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.  And, if you were you banned at another AMC Eagle Forum and cannot log in here?  Let us know and we will fix it for you. 

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.


  • August 04, 2020, 07:12:05 AM

Login with username, password and session length

Author Topic: Fuel injection 4.0/4.2  (Read 102 times)

0 Members and 1 Guest are viewing this topic.

Offline Longhunter

  • Eagle
  • **
  • Posts: 33
  • Thumbs Up 2
Fuel injection 4.0/4.2
« on: July 26, 2020, 01:34:37 PM »
Can you put fuel injection on the 4.2 or can you only put it on the 4.0 head on the 4.2 block?

Sorry for all the questions but as I have stated repeatedly I am not a mechanic. I want to put fuel injection on the Eagle. I am also looking at having the engine and tranny rebuilt. I see several posts here about the goodness of the 4.0 head swap. If I must have the 4.0 head for fuel injection then it is an easy decision.

Thank you.

Offline Canoe

  • Eagle Sundaancer
  • ******
  • Posts: 967
  • Thumbs Up 48
Re: Fuel injection 4.0/4.2
« Reply #1 on: July 26, 2020, 02:04:00 PM »
Cost of putting a 4.0 head on a 4.2 is realatively easy mod. But it should have a different cam to get more of the benefit; more $. And you should have a 2.25" exhaust system.

Cost of rebuilding a 4.2 and add a 4.0 head and 4.0 cam, compare that against putting a good working 4.0 in that already has a cam for it and fuel injection. Again, 2.25" exhaust system.

You can build a stroker (and a 2.5" exhaust), but how much more would you get over a stock 4.0...

Fuel injection needs a pickup to know the engine cycle position. I don't know if you could get adequate notification for that off a dizzy pickup.

To understand the benefits vs. costs, you're going to have to fully check into 258 rebuild, add 4.0 head, add suitable cam, add EFI, go whole 4.0, go stroker.

start with
http://amceaglesden.com/guide/Technical_Indexes

and under 258 
http://amceaglesden.com/guide/How_To_Section
« Last Edit: July 26, 2020, 03:21:08 PM by Canoe »

Offline Canoe

  • Eagle Sundaancer
  • ******
  • Posts: 967
  • Thumbs Up 48
Re: Fuel injection 4.0/4.2
« Reply #2 on: July 26, 2020, 04:11:27 PM »
p.s.
I got an amazing 4.2 rebuild, +0.030, with a 4.0 HO head completely reworked with heavy springs for the valves, and a wider cam, recurved dizzy to match, now a 4.3, hotter coil and ignition module, and its great. Even better with a fake MC2150 but still stock exhaust.

I could have had a 4.0 with a HO head and EFI, for 1/3 to 1/2 the cost of my rebuild, depending on how much of the 4.0 I wanted to replace (timing chain, oil pump, valve job, porting, etc.).
I was just fixated on adding a 4.0 head to a 4.2...

Offline vangremlin

  • Administrator
  • AMC Eagles Den Addicted
  • ******
  • Posts: 3947
  • Thumbs Up 191
Re: Fuel injection 4.0/4.2
« Reply #3 on: July 27, 2020, 07:39:27 PM »
You can also go with a throttle body style fuel injection.  Not as good as using the system from the Jeep 4.0 engine, but a step up from a carb and several options to choose from and it's an easier install.  I got a TBI unit from Performance Fuel Injection in my Kammback mated with a 4.0 head and upgraded cam and its much nicer than the stock setup.
1981 Kammback 258 - "Pepe"
1980 Coupe 258 - "Ginger
1972 Gremlin X 304
1978 Gremlin 4 cyl 121 - sold
1964 TBird 390 - sold

 

SMF spam blocked by CleanTalk