Sparkplug help

[Thechief]

can some one help me read my plugs?

sbc fast burn heads
DUI dizzy
MSD 6 box
NGK TR55
55 gap (not sure if this is too big)

 

[MrSony]

Never heard of a V7 Before.....1, 3, 5, 7 look fine, just normal. 2 seems lean and 4 and 8 seem like they were dead. Is that oil or gas on the plugs? If its dead it could be both, like a busted plug wire or its shorting/grounding somewhere.

 

[V8 Rumble]

I also have fast burn heads. GM used MR43LTS gm part #05614210 on these heads. .045 gap.

 

[V8 Rumble]

http://hesstonspeedway.com/wp-content/uploads/2015-gm-ct400-19318604-specs.pdf

Spark plug specs are on page 4.

Here is a cross reference chart.
http://www.sparkplug-crossreference.com/convert/AC_DELCO/MR43LTS

 

[Clarmo]

The more HP you have the less gap you should run. I'd use NGK TR5 with .035 gap.
Agreed 4&8 don't seem to be firing. Is #6 In the socket? If so...it's not firing well either.

 

[pontiacgp]

The more HP you have the less gap you should run. I

not according to this guy

"I have been dyno testing for over 40 years. The ONLY time I have ever seen plug gap make any difference is when you make it BIGGER.. I one instance, I got a 22 horsepower INCREASE by going to an 080 gap, from a 035 gap. I will admit, that is a real big difference, but I have had several guys tell me that the big gap was a big HP increase. I always run them at 055 to 060 in my serious race engines- The big gain was on a 990 HP big block, and the engine just would not make over the 1000 HP number.. When I did this, it was a really big deal, to make 1012 HP


JOE SHERMAN RACING"

 

[pontiacgp]

If you have headers it's easy to tell if a cylinder if not firing with a temp gun.

 

[Thechief]

thanks everyone for the info

 

[Clarmo]

not according to this guy

"I have been dyno testing for over 40 years. The ONLY time I have ever seen plug gap make any difference is when you make it BIGGER.. I one instance, I got a 22 horsepower INCREASE by going to an 080 gap, from a 035 gap. I will admit, that is a real big difference, but I have had several guys tell me that the big gap was a big HP increase. I always run them at 055 to 060 in my serious race engines- The big gain was on a 990 HP big block, and the engine just would not make over the 1000 HP number.. When I did this, it was a really big deal, to make 1012 HP


JOE SHERMAN RACING"

That is a ton of HP with plug gap. Do you dyno with the same ignition system on everyone engine? There might be something not quite right there. The only thing that really changes is the timing of the spark when you change the gap. The spark doesn't do anything but light the fuel (at the proper timing)
We run .010" gap on my buddies 3000hp ProMod

 

[pontiacgp]

That is a ton of HP with plug gap. Do you dyno with the same ignition system on everyone engine? There might be something not quite right there. The only thing that really changes is the timing of the spark when you change the gap. The spark doesn't do anything but light the fuel (at the proper timing)
We run .010" gap on my buddies 3000hp ProMod

A friend of mine drove Nascar trucks andand in Nationwide, he explained to me they test plugs to see what gives them the most power. They start off with a .030 gap and work up from there on a dyno. He would not tell me what gap they found to have have the best power but he did tell me the Champion plugs came out on top. We tested plugs on our Leitch race engine and 604 but we didn't have the budget that Nascar teams have so it was a much shorter testing session. But we are running on pump gas unlike a 3000hp engine