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I am using an NGK plugs. It is a heat range 8 plug but I still seem to have some carbon fouling going on. The carb seems to be setup good as the plug are no longer gas fouling. Should I go to a hotter plug?
 

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Run it down the road flat out , bring it back and pull them out. If they look ok , you may want to leave them . We use NGK all the time they are great plugs,I'm not sure what you mean by heat range 8 . Find out the recommended plug from your builder and crossover the number to NGK . I don't think that 1 step hotter will hurt anything unless your ulta high comp or blown. You may also try advancing the timing a degree or 2 If you have an MSD you may want to look at the instructions I just read them again and noticed plug gap recommendations . It's in the instructions for the box on the website. I think by starting the fire sooner (timing) and a hotter plug you might score. Glad to hear the carb is sorted out . Bob
 

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carb set up???

Kerry we talked awhile back on carb set ups. What did you end up with for jets and PV #'s?
I'll check to see what plugs ford put in my 347. thanks
Stan
 

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Greg knows more about the part # than I do I missed that info. Mine came back from the builder with the dyno plugs (cold) still in it !! Changed them , adjusted the timimg and a different power valve and a spring in the distributor woo hoo. Bob
 

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plug #

Kerry Checked my # motor craft agsp 32C Also my plugs are a rusty tan, the electrod has a white deposit running around the entire circumfrence at the tip, very light just visible. Anyone tell me what that means??
Thanks Stan
 

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2001C5....Bob's advice is spot on IMO . When we run about town or idle has little to do with performance pluig reading and much to do with lower circuit AF tuning. RPM's make the difference. NGK Tech Line were terrific when I had questions. Given street limitations it was recommended to bring my car up in the mid 5's in 2nd and hold it there 5-10 secs, quickly hit it , get off, shut her down, roll it off the road then pull plugs.
I laid a few plugs on a towel and took some good digital close up shots focusing as much on the depth of the ceramic cone as the tip. I called back NGK Tech ,e-mailed the photos while on the phone and was advised to drop from the 9's to the #8 plugs.

Stan....If I recall a plug is in the proper heat range if the white area you're speaking of ends "between" the electrode base and where it starts to curve .
 

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Discussion Starter #8
Kerry we talked awhile back on carb set ups. What did you end up with for jets and PV #'s?
I'll check to see what plugs ford put in my 347. thanks
Stan
I ended up buying another mighty demon. I am sending the first one in for service. I left the 71 and 79 jets in the new one, put in a 4.5 or 5.5 (can't remember off hand) PV and it works very good. I still need to tune the PV by using a vac gauge, but I am very pleased.

The plugs I am using are V-Power racing, stock # 4554, the NGK # is R5671A-8. I assume one step hotter would be R5671A-7?

Here is a little more info...

I have had these plugs in for for about 100 miles. They were looking good the first few times I checked them. They even made it through a parade and still looked good. I flooded the car by accident about a week ago. After it was flooded, I did get the car started but only took it around the block and then stored the car for a week. I pulled a plug after it set a few days and saw the carbon buildup. I drove it yesterday for about 40 miles. Pulled a plug last night and still had the carbon buildup, but no gas fouling. It seems they were doing great until it was flooded one time. Only other change was I richened the 4 idle mixture screws about 1/2 turn. With the really cold weather the car did not want to idle when I came to a stop. After adjusting the mixture it was great.

thanks
 

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Kerry you probally never really burnt off all the carbon deposits with only 40 miles of around town driveing. May still be seeing some left over deposits.
What you see on the ceramic tip. Is mostly from the carbs idle and low speed curcuit jetting. Rich here and it shows up near the insulators tip, right where the electrode comes out of the porclean on the prclean itself. black ring up top would be rich. Too lean or plug too hot ceramic would look shinny,or glazed.
The main jets mixture like what you would see if doing some hi rpm or wot runs. The mixture ring will be down inside the plugs shell where the porslean meets the metal shell of the plug.
either a bright light and magnifying glass to read or cut the shell away from the plug to see.

Kerry,how does the ground strap itself look? Is the actuall strap black it's entire lentgh? Is it only black part way up from where it is attached to the plug base?
Also how does the shell, non threaded part look?
A too cold of a plug heat range can have a black and sooty shell. It can also have a black ground strap. The ground strap itself should be clean of carbon or any noticable deposits from it's tip to just past the bend where it's welded to the plugs shell. Should be a noticable line just below where this strap makes the bend closer to the point it's welded to the shell.
Be aware timing will also have an effect on this(ground strap) and where that line is actually seen on it.
Not enough timing or too rich can carbon the strap as can too cold of a heat range.
Unless you see signs of plug being too hot. glazed porclean,shinny no longer chalky looking porslean. or blueing of the electrode or groundstrap you'll be safe to up a step in heat range.
It tough to choose heat range when doing around town driveing. Really need some wot or higher rpm running to help select range.
It's almost impossible to ead plugs while still tuneing the carb. Deposits stay on the plugs for such a long amount of time it's easy to get false information when looking at them. Reason so many sets of plugs are used when tuning carbs. It gives fresh info with no left over coloring or deposits. I like to at least replace 2 plugs on each bank when jetting till close for better reads. Once done new set for final tweaking and adjustments.

