Another Spark Plug question - 408 Cleveland Stroker

[73pony]

Looking for recommendation for plugs (heat range) and gap for this set up.

408 C Stroker
Bore 4.03
Stroke 4.00
static compression 10.9:1
Trickflow Aluminum 225 CC Heads
Custom DUI ignition from Performance Distributors
Edelbrock Air Gap Intake
Headman headers
Cam Specs
229/239 @ .050", 114 LSA, 108 ICL, .614/.623 lift (Spec'd by Brent at Lykins Motorsports)

Thank you in advance for any help with this. I apricate it as always.

 

[Cleveland Crush]

My opinion:
As to gap: ~.035-.045" experiment a bit then pick your poison.
As to plugs for your TF's: Motorcraft AGSP32C/SP406 (a medium cold Copper plug)

https://www.amazon.com/Motorcraft-SP-406-Spark-Plug/dp/B000WI33R2

 

[turtle5353]

I run NGK plugs in my 408.

 

[basstrix]

I found this chart helpful. Ford used the same heat range for several different engines. Seems like the higher compression/performance got the colder plugs. ARF vs BRF is the thread size.

 

[c9zx]

Looking for recommendation for plugs (heat range) and gap for this set up.

408 C Stroker
Bore 4.03
Stroke 4.00
static compression 10.9:1
Trickflow Aluminum 225 CC Heads
Custom DUI ignition from Performance Distributors
Edelbrock Air Gap Intake
Headman headers
Cam Specs
229/239 @ .050", 114 LSA, 108 ICL, .614/.623 lift (Spec'd by Brent at Lykins Motorsports)

Thank you in advance for any help with this. I apricate it as always.

Have you done a DCR calculation for this combination? You'll need to know where the intake valve closes to do so.
http://www.wallaceracing.com/dynamic-cr.php Chuck

 

[73pony]

Have you done a DCR calculation for this combination? You'll need to know where the intake valve closes to do so.
http://www.wallaceracing.com/dynamic-cr.php Chuck

Yes. DCR comes in at 8.47 according to both Brent and Tim. and I got the same on the Excel sheet that was posted on this forum.

 

[c9zx]

So what are you going to use for fuel? It doesn't sound like a pump gas friendly combo to me. If Brent and Tim say it is then I am wrong. They are both really good at what they do. Chuck

 

[73pony]

So what are you going to use for fuel? It doesn't sound like a pump gas friendly combo to me. If Brent and Tim say it is then I am wrong. They are both really good at what they do. Chuck

Both of them agreed I am good with 91-93 octane given the chamber design. They wanted to target DCR below 8.7.

 

[c9zx]

Thanks for sharing the information. Good luck with the build and keep us updated. Chuck

 

[Hemikiller]

Trick Flow recommends Autolite 3924 plugs for their heads. They also offer the AR3924 racing plug. Those cross to NGK BKR6ES-11 and BKR6ES respectively.