Spark plug for EFI

[ScottyG]

Ngk xr5 gapped at .040. No need to gap at factory specs. You should have updated ignition system anyways so open the gap up a tad and run some low resistance 8.5mm wires and see how the plugs look after a few pulls. Dont let it idle .
I might try even the xr4 next to see how it runs on a hotter plug in my dads efi 383 since his ignition is not from 1969

 

[furious70]

Dizzy = distributor. Using the"first"one. The lean burn dizzy is a great choice because it's a cheap OEM part that has neither mechanical nor vacuum advance in it. Perfect for computer controlled timing.
Unless you need a cam sync to run sequential efi. My box has that feature but I didn't deem it valuable enough for the cost of a dual sync dizzy back in 2009 when I first went efi.
I picked up a cheap dual sync along the way but it's hall effect and would need a different driver

 

[__Larsson____]

Ngk xr5 gapped at .040. No need to gap at factory specs. You should have updated ignition system anyways so open the gap up a tad and run some low resistance 8.5mm wires and see how the plugs look after a few pulls. Dont let it idle .
I might try even the xr4 next to see how it runs on a hotter plug in my dads efi 383 since his ignition is not from 1969

i use 8.0mm StreeThunder Universal Spark Plug Wires now, would the .5mm do any big difference?

 

[RJRENTON]

i use 8.0mm StreeThunder Universal Spark Plug Wires now, would the .5mm do any big difference?

No....but define your expectations.....lower resistance or higher dielectric strength or color or appearance.....???
BOB RENTON

 

[__Larsson____]

No....but define your expectations.....lower resistance or higher dielectric strength or color or appearance.....???
BOB RENTON

Oh i don't have any, more then i want them to give the plugs what they need u know. And black wires is what i prefer. I know nothing about this stuff, like in depth.

 

[RJRENTON]

Oh i don't have any, more then i want them to give the plugs what they need u know. And black wires is what i prefer. I know nothing about this stuff, like in depth.

Perhaps you should "ask" the plugs what they need (or want)......did you research what's available??......Do your own research (educate yourself) that way it's your decision so you can't be wrong....no matter what you decide.....
BOB RENTON

 

[ScottyG]

i use 8.0mm StreeThunder Universal Spark Plug Wires now, would the .5mm do any big difference?

The little bit bigger size helps with better insulation and can handle better spark. A lower resistance wires can help with performance were spark energy is needed.
If your car is modified for performance I would maybe look into getting different wires

Your plug wires have a 500ohms per foot which is good if u have like a efi sniper kit or equivalent and a nice radio and speakers . But a lightly modded engine these will do as well .

Just put a set of new plugs in and do some Hits and check them . And than do some city driving and check them . If you do more city and cruising driving a hotter plug will help for a cleaner burn . Just watch at WOT

 

[__Larsson____]

The little bit bigger size helps with better insulation and can handle better spark. A lower resistance wires can help with performance were spark energy is needed.
If your car is modified for performance I would maybe look into getting different wires

Your plug wires have a 500ohms per foot which is good if u have like a efi sniper kit or equivalent and a nice radio and speakers . But a lightly modded engine these will do as well .

Just put a set of new plugs in and do some Hits and check them . And than do some city driving and check them . If you do more city and cruising driving a hotter plug will help for a cleaner burn . Just watch at WOT

Thanks for the tips mate! So they are a good set for with my Sniper, thats good! I would say my engine is lightly modded, with a XE268H cam and flat top pistons and 906 heads. im thinking of getting the NGK 7355. I hope they will be a good choice.

 

[RemCharger]

Thanks for the tips mate! So they are a good set for with my Sniper, thats good! I would say my engine is lightly modded, with a XE268H cam and flat top pistons and 906 heads. im thinking of getting the NGK 7355. I hope they will be a good choice.

A better choice would be an NGK 3332!
IMO!

 

[ScottyG]

Thanks for the tips mate! So they are a good set for with my Sniper, thats good! I would say my engine is lightly modded, with a XE268H cam and flat top pistons and 906 heads. im thinking of getting the NGK 7355. I hope they will be a good choice.

i would get the ngk 3332 xr5 IMO and open gap to .040

 

[__Larsson____]

A better choice would be an NGK 3332!
IMO!

Oh? Why? I've been told Iridium would be good to use?

 

[RJRENTON]

Oh? Why? I've been told Iridium would be good to use?

Do you always listen to "hearsay" ?? Who is your source of information or "recommendations"?.....and WHY do "they" say it's "good to use".....at 3x-4x the cost per plug.....will you get 3x-4x more performance for your dollars spent.....not likely.....that is if your "buddies" insist you'll get more hp......make up your own mind.....do your own investigations........
BOB RENTON

 

[__Larsson____]

Do you always listen to "hearsay" ?? Who is your source of information or "recommendations"?.....and WHY do "they" say it's "good to use".....at 3x-4x the cost per plug.....will you get 3x-4x more performance for your dollars spent.....not likely.....that is if your "buddies" insist you'll get more hp......make up your own mind.....do your own investigations........
BOB RENTON

Well dude,

I ask people about their experiences, that's my part of my research. I told you before, I know NOTHING about these things thats why i ask, I can put a car or an engine together but that's where my knowledge ends more or less atm. One admin on the Holley forum told me that Iridium spark plugs conduct electricity better and require less voltage to fire the spark. for example. Thats why i was going for the 7355 instead of the 3332.

 

[furious70]

Usually the more modern stuff is for going 100k miles without changing them from what I understand. Xr5 in NA and xr7 in boosted engines for me fwiw.

 

[__Larsson____]

Usually the more modern stuff is for going 100k miles without changing them from what I understand. Xr5 in NA and xr7 in boosted engines for m

makes sens.

 

[RJRENTON]

makes sens.

It likely makes more SENSE as well.....but......sooner or later, you've got to pick a point it time and make it your starting point....or continue to search for the unknown.....then, you'll find that time has passed you buy and you'll be back at your starting point....still scratching your head wondering what to do next....or not....like the old proverbial expression...about using the bathroom.....???? ..waiting to see what appens next......???.......just an additional point to ponder......
BOB RENTON

 

[ScottyG]

Am going to agree with RJ . Spending over double for a plug for nothing in return at ur levels I would say get the ngk xr5 . Even if u did get the 7355 plugs for better spark ur plug wires are not the best for the plugs let’s say . Ur over thinking stuff. But it’s not my money . I will give out tips and help but at the end of the day it’s your car and ur money.

 

[__Larsson____]

Am going to agree with RJ . Spending over double for a plug for nothing in return at ur levels I would say get the ngk xr5 . Even if u did get the 7355 plugs for better spark ur plug wires are not the best for the plugs let’s say . Ur over thinking stuff. But it’s not my money . I will give out tips and help but at the end of the day it’s your car and ur money.

and I appreciate the help

 

[Caterpillars]

If your heads are chrysler iron heads then you need short reach plugs.

Tell me more = I have a 383 motor and it runs bad. I has solid lifters so I check the valve adjustment and set at 28 intake 32 exhaust. I then took the spark plugs out and they were black and one looked like it was dropped because the gap was very small. The plugs I put in were RN 12 YC and have a long reach. They are iron heads - I'm wondering if I using the wrong plug and maybe the piston is hitting the end of the plug - actually had two plug that looked like they were dropped with no/or small gap. It's a new rebuild and am trying to get it to run good. Has a mallory HFire box and a mallory coil - should be getting good spark. Efi mallory distributor. Suggestions/help appreciated...

 

[kiwigtx]

Not exactly sure what a "dizzy" is??

A popular song from 1969.