Brought to you in part by:

.

Shop Eastwood for your Auto Restoration Needs!


  Mustangsandmore Forums
  '64 1/2 to '73 -- The Classic Mustang
  Spark Plug Gap ????

Post New Topic  Post A Reply
profile | register | preferences | faq | search

UBBFriend: Email This Page to Someone! next newest topic | next oldest topic
Author Topic:   Spark Plug Gap ????
70 Pony
Gearhead

Posts: 1814
From: Glenmoore, PA, USA
Registered: Jan 2000

posted 07-10-2001 04:39 PM     Click Here to See the Profile for 70 Pony   Click Here to Email 70 Pony     Edit/Delete Message   Reply w/Quote
Using autolite 3924's...(Called for by Trick Flow Heads)... with a moderate ignition system...Mallory unilite distributor...MSD entry level "Blaster Box" and MSD Blaster Coil..accel 8.8 wires and a 750 Holley DP'er, jetted at 72 and 78 with an 8.5 power valve....
Any thoughts on a good spark plug gap (at least to begin with)... THANKS

------------------
EDDIE D
Resto Mod '70 Sport Roof
Arrest Me Red

IP: Logged

Doc
Gearhead

Posts: 466
From: Redwood City, Ca. USA
Registered: Jan 2001

posted 07-10-2001 11:46 PM     Click Here to See the Profile for Doc   Click Here to Email Doc     Edit/Delete Message   Reply w/Quote
The gap of a plug depends on fuel mixture, a lean mixture needs a wide gap to insure both air and fuel are in the spark gap to ignite the mix, a rich mix can run with a smaller gap and is easier on wires, cap and rotor. Yours should run good at .025 IMO.

IP: Logged

70 Pony
Gearhead

Posts: 1814
From: Glenmoore, PA, USA
Registered: Jan 2000

posted 07-12-2001 01:53 PM     Click Here to See the Profile for 70 Pony   Click Here to Email 70 Pony     Edit/Delete Message   Reply w/Quote
DOC......025 !!!! I think the stock 302 was .035....are you sure.....
Cause I'm in the .040 range.....

Thanks.....Not 2nd guessing you....just wanted to make sure you meant .025....
I figured a nice gap would make a nice spark for more complete combustion....as long as the spark could travel the distance...

------------------
EDDIE D
Resto Mod '70 Sport Roof
Arrest Me Red

IP: Logged

66351stang
Gearhead

Posts: 677
From: sayville,newyork
Registered: Jul 2000

posted 07-12-2001 02:20 PM     Click Here to See the Profile for 66351stang   Click Here to Email 66351stang     Edit/Delete Message   Reply w/Quote
leave them at the stock gap(.035) and take it from there

------------------
ponycar66,have you flown in a ford latley???????
66-COUPE W/351SVO
glad i had a v-8 !!!!!!
84.5 gt350-61 falcon 302
have a great day!!!!!!!!

IP: Logged

Doc
Gearhead

Posts: 466
From: Redwood City, Ca. USA
Registered: Jan 2001

posted 07-12-2001 03:20 PM     Click Here to See the Profile for Doc   Click Here to Email Doc     Edit/Delete Message   Reply w/Quote
.035 will work as will .045 but wider gaps put more stress on components and don't make more power. If your car were stock, with stock jetting .035 would assure some gas molecules would be in the gap along with air so it'll light the mix, a gap of .025 can be used any time the mix is rich enough, if you close a late, lean smog motor gap to .025 it will miss and not run well if it runs at all. The whole job of the plug is to light the mix and if it'll do it at .025 it is better for all the rest of the parts. Also when the revs go up there's less and less time for the coil to build a full charge the smaller gap will let more of the weaker spark through so there are other reasons for doing it that way.

IP: Logged

lyle29464
Gearhead

Posts: 827
From: Mt. Pleasant S.C.
Registered: Mar 2000

posted 07-12-2001 10:35 PM     Click Here to See the Profile for lyle29464   Click Here to Email lyle29464     Edit/Delete Message   Reply w/Quote
When I cant find a feeler gage I just use a thin dime. If you dont have a thin dime use a nickel and five pennies.

IP: Logged

70 Pony
Gearhead

Posts: 1814
From: Glenmoore, PA, USA
Registered: Jan 2000

posted 07-13-2001 09:53 AM     Click Here to See the Profile for 70 Pony   Click Here to Email 70 Pony     Edit/Delete Message   Reply w/Quote
Gotcha DOC....Thanks for the input...very helpful and thanks ...66 Stang...and LYLE , I like your math !!!!!!

------------------
EDDIE D
Resto Mod '70 Sport Roof
Arrest Me Red

IP: Logged

All times are ET (US)

next newest topic | next oldest topic

Administrative Options: Close Topic | Archive/Move | Delete Topic
Post New Topic  Post A Reply
Hop to:

Contact Us | Mustangsandmore Front Page

Copyright 2003, Steve LaRiviere. All Rights Reserved.


Ultimate Bulletin Board 5.47d

Amazon Honor System Click Here to Pay Learn More

[Build a free Mustangsandmore.ws Home Page!]

[About M&M][Acronyms][Calendar][Chat][Classifieds] [Members' Pics] [M&M Mug Shots]

[ Mustangsandmore.com Bookstore] [Mustangsandmore.com T-Shirts][Tech Articles]