As the title says. What type spark plug tip is better with a boost/N2O application? A projected tip or non-projected tip spark plug. Thanks.

Ken R.

 

Non projected.

 

So 1racerdude, why non-projected over projected? Just curious. I've never ran a non-projected plug but now i'm running more boost and n20 on a stroker and I think i'm having issues with my current plugs, which are projected AC's 1 heat range colder then stock (R44LTS6) and gapped at .035. I have a set of NGK's that i picked up yesterday that are 2 heat ranges colder but are projected also. Wanted to find out the scoop before putting them in. My buddy is running a high boost stroked mustang turbo on the bottle and had to go to a non-projected plug way colder then stock gapped at around .025. He was having the same issues as me. You happen to have a number to maybe an NGK or Autolite 2 ranges colder but non-projected? Thanks for the reply by the way.

Ken R.

 

No numbers on the overseas plugs,I use Champions.
The long nose plug is easier to blow the fire out from the boost and they don't transfer heat as well as recessed nose. Boost is the same thing as NO2. More prone to detonation also.
.035 should be good enough on the gap if ya are running an aftermarket ignition.
Ya need to get colder than 2 steps.

 

I run an NGK with an "11" heat range with my boost+N2O combo. The tip is not recessed, but it is flush. Gap is 0.035".

Rich

 

I have the same exact question. I am running a set of AFR 227 heads on a nitrous motor (300 shot). I am currently running the NGK 5672A-10 (stock number 7942) which is a projected tip plug, but what LR is saying is I should run a NGK R5671A-10 (stock number 5820) which is a non projected tip plug. Do I have this right?

Michael

 

Non projected, though you need to monitor your plugs and piston crowns as well as how your engine operates to decide if these are really needed.

Rich

 

If that's the right heat range and part number.
Gap them at .035.
Take a look at rskrause's post above he runs it all and has experimented with it.
I never run two power adders,make enough HP with one.

 

Wow! So i'm way off on my plugs. So with my LT1 castings, i need to be running a Tapered Seat 14mm x .708" reach, correct? Was just breezing through the Jegs catalog and looking at the NGK's. They list a .460" and .708" reach in a tapered seat but the .408" is the only non-projected tapered seat they list. Would anybody happen to have any of the NGK numbers off hand for the non-projected plugs? I'll start searching the web and see if I can find some but if anyone has them, it would be much appreciated. Thanks for all the info guys.

Ken R.

 

An interesting link on spark plug selection. I don't know enough to select a plug for an engine with a 300-shot, so I let the pro's do it on an engine dyno, and ended up with a Champion S57YC, which appears to be a slightly projected nose plug.

http://www.childs-albert.com/catalog...park_plugs.pdf

A cross-reference table:

http://www.dragstuff.com/techarticle...reference.html

 

I have an NGK catalog at the shop, but I am pretty sure it is on-line.

LR: there IS a logic to two PA Allows a very mild cam, HR setup to make huge hp when race gas is added. Turbo can do the same by adjusting the boost. But I have never been a fan of turbos. Can't say why, I just don't like them.

Rich

 

A Procharger set at 26# will get ALL ya want and idles like an old 30/30 Duntove.So will a dual 500Hp shot each staged of course.One on 400 the other on 300.

5.36 in the 1/8 mile with a 1.26 60" on DR's with the blower. Have yet to see a clean pass on the NO2.

 

26psi is not gonna be pump gas friendly though, IMHO.

Rich

 

Ya are correct.

 

Ok, so I returned the set of NGK's i had to NAPA. The were BR7EF's, which is a 2 heat range colder plug for an LT1 casting as stated in HarrisSpeedWorks spark plug post in the nitrous section. I'm assuming i'm correct in saying that for the LT1 heads, we need a 14mm x .708" reach 5/8's hex plug. But I was checking out the NGK catalog at NAPA and if I read it correctly, it said a BR7EF was a 14mm x 3/4" reach 5/8's hex non-projected plug. Would a .708" reach vs a 3/4 be an issue? Should the LT1's use a .708" or 3/4" reach? I asked him if he could pull up an 8, 9, or 10 heat range in that plug and he couldn't. Don't know if they just didn't carry them or that plug doesn't go hotter then that. Couldn't find what I was looking for cause the NGK book is like a phone book and didn't want to take up too much of the guys time, so i'll start searching online. One more question, would it be better to go with a cut back ground or standard? Wondering about that one too. So Rich, what part number NGK's are you running? Thanks.

Ken R.