What spark plug does the factory book call for in a 360 magnum.
- Thread starter maca
- Start date
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magnummopar
Well-Known Member
Champion plugs are a POS, get a set of NGK 4291. We have an ignition upgrade kit that is MSD wires, MSD coil, NGK plugs, Brass terminal cap and rotor for $200. You bump the plug gap up about 50% and get great results, MPG, idle quality and throttle response are all improved. The factory ignition is pathetic, the only thing still using .035" plug gap these days are riding mowers...cant light a fire without a real spark
Thanks guys.
I wanted to know as I am chasing a problem and the guy helping me asked what the factory plugs are. My timing mark is jumping around a little. It never used to move and was rock solid before I rebuilt my engine. The only thing that is different is I am now running much heavier valve springs and instead of a msd-6al box I am now running a locked dizzy with a msd 6al-2 programmable. The plugs I am now using are ngk v-power R5671A-7 gapped to .035 as I am running boost and was told to close the gap for boost.
Valve springs have gone from 120 seat and 300 open to 180 seat and 420. I did not have an issue before so I never ran a timing chain tensioner but I was thinking that because of the extra spring pressure I may need to run one now.
here is the video
[ame="https://www.youtube.com/watch?v=j3n4AYc-fwY&feature=youtu.be"]Timing mark jumping around - YouTube[/ame]
I wanted to know as I am chasing a problem and the guy helping me asked what the factory plugs are. My timing mark is jumping around a little. It never used to move and was rock solid before I rebuilt my engine. The only thing that is different is I am now running much heavier valve springs and instead of a msd-6al box I am now running a locked dizzy with a msd 6al-2 programmable. The plugs I am now using are ngk v-power R5671A-7 gapped to .035 as I am running boost and was told to close the gap for boost.
Valve springs have gone from 120 seat and 300 open to 180 seat and 420. I did not have an issue before so I never ran a timing chain tensioner but I was thinking that because of the extra spring pressure I may need to run one now.
here is the video
[ame="https://www.youtube.com/watch?v=j3n4AYc-fwY&feature=youtu.be"]Timing mark jumping around - YouTube[/ame]
magnummopar
Well-Known Member
I don think spark plugs have much to do with timing "jumping" around. I doubt valve spring pressure will affect timing either. Stock plugs are nothing more than a starting point if you are running anything other than FI or carb. Blowers, turbos etc all require different tuning, plug gap, heat range, etc etc etc. I would think bad damper or msd box but I am no blower/turbo expert.
Thanks for the reply.
I will hook up another ignition I have and try it.
I only thought the valve spring pressures may be the cause as they are much heavier now and I do not have a timing chain tensioner as it was fine before. Does this seem like excessive play for the dizzy button bearing in mind its just the slotted set up.
[ame="https://www.youtube.com/watch?v=h8_fqMh4Jas&feature=youtu.be"]Dizzy play - YouTube[/ame]
I will hook up another ignition I have and try it.
I only thought the valve spring pressures may be the cause as they are much heavier now and I do not have a timing chain tensioner as it was fine before. Does this seem like excessive play for the dizzy button bearing in mind its just the slotted set up.
[ame="https://www.youtube.com/watch?v=h8_fqMh4Jas&feature=youtu.be"]Dizzy play - YouTube[/ame]
I think your right. I have been told to change plugs, leads, etc but I don't think they would make this issue. I need to buy another dizzy and leads for my other engine soon. I will swap the dizzy out for a test and see how it goes. I can run it without the msd box for a trial run.
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