Stanley,faint white looking deposit right at the very tip of the electrode is ok. Shows plug is not too cold.

Of course a pic of your plugs may help some also:)
 

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Thanks

Hind Sight thanks for jumping in, was hopping you would!
Kerry I have 67's and 79's in my carb and a 4.5 PV. Runs great "IF" I go wot, but if I try to run the RPM's up pretty quick on just the primarys it falls on its face. I'm figuring the PV isn't opening and I'm running out of fuel, going to go back to the 6.5PV guessing from what H.S. said that my plugs must be looking OK.
Stan
 

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Discussion Starter #11
I am going to install some plugs 1 range hotter. I had been gapping them at 42. Any thoughts on what I should gap the hotter plug at?
 

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Discussion Starter #12
I went ahead and pulled all the plugs. They look bad but the car really was running good. As I said earlier these plugs looked good during 3 or 4 checks and then I flooded the car during a semi-warm start.

I find it odd that they all are carbon fouled except one that looks to be gas fouled.

Seven look like this..


Here is what the other one looks like..


I am going to chicken out on the hotter plug. I am going to put the same heat range plug back in and bump the timing alittle. I was running 23* initial timing with a total of only 31* due to a Don Gould advance stop bushing. I am going to bump it up to about 25* initial. I know it sounds high, but I have had it that high before with no hard starting issues.
 

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Kerry,
Those look pretty bad after a 40 mile drive. How did you drive the car? Easy, hard, crusing? Reading a plug involves not only looking at the tip but the side electrode, and end of threaded area as well. From what I've read, seen and experienced first hand I have to say that engine is running very rich. See how the side electrode and threaded area are powdery? Those areas indicate a rich mixture independently of the porcelan tip. A hotter plug will clean up the tip area but the fat mixture will still be there and is most likley an issue you may not be aware of. That soot is also all over your heads, pistons and exhaust valves. What I suspect is your engine like mine runs great in the 11.8 to 12.5 AF range (cruise and WOT) but the plugs looked like yours (not quite as black), the mpg sucked, and the oil got dirty in 1000 miles.

Now that I'm rejetted and modified (Holley 570) the plugs look real nice with the ground electrode half clean, the threaded part dry and not sooty, and the tip is off-white. That's with an AF of 13-14 cruise and 12-13 WOT.

I would suggest you try the timing change and also look into the AF ratio. I bet your pipes are sooty as well.

Here's a pic of one of my plugs (stock FMS plug) after a 50 mile cruise at various throttle settings. This plug has 4,400 miles on it.


Greg
 

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Kerry you'll need more total advance to make the little Ford motor run . The limiting bushing is probably why it falls on it's face . Remove it . Forget about setting the initial lead and set the timing at 28-34* at full advance with any vacuum advance disconnected . You'll be surprised where the initial lead ends up when you set the timing this way. This may also improve your throttle response. Good to know about the NGK tech line . Never needed it .....yet .... Good luck, Bob
 

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Discussion Starter #15
Here's an update.

I changed the plugs and set the total timing to 32*.


I left the house and when I would come to an idle the car wanted to die. It was only about 35 degrees out so I richened the 4 idle curb mixtures screws 1/4 turn. In hind sight maybe a idle eze adjustment would have been the right call for the Demon. Then when I would get on the gas the car was breaking up. I pulled over and richened the 4 idle curb mixtures screws 1/2 turn. The car ran very well and no longer tried to breakup when I stepped on the pedal.

Was this the right thing to do? I have read the manual over and over and do really not understand the idle curb mixtures screws. They are the only mixture screws, right?

After about 20 miles I came home and pulled the plugs. They were as black and shooty as the pics I posted yesterday. No need for more pics, they look exactly the same.

Remeber, I drove in a parade at idle for 2 hours a few weeks ago and the plugs were perfect when I checked them. Really all I have changed is the 4 idle curb mixtures screws. I can set them back to 1 1/8 turns out which is where they were at the parade. In theory then plugs should be clean like they were before, but I would have the idle and break up issue. I think the idle eze can fix the idle issue, what do i do about the break up issue?

thanks
 

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Kerry agree with what was said about running more total timing. I shoot for 34-36* when fully advanced.
At what rpm does the timing start advanceing. If starting too late,this can add to the problem. You want to see timing starting to advance around 15-1800 rpms or just slightly above idle speed. Fully advanced around 3-3200 rpms. Having a too slow of an advance rate,makes the engine rely on it's initial only and may be why a high amount of initial is needed. Most times 20* is usually enough initial once done. Keep in mind each engine is different ad may need slightly different setings. The above should be very close to what you'll ed up with.
Gap plugs at .035". Never found any benefits to a wider gap then this in a street motor.

