I'm thinking more seriously of a 4.0 swap, given we'll have the space to do so sometime this or the following year after we move and a pole barn is built. Until that comes, though, obviously this will stay on the shelf.

That being said though, I like to plan ahead. I plan to aquire a 99-00 Ford Explorer with the 4.0 SOHC. "But Arctic, it would make more sense to get a Ranger with a 4.0." You may remark. Yeah, that's true; however there's a reason why I'd go with an explorer over the Ranger. Price. Around my area I can find explorers for under 1000 dollars in some cases. Under 2,000 in most cases. Not to mention, the Explorer I may end up with could have an overhead console, center console, etc which would sell for some good money. That being said though, the drivetrain is the main concern. As long as it runs and drives with no major problems, the rest is all optional.

But, anyway, back to the point of this thread before I get too far off track. Once I have the vehicle, and the engine out to where I can start replacing things (gaskets, plugs, wires, etc) and hitting it with the degreaser in that same breath, I'd like to bolt on some performance parts to squeeze little more go out of this engine. I don't expect any miracles, though.

Immediately, a supercharger and perhaps an upgraded coil pack come to mind, along with the obligatory plugs and wires to match, motorcaft of course.
Thoughts? Suggestions? Anything to watch out for? All is welcome and greatly appreciated.

PS: If anyone wants to know more of what I plan on in greater detail that's beyond this post's scope, check my project log. (Shameless plug)

 

You need to check the timing chain rails, tensioners and chains. That range year Explorer had issues with the rails.

 

I would assume the rails have something to do with the infamous timing chain noise I'e heard about?

 

Yes, put in the newer designed timing chains, tensioners and cassettes(rails).
Replace front and rear main seals(crankshaft)
Replace Knock Sensor(under intake)
And of course oil pan gasket

Check thermostat housing, these are prone to leaking, replace if in doubt.

Not much bolt on power parts for the SOHC
Factory Exhaust is tuned for mid-range power, so low-range headers could be added if thats where you want the power band, make sure they have O2 sensor bungs.

4.0l SOHC runs 9.7:1 compression ratio, which is why it needs the Knock sensor, it's the only thing that allows it to run on 87 octane, lol.
Because of the higher compression it is not the best engine to add boost to, it will increase power but not as much %-wise as when boosting lower compression engines.
So you may not be too impressed for the money spent on turbo or super charger.

There are people who have had good results with changing computer software on the 4.0l SOHC computers, noticeable performance increases and better MPG depending on selection

 

Thanks for the info. Definately a lot to consider. Will definitely do a lot of replacing, or at the absolutle least a thorough inspection.

Software is definitely something I'd like to try, at risk of blowing the engine.