Engine swap questions possibilities.
 

This is all hypothetical just curious of possible results. I have an 02 explorer 4x4 and was curious how difficult it would be to put that v6 into some sort of economy size car. How hard would it be to switch to standard trans and front wheel drive.
Reason I'm curious is due to the efficiency of this engine. 22-23 mpg with a brick that weighs around 4200 lbs. Dropping this motor into a car like a Saturn which is around 3000. Assume the larger motor weighs a tick more so around 31-3200 lbs. With the drastically improved aero and 1000 lb weight reduction and most likely 6 speed manual what would anyone's fair guestimate be for fuel milage? I feel it wouldn't be too difficult to push 40+ but I may be delusional. Obvious upgrades like extra aero spats grill block and partial underbody panels. My dreaming may turn into a reality if there is any positive concensus to my ideas.

Is that a Cologne V6, right? Have you already compared its bellhousing pattern to the Essex V6 which had been used in the Windstar/Freestar? Though I can't remember any FWD application for them to be fitted with a manual transmission, doesn't seem to be unachievable.

I vote delusional. 40+ is hard enough for a four cylinder to achieve.

Nope haven't compared to anything yet. It is the Cologne v6 though. I feel if done with taller geared M6 trans the milage goals would be achievable. It's just the how difficult will it be to make it happen that shys me away. I'm sure plenty transmissions have a better set of ratios than my Cruze eco lol.

Hello 14'ecocruze,

That's the SOHC 4.0 derivative of the venerable Cologne V6 as cRiPpLe_rOoStEr points out. I've got it's previous incarnation, the OHV (pushrod) 4.0 V6 in my 2000 Ford Explorer manual trans. Do you have the manual trans in your '02? 2002 was the last year for the manual trans in 4-door, the 2-door kept it available for another year or few until or right before it was dropped from production. IIRC. If you do have the manual trans, I'm very jealous.

What are your goals for the swap? If it is just efficiency, you're going the wrong way - most mid-size to economy cars have sub 3.0liter engines already, so you can run them at higher overall load to get better average BSFC out of them. Putting in a larger engine that won't work as hard would be a backwards step in efficiency. Generally, folks have found that by the time they've done a bunch of aero work, load reduction, etc. they are no longer operating the engine in an efficient regime - time to swap a smaller one in.

As for the practicalities, I can't find any Cologne V6 engines in a transverse application at all. The Aerostars that had them were front engine rear drive. So you'd need a transmission/engine adapter, clutch/flywheel adapter, custom oil pan, custom motor mounts, and the fun wiring stuff. Your engine is PATS (Passive Anti-Theft System) so you'll need a custom tune to delete that, else you need to keep a chunk of the dash and steering column from the Explorer plus a key from it to make it run in the new chassis.

Saturns were available with 4-cyl engines and manual trans from the factory, though you may need to look around to find one.

If you want an immediate upgrade with zero labor to ~30+mpg (completely stock, aside from worsened aero due to front end damage, and lighter weight due to rust), I've got a 1999 Chevy Prizm 1.8L 4-cyl manual trans I'll trade you straight up for your 2002 Explorer 4.0L V6 manual trans. :-)

Thanks Frank Lee lol with the right transmission I know it's possible. Transmission is the key for the idea to work. Last trip I took the explorer on over 30 miles was 46 miles if I remember right and average pesomistic torque setting mpg and DIC slightly ..5-1 mpg optimistic was 28 mpg. I've done some math and 1000 lbs alone will bump that number up significantly. Cut aerodynamic drag in half and higher should be attainable.

That makes a lot of sense. Thanks for the input seems it would be an expensive task if I wanted to experiment with it. Sorry not a manual transmission. If it were I guarantee I would be breaking 30 mpg mark. Drive like a grandpa to get 60+ mpg in the cruze. Takes dedication to do it for a whole tank.
So the antitheft throws a massive monkey wrench and the dream along with additional parts if I wanted front wheel drive.
Loving the engine in it. Well maintained except spark plugs until I got my hands on it. 260k miles runs like a top and still seems to have plenty of life in it. Maybe my dream should switch to just putting a manual transmission into it. Sounds cheaper and Probably get 4+ mpg gain just due to my driving with a manual. The torque converter lockup thread I was thinking on maybe my best bet to get 30 mpg for cheap but shifting on your own is sooooo much better than dinking around with a throw switch.

Get the mounts and trans from a 2005-10 mustang, then drop into a fox body, some the problems you will encounter will be that the 60-degree v6 is taller than the old 90-degree 5.0 v8

Hello again 14'ecocruze,

Apparently the tune to remove or reprogram the PATS is ~$250 or less, depending on where you go - not insurmountable, and it is likely included "free" if you're already paying about the same amount for a performance/economy tune.

Putting a manual trans into an Explorer has been done (the factory did it, so you can use all factory parts) - poke around on the web, you'll likely find a decent writeup or few. Note that most swaps were with V8 Explorers, so the transmission, driveshaft and transfercase info are different, but the wiring changes and overall scope of what parts must change/be added are the same.

260k miles? Have the timing chains been changed? They are a weak spot still on that year 4.0 SOHC, and you have to pull the engine to get to the rear one.

You're doing better than I am MPG-wise so far - the SOHC is a more efficient engine than the OHV, and the lockup 5-speed auto isn't bad for highway mileage.

Yeah it's great from 50-70 mph. For a v6 and the weight of the vehicle it has plenty of power. Hauled a 17' boat 150 miles too and from our yearly camping location. If the suspension wasn't worn out so bad it would have been hardly noticeable. Torque wise it pulled no problem even in its old age lol
Highway milage has improved about 1.5-2 mpg with roof rack xbar removed and about 70% upper grille block. Looking into a few other things before drastic. Body seems to be going before motor. I'm also under the impression that the timing chain was replaced by the original owner. Was the wife's vehicle long before we got together so not really sure on details. Can't hear anything to indicate problems with it.

There are many things that could be taken into account, such as the air-to-fuel ratio, compression, RPM range and how the cam profiling and the headers can lead to an optimized low-end output. Sometimes I actually consider doing a similar project to tune an apparently "oversized" and "outdated" engine and fit it into an econobox.

So I'd be looking at putting in a Ford Turbo Diesel engine from Europe. Go with the same brand of engine because it makes things a lot simpler. Make sure you get the wiring harness and ECU as well.

Specifically the 2.0 tdci from the Ford Mondeo

Look here for the fuel consumptions:

- 2011 Ford Mondeo MPG - Actual MPG from 9 2011 Ford Mondeo owners

This 2.0tdi should easily have the torque of the old 3.5 petrol engine and it's more likely to feel more powerful than the original engine.

You can see people are getting 41-48mpg from those engines.

Taking an engine from a 5000lb, 15.0 CdA 20mpg vehicle and putting it into a 2500lb, 7.5CdA vehicle will not automatically result in 40mpg, which many vehicles that size already get. When I first got into ecomodding I actually thought the opposite - why did the F150 I was driving have a 5 liter engine producing 170HP, when Honda was building 1.6L engines which also peaked at 170HP? Wouldn't swapping the huge engine for a smaller one improve economy, without losing any peak power, even if gearing needed to be different?

Neither is strictly correct, because all engines have an RPM and load range in which they're most efficient, and it's best to pair an engine with a vehicle whose weight and drag put a load on the engine which is most often in that ideal range.

Take for example the 3 cylinder 1.0L engine in my Insight. It's most efficient between 1700 and 2300RPM, at about 75% load. In my car, I can cruise on the highway in excess of 100mpg because the engine is perfectly sized to stay in that range. If I were to put that engine into another heavier and let aero vehicle, I would need to regear it. In a typical econobox (weighing about 50% more) it would likely need to be spinning at 3000-3500RPM, where it's significantly less efficient, so despite the new car only needing maybe 50% more power to go down the road, it would almost certainly take more than 50% more fuel, resulting in a lot less than an ideal 33% lower MPG.

The same is true of dropping a big V6 into my tiny aluminum car. To produce the power needed to go down the highway at high load, the engine would likely only need to be spinning at something like 6-800rpm, where it's extremely inefficient. Alternately, it would be running at low load, where it's also a lot less efficient. Putting a bigger engine in this car, even with the same peak BSFC, would be guaranteed to result in worse economy.

Even though a higher-displacement engine might seem overkill when fitted to a small econobox since it would eventually not operate at a load that would lead it to reach its best BSFC figures, it still doesn't sound totally unjustifiable. I'm just not sure if the Cologne V6 has enough aftermarket support to provide cams and headers that would improve its low-end output and make it less rev-happy in order to match the requirements of a lighter and more aerodynamic econobox that would have it matched to a higher gearing.

BTW sometimes I actually feel tempted to do a quite similar project, even though I would want to go even further and try a flathead engine since they're noticeably less rev-happy, and the inherently lower compression on them would easily enable lean-burn.

Maybe not unjustifiable, but most of the time it's exactly the opposite of what would help improve economy, if that's your goal. Generally speaking, downsizing (a little, at least) improves economy. That, or re-gearing. Downsize too far though and you're pushing a small engine out of its efficient zone.

Downsizing vs. downrevving, that's somewhat of a great dillema. I'm not totally unfavorable to downsizing, but it's more than simply dropping a smaller engine and leaving all else equal. There were times when subcompact cars fitted with naturally-aspirated 1.0L engines held over 70% of market share in my country, basically due to fiscal benefits, but it was not unusual for the very same cars to get better mileage in export markets where displacements around 40% to 60% higher were the standard, since it enabled the usage of higher differential ratios and a decrease to the engine speed while cruising.

OTOH a truly-downsized engine, fitted with forced-induction and direct injection, is likely to fare better than a naturally-aspirated one with a larger displacement and port-injection, mostly because direct injection enables it to run leaner, but there are also some concerns about long-term reliability that still favors old-school engines and downrevving among some conservative folks.

In the 'states we have the opposite issue, with most cars coming with far more displacement than is necessary.

Considering that certain trucks made in Brazil and Argentina had smaller engines than their American counterparts, I could agree with you on that matter, even though it's still quite arguable.