Re: Please help me read my spark plug
[Re: jbeintherockies]
#2710292
10/27/19 01:24 AM
10/27/19 01:24 AM
|
Joined: Aug 2003
Posts: 43,315 Bend,OR USA
Cab_Burge
I Win
|
I Win
Joined: Aug 2003
Posts: 43,315
Bend,OR USA
|
The porclyn is NOT chipping off, it is chemical deposits from combustion that you are seeing chipping off ![up up](/ubbthreads/images/graemlins/custom/thumbs_up.gif) What type of heads (aluminum or iron)and compression are you running? You might want to try a #65 plug in your motor to see if that hotter plug will burn hot enough to prevent those deposits ![twocents twocents](/ubbthreads/images/graemlins/custom/twocents.gif)
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
|
|
|
Re: Please help me read my spark plug
[Re: Sniper]
#2710388
10/27/19 02:34 PM
10/27/19 02:34 PM
|
Joined: May 2011
Posts: 220 Aurora, CO
jbeintherockies
OP
enthusiast
|
OP
enthusiast
Joined: May 2011
Posts: 220
Aurora, CO
|
Hello, I have been using Exxon/Mobil Synergy Supreme premium gasoline mixed with about 5 gallons of Sunoco 260 (100 octane). https://www.exxon.com/en/synergy-supreme-plushttps://www.sunocoracefuels.com/fuel/260-gtAdding the 260 really helps with fuel boil. About the car, '68 Barracuda FB Formula S, 3.91's, 5 speed manual, DLI ported X heads, M1 intake, holley carb, mech roller cam (about 248@50), about 9.7:1 compression ratio, bored and stroked to about 386ci. Timing is 22 degrees initial, 37 total all in at 2500. Vacuum advance adds about 8 degrees of advance. This engine likes a lot of advance, meaning I could probably go with a little more initial and total (2-3 degrees). Maybe it wants more timing to burn off some of the deposits? Cab's suggestion of a hotter plug is interesting; I could give it a try and listen carefully for ping/rattle. If you need any additional info, please ask. What pump gas are you guys running in your cruisers with carbs?
|
|
|
Re: Please help me read my spark plug
[Re: jbeintherockies]
#2710479
10/27/19 09:29 PM
10/27/19 09:29 PM
|
Joined: Aug 2003
Posts: 43,315 Bend,OR USA
Cab_Burge
I Win
|
I Win
Joined: Aug 2003
Posts: 43,315
Bend,OR USA
|
The race fuel is making the deposits on your plugs, at that compression ratio and any altitude above 4500 you don't need any fuel additive or race fuels ![twocents twocents](/ubbthreads/images/graemlins/custom/twocents.gif) Based on how much total timing your running I'm assuming your above 5000 FT altitude, correct? On your deal I would change to the #65 Autolites with no other tuning changes other than dropping the race gas to your tank ![twocents twocents](/ubbthreads/images/graemlins/custom/twocents.gif) I use to help several NHRA stock class racers that ran 340 motors, one ended up setting the E/SA record that stood for two years, later on he held the C/SA record with a Challenger I sold him that he made into a 340 6 pack T/A clone car, that car was a rocket ship ![up up](/ubbthreads/images/graemlins/custom/thumbs_up.gif) None of those Stocker motors, 1970 4 barrel, 1970 six pack and the1971 340 four barrel motors like more than 33 degree total at the track or on the engine dyno under 4000 Ft altitude in SO CA ![shruggy shruggy](/ubbthreads/images/graemlins/custom/shruggy.gif) IHTHs ![thumbs thumbs](/ubbthreads/images/graemlins/custom/thumbs.gif)
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
|
|
|
|
|