Engine Upgrades?

[BLennon]

Hey guys,

So there is nothing really wrong with the stock AMC 258 i6 / 4.2l that's in my '82 scrambler, but slowly I want to start replacing some stuff under the hood. Nothing major like a new engine, just things like the starter or distributor. My question is where should I start? I don't think I need that much more power or anything, I'm aiming more for just being dependable and efficient. I would definitely like better gas mileage if possible.

Thanks, Bobby

 

[coldwater]

Hey guys,

So there is nothing really wrong with the stock 258 that's in my '82 scrambler, but slowly I want to start replacing some stuff under the hood. Nothing major like a new engine, just things like the starter or distributor. My question is where should I start? I don't think I need that much more power or anything, I'm aiming more for just being dependable and efficient. I would definitely like better gas mileage if possible.

Thanks, Bobby

Your AMC 258 i6 / 4.2l is a fine engine, and you can indeed give it a little more punch with a few upgrades. The stock carbs are at best..well... A webber or an Autolite 2100 are one of the best upgrades you can do for your Jeep, and you will notice an instant change in performance. A header is right up there as a performance inhancer. Open up the exhaust system with a big tube and a higher flow muffler, and you can get the best from your new carb. At this point, the distributer may be less than it was when it was new, and may be robbing you of power and economy. A stock dist is pretty cheap to buy, and easy to install. If It still has all the junk emissions plumbing, I would kill off every single bit of it. Just get rid of every part and piece, and toss it in the trash. Many of us have upgraded to higher energy ignition systems, and can tell you first hand that they are well worth the money spent. I have done all these upgrades to my 6, and my average mileage for my 78 CJ7 is about 20 mpg. I have gotten as high as 28, but never lower than 18, and the day to day driveability is night and day better than stock. Feel free to ask specific questions concerning any of the things mentioned, as a few of the guys here have just done them to their CJ's, and will be happy to help you out.

 

[BLennon]

Thanks a lot for the advice...
A couple more questions: What are some examples of the emissions stuff? I have a repair manual with a chapter on emissions so I'll check that out there.

What kind of ignition system would you recommend?

I plan on replacing the spark plugs/wires and that kind of tune up, but is there any other type of engine tune up I should look into doing?

Thanks again

 

[CJ]

The AMC 258 i6 / 4.2l is arguably the best engine AMC ever made and pretty much ranks up there with any I6 ever made too!

I see your in Pensacola, since FL has no emission testing - I too would rip out all the emissions and make a free running I6...

The AMC 258 i6 / 4.2l responds very well to all normal hot rod hop up parts and techniques. Carb, intake, ignition and exhaust.

As for your last question, " What kind of ignition system would you recommend?" - that is kinda subjective as there are many, many upgrades that are years ahead of the stock ignition. Some like MSD, others Jackobs and the Team Rush upgrade is a very popular mod.