I've run into the opportunity to buy a 1992 Ford Exploder 4x4 ( ) for $200 bucks. I know, I know, $200 bucks, it's gotta be a piece right... well the guy selling is a friend of my good buddy, and he basically got sick of driving it and bought a BMW. his parents are fairly well off, and were just gonna send it to the scrap yard so as not having to deal with selling it. It has 170K on it, but the engine is a Jasper re-power with 15K on it.

I've always liked these Explorers, but I'm a little concerned as the 4.0L OHV engines are rated at 155 HP (doesn't seem like enough to move a truck this heavy the way i would drive it)... Which finally brings me to my question:

What is the cheapest and most effective series of bolt-on mods you guys have done to get close to 200HP out of your 4.0L's? The TQ number seems ok...

I've driven my dad's Land Rover Disco SE7, and it's rated at 190 HP and 220 TQ and it's a 4.0L V8... I'm pretty happy with it's performance so even 190 HP would probably do me.

Also (yes I'm almost done yapping ) I have a list of mods together that might work to get close(?)

List:

BBK Single 66mm High-Flow TB
Vortech MAF
HYPERTECH Chip
PACESETTER 1½ Inch Headers
High-Flow Cats
FLOWMASTER Force II 2.5in Exhaust

This all is a little over a grand (which isn't to horrible).

What do you all think?

 

I was hoping some 4.0 guys would chime in here, but I guess not...(so far!)

I'm thinking those things will help and it may be enough to keep you happy, but I'm not sure you'll achieve your goal of 35-45 horses out of those mods. For that I'd think you have to go a little deeper into the engine. Also, with the intake mods you have in mind I think you need to bump up to bigger injectors.

But hey, an Exploder for 200 bucks...hard to beat that! Good find!

 

I think the headers and high-flow cats will make the biggest difference. I also think people put waaay too much faith in bolt on stuff, like the throttle body. An easy way to tell if the intake is restricted is to get a vacuum gauge. I know, old fasioned, but it works. Hook it up to one of the multitude of ports on the back of the upper intake. Go drive it. Floor it, and watch what happens. If the needle rises above about 1" vacuum, then there are potential gains to be had. If it stays low, there are no gains to be had there so dont waste your money.

If you really want more horsepower, do it the old fasioned way. Internal motor mods.

You can swap a set of later heads on the motor for more compression. These would be '95 to '97 4.0L OHV heads. A junkyard and a competent machinist are your best friend here. You'll get about 10:1 from what I hear, although I dont think it's quite that much. Your machinist can CC them and help you figure up compression. Port them while you have 'em out. Competition Cams makes a couple of grinds for the 4.0L, a smaller one and a larger one. I recommend the larger one if you're going with higher compression, as this will lower the dynamic compression ratio back to where you can run it with gasoline and not have it ping and blow head gaskets.

Then you can start thinking about throttle bodies and MAF's...

Edit: Good find! A $200 Explorer should not be passed up. I think you'll be surprised how the stock 4.0L can motivate one. You'll feel the torque. At higher speeds, you'll definately notice it's lacking HP though.

 

Ah yes, I have found the cams on the COMP CAMS website. I've created the cams and tried modeling them in Desktop Dyno compared to a stock one I found. The 256HR offers more torque earlier on and less HP, whereas the 270HR offers a little less low end torque but more HP and what looks to me a better curve for both so long I can push the engine to 4500... (which I've read is about the rev limit on the 4.0L?). I know Desktop Dyno isn't that accurate by the time your done but it seems close on everything else I've modeled. What is the approximate real world gain for the 270HR? DD says about 35HP gain over stock...

I was originally thinking bolt-ons because the engine has an existing warranty that I think is void if you delve into the long block, changing cams, adding hi-comp heads...


Oh as a side note, turns out the 170K on the truck is the same as the original A4LD, and you know what that means...

I do an insane amount of research before I buy something, and I thank you guys for helping me out.

 

I'm actually doing a 4.0L buildup at the moment. Feel free to go read my thread about it here:

https://www.ford-trucks.com/forums/5...e-a-motor.html

You have to be careful with Desktop Dyno and the 4.0L. They have the bore and stroke wrong in their short block selection. It should be:

Bore = 3.952"
Stroke = 3.32"

I have actually found Desktop dyno to be fairly accurate. Within 10% can be expected with reasonable certainty. I modeled the stock motor and it came to exactly 155hp, so it cant be that far off!

It's when you combine the mods that you really start gaining HP. For instance, the heads alone wont gain much. The headers alone wont gain much. Just putting in a cam wont do much. But when you do all of them, you gain a lot more.

