Autolite double platinum plugs? Also indexing?
 

Are they good for a racing application? Naturally aspirated. 13.5 to compression.
I've never used them, but they are a semi retracted tip (half way between the plugs I am currently using and the stock champion plugs) plug with a fine electrode.
They will fit without worrying about the pistons colliding with them.
Also how should the plug face. If I use the indexing washers?

Re: Autolite double platinum plugs? Also indexing?
 

Art,
Double Platinum plugs were not designed for a high compression racing engine; the Platinum coating is just for protecting the electrode from wear and corrosion; designed for daily use and a longevity and not performance.
Find a real racing plug that has a colder range than the current OEM plugs and see how a bare or Copper, non-resistance electrode plug works for you.

Also, my preference have always been the racing plug offerings from NGK or Autolite.

http://www.ngksparkplugs.com/docs/RacingSpecs2010.pdf

Re: Autolite double platinum plugs? Also indexing?
 

Artie, only time I ever saw any reason to indexing plugs was to prevent knocking the ends off. I have played with indexing with the car I have now and saw nothing. But, I don't have Hemi chambers. Might make a difference.

I would use plain old non-platinum Autolite plugs. I would want my plugs at least .050" off the pistons at TDC. Closer may require more advance. Something to play with.

Re: Autolite double platinum plugs? Also indexing?
 

Thanks but there are no plugs in their racing series that will fit. I run a 14mm tapered seat with a 1 inch reach plug.
I need the resistor plug so it doesen't interfere with the ECU.

Re: Autolite double platinum plugs? Also indexing?
 

I'm shooting for at least .050 (Aluminum Rods). I don't think indexing will make any difference except maybe for clearance. I have the washers But didn't know anything about them.
The regular plug has to much tip extended. I'm afraid I could knock the ground wire off and cause some damage. Was going to try to stack 2 washers together, but that doesn't look like it will work.

Re: Autolite double platinum plugs? Also indexing?
 

Art, what is the part number of your current plugs?

Re: Autolite double platinum plugs? Also indexing?
 

Art, I had a brain fart (nothing new) but extended plugs often need a half degree or so less advance than retracted tips. Changing types of plugs may change that too. Naturally you want to try less first.

Re: Autolite double platinum plugs? Also indexing?
 

The plugs I've been using are Brisk RR12S The stock plug would be a Champion 470.
The plug I'm going to try is an Autolite APP5263.
My cylinder head is from a 2000 PT Cruiser.

Ed I've heard the same thing about the extended plug and the timing. I'll take some out before running it. I ran more timing than other comparable neons. Could have been the retracted tip.

Re: Autolite double platinum plugs? Also indexing?
 

Here are some pics of the plugs
http://i203.photobucket.com/albums/aa12/rt1092/036.jpg
Brisk RR12S on left, Champion 470 (stock) center Autolite APP5263 on right.
http://i203.photobucket.com/albums/aa12/rt1092/035.jpg
http://i203.photobucket.com/albums/aa12/rt1092/034.jpg
Brisk plug in head
http://i203.photobucket.com/albums/aa12/rt1092/033.jpg
Autolite plug in head

Re: Autolite double platinum plugs? Also indexing?
 

Art,

I would recommend the following Autolite Racing plug numbers:

AR3932X or AR3933X

The AR3932X is a colder plug.