S-10 trying to have it both ways!
 

howdy folks, I've got a few questions for the hive-mind, and I believe ecomodders is the place to get answers.

I drive a 99 s-10 2.2 5spd, std. cab short bed as my daily driver, getting 26mpg avg., depending on fuel quality.
my daily driving is rather minimal, 4 miles to work, and then back again. light traffic, minimal hills, the usual. around 150k miles on the clock.

on weekends, I make a 150 mile round trip to visit my girlfriend. The drive is 70% interstate highway, and 20% steep, twisty, but paved mountain roads, and about 10% dirt and gravel mountain roads.

I've got plenty of top-end power at 70+mph, keeps up with traffic just fine...but is sorely lacking bottom end torque. I'm often loaded down with a canoe, or mountain bikes, camping gear etc. and the poor little thing struggles when the going gets steep, and is generally slow around town.

I see 3 ways around this without totally trashing my fuel economy

I could do the usual N/A mods...intake, exhaust, underdrive pulleys, e-fan etc. and probably gain a small amount of economy, pick up a small amount of power, but spend relatively little money. the motor could probably use a rebuild sooner or later, so this would be an ok stop-gap.

I could rebuild the 2.2 and add a small turbo...they make a manifold with a t-3 flange...maybe run 5-8lbs of boost, and pick up more power than the above option, spend a lot more money, and possibly gain some amount of economy. In this situation, I'd likely go all out...forged pistons, camshaft, gapless rings, injectors, megasquirt PCM, increased compression, and water/methanol injection, as well as the supporting mods in option#1.

my third option is to pull the 5.7 vortec L31 motor out of my rusted out '99 express 2500, detune it a bit...or a lot, considering it makes 3x the torque of my 2.2, mate it to a t-56, and have all the power I need, minimal expense (full swap kit is under $600), and again, probably lose a bit of economy...or not? I've never done a v-8 economy build, just mo'power builds in the past.
I'd be able to pull some pretty tall gears, but I'd be adding 200+ lbs to the front of the truck.
For perspective, a fullsize station wagon like a Buick Roadmaster pulls down the same highway mileage as my s-10 with a 5.7 v8 and a 4-speed auto.

what does everyone think?
I'm no stranger to engine swaps and rebuilds, and I've got a budget of a few thousand dollars.

I'd like to keep fuel economy as good or better, and will explore aero-mods at a later date.

Any chance a hybrid addaption would work?

What about a hefty alternator that you turn on when braking to charge a battery to run an electric supercharger?

I'm starting with a 5spd v6 s10 with a blown motor. Im probably just going to rebuild the v6 for reliability and simplicity.
I was considering a v8 or even diesel swap but i have done swaps before and the cost, mantinence and all the unknowns that go with a swap would probably negate any potential savings in gained fuel economy. Same problem with a turbo, turbo ing an engine is always less reliable and the cost of the parts and need for premium fuel would make the savings from potential mpg gains less significant.
I've had a few s10s.
I've learned that these trucks get their best economy around 55-60mph any more and it starts to drop.
Maybe start with a tune up using quality parts and swap all the fluids for synthetic. Skinnier tires may help when the time to replace them comes.
If the truck goes good at 70 but the engine is lugging around town, swapping the rear end to a deeper gear will hurt mpg on the highway but may help in town.
A free flowing exhaust with a lighter/ smaller muffler may be worth trying too

If you do a lot of highway driving almost all your gains to be had will be had with aero mods.

Thanks for the quick replies! Please keep in mind, the existing motor is in need of a rebuild within the next year or two, and I'm looking for some more bottom end torque.
I've already done the synthetic fluids, tune up, and low rolling resistance tires...but that doesn't get my oil pressure back...or make my lifters any quieter...or fix my leaking rear main seal.

So the choice comes down to rebuild an already somewhat inadequate motor for my purposes, and still struggle on hills, or try to make an improvement.

