Spark Plug for Cammed car

[Savage-wp]

Hi. I've been told that i need to run a colder plug on my car because it has a cam in it (Livernois stage 2c). Rick @ Livernois said i need a NGK TR6. What is the full part number for this plug. I am in South Africa, and the parts guys here are not so clued up. they just tell me that is not a full number.
Thanks for your help.

[Savage-wp]

Hi MGM GT. Thanks for the reply. That is a normal copper electrode spark plug. Is it better to run a copper electrode or an iridium electrode. The car has standard AC Delco plugs, which are iridium electrode with a 5.5 heat range. I can get a 6 heat range iridium plug.

[Savage-wp]

hi mgm gt. I'll get a set of copper plugs. the number you gave me, 4177, is an americans ngk part number. the guys here don't know what it is. what is the number (and letters) on the side of the plug. thanks for your help.

[GRRRR8]

4177 is the stocking # and TR6 is the part #. Change them every 12k-15k. No need to change every oil change.

[Savage-wp]

Hi grrrr8. Is TR6 the complete part number. I've been speaking to the local ngk guys here in South Africa, and they don't have a TR6 they have longer codes, and TR6 is part of the code, but there are a good few with TR6 in the part number.

[Savage-wp]

Ok, I have managed to sort this out. The parts salesman told me there is no such thing as a NGK TR6, it's not the complete number. Well, I downloaded the catalogue from NGK South Africa's website, and searched through it. And i found the TR6. So on Monday I'll be going back to this salesman and showing him where to find it in his catalogue. Thanks for all you help.

[norm8332]

Autolite AR103 are working for me.

[Savage-wp]

what gap should I run on the TR6?

[GRRRR8]

what gap should I run on the TR6?

.040

[Mike@NewEra]

Just to clarify, you generally don't need a colder plug when changing the cam, but it helps when you have aftermarket heads that increase compression.

[metoo]

True no need "per say" as they will still work just fine for longer, but $16 is cheap insurance.


...but I wouldn't be so keen on fooling with the threads, an more importantly, the spot face around each hole more often than necessary.

[desertg8]

what do you mean by fooling with the threads and the spot face? you lost me.

[STL_G8GT]

I have a mild cam in mine, but am about ready to change plugs.

Whats the consensus on what type of plug to use, and should I consider a step colder if all I've swapped is the cam? (No head work, forced induction, etc)?

The car is about to turn 30k miles, and has had the cam for about 15k.

If I did swap to a step colder should I relook at the tune?

Thoughts?

[GRRRR8]

The rule has always been if you add 100 NA HP drop 1 heat range. You might want to look at AF with a wide band, but it won't make a huge AF difference.

[STL_G8GT]

Thanks Charlie... By the time I add my headers, CAI, and cam in the mix I'm probably realistically in the 70-90rwhp range. What are your thoughts on a plug recommendation?

I'm going to pull the stockers this afternoon and see what they look like.


The rule has always been if you add 100 NA HP drop 1 heat range. You might want to look at AF with a wide band, but it won't make a huge AF difference.

[GRRRR8]

I would do with a TR6 and be done with it. Also keep in mind that from the factory our cars were 285-300 at the wheels. Most can get 365-390 rwhp with bolt ons.

[GT Drew]

You should look at the colour of your current plugs. If they are the normal tan colour and you are not getting any knock. There would be no advantace to going to colder plugs.

[STL_G8GT]

I pulled them and they look pretty darn good, whitish color, no spotting... I think im good as it stands... guess I need to just make some more power :-)

[desertg8]

Whitish usually means they are running hot. Also if you see my post in tuning look at the porcelin. If it is completely white in the hidden area another sign they are running hot. I ordered the tr6ix plugs for mine. I live in the desert and it is going to be over 100 in the coming months. Also if they are whitish you may have other problems. As Charlie asked me what is your afr???

[Savage-wp]

Everybody i spoke to recommended the NGK TR6 plug for a cammed car. NGK in South Africa is so useless they can not get this plug. I had to order from the States.
They have arrived and are awaiting installation. As soon as i get a chance i will pop them in.
The stock plugs have been in the car for a while with the cam, and seem to be doing ok.

[johnbell2]

The rule has always been if you add 100 NA HP drop 1 heat range. You might want to look at AF with a wide band, but it won't make a huge AF difference.

That was my understanding. I'm running +113 rwhp from baseline plus about half a point higher static compression due to gasket swap - I went with NGK TR6. Runs great even in Texas heat.