Previous Thread
Next Thread
Print Thread
spark plugs ? #2436711
01/18/18 03:06 AM
01/18/18 03:06 AM
Joined: Apr 2016
Posts: 112
Illinois
S
sixbbl 69 Offline OP
member
sixbbl 69  Offline OP
member
S

Joined: Apr 2016
Posts: 112
Illinois
69 440 six bbl with mopar performance alum heads.525 hp pump gas. what type and number plug should i start with for first start up.

Re: spark plugs ? [Re: sixbbl 69] #2436712
01/18/18 03:07 AM
01/18/18 03:07 AM
Joined: Oct 2008
Posts: 1,176
East Coast
A
A/MP Offline
super stock
A/MP  Offline
super stock
A

Joined: Oct 2008
Posts: 1,176
East Coast
stock '69 440+6 plugs

Re: spark plugs ? [Re: A/MP] #2436714
01/18/18 03:11 AM
01/18/18 03:11 AM
Joined: Apr 2016
Posts: 112
Illinois
S
sixbbl 69 Offline OP
member
sixbbl 69  Offline OP
member
S

Joined: Apr 2016
Posts: 112
Illinois
J11Y won't fit the heads.

Re: spark plugs ? [Re: sixbbl 69] #2436719
01/18/18 03:48 AM
01/18/18 03:48 AM
Joined: Sep 2014
Posts: 4,457
Washington
M
madscientist Offline
master
madscientist  Offline
master
M

Joined: Sep 2014
Posts: 4,457
Washington
RC9YC champion

Use a 12 if it's under 10:1


Just because you think it won't make it true. Horsepower is KING. To dispute this is stupid. C. Alston
Re: spark plugs ? [Re: sixbbl 69] #2436911
01/18/18 04:20 PM
01/18/18 04:20 PM
Joined: Aug 2003
Posts: 43,007
Bend,OR USA
C
Cab_Burge Offline
I Win
Cab_Burge  Offline
I Win
C

Joined: Aug 2003
Posts: 43,007
Bend,OR USA
Do you know the compression ratio and octane rating you will use?
I have a 505 C.I. 440 block that has right at 10.08 to 1 compression and I'm going to use Champion RC12YC on our local pump swill. I've had other pump gas motors with a little more compression, 10.78 to 1, that I used champion RC9YC and Autolite AR3911 non resistor race plugs and AR3910 non resistor race plugin them with good results up
I went out to the shop and got couple of other Autolite resitor street pump gas plugs, 3924 and maybe 3925, which is hotter, if they make that plug number now scope
Good luck, let us know what you use and your results scope

Last edited by Cab_Burge; 01/18/18 08:18 PM.

Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: spark plugs ? [Re: sixbbl 69] #2437750
01/20/18 12:08 AM
01/20/18 12:08 AM
Joined: Apr 2016
Posts: 112
Illinois
S
sixbbl 69 Offline OP
member
sixbbl 69  Offline OP
member
S

Joined: Apr 2016
Posts: 112
Illinois
thanks Mad and Cab







Powered by UBB.threads™ PHP Forum Software 7.7.1