I know modifications cost money, but fuel economy is only half the equation here. What makes the 5.7 swap so attractive is that I already have a good running motor and the complete donor vehicle of the same make and year.
That old 3/4 ton van got 19mpg average pushing 3.73 gears, with an extra 1000lbs of body and frame, and the aerodynamics of a brick.

Obviously, it'll be more work than my other options, but I do have a well equipped shop and plenty of extra hands to help.

Does anyone have any real world experience with this combination?
I've found a few threads with folks proposing a similar project, and plenty speculation and bench-racing, but not too much in the way of results.

I briefly considered using a large truck alternator with the rectifier and voltage regulator removed as a sort of hybrid drive experiment. it could, with appropriate switching, be utilized as both a 3-phase generator, as well as a motor, but the battery, charge controller, and variable frequency drive would cost as much as an engine rebuild.

I do really like the idea though. I think i could make an adapter plate to bolt one down in place of my a/c compressor, and allow it to apply torque to the drivetrain through the crank pulley.

I'd probably torch off more than a few serp belts before I got all the bugs worked out!

I feel that realistically fuel economy with a v8 would probably be the same as the 2.2 simply due to the extra 3.5 liters of combustion chamber needed to fill with fuel/air.
That being said I had an auto 4.3 v6 4x4 truck and an auto 5.3 v8 4x4 truck that both got the same mileage
I suppose an economy tuned or flashed ecu could net some gains.
The 5.7 probably makes the same power at 2000 rpm as a 2.2 at 5000 so with tall gears in the rear you may see improvement.
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Gasguzzler, that was exactly my line of thinking. It would net me the low end torque I want without losing much if any fuel economy, as well as being a reliable, long lasting engine that I already have.

Then I started poking around the shop, and kicking ideas around...seems I've got quite a few motors lying around.

there's a subaru 2.2...probably gonna be the same low torque problem as my chevy 2.2, but they do love forced induction! plus it could be built while I drive around with my leaky chevy 2.2...hmmm. clutch and adapter plate could be interesting to source.

then there's a pile of jeep 4.0 and 4.2 inline sixes...boy i wish there was room for one of those under my little hood! lots of low end torque, reasonable displacement, good aftermarket support, and some real low lift/duration cams available...again, not pushing a 4500lb brick around would probably wake one of those up nicely.

a guy can dream I suppose.

back to reality...assuming I do the 5.7, I'll need to source a transmission, and it'll be a manual for sure.
the most expensive route is a t-56, but I could retain my axle gear ratio because of the double-overdrive.

I could go 5-speed, like a t-5 or nv3500, or an ax-15(that I have lying around already). cheaper, but I'm in for a re-gear if I want to see any real MPG gains.

I've also heard that a 4-speed has less parasitic loss than a 5 or 6 speed because of the lack of an intermediate shaft and one less gear cluster, but I'd be going crazy tall with my axle ratio, and I'd have pretty wide ratio changes between gears...seems like it wouldn't drive as well.
my feeling is that the 5 or 6 speed will be the way.

Have you seen this?
https://ecomodder.com/forum/showthre...mpg-33961.html

yeah, I ran into that thread before. It's rather impressive what can be done with gearing! I don't have any plans to take things that far, because I'm also interested in my ability to climb rather steep grades while loaded, and drive on the interstate for an hour with a canoe on top, but if I could eek out 30 mpg from a daily drivable 350 powered s10, I'll have exceeded my goals.

what I like about this approach is that I can build a drivetrain, and amass the parts needed to complete the swap while I'm still driving the truck, and then just borrow a car for a week, take off work, and complete the install without a major life disruption.

E assist mod it will add power without changing much

ecomodder.com/forum/showthread.php/gms-eassist-34290

ecomodder.com/forum/showthread.php/controller-mods-build-e-assist-altermotor-35003

i'm interested because i got a free space were the A/C goes on the engine ( it has Eletronic A/C)

plus if i got the lithium battery pack i'll have 40 spare NiMH cells .... i know they are spent but can be still useful

The diesel Dasher I just sold was a good candidate, with a slant four with the alterantor underneath. The big hurdle was the serpentine belt and idler arm.