Questions. At present how are you seting the carbs initial adjustments?
Are you seting front and rear t slot exposures equal, then doing the same for each mixture screw? Idle speed being set by the idle eze only with no further adjustments to the curb idle speed screws once slot exposure set? Curb idle speed screws only being used to set t slot exposure and not idle speed. Remeber as you increase slot exposure. you richen idle afr's.
This is what "most" times works for setting up a BG carb that is used for street/strip.
This is also how I would "first" attempt to set these carbs up.
However this is not always what ends up working the best for a street driven engine that does'nt see much wot operation.
Sometimes a different set up is needed to keep the engine running cleaner at low rpm,low speed operation like you would see when driveing around town or cruising.
It can usually be done to carb's that have the idle eze feature since this(idle eze) can be used to allow additional air into the engine.
You will also need to be running a pcv vlave on the motor that I'm pretty sure you are?

Once timeing rate of advance along with amount of total timeing is correct. Then float level is rechecked and set so fuel is just at the lowwer threads at idle,front and rear.
Mixture screws set for best(smoothest) rpm's and vacum.

If new plugs that can be a step up in heat range still look carbon fouled.
You can try the alternete set up of the carb better suited for street useage.
This involes closeing the rear throttle blades compltelly,then opening them up 1/8 of a turn from closed with the idle speed screw only.
Set front blade at the normal .020" or square t slot exposure.
Next set curb idle with idle eze screw and move to the idle mixture adjustment.
What you will find now is when setting idle mixture. The front screws will end up at a similar setting of 1- 1+1/2 turns out. But the rear screw "can" end up about 1/4-1/2 turn less.
The secondarys will only be feeding thru the idle "hole" and not thru the t slot itself makeing for a leaner idle/low speed afr.

This set up allows less fuel to be fed from the secondary side of carb at idle and also at low rpm cruise. Engine is now relying on the primarys to supply it's idle,transition and low speed cruise afr's.
This is due to having the secondary t slot closed off so not to add fuel.
This can only work if your able to get a high enough idle speed by useing the idle eze screw(air screw) without needing to crank open the primary blades so far as to over expose the primary t slot.
No need to fed engine from the secondarys t slot if not needed. Just waste gas and makes for a difficult tune at low speed and cruise when only operating on the primarys.

Unless you find a problem in how the timeing is advanceing or how fast it's advanceing.
Or problem with weak ignition or float level too hi.
The reason for the too rich of a low speed and cruise rpm's. Cruise rpm's being about 2500 rpm or lowwer. Around 2500 rpm and higher,mains are starting to add fuel to the already supplying ifr's or low speed jets.

The carbs ifr's(idle feed restrictors) are too large. You can sometimes compensate for this by useing the set up mentioned above if thier not too overly large. Next step would be replace them with smaller ones. Your carb has screw in replaceable ifr's so it's not a difficult job if needed.
In general that carb would come thru with ifr's in the .035-.038" range. In reality your engine combo would probally do well with ifr's in the .030-.032" range.
They come jeted this way to be sure they are rich enough for whatever engine carb gets bolted on. But also to help eliminate a lean dip in afr between shifts when going down the strip,and also helps if useing the 1 to 1 linkage instead of the progresive linkage. They work well for a race motor but are almost always too large(ifr's) for a street driven motor.

Install new hotter plugs
correct timeing total amount and recheck advance rate
Recheck float level front and rear.
do a quick check of coil out put. a visual at the coil wire or spark plug wire when cranking too see nice blue spark.

Once carb and ignition is dailed in. No reason your plugs won't look the same as what Greg pictured. Main problem is overlly rich idle/slot jetting caused by too large of ifr's.
Find above adjustments are not enough to correct the problem.
Measure the ifr's and if too large, I'll send you some smaller ones to install.:)
 

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Weee doggie, carbs is hard , and you even have an eze button!! HS is the man with Carbs . I'm going to stick with what I know , how to open a beer !! Good luck and Happy New Year, bob
 

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If you had clean plugs once and made no changes other than the idle screws, then in theory, all other things being equal, the plugs should clean up and the engine whould run as before if you return the idle screws back to the earlier setting.

Several other causes can make your plugs black. Choke staying on too long or closed too much, too high a fuel pressure or a high float level resulting from a dirty/stuck float valve.
 

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Discussion Starter #19
Thanks Hind Sight. I am going to re-read your post a few times today and get to tunning. It is in the 20's here today so it maybe a few day before I report back.
thanks
 

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H.S. thanks for jumping in again. Since Kerry and I are both working on the same carb and motor set up you are really helping us both! ONE question, at 1K RPM my motor shows 9" Vac. should I go back to my 6.5 PV and get away from the 4.5 PV I have in now? Motor runs great when I go WOT, but if I run RPM up on just the primarys motor falls on it's face like I'm running out of fuel.
THANKS, Stan
 
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