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indexing plugs #628156 03/01/10 07:06 PM 03/01/10 07:06 PM
Joined: May 2004 Posts: 3,210 robin hood country deaks OP master
deaks OP master Joined: May 2004 Posts: 3,210 robin hood country	I am fitting my 76cc RPM heads to a new short block with 12.5.1 venolia domes, will i need to index the plugs and where can i buy the washers to do it. Mick

Re: indexing plugs [Re: deaks] #628157 03/01/10 07:50 PM 03/01/10 07:50 PM
Joined: Aug 2003 Posts: 43,213 Bend,OR USA C Cab_Burge I Win
Cab_Burge I Win C Joined: Aug 2003 Posts: 43,213 Bend,OR USA	Quote: I am fitting my 76cc RPM heads to a new short block with 12.5.1 venolia domes, will i need to index the plugs and where can i buy the washers to do it. Mick Mick, every motor is different, I'm sure there is no way to say absolutely yes or absolutely no! Take one of the plugs you want to race with and install it(with the head off) so the bend of the ground strap is pointed striaght down so it will hit the piston dome. Install the head with the gasket your going to use ( make sure and install the rod and piston) and then rotate the motor slowly from 20 BTDC to 20 degrees ATDC, you may want to install some clay on the sparkplug end also. check the results and go from there I use to thank that there was around .01 to .02 ET increase by indexing all eight plugs in my M.W stocker there wasn't , it was the weather changing making the ET changes All the other racers where seeing the same increases without opening there hoods Are you using a projected gap plug or a non projected tip plug? the last thing is are the Venolia pistons tops designed for the Eddy heads only or are they a generic shelf piston for 440 motors with a standard pop up dome? Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)

Re: indexing plugs [Re: deaks] #628158 03/01/10 07:55 PM 03/01/10 07:55 PM
Joined: Jul 2005 Posts: 134 Flyover Country 340king member
340king member Joined: Jul 2005 Posts: 134 Flyover Country	I usually have extra plugs around and just try fitting several to see where the ground strap ends up. Usually 12 plugs will get you in the ball park. I never use the washers. This comes from doing the same thing on tapered seat plug engines.

Re: indexing plugs [Re: 340king] #628159 03/01/10 08:08 PM 03/01/10 08:08 PM
Joined: May 2004 Posts: 3,210 robin hood country deaks OP master
deaks OP master Joined: May 2004 Posts: 3,210 robin hood country	The motor had stage VI heads on it, i presume they have straight plugs but i'm not sure. Without going in the garage to look now, i think the plugs are AR3930. Mick

Re: indexing plugs [Re: deaks] #628160 03/01/10 09:05 PM 03/01/10 09:05 PM
Joined: Jun 2009 Posts: 644 Minnesota Barnstorm mopar
Barnstorm mopar Joined: Jun 2009 Posts: 644 Minnesota	Hi Mick. We don't do it anymore even in the SS/AH motors. Big MSD spark doesn't care. Kinda like cool cans,faded away. 5839324-100_2208[640x480].JPG (53 downloads) The little old lady from Pasadena is back!

Re: indexing plugs [Re: deaks] #628161 03/02/10 03:36 PM 03/02/10 03:36 PM
Joined: May 2004 Posts: 3,210 robin hood country deaks OP master
deaks OP master Joined: May 2004 Posts: 3,210 robin hood country	Sorry, plugs are BK6RE projected tips. Barnstorm I dont understand what you mean, i have got msd 6al though. Mick

Re: indexing plugs [Re: Barnstorm] #628162 03/02/10 04:45 PM 03/02/10 04:45 PM
Joined: Oct 2004 Posts: 8,165 Left Coast B BobR master
BobR master B Joined: Oct 2004 Posts: 8,165 Left Coast	Quote: Hi Mick. We don't do it anymore even in the SS/AH motors. Big MSD spark doesn't care. Kinda like cool cans,faded away. Exactly. Indexing is a waste of time unless it for clearance.

