Completed Project My 98 super charged EX

1998 Explorer 4.0 SOHC
Bought it with a melted alternator/wiring harness from a junkyard for $1,000
Fixed it, drove it for two weeks, then I boosted it.
Started with an M90 supercharger kit from www.Bansheesuperchargerkit.com
Upgraded to an M112 Lightning supercharger that was a prototype kit.
Next was the M122 off a 2012 GT500
I have reached 20 lbs of boost (with ARP head studs) and a 12.83 in a quarter mile.

Pictures
1. How it looked when I brought it home.
2.The M90 supercharger installed
3.The GT500 supercharger installed
4.How it looks now
5.Wheelie

 

[CDW6212R]

I have replaced the wires, spark plugs, and ignition coil. And I did replace fuel injectors (including the one with the blown out o-ring).
Also the O2 sensor, even pulled the sensor out to rule out back pressure from a clogged cat.
The misfire is only partial, like an A/F mixture problem. Not even steady enough to set misfire codes.
I own lots of diagnostic equipment, even Factory stuff and I have access to Fords online stuff except for labor times.
This is just a weird problem probably caused by the nitrous backfire.

Maybe a cracked ring land but how do you test to prove that is the cause before tearing the engine apart?
Compression looks good 175-185 all cylinders, leakdown passes as they are all less than 20%.
My next test will probably be a running (dynamic) compression test.

Excellent work, I figured you had that all possible.

Given all the checks, the piston issue or similar wild things are viable thoughts. Mine would be wiring, given the age, brittleness, I'd think about checking continuity of items like the coil wiring, injector wires etc.

 

[boominXplorer]

Small head gasket leak? Notice any coolant loss?

 

[4pointslow]

Good thing your a patient man. This issue is crazy.

I normally love engine performance diagnostics but the temperatures just dropped so it's racing season.
Cant go racing with a broken truck though! LOL
Another video being posted very soon, uploading now....

 

[4pointslow]

Small head gasket leak? Notice any coolant loss?

No coolant loss.
Also no blow by out breather hose when disconnected, actually had a small vacuum from the PCV system like it should.

 

[4pointslow]

Excellent work, I figured you had that all possible.

Given all the checks, the piston issue or similar wild things are viable thoughts. Mine would be wiring, given the age, brittleness, I'd think about checking continuity of items like the coil wiring, injector wires etc.

I had a lab scope hooked up to the ignition coil primary circuits, and the fuel injector circuits looking at current and voltage.
Nothing noticeable there.

 

[4pointslow]

Here are the latest test results.

 

[4pointslow]

The latest test results are in!

 

[MrQ]

That power balance test looks exactly like what I saw on my friends WDS, except mine was on the V8. I did everything you did, changed injectors, checked for vacuum leaks, replaced all the intake gaskets, even switched over to a return-less fuel system. Nada. So I thought its a problem in the head. Tore it down week before last, everything was beautiful so I did a TDC on cylinder 8 and found I had bent the rod, not too badly, but enough for it to be really down on power and have a vibration.

What was weird is it passed a relative compression test, but the power balance said there was something wrong. Granted you are doing an actual compression test which is better indicator than a relative.

Not saying its your issue, but I feel I should point it out since my results were similar.

 

[4pointslow]

Thanks MrQ,
I am thinking it is going to turn out to be something very similar.
A nitrous backfire could bend a rod or crack a piston etc.
I am planning to smoke test the exhaust system to check for false O2 readings on that bank, if nothing shows up I will probably start pulling the motor.
Either way I am having fun with all the diagnostic tests and trying to film/document them.

 

[donalds]

Thanks MrQ,
I am thinking it is going to turn out to be something very similar.
A nitrous backfire could bend a rod or crack a piston etc.
I am planning to smoke test the exhaust system to check for false O2 readings on that bank, if nothing shows up I will probably start pulling the motor.
Either way I am having fun with all the diagnostic tests and trying to film/document them.

Any updates I'm very curious

 

[4pointslow]

Sorry, no updates, put both supercharged Explorers (1998 and 2004) in the garage for the winter.
Driving my 1998 4 door and 2001 Ranger at the moment.
I have been thinking about what to do with the truck next year.
Might get a trailer and go full race with it. Thinking about LS swap too since I saw a complete 4wd drivetrain for 1200.00
If I do the current supercharger setup will go into something else.(maybe my Ranger?)
Not sure what I am going to do but I want to run low 12's consistently and I think I have pushed the 4.0 to it's limits.
Got 4 months to think about it I guess, I still want to diagnose the problem with bank 2.

 

[donalds]

I say stick with the 4.0 that's what's makes it interesting
Imo

Everyone does a ls swap the shoc is what makes you different

 

[CDW6212R]

I say stick with the 4.0 that's what's makes it interesting
Imo

Everyone does a ls swap the shoc is what makes you different

A Coyote 5.0 swap is the hot Ford swap now. That won't fit I'd bet, but maybe the 3.0-3.7 TT engines might, though most are sideways engines.

 

[donalds]

A Coyote 5.0 swap is the hot Ford swap now. That won't fit I'd bet, but maybe the 3.0-3.7 TT engines might, though most are sideways engines.

