Part #?

Mightymousy?

 

TR8's are already in your car John

 

Where do you guys buy these Tr8's? Everytime I look them up at the local parts store they cant find it them...
































Thats because they dont make them! NGK R5671A-8's No where on the box does it say TR8

 

NGK 7173 i have posted a photo of it before

it is the cross reference for an autolite ar 3911 exept with a full tip for longer life

you will definitely mess up the plug threads if you jam an acorn seat plug in an all pro head.

 

you would be correct,lucky for me the plugs are just started be hand and no tightened yet thanks

 

is that the correct part # for a plug with a similar heat range to a TR8??

 

i know it is colder than a tr-6, but i didnt get that far into it.

 

http://www.ngk.com/more_info.asp?AAIA=&pid=3252

http://www.ngk.com/results_cross.asp?pid=TR6&x=0&y=0

the top part number says nothing about TR anything in it...is there something we are missing here

 

Bringing this one back up.... Dave you mostly running 7173's right now? Are you running gasketed plugs for your AllPro heads?

 

7173 is whats still in the car, they are gasketed, they are a cross reference to an AR-3911 but with a full tip (last much longer, normal life plug), all pro's do not have a taper seat

 

Thanks Dave. What did you gap yours at? I've got a full set of 3911's around, but only a half set of 7173's. I hope to make a few passes pretty soon.

 

the 3911's will lose the tip fast and gap open, this was a problem for me in a street car applicatioin, but if they are new they will perform as good as the 7173

i used them as gapped from the factory at .030 or 35 i think

 

Thanks been a while since I tinkered with the Formy. I'm spacing out (maybe lack of sleep due to new baby), but what was the concensus around the AllPro heads, we need a gasketed plug since the plugs are more recessed?

 

because the heads are not machined to accept a tapered seat (normal style) plug
if you try a standard style plug you fill f up the first few threads into the head

 

Dave you street drive on these? How long you get before you need to change them? Just curious?

 

I am also interested in the correct plug for a standard head in a 7-8 heat range. I had zero problems with tr6's at 900 rwhp but im guessing colder is safer.

 

Curious as well I am going with the TR-7's, whatever part number they are??? Don't have them infront of me, I think they're the one's you guys are talking about, I hope

 

This thread was for the AllPro heads, since they are machined a little different and so require a gasketed spark plug.

 

yes this is the plug that stays in the car full time. i have not worn out a set yet, but i have replaced them when doing head gaskets etc. just for good measure.

they will last as long as any other normal car spark plug would. they are not a racing fancy tip short life type of plug.

 

These ones right Dave?

http://store.summitracing.com/partde...5&autoview=sku