OP -- As I understand the engine options, it's I4, boxer 4 else V8?

When it comes to turbocharging a port-injection engine, it's also worth remind they may need a richer AFR to prevent knock, even when an intercooler is also used. Is the injection on your truck a continuous-flow type? Maybe if you do a rebuild and add the turbo in the same process, switching to a sequential fuel injection may be a reasonable choice and overcome any fuel-economy penalty from an enriched AFR.


I would rather adapt some other engine into a Subaru than adapting a Subaru engine into anything else. I used to love Subaru until my father got an Impreza.

The e-assist Is an interesting option, but as a GM dealer tech, I'm not exactly impressed with the factory e-assist alternator/motor currently on the market. Seems a bit undersized to have much effect, but I'm no engineer.

As for engine options, yeah those three, plus some AMC inline sixes, and a 500 inch Cadillac big block are the ones currently taking up space in my garage.

I'd be open to other options if somebody has a REALLY good idea lol!

A guy at work is pushing me toward a small diesel, but with diesel fuel currently a dollar a gallon more than gasoline in my area, I feel as though I'd spend as much or more at the gas pump.

My existing 2.2 I-4 is a sequential port injection motor, if that matters to anyone. It really does fit well under the hood and is a breeze to service. That was the main reason I bought it back when gas was cheap.

It can be hard to make a more powerful engine more fuel efficient. An ICE tends to be most efficient at higher loads at lower RPMs. So you throw in a big block and you're allways running at very low loads unless you hypermile and pulse and glide everywhere you go.

A forced induction engine will usually need to have a lower compression ratio that will also lower its fuel efficiency, not to mention when you hit the throttle it will need to enrich. Or you need to buy premium, or all of the above.

One solution is go with the smaller engine with forced induction and use water injection so you don't need to lower the compression ratio or premium fuel or have a highly enriched mix at higher loads. But be aware that if the water injection fails, bye bye engine.

You can also run and engine at a "higher load" so to speak with a well designed EGR system. Cooling the exhaust gas seems to help this even more.

with any boosted application I'd strongly consider water/meth injection. depending on the pcm and water/meth injection controller, timing can be retarded from a low water sensor the same way a knock sensor signal can trigger a timing retard event.
Speaking of water/meth injection, I've been wanting to experiment with it in a high compression n/a application, triggered by the drop in manifold vacuum when the throttle opens far enough to need accel enrichment.
timing could be very aggressive.

I'm not trying to set the world on fire with this s10 build though...just have a strong running, durable, efficient truck that I can really pile the miles on.
Not something to set records or win races with.

Longevity, Power, Efficiency.

Pick two?

Water (and meth) are a risk. With enough combustion pressure no amount of ignition timing will save the engine if it fails. Add too much water and hydrolock the engine and break things. Even if it works correctly, water isn't a good lubricant and can cause cylinder wall wear.

Diesel fuel is more expensive, but there's seemingly no limit to compression ratios and boost pressures in a Diesel in comparison to a gasoline engine. My diesel had a 23:1 compression ratio and I got 50mpg in that old 1985 car.

I thought it was understood that I'm not planning to push this thing to the outer limits.
I realize that you can take anything to an illogical extreme and blow a motor up. That's not what the discussion is about though.

longevity, power and efficiency are not some "pick any two" mutually exclusive paradox. it's a balance, and I'm trying to tilt that balance just a little. My truck's motor is in the autumn of it's life, and I'm trying to make a smart decision about the next step based on what I have available to me.

clearly, the chevy 2.2 was a commercial success, and isn't bad by any means. It gets acceptable gas mileage, and has a lot going for it...just not bottom end torque.
The only two ways to tilt that balance are going to be either extract more torque from the 2.2 liters I'm working with, or get some more displacement.
obviously turbocharging a 2.2 creates more wear than not doing it, but the benefit is less weight, fewer parts to swap, and an overall cheaper, easier project. It needs rebuilt anyway, so things can be done to improve wear characteristics in a turbo application. oil squirters, forged pistons, floating wrist pins, improved oiling, and roller valvetrain upgrades come to mind.

