Plug reading

[RJRENTON]

Yes the mixture screws are the same left to right, front to rear. And I have a 1/2 spacer.

The 1/2" spacer could be causing your problem. The spacer causes a mixture pressure drop, which causes a velocity decrease which could affect mixture distribution in the manifold's long branch/runners.....just a thought.....Btw...the idle mixture screws don't effect off idle to main nozzle transisition....usually depends on the off idle air bleeds/fuel emulshon circuit......depends on the carbs model and brand......
BOB RENTON

 

[gtxrt]

your running a plug for over 10:1 compression or for racing.

 

[Aron Gleason]

This may help. What single plane manifold?
Jim

View attachment 1869787

M1 single plane intake

 

[RemCharger]

If there's a distribution issue , it will be the carb, not intake/ spacer combo.

 

[Aron Gleason]

If there's a distribution issue , it will be the carb, not intake/ spacer combo.

True, im sure its a matter of dropping jets in the front and rear. And doing some fine tuning elsewhere.

 

[gtxrt]

you never said what carb what fuel pressure and where are your float levels are set at or did I miss that.

 

[Aron Gleason]

you never said what carb what fuel pressure and where are your float levels are set at or did I miss that.

Its a modified 950 quick fuel/thumper carb. 6lbs of fuel pressure. Floats are set in the middle of the sight glass.

 

[gtxrt]

I hope the dodge safety sheriff doesn't pull you over cause you have a race car with racing carb, racing dist with no vacuum advance and racing spark plugs. lol

 

[Aron Gleason]

I hope the dodge safety sheriff doesn't pull you over cause you have a race car with racing carb, racing dist with no vacuum advance and racing spark plugs. lol

If he does, I'll just tell him to line it up and we'll race.

 

[QuickBpBp]

Curious. What's the combo you are running? Heads, cam, compression, convertor and gears. Exhaust size and does it go to the bumper?

 

[HEMI-ITIS]

Were those plugs pulled after a pass or after idling for 5 minutes? A very important piece of information LMOL!

 

[Aron Gleason]

Were those plugs pulled after a pass or after idling for 5 minutes? A very important piece of information LMOL!

I pulled the plugs after a 10 mile cruise.

 

[Aron Gleason]

And i dropped down on the idle feed restrictors from .035 to .033.

 

[HEMI-ITIS]

In order to properly read a plug you need to turn the key off at full throttle after an 1/8 0r 1/4 mile pass.
The reading is not accurate on that plug.........

 

[Aron Gleason]

In order to properly read a plug you need to turn the key off at full throttle after an 1/8 0r 1/4 mile pass.
The reading is not accurate on that plug.........

Yes i know that, but I haven't raced the car in 20 years.

 

[RJRENTON]

Yes i know that, but I haven't raced the car in 20 years.

IMO....go up one heat range hotter spark plug (NGK or Autolite or Champion or what ever brand is in vogue at the time) and don't worry about inconsequential things.....enjoy the car.....change plugs once year....plugs are cheap......
BOB RENTON

 

[gtxrt]

go up one heat range hotter spark plug

I think someone said that in post #6. but I guess that would be too easy. plus always run a vacuum advance on the street to keep the plugs clean.

 

[BSB67]

I think the answers to post #30 would be helpful.

And, tell us about it’s idle characteristics and where the idle mixture screws are set.

I agree with both Hemi-itis’ posts. Not too sure what operating condition the plugs represent. Probably blended.

A lean miss at idle will make a plug look like that in a minute. People tend to explain it away as a big cam, and then start chasing a rich condition.

 

[RJRENTON]

I think someone said that in post #6. but I guess that would be too easy. plus always run a vacuum advance on the street to keep the plugs clean.

Too easy is insuring that the torque on the right rear tire's valve stem cap tight but not too tight.....or are you just looking for something to do then report your detailed findings? Sounds like someone from California, who sufferers from OCD,. presents detailed explanations of vacuum advance readings in one degree increments and speculates which is the best. If you're looking for something to do, try different heat range and brands of plugs.......in spite of all the opinions that NGK is the only brand to use (you run the risk of the world coming to an end if you don't use NGK), why don't you experiment a little....then we all can debate why, what ever your determination was or is, is incorrect....because ....it isn't how i have MY car set..???.....Now we can debate the virtues of synthetic oil, or best wax, or alternator amp gauge vs volt metergauge, using distributor vacuum advance, either ported or manifold sourced is best....... just a casual observation.......
BOB RENTON

 

[RemCharger]

The only risk you run by not using NGKs is misfiring plugs. Not the end of the world .