ITIS]

I would start with a compression test and a leak down.Looking at plugs after driving and idling around is not a true reading.Supposed to click it off in high gear at peak RPM.In the street you can get away with the top of 2nd.
A friend of mine has that set up,his also sound like a 340 out the 2 tailpipes!

 

[Darter6]

I forgot to add that after sitting for several years,put some miles on it and then start dialing it in.Get that baby loosened up !

 

[Darter6]

Listen to this

 

[Darter6]

I sure miss that car.......

 

[MarPar]

Gentlemens, all your help is much appreciated. I will read up more on heat ranges and different plugs over winter when I have more time. Im sure Ill have more questions lol

So I have decided to slap the same plugs back in-all gapped at .30 (for now), check the carb over, and take a good gander at the gas tank. And hopefully fire her up before the snow flies.

She ran pretty well before I parked her, so im just doing some preventative maintenance to get her fired up again.

But that tank is what kinda worries me. It's full, and it has two doses of sta-bil marine in it; one for every year she's been parked. And she has been in a heated garage, if that helps.

I ran a scope down the filler neck a couple weeks ago and the gas looked the fine and no varnish smell either. Though I could not get a good look at the bottom or top of the tank itself.

All signs look promising, but im still hesistant to fire it up. All the horror stories of old gas has me spooked.

Thoughts?

 

[metaldad]

i have a drill operated pump, you could borrow.
a harbor fright hand pump somewhere, that will spill more than transfer
clear tubing, where we can devise a syphon.
sounds like a 12 pack afternoon

 

[MarPar]

i have a drill operated pump, you could borrow.
a harbor fright hand pump somewhere, that will spill more than transfer
clear tubing, where we can devise a syphon.
sounds like a 12 pack afternoon
:beer:

That sounds like great afternoon, Bob. We'll talk.

 

[Ski 61701]

Heres another thing to look at, well a couple. Your first cylinder might look a liitle darker due to the fact its closest to the water pump and it gets cooled first whereas the back cylinder is the farthest away and will be a tad hotter. Both of which could affect the looks of the plugs, just something to think about.
What colour step up springs are in the carb? If they have too much tension , at idle, your metering rods are going to be bouncing up and down, thus giving you a rich looking plug. You need to loosen the metering rod covers a twist them so you can see piston. Tighten the screw down, and warm the car up, or better yet do this on a warm engine. With the car idling, look at the metering rod pistons, they should be sucked down. If they are moving, you need a lighter spring. Goal is to have piston down, and once you rev it piston should be up thus allowing more fuel in the motor.

 

[multimopes]

Howdy Mar,
First off I love both of your cars. Aside from all of the great info you received, just a little info from yesteryear, if I remember and if things haven't changed a whole lot. By the way, (Slant6Dan) might have some good info as well. Way back when a bunch of friends of mine had slant6 Darts, Valiants and Barracudas, some guys fiddled with them by installing a 4 barrel setup and headers, much like yours. As time went by they found that the only 4 barrel manifolds they could find were I think made by Offenhouser. It seemed that no matter how hard they tried, they kept fouling the plugs, especially the #3 &#4. It turned out that Offenhouser claimed the manifolds were only for racing as no matter what they tried to compensate for with different heat ranges in different cylinders, the same thing kept happening. Evidently, Offenhouser bored the inside of each runner the same size. Because the middle two were the shortest, the cylinders always loaded up. I worked for a Dodge truck dealer back around 1976-77 when the first Super 6 engines were coming out. When Chrysler engineered the 2 barrel manifold for the slant, I believe they balanced the flow to each cylinder by using different size openings in the runners. #1 & #6 were the same, #2 & #5 the same and of course #3 & #4 were the same. If I remember, Chrysler claimed the Super 6 could almost equal the 4 barrels without the fouling problems making street drivability a no-issue. Also, I had to prep a few of the new pickup trucks back then and they ran so well I thought they had a V-8 in them until I popped the hood. I don't know how things have progressed in the after market these days or what make of manifold you have but it could be an on going thing, hopefully not. (Those old Hyperpaks were really something in their day.) As a matter of fact, I am quite sure I still have an old Offy 4 barrel manifold for the slant from those days, I just saw it the other day. I had several /6's over the years and several Darts. I came upon a very rare setup for the slant which was an aluminum manifold with 2 (one barrel) carbs on it. I installed it on my 63 Dart. It didn't run that great but sure as hell looked cool. I have pictures of it somewhere. Ran that for a few years until the bottom cracked out of it under one carb while driving and I never found all the pieces so I went back to stock.
A little long winded and most likely not much help but that's my story and I'm stickin to it!
By the way, please add the Dart to your photo Garage! Thanks and good luck.

