I just put NGK spark plugs in my hopped up 8BA and the results are amazing. Starts like a rocket. Can I use these plugs in a 59AB? Thanks.
I got NGK in my C59A. Like the old school threaded stud/knurled nut for the plug lead wire. [edit] Checked again, and I actually got the 3212 NGK plugs (exact same as the 3112, but different heat range) and used the knurled brass nuts from Brillman. https://brillman.com/product-catego...products-j-spark-plugs-spark-plug-thumb-nuts/ NGK Heat Range Chart. Interesting that they say there is no direct comparison for heat range with Autolite plugs. https://www.ngk.com/heat-range-conversion-chart-2
What's the number on the NGK plugs you're using? I'm using Champion RC12YC in my 59 because that's what Edelbrock recommended.
Not sure if you were asking me, or the OP. I’m using the NGK 3112. https://www.amazon.ca/dp/B000CSIRIC/?tag=atomicindus04-20
This is the first question that must be answered. Many folks are running aftermarket aluminum heads which opens up a new can of worms. There is no one good answer for aftermarket heads. I believe Edelbrock's use 3/4" reach plugs. I run extended tip Champions on Edmunds heads because of the spark plug location. We had an extensive discussion on the Ford Barn about this and came to the conclusion That Offenhauser heads require a special spacer to position the plug properly. And there are many other varieties. Almost all aftermarket aluminum heads use longer reach plugs than stock. There is a reason for this, mainly cast iron is stronger than aluminum. I've seen heads with the bottom 2 or 3 threads all carboned up from running stock length plugs in aftermarket threads. I've seen heads with the bottom threads chamfered out to unshroud stock length plugs. Both of these are wrong and decrease efficiency. The point here is to determine the proper fitting plugs first, and then start worrying about plug brand and heat range.
Tubman gave the suggestion/answer in post 10 that has to be addressed first and formost. All flathead heads are not created equal and the newer aftermaket heads often don't use the same thread diameter orr reach that stock heads or older aluminum heads do. Throw in that the Champion R12YC is 14 MM 3/4 inch reach resistor plug while the NKG 3112 is 14 MM .437 reach non resister plug. There are a crap ton of things involving picking the right plug for your application and your specific use.
I use 3212 (B-6L) in a stock 59AB. I bought a bunch when summit was selling them cheap years ago. Funny thing is it fits the Studebaker also.
NGK B6L is the way to go on a 59A Ford flathead. This is an excellent spark plug to use on the 59A engines. My 59A flathead runs great and starts right up first time, even after sitting for two or three weeks. The spark plug length seems just right for most aluminum heads.
I would be careful about making blanket statements like this. And there is no such thing as "just about right" in engine building.
I edited my post and eliminated the word "about". So does that suit you now or have I still got it wrong? The heads I am using are NOS script Sharp heads and the spark plugs fit and work perfectly.
From bitter experience, I know that Edelbrock, Edmunds, and older and newer Offenhauser heads all take different reach plugs. Sharp's I have no experience with, but you can bet your boots I'd check 'em carefully before I used them. It's not that hard to turn them upside down and check. Here's what a well fitting "J" series (1/2" reach) Champion looks like in an Edmunds head. This an extended tip plug ("Y" suffix) which works great in an Edmunds head with the relocated spark plug. Don't try this with any other brand, as the valve will close up the gap in one revolution. Also, you never know what has happened to a set of used heads in their former life. I have seen aftermarket heads spot-faced on the top side or ground out on the bottom side so stock 3/8" plugs will "fit". Unless they're brand new with a factory recommendation for what plug to run, each set is an adventure.
My 59A engine was built by Brothers Custom in Detroit Michigan. Before the heads were installed everything was checked for clearances and the NGKB6L plugs were installed and everything tested on Bill's engine test stand. No problems, everything worked as it should and has ever since, and that was about 6 years ago. I got two pairs of new Sharp heads that were made by Wilcap from a friend of mine before the prices of new heads went out of sight. Excellent heads. I like to start with new heads on a new engine build. That way you know exactly what you have and you can go from there. The Edmunds heads you have would be used heads and would have to be checked carefully. Heads could have been milled and also should be checked for hardness. Some of the old heads can go soft over time and lose their hardness. I had that happen with a pair of older Edelbrock block letter heads. The aluminum just came off in strands when the pockets were being milled. Heads were too old and the aluminum became soft. I don't know who can afford a set of new Offenhauser heads anymore. Their prices on new heads are higher than nuts on a giraffe. I would love a set of their new thick heads that they have made a few sets again, but they are in the $2500 range for pair of new heads. Anyways the OP wanted to know if the NGK plugs will fit a 59A engine and the answer is yes.
Obviously, the Edmunds heads I am using are used. The relocated spark plugs offer so much of an advantage, that they are all I use. I have a set of new, unused Offenhauser's on the shelf, but plug fitment problems (and the superiority of the Edmunds) have kept them there for the last 20 years. I have never experienced the problems you have mentioned on any of my heads. This is probably because I am pretty picky about what heads I will buy and I will pass on any that that are not in the best of shape. Every set I have obtained had plenty of "meat" left, and all had to be milled to bring the quench down to the recommended .045" to .050". I fit every head individually to each engine to obtain optimum quench, which I believe is very important for an engine to operate at top efficiency. Did you fit your Sharp heads for optimum quench? Just curious. I have had the heads on my DD '51 coupe since 2016 and on my "Hot Rod Motor" since 2020 with no problems. I am still running the original plugs on both engines. A check last summer showed the plugs in the '51 to still be in excellent shape. I agree with you about used heads if you are trying to rehabilitate a set of "wall-hangers" with re-doming and heli-coils, but that's obviously not what I do.
Got all my spark plug wire stuff from Brillman. Got the stranded copper wire. One end already had the loop to go over the stud on the spark plug, and I crimped and soldered the terminal at the other for the dist cap.
NGK B4L or B6L will work perfectly with 8BA and 59A Ford heads. They also work great in many brands of aluminum finned flathead heads. BUT with aluminum heads its important to check the valve to plug interreference in any flathead especially if a higher than stock lift cam has been installed. These plugs are also a perfect replacement for the Champion H-10 plugs. NGK plugs are used in all the flatheads I'm involved with including the ones that run well over 200MPH Ronnieroadster
I will take issue with this statement. Edelbrock heads take 3/4" reach plugs. You can't be saying that 7/16" reach plugs are a good fit for them? I run 1/2" reach on Edmunds heads; I sure want to fill that last thread in the head, and I want that projected tip out there where it does some good. A lot of us went through the exercise on The Ford Barn where we decided that nothing fits Offenhauser heads perfectly and spacers are required. Fitting aftermarket heads on a flathead is more than just boltin' 'em on, especially given the number of used, modified heads out there.
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