The 5.7 swap certainly has durability going for it, as well as world class parts availability...there isn't much you can't get for a small block chevy. Obviously it's a winner on the power front. There will be some additional expense in sourcing a transmission and swap kit. I'm ok with that. there will also be a considerable weight penalty, which should not be overlooked. Based on what I've seen done from the factory by General Motors, especially with regard to the fullsize granny wagons of the 90's, I think maintaining or even improving my efficiency is not out of the question with intelligent tuning and gear ratio selection.

The question I'm trying to answer is how does the idea of a low boost turbo 2.2 build stack up against the 5.7 swap in terms of real numbers?

Is there really any significant mpg benefit to be gained by choosing one approach over another? Please keep in mind the intended use...mixed driving, loaded most of the time.

How much are you willing to spend on the truck? A lot of the mods spoken of on here will probably never pay off not to speak of all of the opportunity costs in time.
I would just do what everyone does to small trucks: delete almost all of the accessory drive and regear the rear end as low numerically as possible.
OR just go get a v6 Ranger/s10. The 3.0 only gets 1-2mpg less than the 2.3 and will tow 4000lb. I was able to get 25 mpg tanks with a 96 Ford Ranger 3.0-5speed with 3.73 gears. If I am able to get it 3.08 swapped it would be a 30mpg capable truck that would tow 1500lb objects respectably.

Reminds me of the ad on the CRX when it first came out with the extremely overgeared trans and the engineers were talking about how fun the car was because you really had to maintain momentum to keep it going in high gears lol.

My experience with a swap, from a 1.0L to a 2.4L, was that even with re-gearing, I lost around 40-50% fuel economy. Granted, it was an exceptionally efficient 1.0 with great gearing for economy to begin with, and the new engine makes the car near supercar quick. The new engine is really hard to drive at ten tenths though, and while it's a hoot, driving a slow car fast by wringing out everything a small engine has is pretty entertaining too. The extra utility the engine swap brought has a monetary value, but were I you, I'd rebuild the stock engine and maybe bump compression a hair, or go with a *very* small turbo. That has its own issues though - aftermarket turbos inevitably have leaks or things rubbing that cause ongoing maintenance.

Stroker crank for low end torque.

Do they make a stroker crank for it? that could be a pretty sweet option!
I was thinking a small turbo with a t-3 flange, considering that's how the aftermarket turbo manifold is configured.
my budget is right around $3000, but if it stays together for a while, that'll increase.

Since the 1940s speed shops built up the journals with weld metal and then machined it back down to a new center.

Forged cranks came later.

My favorite solution is TURBOCHARGER.

You keep the same engine, same fuel economy when not in boost, more power when needed.
Really the only big changes are mechanical of adding the turbo then the electrical of finding a compatible Ecu for tuning.
Sell the 5.7 to fund the rebuild/turbo

I re-read your original post. No need to get exotic on the rebuild, the stock engine should handle low boost without any issue.

Most likely a boosted 2.2 would pull like the 3.8L 60-degree V6, considering that a turbocharged engine in a FIA-sanctioned racing series would be classified as if it had a 70% greater displacement. The same seems to be usual regarding normal vehicles too.

Another approach is to change the transmission. The late model Chevrolet Colorado has a six speed manual transmission with a wide ratio range. First gear is 4.47:1 and sixth gear is 0.61:1. That's a 7.3:1 ratio range from first to sixth. Drop in that transmission and change the rear end to get the same total ratio as you have now.

You would have a lower first gear, so better ability to start out. And use your tach. It's OK to run it to near redline occasionally. My old Colorado had no trouble accelerating to speed on a short uphill onramp. I just needed to run it to redline in first and second gears, and speed shift.

There is usually some compromise, but sometimes a different gearing may be a cost-effective measure too.

It seems that nobody is suggesting the fairly obvious choice here. What OP need to put in his S-10 is another GM 2.2, the Ecotec. The first generation L61 is a simple engine to hook up and run and I can speak from experience that they’re pretty efficient. They also happen to love boost if the ~140hp/145lb/ft in stock trim is insufficient, and there are factory parts that can accomplish that from a junkyard, cheap. I’d wager that 30-35mpg wound be very doable with modest gearing and maybe some aero that were done at the same time as the swap

Brazilian S10 and Blazer had 8-valve 2.2 and 2.4 versions of the Opel-designed Family II engine, a direct predecessor to the Ecotec. The post-facelift "Samba" Blazer assembled in Indonesia had the 2.2 and 2.4 Ecotec engines sourced from Australia.

"Always less reliable?" Isn't that a bit of an absolute? I only saw reliability issues when people slap a turbo to a car without building the car to handle it. i.e. no real plan: no remapping fuel curves (or going to aftermarket FI computer that can detect and properly handle boost), no wideband O2 sensor tied into FI system, no ensuring fuel system can deliver the fuel (as opposite to be on its last legs), and so on. And they they decide to do burnouts, go lean, throw rod or grenade transmission, and it is the turbo's fault, not them being idiots.


Just because you are going to turbo an engine does not mean it can only be used to do 10s quarter miles or faster. A lot of factory turbo cars are built with relatively small turbos so they are useful on the low end, as in passing someone or getting up to 45mph at a brisk acceleration. At highway speeds the turbo is not doing much unless you are climbing mountains, when it may also help the engine see sea level air pressure.

With that said, I know of at least one 2.3L car doing 500HP which did not have any issues besides normal maintenance for more than 10 years now. The fact the owner does not drive it as if he has to drop the clutch between traffic lights may be a factor. Still, I thought this thread was all about economy, so methanol injection, forged crank and rods, and dropping the CR to 8.5:1 really do not belong here.

If turbos did not help with fuel economy they would not be used in 18 wheelers.



In the 80s the recipe to deal with boost was to add 30% more fuel. In more modern times, a wideband O2 attached to a FI system that is smarter than the average politician can do a lot. Add support for knock sensing (you could copy the old APC system if you want to be lazy, but nowadays you can do much better) and ensure your FI system can adjust ignition timing and boost on the fly, and you may have a good starting point.


FYI, I do not remember the last time I saw a factory turbo car without intercooler. I have seen people build their own forced induction, specially supercharged ones, without it but then again some think that intercooling and wideband O2 sensors are witchcraft, and the only approved fuel system is a carburator.



Most cars using turbo for economy have compression ratio around 11:1 nowadays. They usually are set to handle under 10psi of boost, but more modern fuel systems can push the envelope.



I too agree that would be the smartest thing to do: modern engine with modern FI system.

ME personally, 4.8 LS would be a smart swap and then find the aussie version of the tune to incorporate the lean cruise or you could go with the 4 cyl ecotec or the v6 3.0 or 3.6 all depends on your funds and availbility and mechanical ability. then of course aero

Diesels are a whole different deal, even though nowadays as direct injection became more common on gassers a turbocharged gasser with direct injection may eventually reach a better fuel-efficiency than a port-injection one with natural aspiration within the very same displacement bracket.


When those Fueltech aftermarket programmable ECUs became more popular within the drag-racing scene in Brazil, carburettors started to get out of favor among street racers too.


No wonder nowadays I see many engine platforms which still resort to the good old port-injection for the naturally-aspirated versions, yet they switch to direct injection for the turbocharged ones.

Go for the low hanging fruit. Reduce any rotational mass. Electric fan, under drive pulley, lighter rims and if MT lighter flywheel. Just the fan & flywheel would make a big difference.

Even just the fan would be a great improvement, plus it's a much lower-hanging fruit :thumbup: