Old spark plugs

[greg g]

These AC45r plugs were installed in my rebuilt 230 in about 2007/8.  So 40k miles or more. Left to right  is 1 - 6.  5 & 6 have a bit of PB blaster to ease removal.  Were gap checked 2 years ago at .032,  Today they checked in at .033.  Stock distributor original coil.  New set of NOS AC45r going in at .033.  What other changes or adjustments should Iook to do?

[greg g]

These AC45r plugs were installed in my rebuilt 230 in about 2007/8.  So 40k miles or more. Left to right  is 1 - 6.  5 & 6 have a bit of PB blaster to ease removal.  Were gap checked 2 years ago at .032,  Today they checked in at .033.  Stock distributor original coil.  New set of NOS AC45r going in at .033.  What other changes or adjustments should Iook to do?  These are going in my traveling box.

Edited September 1 by greg g

[greg g]

Two too many!

Edited September 1 by greg g

[Ivan_B]

3 hours ago, greg g said:

5 & 6 have a bit of PB blaster to ease removal.

Use graphite or copper next time 😉

[Loren]

On the topic of old spark plugs, old being the key word as opposed to worn out spark plugs, I offer a plug that hasn't been made since 1965.

I became aware of these via a friend of my Dad's, EJ Brown who was one of Briggs Cunningham's mechanics.

Back in the 1950s EJ thought these were the secret weapon.

My Dad put a set in our 49 Mercury and he ran the wheels off that thing.

My experience with them was with my Quarter Midget when I was a kid. It normally had a Champion plug and it was hard to start with so so power. You put the Jet Ignition plug in and Hang On! I maybe biased but I was impressed!

It's a "pre-chamber" type plug in that it has a chamber in its tip like the pre-chamber of some diesel engines.

One thing that bothered me was the numerous types that were made. It seemed like every engine had its own part number and design. With so many types it's no wonder the company finally closed down. The inventory must have been massive.

Unlike regular spark plugs which have very minor differences the pre-chamber plugs had those plus the tip designs for each engine.

There is a company in the UK which makes a pre-chamber unit for a regular plug that is supposed to preform the same. But they only make 14mm 3/4 inch long units and they are pricey.

I've chatted with several "Spark Plug Collectors" and nobody ever heard of them. So...

For your entertainment I offer this photo of some I have gathered.

[sidevalvepete]

I keep learning stuff here. Thanks Loren. Unfortunately, no guarantee I will retain it, or I will forget where I learnt it...

Still, even the initial enjoyment is enough to keep me checking through the posts.

And pictures too!!!

[Ivan_B]

I've heard about pre/forechamber gasoline engines, in the past

Maybe that's what these sparks were originally for? The "problem" with mass engineering solutions is that it tends to settle with the most effective/cheap etc. option. So the fact tat something works well, at some point, does not necessary makes it good in the long run if we take into account all the other considerations.

[greg g]

According to Pat Goss on Motorweek, the deposit on the ground side is from oil mist from valve guides.  So in the spirit of Derek on Vise Grip Garage, I'll pretend I didn't see that.

[Sniper]

3 hours ago, Loren said:

On the topic of old spark plugs, old being the key word as opposed to worn out spark plugs, I offer a plug that hasn't been made since 1965.

I became aware of these via a friend of my Dad's, EJ Brown who was one of Briggs Cunningham's mechanics.

Back in the 1950s EJ thought these were the secret weapon.

My Dad put a set in our 49 Mercury and he ran the wheels off that thing.

My experience with them was with my Quarter Midget when I was a kid. It normally had a Champion plug and it was hard to start with so so power. You put the Jet Ignition plug in and Hang On! I maybe biased but I was impressed!

It's a "pre-chamber" type plug in that it has a chamber in its tip like the pre-chamber of some diesel engines.

One thing that bothered me was the numerous types that were made. It seemed like every engine had its own part number and design. With so many types it's no wonder the company finally closed down. The inventory must have been massive.

Unlike regular spark plugs which have very minor differences the pre-chamber plugs had those plus the tip designs for each engine.

There is a company in the UK which makes a pre-chamber unit for a regular plug that is supposed to preform the same. But they only make 14mm 3/4 inch long units and they are pricey.

I've chatted with several "Spark Plug Collectors" and nobody ever heard of them. So...

For your entertainment I offer this photo of some I have gathered.

 

 

Hmmm

 

https://www.mahle-powertrain.com/en/experience/mahle-jet-ignition/

[Loren]

I’ve checked out the Mahle system it is interesting. Not something you can screw in like a spark plug, it’s much more complex. I can’t even say for sure if the pre-chamber spark plugs such as the Jet Ignition plugs could have any value in higher compression OHV engines. I really doubt that they would work with multi spark ignitions. They remain a curiosity from a by gone era.