258 build

[powdertwoplanker]

Good day to all, I just pick up a used AMC 258 i6 / 4.2l (AMC 258 i6 / 4.2l ) block. Well I got a few other things with it but its all going to get tore down an rebuild. I been researching other builds an haven't found anyone that's used the F.A.S.T. fuel injection system yet.
http://www.fuelairspark.com/fas/ez-...ystem-master-kit-w-inline-fuel-pump-kithtml/]
If i missed a post about it sorry. Please point me in the right direction an if you can give me some search pointers, cause I tried many different combo's

So the build plan is to do the minimum amount of machining, change the cam an switch to the 4.0L head. I would like to do a header of some sort an maybe a different intake. I still have a lot of research to do on all of this so if you have any input it would be much appreciated. I like the fast system because it doesn't call for a different or another computer. It also seems like a little easier to work with and on. I know i could just get a donor jeep with the head an injection stuff on it an have all the parts but it seems like a lot more work. Cheaper yes, but also more things to go wrong. I also don't have to worry about emissions as by the time it goes in to my 1985 CJ7 , it should be exempt

So if you have any thoughts, experience or places to do some research please send them my way



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[Neuner]

What intake are you going to use for the 4-barrell, Offenhauser?

I hate Bosch O2s since they caused me so much trouble. That may be only with 4.0 systems though.

 

[Lumpy Grits]

Gotta remember that the AMC 258 i6 / 4.2l /AMC 258 i6 / 4.2l is a tractor engine that's redlined at 4500rpm in stock form.
I would put my time & $$$$ into a AMC 401..........
LG

 

[powdertwoplanker]

Not sure what intake yet, I'm not sure whats available for them. Would like to stick to the inline 6, has i have it. Plus TF999 would probably have to be swapped adding another expense. Also I don't see a need for V8 power. It will be a DD til i have kids, so having a V8 just to drive around boulder seems over kill. Also, maybe I'm wrong, but i think switching to a V8 would mean changing axles cause i would start to break parts in the Dana 30 an AMC20 . Not that they wont break behind the AMC 258 i6 / 4.2l more with more power comes more problems:-)

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[Lumpy Grits]

AMC put 8's in CJ for years with the same axles you have.
I know Boulder Colorado well(born in Colo.). At your altitude, an '8' is nice for the power on the hills.
Your choice/your money to build up that 6--Just not the way I would go.
Good luck,
LG

 

[Neuner]

I understand the route your taking with the quick plug and go injection system but have you tossed around putting in a 4.0? It is more work on the wiring side but less mechanical work than you have planned. You could then spend a little more as you are planning on doing anyways and get a pre-made wiring harness.

However, there are some minor customized components you have to work out like the power steering lines, fuel line and exhaust pipe connection.

I had a 4.0 XJ when I lived in Boulder and it performed awesome whether along the front range or up in the mountains.

 

[Peanut Butter]

Here is an episode of Engine Power you might want to watch: Project 242: AMC Jeep Six | Engine Power | PowerNation TV - Full Episodes

LG: you might want to watch this as they did a pull of 5000 rpm for the max horsepower reading. (yes I know it was modified)

 

[Lumpy Grits]

Cool vid-THX

LG

 

[HackFabrication]

Here should be the link: http://www.fuelairspark.com/fas/ez-...tion-system-for-jeep-6-cyl-w-fuel-systemhtml/

Seems like a decent system. Definitely an alternative to Howell and MoPar.

I'd want to ask them how much cam could be run with it. Put it on a good flowing intake manifold, and add some decent headers, you might be able to build yourself a screamer.

What size tires, and axle ratios do you plan on running?