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Nobody will ever convince me to run a projected tip spark plug at medium to high boost levels, why give it even a chance when non-projected tip plugs like the BR7EF, B8EFS, 5671A-8, etc idle just fine.
I plan on running about 24#'s of boost (max, and normally probably around 18-20#'s). I also plan on running 93 octane plus meth injection on a 8.8:1 CR.
I cross referenced and it looks like;
Autolite Spark plug
NGK 5671A-8 is Autolite 2614
NGK 5671A-9 is Autolite 2612
Which would be better for my application to start and would .22 gap be appropriate?
What turbo are you using Speed Junkee? Compression?
Projected power?
Turbo plan is the S400 96mm turbine with the 84mm compressor wheel 1.10 T6 flange. CR is 8.8:1 as mentioned in my earlier post. Goal is 1,000 at the wheels with the T-56.
I have a set of TR6's @ .022 and with 12-16psi I can see the heat mark on the strap is past the bend...and I barely stay in boost around here. BR7's are next.
Ron can you tell me more about the cut-back strap? I had to bend the strap on the TR6's to achieve a .022 gap and the strap curves too much to do this for my tastes. Does the "cut-back" strap stay a bit more squared-up to the electrode?
Pretty common practice in the race world if you do a google search. All the autolite racing plugs have a cutback ground strap and are "side gapped". This basically just gives you a shorter ground strap so it will act like less of a glow plug in extreme heat.
Side gapped recessed plug VS a standard protruding plug (and no those aren't my mangled fingers )
Autolite AR474 "racing plugs" are what I would run for most 20+psi LS motors. If I didn't need a resisted plug I'd be running them. Best performance plug for the money IMO. They are an "8" heat range on the NGK scale. Also have a "special" electrode material. My local parts stores could order these cheaper than summit/jegs.
I am interested in knowing also. Did a search and see that norbs over at turbobuick.com uses them but that doesn' tell us anything about how they would run in our engines.
Pretty common practice in the race world if you do a google search. All the autolite racing plugs have a cutback ground strap and are "side gapped". This basically just gives you a shorter ground strap so it will act like less of a glow plug in extreme heat.
Side gapped recessed plug VS a standard protruding plug (and no those aren't my mangled fingers )
Autolite AR474 "racing plugs" are what I would run for most 20+psi LS motors. If I didn't need a resisted plug I'd be running them. Best performance plug for the money IMO. They are an "8" heat range on the NGK scale. Also have a "special" electrode material. My local parts stores could order these cheaper than summit/jegs.
Speed Junkee, if you saw the LT1 we built that makes 900rwhp with TEA/TFS LT4 heads we run a 8 heat range plug in that motor.
If you are shooting for 1000rwhp with 8.8:1 compression a 8 heat range plug should also work for your usage. That said, you may find that if you read a fresh set of plugs that were shut off at the end of a run/pull that you could end up needing a 9 heat range plug.
Speed Junkee, if you saw the LT1 we built that makes 900rwhp with TEA/TFS LT4 heads we run a 8 heat range plug in that motor.
If you are shooting for 1000rwhp with 8.8:1 compression a 8 heat range plug should also work for your usage. That said, you may find that if you read a fresh set of plugs that were shut off at the end of a run/pull that you could end up needing a 9 heat range plug.
That sounds good. My question is what Autolite plug is that though?
Martin, not sure if you saw what I posted earlier or not. I already cross referenced.
Autolite Spark plug
NGK 5671A-8 is Autolite 2614
NGK 5671A-9 is Autolite 2612
I just wanted to verify this with you and get a confirmation that I should indeed try the Autolite 2624 first, and then try the 2612 as you mentioned for appropriate heat range.
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