Now you are talking Yeeyeee

 

[4pointslow]

Anyone got a Coyote 5.0 4wd drivetrain for $1200.00?
We could go with something really exotic like a Lamborgini or Ferrari engine swap too but not on my budget.
If I had a 4.0 sohc Built to withstand more power it will cost me upwards of 6,000 and even then it may not last.
I'm just looking for a way to spend more time racing since my year was cut way to short, and I want to run no slower than 12's even in hot weather.
I need sponsors! LOL or to hit the lottery. haha

 

[CDW6212R]

I agree the 4.0 is near its limits in stock form. The building choices for those is nothing like a common engine, such as the SBF. It would cost a lot more for head work for sure, which might be the biggest gains beyond bore/stroke changes. The shortblock possibilities would be harder too, plus likely not feasible. I don't know anything about the 4.0, I expect there's not much beyond rod and piston quality upgrades. The heads may have room for good porting, slightly bigger valves, but custom cams would be a big item to want. Those as a final touch would be worth it, hopefully along with gains in the rest of the engine. If any of that is possible, I could see $5k being the cost. That's a lot for an unknown result, and the transmission is still a weak link.

I wouldn't do it given the transmission, that alone is why I want to V8 swap my mail truck. I don't trust it in a mild long term application.

Dumb question, what are the dimensions of the late 90's truck V6's, the 4.2 I think it is? Those came with a 4R70W behind them, the same 302 SBF version. If that fit, it could be a good platform to use, if the heads have flow potential like aftermarket SBF heads(say 250cfm and up). I think stock SOHC heads are likely not much more than 200cfm, but what's needed is in the range of 300cfm, for a feasible cost.

SBF heads you can buy for $1500 out of the box like that, but to port lesser heads to get there, can be $500 and more. What I have to build my blower project cost me $1800(ported 170TW heads), which flow 315cfm @.600 lift. That's a good price for that flow level, but can that be done with any of the V6 heads?

 

[410Fortune]

the old 3.8L V6 was nothing more then a 302 with 2 cyl hacked off
they are good powerplants, but its like "meh" why not go full 302
Not much performance aftermarket of any market for that matter for the 3.8 and 4.2

The whole reason I never supercharged a pushrod 4.0 and bit the bullet, went full v8 conversion back in 2005 is because of the A4Ld/5r55e auto trans....the v6 trans, even the manuals, just do not take the power without killing your dreams and wallet

 

[vroomzoomboom]

the biggest thing that i like about this truck is that its a v6. nobody would ever think about a v6 supercharged or not holding a 12 second time slip. please dont go to the dark side. they dont have cookies no matter what they say. if your going to do any motor swaps what about a ecoboost 4 from a mustang? im sure your familiar with those motors. i would also have to think there is aftermarket support on them.

 

[CDW6212R]

the old 3.8L V6 was nothing more then a 302 with 2 cyl hacked off
they are good powerplants, but its like "meh" why not go full 302
Not much performance aftermarket of any market for that matter for the 3.8 and 4.2

The whole reason I never supercharged a pushrod 4.0 and bit the bullet, went full v8 conversion back in 2005 is because of the A4Ld/5r55e auto trans....the v6 trans, even the manuals, just do not take the power without killing your dreams and wallet

Yeah, any engine swap in these should come down to the transmission. How strong is it, can it handle the weight and stress levels.

I wouldn't do the LS either because of the brand, but I also love the results of your V6 truck. I can see the 4.0 making more power, 450hp+, but the transmission is not worthy of that. It may last a month, a year, or maybe just a week, but not as long as you want it to. I wish the later transmissions had been same bell housing patterns as the SBF, and the mod motors themselves. Then it would be electronics. But it's not, so you have to be very innovative to figure out what is the best for the project.

How much have you dug into the SOHC engine upgrades, and the costs of course? If it's possible to improve the airflow versus stock, a good bit, then I'd look at raising the boost, and upgrading the trans. I could see 20-25psi, a 4R70W, and bigass exhaust, with 11's at the track reliably. But what would the engine cost, the trans adapter/controller(one still on the Corral now), and the blower parts?

 

[4pointslow]

I already have done heads and cams, back in 2017.
Truck didn't get much faster but boost did drop showing less flow restriction. I know I have maxed out flow through the engine.
I even tried different pulleys with more boost but the truck did not get faster, it just heated up the intake air more.
So That's why I added Nitrous and that did bring more power in hot weather.
A built 4.0 SOHC short block will cost 6,000 and the only person I would trust building it would be Tom from Supersix Motorsports.
No one else with a good reputation is into building these.

If the truck didn't start having this problem on bank 2, I would have beaten my best 12.80 run by now in colder weather.
I love racing at the end of the year- September-December and am quite disappointed that the truck is down.
I was having fun running diagnostic tests but then I had to make a career change after 14+ years and that put things on hold.
Now its cold and I don't even feel like going outside the house, lol. I am definitely looking forward to next year when it warms up again.

As far as engine swaps go I would probably only consider the pushrod 5.0 since they came in Explorers anyway, or the LS engine that I am looking into.
I don't care if anyone doesn't like Chevy engines/cars or whatever, I am not against any manufacturer as I worked on them all for the first 16 years of my career.
I might just stay with the 4.0 SOHC anyway but I am considering a change because I feel I have just about maxed out my combination.
With the 4wd drivetrain I am looking at I can keep my street tires, stock rims, and there are used Superchargers for about 2500 on eBay already.
I would definitely enjoy adapting this drivetrain to my truck and could make videos of the process to put on my YouTube channel which grew to 400 subscriptions this year.
Then again I could just buy a used 4.0 SOHC for about 500.00 from a junkyard if the one in the truck is damaged.