I was pondering the same. I don't have any suggestions here but I don't think changing spark plugs is the solution here
Electrical Spark Plugs
- Thread starter jimzzilla
- Start date
I was pondering the same. I don't have any suggestions here but I don't think changing spark plugs is the solution here
DadLife0724
Active Member
The issue lies on the 4 corners, not bank to bank.
I second the notion of the carb spacer type, open or 4 hole?
I second the notion of the carb spacer type, open or 4 hole?
That's a valid point, compare the rotational order of the fat cylinders, are they next to each other in order? look for spark skatter inside the cap, check for a crack.
What were the results and were the cylinders balanced? Have you done a leak down test? Just trying to rule out any mechanical issues.
Open.Definitely a distribution issue rather than spark in my opinion.
The possibility of a bad distributor cap causing a weak spark on those cylinders,
I need to look and see what the floor of that intake looks like, is the spacer open or a 4 hole unit?
Definitely a distribution issue rather than spark in my opinion.
open spacer.
The possibility of a bad distributor cap causing a weak spark on those cylinders,
I need to look and see what the floor of that intake looks like, is the spacer open or a 4 hole unit?
So has this problem been there the whole time or is it recent? If it’s recent you may want to do it again.
I have had the problem the whole time, been on the road for about 5 years. I do not have any complaints as to how it runs, it runs great.
The only complaint I have is as I said the 4 corner cylinders being richer than the inner 4 cylinders.
The plugs end up getting fouled after about 20 hrs of run time and the O2 sensors last maybe 30 hrs before they malfunction.
The oil gets Black and has a gasoline smell so I change the oil when I change the plugs.
My tuner says it runs on the rich side but that is the best he can do to keep idle and driveable.
He said if that is not good enough then I should go the way of aftermarket EFI.
Well all I can tell you is that the 351W in my Thunderbird has a CarbShop 830 on it with a Victor Jr and the corners run just a shade lighter on the plugs than the center four. I have always attributed this to the shorter path of center four runners getting a little more fuel at higher rpm. When running the nitrous the corners are pilled one step higher than the center four on the fuel side to compensate for this and the plugs look dead even.
So from my experience and my engine builder's experience (he is the one that tuned the car) the corners run lean on carbureted motors. This is why your situation is weird but intriguing.
So from my experience and my engine builder's experience (he is the one that tuned the car) the corners run lean on carbureted motors. This is why your situation is weird but intriguing.
Wonder if it is a fuel atomization issue i.e. its not getting atomized small enough so the corners cannot move the heavier particles to them like the center ones can?
I was told that is as good as it gets to not have drive ability issues, I am unable to do it myself.
That's why I wanted to try 1 range hotter on the plugs.
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