News: Putting FUN and FRIENDLINESS, FIRST into owning and learning about AMC small bodied cars, primarily Eagles, Spirits and Concords as well as vehicles built in AMC's Mexican subsidiary, VAM.

The AMC Eaglepedia can now be accessed using the buttons found below  This is a comprehensive ever growing archive of information, tips, diagrams, manuals, etc. for the AMC Eagle and other small bodied AMC cars. 

Also a button is now available for our Face Book Group page.


Welcome to the AMC Eagles Nest.  A new site under "old" management -- so welcome to your new home for everything related to AMC Eagles, Spirits and Concords along with opportunities to interact with other AMC'ers.  This site will soon be evolving to look different than it has and we will be incorporating new features we hope you will find useful, entertaining and expand your AMC horizons.

You can now promote your topics at your favorite social media site by clicking on the appropriate icon (top upper right of the page) while viewing the topic you wish to promote.


  • November 23, 2024, 10:05:08 AM

Login with username, password and session length

Author Topic: 4L conversion spark plugs  (Read 2955 times)

0 Members and 1 Guest are viewing this topic.

Offline Obscurity

  • Eagle Sundaancer
  • ******
  • Posts: 939
  • Thumbs Up 22
4L conversion spark plugs
« on: April 18, 2011, 12:34:45 PM »
Hey, I'm sure there is something on the Nest somewhere, but I haven't found it.
I got the 4L conversion head from Clearwater cylender heads. I know I'm going to need spark plugs for the 4L, does anyone know off the top of their head whether there are differences in the 4L plugs? I can't find the information on my cylender head (I moved, its around somewhere, but it'll probably be a week of digging through paper to find it!).
Also, does anyone know what kind of gap I'll need? The block is bored to .40 (if I recall correctly, I'll have to double check, Comp Cam, 2bbl Webber carb. Thoughts or suggestions? I really want to get the plugs today, and an oil filter if NAPA actually has one in stock (Canadian Tire didn't).
Thanks all!
"In order to attain the impossible, one must attempt the absurd" -Miguel de Cervantes

Offline eaglefreek

  • Moderators
  • AMC Eagles Den Addicted
  • *****
  • Posts: 4011
  • Thumbs Up 209
Re: 4L conversion spark plugs
« Reply #1 on: April 18, 2011, 01:19:04 PM »
The Eagles 4.2l and the 91-95 Jeep with a 4.0 both use the same plug. Go with your favorite brand Autolite, NGK etc. Regular old copper cores are fine, no need for platinum or iridium. If you experience spark knock you can use a colder plug from an 87-89 Jeep with a 4.0. As far as gap, that depends on your ignition. If stock just go with stock specs. If MSD or HEI you can open it up. I run mine at .045 with a MSD box.
1986 AMC Eagle Wagon 4.2L/4.0L head, AW4,NP242, Chrysler 8.25" rear.
1981 AMC Eagle Wagon As Seen On TV  Lost In Transmission


 

"I know he'd be a poorer man, if he never saw an eagle fly,
Rocky mountain high"  John Denver
Click for Fayetteville,TN Forecast" border="0" height="100" width="150

Offline Obscurity

  • Eagle Sundaancer
  • ******
  • Posts: 939
  • Thumbs Up 22
Re: 4L conversion spark plugs
« Reply #2 on: April 18, 2011, 06:37:04 PM »
Whoo hoo, thak you eaglefreek! I picked them up with an oil filter an hour ago. Went with Platinum, less than a dollar more each than the copper. Just that much closer to the first start of the new engine  :hello2: I will be upgrading to a different ignition....eventually.
The parts guy asked what vehicle the parts are for (didn't know for sure what vehicle the head would be for, stock, just gave him the basic info you gave me) then the he tells me to look on the insurance papers and it'll tell me for sure, a Jeep or an Eagle, a '90s model or an '80s....uugh. Wouldn't believe me that I was looking for parts for the same engine. We were both rolling our eyes by the end, both convinced that the other one was a jerk, lol, I should be used to this by now!
"In order to attain the impossible, one must attempt the absurd" -Miguel de Cervantes

 

SMF spam blocked by CleanTalk