Back to basics... spark plug gap?
#1020091
06/25/11 08:00 AM
06/25/11 08:00 AM
|
Joined: Jan 2003
Posts: 2,309
Tomorrow.
Damned67
OP
top fuel
|
OP
top fuel
Joined: Jan 2003
Posts: 2,309
Tomorrow.
|
Hi All, Just had to clean up some mildly-fouled plugs (old gas and lot's of idling), and thought I'd regap them. Reading through this site, I see many, many different suggested gaps. I read that with MSD boxes, gap should be changed. I also read that a test of different gaps had no resultant change in HP. So, there's a lot of variation for perhaps not much outcome. So, I turn this to you all for your opinions. I've been gapping my plugs at .030 I've got a 10.4:1 505" RB with E'brock heads, a 0.587/0.593 287/294 cam, M1 intake and 1050 Dominator. MSD 6AL box, MSD Blaster 2 coil, MP distributor and NGK BCP6ES plugs. For street and strip, what would you gap them at? Cheers! 
|
|
|
Re: Back to basics... spark plug gap?
[Re: dennismopar73]
#1020094
06/25/11 09:42 AM
06/25/11 09:42 AM
|
Joined: Jan 2003
Posts: 21,067
Niles , Ohio
therocks
oh wait.but hey.lets see.oh yeah.
|
oh wait.but hey.lets see.oh yeah.
Joined: Jan 2003
Posts: 21,067
Niles , Ohio
|
My 440 with MSD and 12.5 domes, 1050 Dominator and Stealth heads I run .040.Its street driven and no problems.My sons 413 with MSD same gap.I run NGK plugs and they seem better than the Autolites I was running.Rocky
Last edited by therocks; 06/25/11 09:43 AM.
Chrysler Firepower
|
|
|
Re: Back to basics... spark plug gap?
[Re: therocks]
#1020095
06/25/11 10:18 AM
06/25/11 10:18 AM
|
Joined: Mar 2003
Posts: 2,498
PA
moparacer
top fuel
|
top fuel
Joined: Mar 2003
Posts: 2,498
PA
|
I think for the most part all a wider gap does on a NA engine is work the ignition system and wires harder. I seen a car a few years back that wouldn't run with a .040 gap and was fine at .035..  I run mine at .035 on gas and tightened it up to .030 when I put alky on it. Blower, turbos and NOS are a different story.
67 Barracuda street/bracket car 11.27-119
68 Dart 502 BB 8.70s-152
414 cid SB Dragster 7.65-174
|
|
|
Re: Back to basics... spark plug gap?
[Re: Damned67]
#1020098
06/25/11 10:45 AM
06/25/11 10:45 AM
|
Joined: Oct 2003
Posts: 7,506
Az
Crizila
master
|
master
Joined: Oct 2003
Posts: 7,506
Az
|
Quote:
Hi All,
Just had to clean up some mildly-fouled plugs (old gas and lot's of idling), and thought I'd regap them.
Reading through this site, I see many, many different suggested gaps. I read that with MSD boxes, gap should be changed. I also read that a test of different gaps had no resultant change in HP.
So, there's a lot of variation for perhaps not much outcome.
So, I turn this to you all for your opinions.
I've been gapping my plugs at .030
I've got a 10.4:1 505" RB with E'brock heads, a 0.587/0.593 287/294 cam, M1 intake and 1050 Dominator.
MSD 6AL box, MSD Blaster 2 coil, MP distributor and NGK BCP6ES plugs.
For street and strip, what would you gap them at?
Cheers!
The wider the better - as long as your ignition system is up to the task of lighting them. I'd go for .040"
Fastest 300
|
|
|
Re: Back to basics... spark plug gap?
[Re: Damned67]
#1020100
06/25/11 08:32 PM
06/25/11 08:32 PM
|
Joined: Dec 2009
Posts: 20,640
in a cattle trailer down by th...
Guitar Jones
Paddle faster! I hear banjo music!
|
Paddle faster! I hear banjo music!
Joined: Dec 2009
Posts: 20,640
in a cattle trailer down by th...
|
I gap mine at .045 with a 7AL, 12.3 on gas but mine's a small block with really good chambers and a lot of quench. Very small chamber and tight piston to head clearance. I'd bet I could run .035 with no problem but I figure if I can get a wider gap I'm better off.
"Follow me the wise man said, but he walked behind"
'92 D250 Club Cab CTD, 47RH conversion, pump tweaks, injectors, rear disc and hydroboost conversion.
'74 W200 Crew Cab 360, NV4500, D44, D60 and NP205 divorced transfer case. Rear disc and hydroboost coming soon!
2019 1500 Long Horn Crew Cab 4WD, 5.7 Hemi.
|
|
|
|
|
