18mm plug adapters like EMC 289

[Mummert]

It took a while longer than I thought. But if you are competing with old iron it might help you.

[SupStk]

Where is the gain, getting the plug electrode deeper in the chamber?

[Mummert]

Its a little bit of everything, deeper electrode, filling the hole outside the intake seat that causes fuel seperation, and .2 compression is nice.
Its looks amazing in an FE chamber, they suffer worse than 289's

[frnkeore]

How much, per set?

[Mummert]

pm'd you

[Walter R. Malik]

Where is the gain, getting the plug electrode deeper in the chamber?

A much, MUCH better selection of available spark plugs.

I used to buy a similar product from "Garrett Machine" until they went out of business.

[PackardV8]

The 18m-to-14mm adapters which place the electrode in the original location have been around a hundred years. So this design advantage for FEs/SBFs come from placing the electrode 1/2" (approx) deeper in the chamber, plus increasing compression. If so, given some (23-degree SBCs) must index electrodes in the original location, which other designs would benefit and which can't fit?

But if you are competing with old iron it might help you.

At a guess, since our Studebaker and Packard V8s are 11-12 degree valve angle and would most likely have room for such an adapter.

[Mummert]

I think its safe to say that the are these are semi expiremental parts. The end user is responsible for clearances, tune up and parts inspection. Pretty normal for competition applications.
I think many older design could benefit from something like this, but many are not setup as well as the old Fords. The 18mm plug hole allows the part to have good wall thickness to help with the heat. Getting the electrode out the hole and more accessible to the mixture is a good thing to.

[Walter R. Malik]

I think its safe to say that the are these are semi expiremental parts. The end user is responsible for clearances, tune up and parts inspection. Pretty normal for competition applications.
I think many older design could benefit from something like this, but many are not setup as well as the old Fords. The 18mm plug hole allows the part to have good wall thickness to help with the heat. Getting the electrode out the hole and more accessible to the mixture is a good thing to.

So, are you planning on marketing them ...?
I think there is a market for them.

[frnkeore]

How does it effect the heat range? Would you run a hotter plug?

[Mummert]

I think its safe to say that the are these are semi expiremental parts. The end user is responsible for clearances, tune up and parts inspection. Pretty normal for competition applications.
I think many older design could benefit from something like this, but many are not setup as well as the old Fords. The 18mm plug hole allows the part to have good wall thickness to help with the heat. Getting the electrode out the hole and more accessible to the mixture is a good thing to.

So, are you planning on marketing them ...?
I think there is a market for them.

We had a small run of them made for guys who want to give them try.

[PackardV8]

How does it effect the heat range? Would you run a hotter plug?

Check my thinking on this. While moving the electrode with respect to the burn pattern affects the heat it sees, adding a mechanical joint between the head and plug body slows heat transfer, effectively making a given plug hotter. So more likely a colder rather than hotter?

[Mummert]

How does it effect the heat range? Would you run a hotter plug?

I would start out pretty normal, I might consider running 1 step cooler.

[BILL-C]

I would like to buy a set!