Engine upgrades, advice please!

Engine upgrades, advice please!

cdlongjr

Active Jeeper
Posts
433
Media
14
Thanks
0
Location
Newark, De
Vehicle(s)
1983 Jeep CJ-5, 1987 Wrangler YJ, 1974 J-10
I'm looking at the following for my AMC 258 i6 / 4.2l :
Weber carb
Single outlet header
Ignition upgrade, (but to what I don't know)
Cam

I'm looking for imput on the iginition & cam,
Thanks
 
Thanks again Brock!
 
AMC 258 i6 / 4.2l upgrades, where to start. I have done all the Team Rush ignition upgrades with the e coil. I did the HEI / Stealth conversion on the duraspark box, I did one with a bad module. I replaced that and still like the duraspark better. Then I followed Hammers CDI upgrade and used the Summit box and I do like it.

I run the Motorcraft carb and back when I ran headers, I liked the single outlet headers the best.

My spare motor has the 4.0 head swap with the Crane Torque cam and I will run the MC 2100 on it also.

I have heard of problems with aftermarket cams and wonder if I had it to over whether I would have used the stock cam. It would have bee cheeper after buying the Mopar Performance vale springs. It does look good on the engine stand.:D

Anyone else having to order their oil filter for the AMC 258 i6 / 4.2l ???? this is what I did to use the 4.0 filter on the AMC 258 i6 / 4.2l .
Terrain Stompers :: View topic - No Oil Filters For The 258
DSCN2104.jpg
 
CD,

I have a question. What is lacking in your CJ that you require an upgrade? Reliability? HP? Torque?

The reason I ask is that since you just purchased this, I'm wondering what you need or want to get out of it? How much off-roading will you be doing? What do you want from this CJ? Why do you need to do these upgrades?

Most are easy and will increase the reliability of the CJ but the cam is the most difficult.

I'm just trying to get a handle on what / why / how you want your CJ to be. I would hate for you to do upgrades just for the sake of doing them when you could be out wheeling instead... :)
 
I will run the mc2100 also. Why dont you run headers anymore?
I run the Motorcraft carb and back when I ran headers, I liked the single outlet headers the best.

DSCN2104.jpg
 
I bought the Jeep new so I have had it for 30 years. I had the single outlet until I had to replace them. Then I ran the dual outlet, they were twice the trouble. Then Ohio started the e check :dung: so I had to go back to the stock set up. Now that they don't e check any more I might go back to the single outlet header again. My exhaust is in good shape so I will wait to see what kind of :dung: the state comes up with next. The Jeep should be old enough that it shouldn't affect me.
 
Gotcha. About 10 years ago Pa. said it was done with emmisons. I bought a dual exhaust kit form someone and a year later had to get new tailpipes made and add cats. I was pissed. $400 for the original exhaust then it got hacked to put in cats.
I bought the Jeep new so I have had it for 30 years. I had the single outlet until I had to replace them. Then I ran the dual outlet, they were twice the trouble. Then Ohio started the e check :dung: so I had to go back to the stock set up. Now that they don't e check any more I might go back to the single outlet header again. My exhaust is in good shape so I will wait to see what kind of :dung: the state comes up with next. The Jeep should be old enough that it shouldn't affect me.
 
I would like to get as much out of the AMC 258 i6 / 4.2l as reasonably possible. I intend to do some serious 4 wheelin' in the future, but don't foresee the rock crawlin'. Most use for now will be highway to get to & from Rauch Creek, Pa. & maybe W Va. I'll probably keep the gearing I have, (373?0, & just install posi traction devices I want the engine right before I continue w/ the suspension. We have done a little crusin' the past 2 weekends & we're about fed up w/ the Carter as most of you know has idle problems. I'm still open o the MC 2100, but some claim the Weber produces more power. I'm here because you folks haven't steered me wrong yet. I have been lookin' @ al the links ya'll are sending. I know the iginition is,t reliable when wet, that's why I want to upgrade it. I know the headers will let her breath better. I'm still up in the air about a cam. (Hold over from the 2 Shelby Mustangs I had as a teenager, but that's another story).
 
I'd swap to a MC2100 if you like carbs, drop a 4.0 head on it and the exhaust that goes with the swap. Later 4.0 headers are stainless tube not cast iron so it's a given upgrade. Those 2 swaps will net the most bang for the buck, the head swap will get you more HP which will help for those longer drives on the paved roads.
 
I have to side with CJ on this one. I have had sevceral AMC 232 i6 / AMC 258 i6 / 4.2l engines over the years, and love them both. I have never found a good reason to go crazy and spend a pile of money "upgrading" them unless you have a specific hard use intended for them, or you just have a bunch of parts available to you for little or no money. I think that too many people fall into the peer pressure build and spend well when It may not be at all necessary. The AMC 258 i6 / 4.2l is a good engine right out of the box, and enjoys good low end grunt, bullit proof performance, and nearly legendary reliability. But If you want more, just a little tinkering will make it better without having to blow your mortgage payments. Simply installing a good carb, (I used a Webber) a header and big bore exhaust, and a good upgraded ignition (I used a Jacobs system) and If possible in your state, gut the emissions system out. For stuff like this, I would allways recommend starting out doing just the tried and true basics and see what the gains will be. Then If you still want more you can start tearing into the engine. Having been both routes, I rebuild to stock, and use simple bolt on upgrades and never unhappy with the results I get.
 
I just want more pep out of the 6 banger. Most of my driving will be highway to get to & from the trail rides. I'm considering the MC 2100 over the Weber. Some of the upgrades stem back to my Shelby Mustang days, (67 GT-350 & 68 GT-500). I want the driveline correct before I start on the lift, etc. I know the ignition needs upgraded. Figuring on the electric fans too,
 
Last edited:
Looks like the MC2100 & 4.0 head. What ignition set up do you guys recommend?
 
Not sure what it costs for 4.0 head swap and new carb, but for 2500. you could put the Mopar MPI on and get everything your looking for and more.
 
You can do a 4.0 head swap and MC2100 pretty check but it requires you to do most of the work and use JY parts. If you do a 4.0 head swap spend a little extra and have a shop go through the head, have the water jackets welded not epoxied shut at a minimum. Me I'm gonna have it welded, valves done, a few other good maint. stuff and maybe a port and polish.
As far as the ignition I like summits CDI setup.
It's on my list of stuff to do.
Look into a ford contour fan setup.
I've posted links on this site in the misc section.
 

Jeep-CJ Donation Drive

Help support Jeep-CJ.com by making a donation.

Help support Jeep-CJ.com by making a donation.
Goal
$200.00
Earned
$25.00
This donation drive ends in
Back
Top Bottom