Re: indexing plugs [Re: BobR] #628163 03/02/10 05:18 PM 03/02/10 05:18 PM
Joined: Jun 2009 Posts: 644 Minnesota Barnstorm mopar
Barnstorm mopar Joined: Jun 2009 Posts: 644 Minnesota	With the stock 60's and 70's standard coil and points system, there may have been some benefit. However with most ignition systems like MSD and the like, they put out so much spark that turning the plug here or there doesn't seem to make a differance in engine performance. The little old lady from Pasadena is back!

Re: indexing plugs [Re: Barnstorm] #628164 03/02/10 05:47 PM 03/02/10 05:47 PM
Joined: May 2004 Posts: 3,210 robin hood country deaks OP master
deaks OP master Joined: May 2004 Posts: 3,210 robin hood country	That is the only reason i'm asking, i'm concerned about clearance and would appreciate some solid advice. Mick

Re: indexing plugs [Re: deaks] #628165 03/02/10 06:11 PM 03/02/10 06:11 PM
Joined: Dec 2008 Posts: 1,200 UK 6 602heavy pro stock
602heavy pro stock 6 Joined: Dec 2008 Posts: 1,200 UK	Mick , while the heads off check how far the plug enters into the head , on my 572 heads the plug stop short of the chamber , i'm sure you'll be fine with the non projected type , these are the one's i use for the nitrous , i would imagine you would be running these type plugs on that combo anyway.

Re: indexing plugs [Re: 602heavy] #628166 03/02/10 06:22 PM 03/02/10 06:22 PM
Joined: May 2004 Posts: 3,210 robin hood country deaks OP master
deaks OP master Joined: May 2004 Posts: 3,210 robin hood country	Adam They are the projected type, that's one of the reasons i asked the question, hoping that someone would suggest a plug or a solution to any problem that might arise. Mick

Re: indexing plugs [Re: deaks] #628167 03/02/10 06:29 PM 03/02/10 06:29 PM
Joined: Dec 2008 Posts: 1,200 UK 6 602heavy pro stock
602heavy pro stock 6 Joined: Dec 2008 Posts: 1,200 UK	Mick , you're question was answered by Cab , you need check the plug in the head with the head off , no one can tell you how much those plugs need to be spaced with washers , maybe they don't? , i would.nt take a chance on somebody else telling me how they did it as all motors are different , personally i would'nt use the projected type plugs with that compression ratio , the non projected type plug will gain you more clearance (NGK BCR) Try Sumit racing for those spacers. Last edited by 602heavy; 03/02/10 06:31 PM.

Re: indexing plugs [Re: 602heavy] #628168 03/02/10 07:26 PM 03/02/10 07:26 PM
Joined: Oct 2005 Posts: 8,879 Ontario, Canada S Stanton Don't question me!
Stanton Don't question me! S Joined: Oct 2005 Posts: 8,879 Ontario, Canada	How many times do you need to hear the same answer before you get it ?!?!?!

Re: indexing plugs [Re: deaks] #628169 03/02/10 07:29 PM 03/02/10 07:29 PM
Joined: Nov 2008 Posts: 363 Aubrey, Texas O oldtimer5151 enthusiast
oldtimer5151 enthusiast O Joined: Nov 2008 Posts: 363 Aubrey, Texas	A spark plug is just a ground for coil. I have indexed plugs in different motors from flat heads, to o.h.v. motors. The only benefit from indexing is to turn the spark plug ground`s back toward the intake valve. The reason is it will receive the gas that leaves the air stream and will hit the extended tip, and ground. The small droplets of gas will absorb the heat off the end of the plug and the absorbed heat will help vaporize the gas. Extended plugs move the timing .125 further into the combustion chamber help controlling the flame on top of the piston. You must take a small points file and file ALL sharp corners off the ground. The spark plug will be in the mix of the heat and explosion.

Re: indexing plugs [Re: oldtimer5151] #628170 03/03/10 05:00 AM 03/03/10 05:00 AM
Joined: May 2004 Posts: 3,210 robin hood country deaks OP master
deaks OP master Joined: May 2004 Posts: 3,210 robin hood country	Thanks for the replies, i will try a different plug to see where i am and go from there. Stanton Dont take it personal, it's just a question. Mick

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