[Healeys] Spark Plugs

[Bob Spidell]

Since we're on the topic--sorta, we now know what the 'official' plug 
recommendation was/is--what do the numbers mean? An N5C is a 'hotter' 
plug than an N3C, but what are the real world ramifications for, say, an 
old Healey 4-banger? As I mentioned, I have the N5C in my BN2, and they 
seem to work fine; presumably, they run hotter than the N3Cs, but what 
does that do for performance, etc.? I know hotter plugs are sometimes 
suggested for engines that burn a lot of oil, but do they cause the 
engine to run a bit hotter? What if I dropped an alloy head on my 100's 
engine, would I want to run a colder plug?

In aircraft piston engines that still run on heavily-leaded fuel, 
residual lead can foul plugs quickly; for problematic engines, a 'fine 
wire' plug is sometimes used (just like it sounds, these plugs have 
smaller center electrodes that are less likely to harbor unburned 
elemental lead).



On 2/1/2021 3:25 AM, Bob Haskell wrote:
> Bob,
>
> Looks like NA8 were replaced by N5C.  But if you're looking for 
> originality:
>
> https://www.ebay.com/itm/3-NOS-Champion-NA8-Black-Body-Spark-Plugs-Austin-Healey-100-4-Jaguar-XK120-MG-TD/393094267661 
>
>
> Cheers,
>
> Bob Haskell
> Austin Healey 3000 BN7/BT7 registrar
>
> On 1/31/21 6:48 PM, Bob Spidell wrote:
>> We are running Champion N3C in our BN2; they work well.
>>
>> The shop manual calls for Champion NA.8 (whatever those are):
>>
>>
>>
>> On 1/27/2021 1:16 PM, Michael MacLean wrote:
>>> Not to get too far off the subject about Healeys, but my Harley 
>>> Davidson (30s technology like our cars) runs the best on the 
>>> cheapest Ford Autolite 4164 copper plugs.  I tried "high 
>>> performance" plugs from Harley Davidson and saw no difference.  Best 
>>> of all they are only 89 cents a piece when on sale and I only need 
>>> two at a time.  Does anyone know for sure which Champion plug works 
>>> for the BN2?
>>> Mike MacLean
>>>
>>> On Wednesday, January 27, 2021, 10:18:57 AM PST, Kees Oudesluijs 
>>> <coudesluijs at chello.nl> wrote:
>>>
>>>
>>> Never had much problems with trouble because of plugs on any of my 
>>> vehicles in the past 55 years. The only thing that is more or less 
>>> important is to gap them, clean them once in a while and replace 
>>> when they are to far gone. I do not think I even did that in the 
>>> last ten years or so. I have nearly always used Champion plugs as 
>>> they are very cheap: between €8 and €15 for four.
>>>
>>> I presume that electronic ignition (Pertronix in my case) may also 
>>> help.
>>>
>>> Kees Oudesluijs
>>>
>>>
>>> Op 27-1-2021 om 18:27 schreef Laurie Wilford:
>>> I continue to use only Champion plugs in my Healeys but have 
>>> experienced at least two episodes of plug problems over the years. 
>>> Based on the number of miles covered that is probably not too bad, 
>>> but the second time was with a newly installed set of plugs. One was 
>>> defective.
>>> Both times the symptoms were intermittent missing both at idle and 
>>> on the highway.  Finally changing plugs was of course one of the 
>>> last things I did.
>>>
>>> Laurie Wilford
>>>
>>> Sent from my Galaxy
>>>
>>>
>>>
>>