If it was me and I had to run gas in it, I'd get the higer compression heads, port them and the intake, run the 270HR cam, run headers and the higher flow catylitic converter (I'm in Iowa so I'd just remove mine...), and possibly 21lb/hr injectors. Then look at the vacuum gauge and see if intake mods are needed or not.

The rev limit of the 4.0L's has a lot to do with the stock cam that's in it and the exhaust manifolds. Really, it is pathetic. It just runs out of breath at about 4500. The mods above should correct that situation nicely.

OBTW, plan on spending about $1000 on that A4LD. Mine lasted to about 210,000 miles. After that, overdrive would not engage. It would still get me down the road just fine though. It was just plain wore out. One rebuild later from a local transmission shop, good as new. They're not a bad transmission really, like anything they just wear out. Sometimes they will give you some problems with overdrive engagement, but that's also easily fixed by a transmission shop. From what I read they will take about 300hp.

Also be aware that they use spacers between the oil pan and transmission. There are three different sizes, and failure to use the correct one can cause all sorts of nasty problems. So be careful there.

 

Thank a lot for the help and info Rusty, the thread included in your post cleared up some things . Seems I have a lot more reading to do...

And yes I did notice D-DYNO had the measurements wrong. I don't trust computers anyway so I look up all the specs.

 

$1000 for an A4LD rebuild is conservative. It can generally run anywhere from $1200-$2000 around here. One good thing is that you've already got the stronger version, the 2.9 version will bolt right up but is weaker so don't let anybody talk you into buying one and putting it behind your 4.0 by telling you they're the same. Or you can swap in a 5-speed manual...

 

I've found quite a few of the 4.0L A4LDs on eBay from reputable shops for around 700-850 dollars shipped (thou you have to be careful these days)... Also there is one place online that builds them for performance use for around 1800 but I think thats a little overkill till I go crazy and decide to go rock climbing... My guess is it will work for a while considering I don't drive very far. I know there are GM 700R4 swaps too, but unfortunately they use a floor mount and not the column shift, which, I've always liked. I always wondered why there isn't a A4LD to AOD conversion kit (or is there?)...

But now I'm about to get myself kicked over to the Transmission Section of the forum so I shall leave it at that!

 

No AOD conversion kit.

You'll also have to make sure you get the 4.0L specific tranny, since the bellhousing bolt pattern matches virtually nothing else.

The 5 speed manual is plenty strong even if you upgrade a lot. The A4LD isn't a POS, but it's hardly strong enough for serious power. 190 HP should be perfectly fine with it, however.

There are upgrade kits out there to strengthen the A4LD, I'd highly suggest rebuilding the tranny, putting in one of these upgrade kits (you can find them on eBay) and/or a shift kit, you'll definetly notice a difference.

Intake, exhaust, chip. Dyno. Heads and cam. Dyno.

I'd imagine that'd put you quite close if not more than 190 HP. Congrats, your only 17 horsepower below the stock 4.0L from newer years. But you'll kill it in low end torque!

 

Would the ZF-5spd work with the 4.0? or would it be too much of a hassle to swap in?

 

It would take some fabrication, that's for sure. The ZF has an integral bellhousing and was never built with a pattern to match the 4.0 so an adapter would have to be fabricated.

Here's a page that should have everything you ever wanted to know about manual tranny applications:

http://www.motivegear.com/tech_info/...nny_guide.html

 

Thanks for all the help, I figured I'd post a follow-up to the first post.

I ended up paying $100 for the truck. '92 Explorer 4x4, the XLT interior (my favorite) is almost mint, and everything is automatic. Thing runs great. It was ordered by the owner of a ford dealership and has a paint DSO for a custom paint (I believe it, as I haven't seen this shade green on anything but Taurus SHO's). I'm not sure how to find out exactly what the color code was. The clear is bubbling off, and the front washer pump is defunct... also the power mirror switch (which I will continue to adjust them the old school way 'til I get the switch). Not allllll bad thou, for $100 I also got a 3.73 LS gear option. It has a few things wrong with it, but it all minor save the gas leak and thats going to the shop Monday as it's to darn cold out to fix! I'm glad I saved it from the crusher, it's just to nice of a truck to meet that fate.

Pics below for anyone interested:

 

Dang, that's a steal for a hundred bucks! It would still be a steal at a thousand bucks...good score!

 

I'll give you $200 for it as it sits Seriously, that is in excellent shape for the price you paid. Great deal. Can't believe it was going to go to the crusher with it being in such good shape.

 

Hmm, must be thinking of a different transmission. I thought the ZF was the same transmission used in the Pantera. However, according to the link you posted, it is for the Super Duty trucks. No way would I want to bolt that to a 4.0 liter engine.