Re: Plug gaps...Gas vs Methanol
[Re: Mopar-Al]
#796637
09/08/10 10:06 PM
09/08/10 10:06 PM
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Joined: Apr 2004
Posts: 616
Dunedin, Fl
DRDart
mopar addict
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mopar addict
Joined: Apr 2004
Posts: 616
Dunedin, Fl
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I am runnung .040 been told as wide as .060 though  plugs might be a little on the cold side though? i am running -7 ngks
[image]http://i682.photobucket.com/albums/vv183/DrDart500/DSC00307.jpg
1966 Charger
1970 Dart 16-1,solid roller,500 ci Tunnel Ram 8" Ati conv,BTE glide, Fab 9 rear strange center sect. Twin Rons terminators on Alky.
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Re: Plug gaps...Gas vs Methanol
[Re: Mopar-Al]
#796640
09/08/10 10:24 PM
09/08/10 10:24 PM
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Joined: Nov 2003
Posts: 6,293
Rock Springs
Bob_Coomer
master
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master
Joined: Nov 2003
Posts: 6,293
Rock Springs
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Going from a .038 gap to a .050+ gap slowed my rig down several numbers, killing noticeable mph. This was all alloy wedge in the 850hp+ range running methanol injection. It just didnt like the wider gaps. Note this was with 15:1+ compression. You might get by with a hair more gap and and lower compression, but see no advantages of running a .040+ gap. The alky burns so clean and eff anyways. IMO Keep the gaps at .040 and below. 
[color:"red"]65 Hemi Belvedere coming soon [/color]
[color:"#00FF00"]557" Indy engine 1.07 60ft 144mph in the 8th 2100 lbs package [/color]
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Re: Plug gaps...Gas vs Methanol
[Re: Mopar-Al]
#796643
09/08/10 11:10 PM
09/08/10 11:10 PM
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Joined: Oct 2003
Posts: 7,506
Az
Crizila
master
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master
Joined: Oct 2003
Posts: 7,506
Az
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All else being equal, the denser the fuel charge the tighter the gap will have to be and you are running a much denser charge with methanol than with gas. .030" might be all your ignition can handle on methanol with that CR. I would experiment with a wider gap though, as a wider gap will almost always make more power - if the ignition can support it.
Fastest 300
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Re: Plug gaps...Gas vs Methanol
[Re: Bob_Coomer]
#796644
09/09/10 07:36 AM
09/09/10 07:36 AM
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Joined: Jan 2003
Posts: 10,010
Frostbitefalls MN (Rocky&Bullw...
gregsdart
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 10,010
Frostbitefalls MN (Rocky&Bullw...
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Quote:
I truly think the compression plays a larger role in plug gap, more so than not. Maybe the higher cylinder pressure and super cold charges make it harder for the current to jump across the dielectric gap 
Maybe I wasnt using enough spark energy, but was on par with what 99% of the other cars are running, but way short of a 44 amp Pro mag Pro mod 
Pretty much sums up what I believe. I also run 15/1, run .032 gaps. I started there to avoid problems with miss fire/cross fire, works just fine.
8..603 156 mph best, 2905 lbs 549, indy 572-13, alky
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Re: Plug gaps...Gas vs Methanol
[Re: gregsdart]
#796645
09/09/10 09:59 AM
09/09/10 09:59 AM
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Joined: Sep 2003
Posts: 2,008
Sweet Home Alabama
MRMOPAR622
top fuel
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top fuel
Joined: Sep 2003
Posts: 2,008
Sweet Home Alabama
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Indy told me to gap my plugs on my 15-1 engine @ .025 on race gas. I have 2 Terminators(2950 CFM) on alcohol and run the Champion C59CX plugs Indy said run in it. I have the MSD dist. the MSD 8261 coil(MSD said I needed to run alcohol)with the 7AL-2 box.
"To Be The Man'You Have Got To Beat The Man"
"T/D and Pro-Bracket Racer"
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Re: Plug gaps...Gas vs Methanol
[Re: Mopar-Al]
#796648
09/10/10 05:45 AM
09/10/10 05:45 AM
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Joined: Oct 2005
Posts: 976
ontario canada
mac56
super stock
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super stock
Joined: Oct 2005
Posts: 976
ontario canada
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Quote:
I am checking the tune up on my dart race car I just got. It runs on methanol/dominator carb. The engine is a 30 over 12/1 440 with eddy heads unported and a team g intake.The plugs are champion number S57C . They are gapped at .030 thou. I have a 6AL msd box, blaster coil and msd distributor.
So my question is... Are the plug gaps different when compared to Gas vs Methanol? I was kinda expecting a .040 gap or .035 at the tighest. Engine runs good for what it is, but i'm running real fat on fuel and planned on leaning it out. The engine temp doesn't get over 170 f and I was told to run it at 190 for best performance on methanol.
I use to run almost the very same combination with .030 gap. Tried opening up to .040 and developed a high rpm miss. In my opinion don't get too hung up on leaning the engine out this is not as critical as when running gas.
Just another for what it is worth if it is a dominator flange team g you will find a big difference if you change to an edelbrock victor with a 4150 flange and run an adapter to the dominator. I can't give you numbers because I am a tractor puller but it was huge. Search old threads and you will hear this from other sources.
This is only if you have room under the hood.
Mark
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Re: Plug gaps...Gas vs Methanol
[Re: mac56]
#796649
09/10/10 10:06 AM
09/10/10 10:06 AM
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Joined: Sep 2003
Posts: 2,008
Sweet Home Alabama
MRMOPAR622
top fuel
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top fuel
Joined: Sep 2003
Posts: 2,008
Sweet Home Alabama
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DRDart,I think my biggest problem was the lifters(rollers going bad)not so much the jetting.
Pieces from the roller bearings got into my oiling system(the pick up on the Indy has about 1/4" opening's in it)and went all thru the engine.
I know that's getting off the topic but maybe it will save someone from making the same mistake I made. I knew all of the pieces had to be in the oil pan,but had no idea the oil pick up holes were that large.
I just got the engine put back together last week. I hope to test it this Sunday. It seems to now like the # 39 nozzels with the timing @ 34 degrees. When I get everything sorted out I want to try the VP M5,they say that will pick you up over the regular alcohol.
Last edited by MRMOPAR570; 09/10/10 10:07 AM.
"To Be The Man'You Have Got To Beat The Man"
"T/D and Pro-Bracket Racer"
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