AC Delco spark plugs gap difference - Chevy Impala SS Forum
 
LinkBack Thread Tools Display Modes
post #1 of 6 (permalink) Old 05-30-2013, 11:01 AM Thread Starter
Senior Member
 
Berns's Avatar
 
Join Date: May 2006
Location: Long Beach, Ca 90813
Posts: 1,144
 
AC Delco spark plugs gap difference

Hello All,
I have been reading thru some threads for spark plugs but most are for the LT1 and what ever information was available prior to the crash for 91-93s no longer appears when clicking on the topic. I am doing a full tune up on my car this weekend cause I have to get it smogged. I was searching Napa and noticed that part no CR43TS which is what the car came with from factory state gap at .35 but the rapid fire plugs state gap at .45. Why the difference?

Car info: 1993 Caprice LTZ - L05 mostly stock with only upgrades being MSD cap and rotor and soon new MSD wires, MSD coil, dual after cat exhaust, tranny with shift kit and JET chip.

http://www.napaonline.com/Catalog/Re...270&Ne=1000000

1993 Caprice LTZ/LS
Smoked headlight, tinted 91 tails, LED interior and exterior, JET chipped, MSD ignition, sounds with Kenwood unit, 20" IROCS w/ 255/35 20 Falkens, dual after cat exhaust and bowtie tips, modded air box, WAY MORE TO COME.....
Berns is offline  
Sponsored Links
Advertisement
 
post #2 of 6 (permalink) Old 05-30-2013, 04:11 PM
Senior Member
 
Rocko350's Avatar
 
Join Date: Apr 2007
Location: Mount Airy,MD
Posts: 3,912
 
Depending on engine condition, the rapidfire plug that is gapped at .045" will idle cleaner and should smog better vs the standard plug gapped at .035". It can conduct its spark energy better and can also shed a bit more heat. Be forewarned though, in cold temperatures with ethanol gas and TBI expect a bit of hard starting and some economy drop off with the rapidfires. The difference between the two is the materials the plug is made from, and the amount of heat each is able to deal with since the rapidfires conduct heat to the cooling jacket a bit quicker.

Chris

94-95 Scan. Free, well written diagnostic software
http://www.mediafire.com/?0elo4c935uc5s

Last edited by Rocko350; 05-30-2013 at 11:51 PM. Reason: forgot to profread. jay caught me VVV
Rocko350 is offline  
post #3 of 6 (permalink) Old 05-30-2013, 07:44 PM
Senior Member
 
ghetto wagon's Avatar
 
Join Date: Feb 2002
Location: Ghetto Garage
Posts: 10,895
 
I never used Rapid fire plugs. I always used the stock AC delco CR43TS for a 350 or the CR45TS for a 305. What is strange is that the TBI Trucks used CR43TS plugs. They cost $12.50* -20 for a pack of 8, They last 30k if your engine is in good shape.

* AC delco spark plug rebate.

Member of Baby wheels inc. 17'' + 15's respectfully.

ghetto wagon is offline  
post #4 of 6 (permalink) Old 05-30-2013, 09:23 PM
Senior Member
 
jayoldschool's Avatar
 
Join Date: Jan 2001
Location: the Great White North
Posts: 5,545
 
When HEI first launched, GM spec'd gaps as large as .060. They brought that number down to .035 (not .35, btw, that's HUGE). Anything between .035 and .045 will work reliably.

Old cars, just like classic rock... 60s, 70s, 80s, and 90s!
jayoldschool is offline  
post #5 of 6 (permalink) Old 05-31-2013, 10:55 AM Thread Starter
Senior Member
 
Berns's Avatar
 
Join Date: May 2006
Location: Long Beach, Ca 90813
Posts: 1,144
 
Thanks to all for your help. I think I will take advantage of the AC Delco rebate and get the rapid fires since I do not drive it daily and the cold temps are not as bad in Cali as other places.

1993 Caprice LTZ/LS
Smoked headlight, tinted 91 tails, LED interior and exterior, JET chipped, MSD ignition, sounds with Kenwood unit, 20" IROCS w/ 255/35 20 Falkens, dual after cat exhaust and bowtie tips, modded air box, WAY MORE TO COME.....
Berns is offline  
post #6 of 6 (permalink) Old 05-31-2013, 08:22 PM
Senior Member
 
ghetto wagon's Avatar
 
Join Date: Feb 2002
Location: Ghetto Garage
Posts: 10,895
 
I think the rebate ends today (May 31st) unless they extended it

Member of Baby wheels inc. 17'' + 15's respectfully.

ghetto wagon is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Chevy Impala SS Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome