4.2l engine swap.

[1991fordexploder]

Has anyone here done a 4.0 - 4.2 motor swap?

 

[ericautopart]

What's a 4.2? Isn't that a GM motor?

 

[94EddieBauerRock]

What's a 4.2? Isn't that a GM motor?

I assume he is talking about the 4.2 V-6 that went into base model F-150s

 

[FIND]

If I were to swap in a V6 to replace an explorers motor, I'd actually go with a smaller motor, like a duratec 3.0. 200hp on a 3 liter duratec and they are plentiful in salvage yards from escapes, the taurus and its variants (note these are the versions without VCT and use standard roller finger followers). 4.2 liter essex = 202 hp..... Really 3.0 escapes got it good.... much more power than a 1st gen explorer and only a couple hundred pounds lighter...

Only thing the 4.2 has going for it is the windsor V8 bellhousing pattern and engine management may be easier... But you can get transmissions that bolt to the duratec, or at least adapter plates..... Only thing you would have to worry about is engine management, and I believe someone has got megasquirt all worked out for running the 3.0 duratec.... Heck, I might even talk myself into trying it if I wasn't so set on going diesel eventually....

If nothing else, an SOHC 4.0 is 210 hp, and by all rights, one should be able to get better mileage out of them than an OHV 4.0.

Though..... getting to that windsor V8 bellhousing for the 4.2.... that does add some points for the argument as to why you would want to swap that way.... A 3.8 out of a 99-00 mustang would give you the same basic block and easy bellhousing pattern, no IMRC, and 190 HP. With the 4.2 you have to figure out how to run the IMRC.... but it isn't that difficult. Still, there isn't much you can do with those engines.....

 

[ericautopart]

I assume he is talking about the 4.2 V-6 that went into base model F-150s

Got it..Never heard of it..I just know if the 300 I-6

 

[sport97]

I would not waste time and money on the 4.2. Its not that great of a motor. Like FIND said it doesn't produce much horsepower over other options. There is another engine swap, 5.0 v8. It also doesnt get that good MPG. My buddy had it in a 2wd f150, and it was a dog, and got poor mileage.

 

[FIND]

a 5.0 being a 5.0 has its good points...... More aftermarket support for bolt-ons and internals. All things being equal, you can make a 5.0 explorer get fuel economy equal to the 4.0 while making more power, though you do generally need to put out a good chunk of money, one that you would likely never recoup in fuel savings. This is why I mentioned the 3.0 duratec. Smaller DOHC engine that has quite a bit higher volumetric efficiency than most engines we could put in an explorer.

Granted, I am just assuming the reason you suggested the 4.2 is because you were looking for increased power without a sacrifice in fuel mileage...

If one could manage a 3.0 swap, you could almost definitely increase mileage with a power increase over the 4.0, and as a bonus, the Ford Contour and Ford Taurus forums have both done quite a bit of brainwork on power adders for the duratec V6 platform.

Of course, this kind of swap would be much more costly and more technical with nearly no technical support available from other members, as it is not something people have done on here....

Personally, if I were to consider any gasser engine swap, it would be a V8. If you have extra money to spend on an engine swap and you want something that is really gonna make your truck better while also increasing fuel economy, swap in a 3.9 liter cummins diesel out of a bread truck or something... Google 4bt swap. Or, do a cummins b3.3 swap. I was only saying that IF I were to put a different V6 in one of these trucks than a 4.0 (sohc or ohv), it would be a duratec 3.0. Of course, I would never swap in a different gas v6 other than a 4.0.

 

[1991fordexploder]

Believe me if I had 3-5k I would get a 4bt in a heartbeat. That or just goahead and buy a bigboy truck and get either an f2 or 350 or a dodge cummins. The only thing stopping me from doing a v8 or diesel swap is mony and a place to do it in.

 

[sport97]

Believe me if I had 3-5k I would get a 4bt in a heartbeat. That or just goahead and buy a bigboy truck and get either an f2 or 350 or a dodge cummins. The only thing stopping me from doing a v8 or diesel swap is mony and a place to do it in.

