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Old 08-02-2010, 03:08 PM   #1
JAB'70
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Ignition Question(s)

I did a little upgrade over the weekend to my pick'm up ('70 c10, 350, 5.7L 4BBL Eldebrock 1406 carb). I replace the HEI with a complete ignition setup - MDS AL6 ignition box, MSD Blaster 2 coil, MSD Pro Billet Distributor, New spark plug wires, new spark plugs (AC Delco R43T).

I set my plugs gapl is set at .45, started it up and it's a rough idle (I have not set the timing yet).

The question is did I set the plug gap to large?

A friend of mind said I quote " they should be set between .35 to .40 you need some really good fire if the gap is set at .45."

I said, I thought the new setup gave really good fire...am I in left field???
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Old 08-02-2010, 03:14 PM   #2
geezer#99
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Re: Ignition Question(s)

I ran the same set up on a 350. Spark plug gap at .55. Made a big difference in how it ran with the wider gap. Ran way better. Just experiment a bit to find your optimum gap.
Some say that an MSD like yours has enough fire power to weld with!!! Get your buddy to hand onto a sparkplug wire while you crank it. He'll find out about power!!!

Last edited by geezer#99; 08-02-2010 at 03:22 PM.
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Old 08-02-2010, 03:20 PM   #3
cdowns
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Re: Ignition Question(s)

you could try the MSD techline too//or if you have the instruction sheets it should b in them
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Old 08-02-2010, 03:27 PM   #4
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Re: Ignition Question(s)

You set the gap just right. A variation will not cause a noticable problem. You need to check your wires & make sure they are not crossed. Set the timing. Check for vacuum leaks.
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Old 08-02-2010, 04:43 PM   #5
truckdude239
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Re: Ignition Question(s)

idle will be bad untill timing is set
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Old 08-02-2010, 06:57 PM   #6
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Re: Ignition Question(s)

I think your spark plug gap is fine. The standard GM HEI uses that same gap. I would set the timing as mentioned as see how she likes it. I was thinking about upgrading to the same pro billet distributor, but I thought it didnt require the 6al box.
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Old 08-02-2010, 07:36 PM   #7
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Re: Ignition Question(s)

Hope you mean .045
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Old 08-02-2010, 10:00 PM   #8
JAB'70
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Re: Ignition Question(s)

Quote:
Originally Posted by BERT306 View Post
Hope you mean .045
Yep! Just fast typing .045 is what I meant....
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Old 08-02-2010, 10:02 PM   #9
JAB'70
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Re: Ignition Question(s)

Quote:
Originally Posted by sleepertruck72 View Post
I think your spark plug gap is fine. The standard GM HEI uses that same gap. I would set the timing as mentioned as see how she likes it. I was thinking about upgrading to the same pro billet distributor, but I thought it didnt require the 6al box.
You can run a pro billet with coil on top. No need for a box.
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with him.; A man's heart plans his way, But the Lord direct his steps." (Prov
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Never look down on anyone unless you are helping them up. SMS.
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Old 08-02-2010, 10:04 PM   #10
JAB'70
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Re: Ignition Question(s)

Quote:
Originally Posted by truckdude239 View Post
idle will be bad untill timing is set
I assumed it would, just threw the question out because my friend insist my plugs are gapped wrong....
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