 

[MarPar]

Howdy Mar,
First off I love both of your cars. Aside from all of the great info you received, just a little info from yesteryear, if I remember and if things haven't changed a whole lot. By the way, (Slant6Dan) might have some good info as well. Way back when a bunch of friends of mine had slant6 Darts, Valiants and Barracudas, some guys fiddled with them by installing a 4 barrel setup and headers, much like yours. As time went by they found that the only 4 barrel manifolds they could find were I think made by Offenhouser. It seemed that no matter how hard they tried, they kept fouling the plugs, especially the #3 &#4. It turned out that Offenhouser claimed the manifolds were only for racing as no matter what they tried to compensate for with different heat ranges in different cylinders, the same thing kept happening. Evidently, Offenhouser bored the inside of each runner the same size. Because the middle two were the shortest, the cylinders always loaded up. I worked for a Dodge truck dealer back around 1976-77 when the first Super 6 engines were coming out. When Chrysler engineered the 2 barrel manifold for the slant, I believe they balanced the flow to each cylinder by using different size openings in the runners. #1 & #6 were the same, #2 & #5 the same and of course #3 & #4 were the same. If I remember, Chrysler claimed the Super 6 could almost equal the 4 barrels without the fouling problems making street drivability a no-issue. Also, I had to prep a few of the new pickup trucks back then and they ran so well I thought they had a V-8 in them until I popped the hood. I don't know how things have progressed in the after market these days or what make of manifold you have but it could be an on going thing, hopefully not. (Those old Hyperpaks were really something in their day.) As a matter of fact, I am quite sure I still have an old Offy 4 barrel manifold for the slant from those days, I just saw it the other day. I had several /6's over the years and several Darts. I came upon a very rare setup for the slant which was an aluminum manifold with 2 (one barrel) carbs on it. I installed it on my 63 Dart. It didn't run that great but sure as hell looked cool. I have pictures of it somewhere. Ran that for a few years until the bottom cracked out of it under one carb while driving and I never found all the pieces so I went back to stock.
A little long winded and most likely not much help but that's my story and I'm stickin to it!
By the way, please add the Dart to your photo Garage! Thanks and good luck.

Thank you for your write up, Mopes!

"Long-winded" is great by me...that's how one learns just that much more.

I have an Offenhauser intake on my Dart. I have never taken it off to see if any of the runners are modified or not though.

I always have had a sneaking suspicion that a 4-bbl is not the best carb for a slanty. 2 1bbls, or better yet one big 2-bbl would be better me thinks. I reckon I need to find me a 76-ish intake Ma made and see how she does. My only stumbling block may be the GIANT cam she has in her. And I need to get rid of this dual exhaust too. Sounds like **** at speed.

Hmmm...giant carb, dual pipes, headers and an unbalanced intake...sounds like a chebby guy built it. All I need is posi rear-end and im set.

btw, I have 3 Mopes. Its a sickness, I know.

 

[multimopes]

I agree but it is a good sickness; I hope I never find a cure! I have 4! My sons Jeep makes 5. Come to think of it , my daughter also has a Jeep, there you have it!
By the way, I don't recall how many cfms your carb is. Back in my day when we walked 10 miles up hill both ways to & from school; Talk was to use a 600 cfm carb which I felt was wayyyyy too much, and being as you have a sizable cam and headers, not too far from what it needs. I had a 360 with headers & duals on a 77 Dodge B200 van and the carb was a 450 Holley with mechanical secondaries. It was a great setup and got 16 to 17 mpg over the road. I personally like mechanical over vacuum as it's easier to just bend a linkage rod then fiddle with a bunch of other stuff. Ever since I thought the 450 would have been a good choice for the 4 bbl slant 6. In my case, I think the guy who put the package together in the van even put smaller jets in primaries to save gas. I dunno but it worked great. Think about it, if you are running off the 2 barrels you are using less fuel. Come to think about it, there was no linkage rod for the secondaries when I got it so I took one from an old 1 barrel carb and hooked it up. It was really easy because I just removed the doghouse on the van and took it out for a ride and bent as I drove. A great setup. I do recall also that those who did use the 4 bbl on the /6 said the only way to keep it from loading up was to keep hammering the throttle. Don't give up on the headers & duals yet! I do remember they were a bit noisy but I liked it. I just turned the volume up on the stereo and smiled!

 

[MarPar]

I agree but it is a good sickness; I hope I never find a cure! I have 4! My sons Jeep makes 5. Come to think of it , my daughter also has a Jeep, there you have it!
By the way, I don't recall how many cfms your carb is. Back in my day when we walked 10 miles up hill both ways to & from school; Talk was to use a 600 cfm carb which I felt was wayyyyy too much, and being as you have a sizable cam and headers, not too far from what it needs. I had a 360 with headers & duals on a 77 Dodge B200 van and the carb was a 450 Holley with mechanical secondaries. It was a great setup and got 16 to 17 mpg over the road. I personally like mechanical over vacuum as it's easier to just bend a linkage rod then fiddle with a bunch of other stuff. Ever since I thought the 450 would have been a good choice for the 4 bbl slant 6. In my case, I think the guy who put the package together in the van even put smaller jets in primaries to save gas. I dunno but it worked great. Think about it, if you are running off the 2 barrels you are using less fuel. Come to think about it, there was no linkage rod for the secondaries when I got it so I took one from an old 1 barrel carb and hooked it up. It was really easy because I just removed the doghouse on the van and took it out for a ride and bent as I drove. A great setup. I do recall also that those who did use the 4 bbl on the /6 said the only way to keep it from loading up was to keep hammering the throttle. Don't give up on the headers & duals yet! I do remember they were a bit noisy but I liked it. I just turned the volume up on the stereo and smiled!

10 miles uphill to and from school!

And your handle is most appropriate!! lmao

So my Edelbrock {nee: Carter} carb is 500cfm...and the exhaust sounds like a hornets nest at 2000+ rpms. 6 into 2 headers with 2.5(?) inch pipes back to dual flowmasters...oye.