Best spark plug for E85

[GaryKephart]

I have a 440 with a 12.5:1 CR. 452 heads. I'm running E85 for fuel. I have a digital 6 ignition. I have RJ12YC plugs in it now. Do I want to run a hotter plug? Is there a plug I can use that won't require indexing?

Thanks

 

[redfastback]

Use a NGK equivalent plug, those champions are junk. Why would you need to index a plug? That's for racing.

 

[fishy68]

I doubt you'd want to run a hotter plug with that much compression. I'd err on the side of safety and run a cooler plug and after it's ran take them out and see what they look like. Indexing plugs really gets you little gain. Like Red said it's for racing where every .001 means something. I've tried it both ways on my 360 and even though I didn't track test it I tested by the seat of the pants and felt no difference at all and I'm pretty sensitive to changes.

But to answer the question the only plugs I know of that don't need indexing are the Bosch platinum plug 2 and 4 plugs. Personally I don't like the looks of the plus 4 plugs though as with 4 electrodes it looks like it could shroud the flame. I am running the Bosch platinum plus 2 plugs in my 4.7 Dakota (got them on sale or I wouldn't normally buy a "gimmick" plug) and they work real good, better than the Champions that were in it and they have lasted good.

 

[GaryKephart]

I won't be able to run any multi-strap plugs. If the strap isn't between 11:00 and 1:00 the piston will tap the ground strap and close the gap. Maybe indexing isn't the right term.

 

[fishy68]

I won't be able to run any multi-strap plugs. If the strap isn't between 11:00 and 1:00 the piston will tap the ground strap and close the gap. Maybe indexing isn't the right term.

Wow that's close. Indexing is the correct term and if things are that close you'll have to index them. Since all spark plug threads in the head vary on where they start you'll have to manually index them.