Electrical Spark Plugs

[jimzzilla]

I have a 1988 Mustang, D1SC Procharged 331 stroker motor, Blow Thru Carb, 586 RWHP. The Plugs in cylinders : 1, 4,5,8 run much richer than cylinders 2,3.6.7
I have been told to try a 1 heat range hotter Plug on cylinders 1,4,5,8. I am getting mixed opinions on weather or not to do this.
Anyone tried this, opinions anyone? thank you in advance, James.

 

[86HO5.0]

Sounds concerning to me. I don't foresee 1 heat range making a big difference/if any on the rich issue.

I'd also be concerned with ignition timing as well. Rich cylinder + more heat=detonation.

 

[gkomo]

I'm no master mechanic, but is it odd that its the fore/aft cylinders only that are running differently? Could that be a sign of something?

 

[86HO5.0]

What does the AFR look like on both banks throughout the RPM range as well?

 

[jimzzilla]

It's a simple set up, Blo Thru carb, MSD 6AL W/ boost reference Aeromotive A100 FPR. I have AFR meters on each collector bur for meters only.
Lite cruising AFR'S 10 - 10.5 full throttle 14 - 14.5

 

[86HO5.0]

I hope you meant light cruise 14-14.5 and WOT at 10-10.5.

That looks a bit rich to me. I'd start by leaning it out by 1/2 point across the board.

 

[Noobz347]

I hope you meant light cruise 14-14.5 and WOT at 10-10.5.

That looks a bit rich to me. I'd start by leaning it out by 1/2 point across the board.

This would be a good place to start.

You might also consider getting your injectors cleaned and flow tested.

 

[Bullitt347]

This would be a good place to start.

You might also consider getting your injectors cleaned and flow tested.

"Blow through Carb"...

I don't think cleaning Inj. is going to help. Lol

 

[General karthief]

Check gasket alignment under the carb too. Make sure the boosters are boosting and air passages are passing air.
What brand carb and type of hat?

 

[AeroCoupe]

What is interesting to me is that on a carb setup the four corners are showing fat and the center four are showing lean which I find to be opposite of what most get. Runners on the corners are longer so they tend to get less fuel. This is of course as long as the ignition system is working like it should.

 

[jimzzilla]

This would be a good place to start.

You might also consider getting your injectors cleaned and flow tested.

No injectors, Blo Thru Carb.

 

[jimzzilla]

Check gasket alignment under the carb too. Make sure the boosters are boosting and air passages are passing air.
What brand carb and type of hat?

 

[jimzzilla]

Ouickfuel blower carb - 650.

 

[jimzzilla]

So has anyone tried installing 1 heat range hotter plugs on the richer cylinders?
I am curious if it can help and can be done or if it is detrimental and not to do it. I have had mixed opinions.

 

[86HO5.0]

Heat range won't fix a cylinder that is too rich, that is a tuning issue.

The only thing a hotter plug will do is increase its resistance to fouling.

 

[Noobz347]

Yeah, yah... I missed the carb

 

[86HO5.0]

Are you running a carb spacer? If so, which one?

 

[General karthief]

Intake type?

 

[jimzzilla]

Are you running a carb spacer? If so, which one?

I do not remember the brand but it is 3/4'' SPACER.

 

[jimzzilla]

Intake type?

Vic Jr intake and Vic Jr Heads.