Is there any problem using Platinum spark plugs with an MSD mag trigger Distributor and an MSD 6AL box? Thanks Rick
A similar question, and I'm hoping Larry has some advice. On any plugs with an MSD 6A system what plug gap would be best assuming the system is working properly, plug wires, coil, etc. good with nominal 10:1 compression: What plug gap should we run? I opened my gap to .045 from .035 and found my idle quality degraded. Is this a bad thing?
In the installation instructions for MSD 6A, and Digital 6, MSD recommends .050-.060 for compression up to 10.5:1. A bigger gap will fire a leaner mixture. Try adjusting your idle mixture a little leaner. See if that makes a difference. If opening your plug gaps makes no difference in overall performance, you are better off running a smaller gap, as this taxes the system, wires, and cap/rotor less.
Thanks Larry. Modifying the idle mixture has always been a challenge since engine mods more than a decade ago. Loss of engine vacuum means I've had to crack the throttle blades too far open for the idle circuit to work properly. I've not been in the carburetor now for ten years and it's time for a rebuild - was considering that "drill a hole in the primary blades" modification so I can keep them closed at idle. Actually Larry our setups are somewhat similar right down to the 118 LC cam. What mods have you made to your Q-jet? I've rejetted to compensate for headers, and changed out the primary metering rod spring to account for vacuum loss. Have you done anything special to maintain your idle circuit functionality? Other than carb mods I run about 14 degrees initial, 1 or 2 degrees vacuum advance, and add a few more with my timing controller depending on the weather.
Brad, My 7042240 Q-jet was set up by John Osborne. 76 jets, 46B primary rods, and BG secondary rods. It works very well. It will idle at 750 in gear, 900 out of gear. I'm running 16* initial, 32* total, all in at 2200 RPM, and 10* vacuum advance. No problems at all. Running the 800 CFM carb on my GS has solved my idle problems. I had a 350 carb on the car when I bought it. It's a lttle cold blooded in the winter with no choke (crossover blocked off)
