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Spark plug for EFI

__Larsson____

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Sp next season im going to install Hyperspark on my 383 with Sniper 650, i asked in the Holley EFI forum if the Autolite 85 was good enough and got the answer that i should go for Idrium plugs, NGK 6341 or Autolite XP3924, they have different pre set gap than 0,035" what i also saw is that it seems to be that the plugs reach further in to the chamber than the Autolite 85 does. Is this okey? What tools do i need to adjust the gap on the plugs?

NGK5688-1.jpg


85_Front.jpg
 
A standard gap tool is all that's needed. They are accurately pregapped though. I put these in my 526 stroker with Terminator EFI. No issues. Indy EZ heads if it matters.

Denso Iridium SK20R11 (3297)
 
Iridiums and platinums are good for new cars you don't want to touch for 100,000 mi(160,000km)
A good Ole ngk XR5 is all you need. Pre gapped at .035
 
If your heads are chrysler iron heads then you need short reach plugs.
The NGK plugs shown are 3/4" reach and the AUTOLITE plugs are 3/8" reach. The HYPERSPARK system may allow for a slightly gep setting, say 0.040" . NEVER PUT 3/4" reach plugs in iron heads designed for 3/8" reach plugs or you will contact the piston. Just my opinion.....
BOB RENTON
 
The NGK plugs shown are 3/4" reach and the AUTOLITE plugs are 3/8" reach. The HYPERSPARK system may allow for a slightly gep setting, say 0.040" . NEVER PUT 3/4" reach plugs in iron heads designed for 3/8" reach plugs or you will contact the piston. Just my opinion.....
BOB RENTON
Yeah thats what i was thinking. Would you still go for lets say AL 85?
 
Yeah thats what i was thinking. Would you still go for lets say AL 85?
Try AUTOLITE AP-85.....3/8" reach, platinum tip, projected core/insulator, medium heat range, 0.035" cap. Now, the NGK boys will come out of the woodwork, saying Autolites are no good.....you decide......just a thought....
BOB RENTON
 
Autolites are ok you could even go with champions if that's what's available
 
Probably be ok....if the heat range is compatible AND you do not mind paying ~ $ 6.00 - $ 8.00 more per plug for the exotic metallurgy than the AUTOLITE AP-85......the choice is yours......it's not likely the engine will know the difference (or care).....just my opinion.....
BOB RENTON
 
Probably be ok....if the heat range is compatible AND you do not mind paying ~ $ 6.00 - $ 8.00 more per plug for the exotic metallurgy than the AUTOLITE AP-85......the choice is yours......it's not likely the engine will know the difference (or care).....just my opinion.....
BOB RENTON
I missed you suggestion about that one, thanks! Heat range is a 5 on the NGK is that good?
 
I've run efi since 2009 with regular plugs, you don't need to have iridium or platinum.
Yes, I do use the appropriate heat range ngk when it was NA and now that it's boosted
 
But do you have Hyperspark?
NO.....I see no need for it.....in my RS23V0A****** '70 GTX, I use a Prestolite Dual point distributor. The engine can go to 6500 RPM without missing a beat, starts and idles smoothly at 1200 RPM because of the cam. BTW... I use either Champion HO-8A or UJ-11G spark plugs, which are NON PROJECTED CORE/INSULATOR design....much to the chagrin of the NGK boys.....and the world did not come to an end......Just my opinion......
BOB RENTON
 
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