[raregn]

I've got a customers 87 GN in the shop today for a tune up and a bunch of other work, I was wondering what spark plug to put in it... It's fairly heavily modifyed with alky inj.

Thanks

 

[Steve Wood]

If he is running quite a bit of boost, I would go with the AC 42s or the Autolite 23s if they are available....035" should be okay.

 

[ULYCYC]

What Steve said but if he has aftermarket aluminum heads different plugs may be needed.

 

[Steve Wood]

you could always put the same plug in that he is using

 

[raregn]

I think he changed them him salf last time so who knows what kind are in there... It has stock heads still.
I've got it for a rough running condition and a miss as well and I'm pretty sure he cracked a plug when he put them in, not to mechanicly inclined.
He does run a lot of boost, I know that for sure.

 

[ULYCYC]

Make sure he didn't cross the wires and or separate the boots.

 

[DCEPTCN]

NGK UR5s. :yup:

 

[raregn]

Make sure he didn't cross the wires and or separate the boots.

Plug wires are deffinatly not crossed, it has it's moments where it runs ok.
I ordered in a set of R42's (we didn't have them in stock) and I get to it this
afternoon. I was just out side checking something else on it and I noticed the intercooler is right out of the hose to the turbo, so That won't be helping anything. The intercooler is just sitting against the hose so it seals just enough to idle but won't hold any boost.