Spark Plugs / Total Timing on blown 540

[esenior]

I've got a Dart 540 (8.5:1) with a Whipple 3300SC EFI supercharger. Was wondering what the recommendation was for spark plugs? Any recommendations for plugs to either get or stay away from?

Also, my builder tells me that I should be running around 34 degrees total timing. This sounds about right for an NA car, but isn't this a bit high for this setup? Any opinions or similar setups?



Getting ready to fire up the motor and trying to take care of these last few things. ---Eric

[anthonys 69]

In hot rod mag they used a cold spark plug part# auto light 3935 for a sbc to give you an idea. I would not use a gimmick plug like split fires etc. In my car which is not running yet. but iv looked into this a lot I’m running a crank trigger and msd box set at 31 deg but under boost the msd box will take 1deg of timing for every lb of boost up to 15 deg. You can run the msd box off a distributor as well. I think for a normally aspirated motor that might be a little high or at the max for total timing. But under boost that’s defiantly high. you’ll need to stop any kind of detonation before it starts. id check with wipple to see what they say about it. good luck

[esenior]

Heard back from my engine builder who recommend the 3933's (2 degrees colder). Thanks for the feedback. I'll give Whipple a call tomorrow to see what they say about timing.

[anthonys 69]

let me know what whipple has to say thanks

[esenior]

Whipple wasn't a lot of help regarding the timing. Said that 34 "may be ok". They did let me know to run 50psi fuel pressure, so at least I got that out of them.