A 5.0 v8 swap wouldn't be any more expensive than a 4.2 swap, and actually may be cheaper. They offered the 5.0 in explorers(just not your body style) and there are several threads to aid you as well. The 4.2 will be kind of a stab in the dark, especially when it comes to the wiring.

 

[Ronin8002]

Not sure about how emissions is in NC...but maybe you could put in a carbed 302. That would be easier from a wiring standpoint I think.

 

[FIND]

General rule of thumb: If you cannot afford a nicer truck, you cannot afford to do an engine swap in the one you have.

 

[1AJeremyD]

the 4.2L actually get the same gas mileage as the 4.6L and the 5.0L in fact it sometimes does even worse in some cases. I had a boss a few years ago with a 2002 4.2L F150 that did only 15mpg on a good day.

 

[FIND]

the 4.2L actually get the same gas mileage as the 4.6L and the 5.0L in fact it sometimes does even worse in some cases. I had a boss a few years ago with a 2002 4.2L F150 that did only 15mpg on a good day.

It is in a heavier vehicle than an explorer... To be honest, I would expect the same Fuel Mileage as a 4.0 if it was in an Explorer.... Small possibility of it being slightly better.... maybe 1/2 mpg if one is lucky.... Problem is that they are less reliable than the 4.0 OHV or 4.0 SOHC IMO. Power doesn't really feel like it is in the right place either.

 

[1AJeremyD]

It is in a heavier vehicle than an explorer... To be honest, I would expect the same Fuel Mileage as a 4.0 if it was in an Explorer.... Small possibility of it being slightly better.... maybe 1/2 mpg if one is lucky.... Problem is that they are less reliable than the 4.0 OHV or 4.0 SOHC IMO. Power doesn't really feel like it is in the right place either.

Regardless of weight you would think a smaller engine would get better gas mileage right? Same goes for the 4.6 vs the 4.0. There really isn't any difference in the mileage. If your doing an engine swap the last thing on your mind is MPGs lol

 

[FIND]

The 4.2 is a more efficient engine than the 4.0 OHV. Bigger does not always equal worse fuel economy. My Lincoln has a 4.6 DOHC, and it gets 25-27 mpg on the highway. A taurus with a 3.0 DOHC gets 25-27 mph on the highway. My Continental is a heavier vehicle on the same platform as the taurus is built on. They are both FWD and aerodynamically very close to eachother.

Think about it, 200 more cubic centimeters, same basic design idea, 45 more ponies. The engine breaths better. More horsepower can mean better fuel economy, as long as you aren't just dumping extra fuel in to attain that extra horsepower. I could swap in a 4.6 or a 5.0 and get better mileage out of them than a stock 4.0. If an engine needs to use more fuel to pull at whatever RPM it is at than another engine, it will get worse mileage. An engine with a higher volumetric efficiency, even if it is slightly larger, will use less fuel at a given RPM on equal loads.

I am assuming the cause for him to consider this swap in the first place was to find an engine with negligible impact on his fuel economy while giving him more power. That is the reason I have mentioned fuel economy so many times.

If it was a direct swap, the 4.2 wouldn't be a bad swap. Even though it is a less reliable engine that feels to me like the power isn't in the right place (I have never seen a dyno chart for one), and even though it has something between 0 and 0.5 options for bolt-ons out of the aftermarket, it does give some great transmission options right out of the box, and it is a more powerful engine near the same displacement as a 4.0. Our engines only get the power the 4.2 gets by putting the cam on top of the engine.

However, given the fact that wiring would be a pain and you would be doing this swap blind with nothing to reference against, I just wouldn't recommend it. If one wanted to do a V6 swap that they will have to do a lot of head scratching on, there are better V6 engines that ford makes.

But, If one could come up with a good way to do this swap, it would be a good swap. On an explorer with a 3.27 and even an E4OD(if you want an automatic), it would be a nice DD. With the 4.2 and 3.27, it would not be as much of a dog as the 4.0 and 3.27, so I would expect better fuel economy.