spark plugs.....

[Kevin Martin]

im doing what everyone else is doing, going from the no longer available 18mm ngk10, to some 14mm plugs and the adapters. ive tried 3 different spark plugs suggested by engine builders, and other who seem to perform well. here's my issue, im actually going anywhere from .7 mph to 1.8 mph slower just putting in these new plugs. any suggestions? one thing that was suggested to me, were the old ngk 10 plugs might have been non resistor, so my wire ends, need to be changed to accomodate the resistor style new plugs??? any help would be much appreciated. thanks in advance kevin

[burl11]

Did you increase combustion chamber volume?

With my 18mm head off, I put in a 18mm plug in one hole and a 14mm plug plus adapter in the other hole. Just eyeballing them, the adapter side appeared to add a little volume to the overall head space, and thereby possibly lose a little on the compression ratio. Just a thought....

I am still running 18mm plugs, but someday the adapters will go in.

im doing what everyone else is doing, going from the no longer available 18mm ngk10, to some 14mm plugs and the adapters. ive tried 3 different spark plugs suggested by engine builders, and other who seem to perform well. here's my issue, im actually going anywhere from .7 mph to 1.8 mph slower just putting in these new plugs. any suggestions? one thing that was suggested to me, were the old ngk 10 plugs might have been non resistor, so my wire ends, need to be changed to accomodate the resistor style new plugs??? any help would be much appreciated. thanks in advance kevin

[fbref5269]

spent 2 days looking for the 18mm plugs

spent 2 days last week looking to those plugs. went to www.sparkplugs.com and they put me in touch with the ngk headquarters in the us. i was told by one of the people there that there are 200 of those plugs sitting in a warehouse in the us, but someone needs to buy all 200 for them to let them go.

frank novotny

[Kevin Martin]

Good info from both of you thank you. Frank I would seriously consider buying them. Might look into that. Kevin

[ZUL8TR]

14mm plugs + adapter

im doing what everyone else is doing, going from the no longer available 18mm ngk10, to some 14mm plugs and the adapters. ive tried 3 different spark plugs suggested by engine builders, and other who seem to perform well. here's my issue, im actually going anywhere from .7 mph to 1.8 mph slower just putting in these new plugs. any suggestions? one thing that was suggested to me, were the old ngk 10 plugs might have been non resistor, so my wire ends, need to be changed to accomodate the resistor style new plugs??? any help would be much appreciated. thanks in advance kevin

First I assume you are talking about the yamato engine.

What is the number on the 14mm ngk plug you are using with the adapter. Ric Montoya notes that the adapter effects the heat transfer of the plug and he recommends the next colder plug compared to the 18 mm base plug. In your case you were using 10 and so an 11 is recommended.

Here is his tech note.

http://yamatoracing.com/technical_entry.php?pid=10

Note that the NGK B-- EGV series are also useable and are the fine wire gold palladium type

[Kevin Martin]

ive tried the br10eix, br10es, and iw01-31.
kevin

[Tom Cronk]

plugs

Kevin
Don't use any R (resistor) plugs in your motor.Use
B9EG,B9EGV, or B10EG,B10EGV.Make sure your
adapters are flush with the top of the combustion
chamber in head.Set timing at 240 to 250%.
Hope this helps
Tom
PS-Some adapters are to long and have to be cut.

[Silas_53A]

I was told by NGK when i called them that these are still made, but have to be special ordered from a dealer like napa.

what about heads that have the 14mm already? has anyone noticed a difference there? I have a brand new 14mm head that needs to be CC'd, but it has 14mm plugs, no adapters.

[Islandmon]

Kevin
Don't use any R (resistor) plugs in your motor.Use
B9EG,B9EGV, or B10EG,B10EGV.Make sure your
adapters are flush with the top of the combustion
chamber in head.Set timing at 240 to 250%.
Hope this helps
Tom
PS-Some adapters are to long and have to be cut.

Tom, is the timing you referenced specific to the 14mm plug or just a general rule of thumb.

Thx,

Sam

[Tom Cronk]

Timing

Sam
Here is what I set timing at

Yamato 80- 220 t0 230% 14 & 18mm heads
102,202,302 - 240 to 260% 14 &18mm heads
Tom

[mercguy]

ive tried the br10eix, br10es, and iw01-31.
kevin

Kevin, ditch the adaptors and buy a 14mm head (assuming this is a 102/302). The head is not expensive at all..........get it...... mill the **** out of it and run the B9ES, B9EGV, BR9EIX, etc plugs...........that will get you to the 70's!!!!!!!

[Kevin Martin]

daren...

thats funny shizzzz!!!! im seriously thinking of the new head, can you guarantee those results??

[mercguy]

thats funny shizzzz!!!! im seriously thinking of the new head, can you guarantee those results??

one of those magical props I sent ya has seen over 70!!!!!!!!!

[Mr_dirt]

Daren, don't give him any ideas. Kevin doesn't "need" to go any faster.