Correct plug gap
Burning Brakes
Joined: Aug 2005
Posts: 1,164
Likes: 1
From: Europe, France
Try them all, I did, 35 to 50 settled on 40. The really weird thing is I think the .050" gap was making my exhaust stink real bad. When I went back to .040" it is much much better, still stinks a bit but doesn't stink up the whole neighborhood anymore.
Don't know if the smell has anything to do with the gaps or not but would be interesting to find someone else who had a similar experience.
I also found the idle sound a little louder and not quite as smooth with the wider gaps, would be interesting to do some chassis dyno runs to find out if you make any more power at different plug gaps
Don't know if the smell has anything to do with the gaps or not but would be interesting to find someone else who had a similar experience.
I also found the idle sound a little louder and not quite as smooth with the wider gaps, would be interesting to do some chassis dyno runs to find out if you make any more power at different plug gaps
Starting from 0.030" up to 0.060", the results are : ETs are decreasing until 0.045" and stay unchanged over this value.
So, in my case, it was unnecessary to increase the gap any further.
Which doesn't mean that it should be the same for everyone...
What I didn't check was economy, because I didn't have the appropriate stuff...
Burning Brakes
Joined: Jan 2007
Posts: 1,057
Likes: 4
From: Concord Calif
I did this experience, not with dyno runs but the simple help of my G-Tech SS.
Starting from 0.030" up to 0.060", the results are : ETs are decreasing until 0.045" and stay unchanged over this value.
So, in my case, it was unnecessary to increase the gap any further.
Which doesn't mean that it should be the same for everyone...
What I didn't check was economy, because I didn't have the appropriate stuff...
Starting from 0.030" up to 0.060", the results are : ETs are decreasing until 0.045" and stay unchanged over this value.
So, in my case, it was unnecessary to increase the gap any further.
Which doesn't mean that it should be the same for everyone...
What I didn't check was economy, because I didn't have the appropriate stuff...
This was a good way to see what your car needs. Not all the other items people come up with!!! Run the biggest gap your system will fire cleanly is where it should be, understand whats going on and then adjust as needed. Good job here.
Burning Brakes
Joined: Aug 2005
Posts: 1,164
Likes: 1
From: Europe, France
Melting Slicks
Joined: Apr 2005
Posts: 2,777
Likes: 105
I run on my 427/435HP Closed Chamber L89 Aluminum Heads (11:1 comp) Stout Solid Cam a MSD 6A with MSD 8572 Distributor and Mallory Mark IV Coil. NGK Iridium Plugs gapped at .041". Runs Flawlessly.....
Last edited by babbah; Jun 29, 2010 at 12:10 AM.
