Engineers: Old vs new engine tech

[bobbywalter]

Can we add fancier words like Brake-Specific Fuel Consumption (BSFC)?

@Chapap: Not sure if you got your question answered, so the below is slightly generalized but you get the trend:

The 1.5L engine in your Honda makes 192hp@5,500/190 ftlb@5,000 with 10.3:1 compression/20.2 psi boost! To do so, it needs direct fuel injection and turbocharger.

Direct fuel injection allows for the high compression/significant boost - There is no gas in the cylinder until the injectors cycle, so no chance of premature combustion (detonation).​

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If you pull off the turbocharger, the naturally aspirated version of 1.5 Honda makes 130hp@6,600/114ft-lb@4,600. So, you can see the massive difference (62hp/76ftlb or 47%/67% respectively) that adding boost contributes. But you still need direct injection to allow the 11.5:1 compression and 4 valves/cylinder to allow the 6,600 rpm power peak.

The next step back is the Duratec 1.6 which makes 99hp@6,000/107ft-lb@4,000. Still 4 valves/cylinder, but you can see the loss in power because port fuel injection isn't as precise as direct, as a result the Duratec only had 11.0:1 compression. The Honda also revs 10% higher = 10% more power. To take advantage of the higher revs, the Honda engine would need lower gears 4.56:1, not 4.10:1 and then it needs a double overdrive 6th gear to slow it down at highway speeds.

But 107ft-lb torque isn't enough for Ranger, so Ford installed the 2.3 Duratec. Which being 42% bigger makes 44% more torque (154ft-lbs) - enough for Ranger.

Going all the way back to Lima, by only having 2 valves/cylinder, reduces volumetric efficiency, reducing both peak torque and power numbers. But there is another significant difference - the Honda and Duratecs are aluminum engines - they cost more, but aluminum transfers heat better. So, you can run higher compression numbers. And the higher compression, the more torque (there are diminishing returns, and material limits).

HotRod did a test a number of years back now, where they took 2 Chevrolet engines of equal displacement: one with largest bore and short stroke, one with smallest bore and long stroke. Heads and cam were the same, mid pack ones for more engines. And the resulting torque numbers were within instrument error on the dynamometer they were using. And power is just torque * rpm/5252.

So, we could make an aluminium 4 valve/cyl. head with direction injection for the Lima, add variable cam timing and a turbo. We'd get about 270hp@5,500/310fl-lb@3,000. (Ecoboost Ranger numbers). There is still the disadvantage of the cast iron block (weight) compared to Duratec/Ecoboost/Honda.

With the fancy head/turbo and associated programming your Lima engined Ranger with a 7 speed manual pinched from @85_Ranger4x4 's Bronco would get fuel economy numbers similar to @sgtsandman's new Ranger - better than your old, but not Accord numbers. The issue is you now have a 270hp engine in place of a 100hp one. And you really need to swap the Lima for a smaller engine to get better economy.

And as noted, you need to changed from rear wheel drive to front wheel drive to increase efficiency/lose weight. Then you need to clean up the aerodynamics of the brick you are pushing down the road.

Direct injection. That is the answer

 

[rusty ol ranger]

if only it was as simple as changing a manifold to add a turbo to my 2.3 Id do it, Im not sure what would fail first, esp since the bottom end of mine is over 150K miles.

I didnt realize the 2.3T was that stout.

 

[don4331]

Just for fun i looked up thunderbird supercoupe 2.3L lima turbo numbers...

190hp and 240ftlbs.

That beats your honda

My buddies 85½ Mustang SVO had 205hp/248ft-lbs; bottom end is fairly stout, especially if you girdle the main caps.

Lima beats the Honda only because they have 50% more displacement. Well, beats it because the power is in more useful range.

 

[scotts90ranger]

The turbo 2.3L's were the exact same as a regular 2.3L except for the 8:1 forged pistons, the stock bottom end is supposedly good for over 300hp before it becomes unreliable... the only difference in the block is the oil drainback port on the passenger side above the oil pan rail...

Yes, they pull hard, mine is a mixmatch of parts, 4 plug head, DIS ignition, Ranger accessories and the rest thunderchicken other than the stock Ranger harness repinned as necessary for the turbo computer... one of these days I wanna go dual plug head... I think I still have enough parts to build another engine...

 

[sgtsandman]

One thing to keep in mind with the smaller turbo charged engines being used to replace the larger naturally aspirated engines. Engine braking isn't as good. If that is important to you. It's a smaller engine with less pistons and therefore displacement. The engine braking on my 2019 as compared to my 2011 is anemic. It's still there but using the engine to slow down when approaching something you want to slow down for but not brake, like approaching a slower moving semi, or holding speed on a down hill without downshifting the 2.3 Ecoboost is disappointing. It does better is you have the cruise control set to a speed but it's using downshifting of the transmission to do it. So, like I said, something to keep in mind if engine braking is important to you.

 

[scotts90ranger]

Yeah, good point, and lifespan... more cylinder pressure (more power/torque) pushes the piston rings out harder against the cylinder walls causing more wear to the cylinder walls or rings meaning the time to overhaul vs a modest power output larger engine is going to be shorter... there's a threshold in there where it isn't much different but after you get past about 14psi boost things are worse...

The bottom end on my turbo 2.3L is pretty horrendous in some situations, it doesn't tractor very well, some wheeling situations I wish I had done a 4.0L swap instead of a turbo 2.3L swap, others I like having what I have... If the BW 1354 was able to be twin sticked I would have less complaints... sometimes I want two wheel drive low range, others I need all 4... in the sand screwing around for a weekend cycling a hub is annoying... and 4x4 is boring sometimes, all I want is 2nd gear low range...

 

[85_Ranger4x4]

One thing to keep in mind with the smaller turbo charged engines being used to replace the larger naturally aspirated engines. Engine braking isn't as good. If that is important to you. It's a smaller engine with less pistons and therefore displacement. The engine braking on my 2019 as compared to my 2011 is anemic. It's still there but using the engine to slow down when approaching something you want to slow down for but not brake, like approaching a slower moving semi, or holding speed on a down hill without downshifting the 2.3 Ecoboost is disappointing. It does better is you have the cruise control set to a speed but it's using downshifting of the transmission to do it. So, like I said, something to keep in mind if engine braking is important to you.

I think that is more variable valve than displacement.

My old laser seemed normal, engine braking in my brother's coyote mustang feels like the spark plugs are out of it... Nothing there.

 

[bobbywalter]

The engine braking issue is tune. The throttle by wire can be open with no fueling and the phase overlap ....

Direct injection...with the give and take with the tune ..... Leads potentially to maximum life and maximum power.


Caveats I seen .. which they can't do...

Catch can....and port injectors to keep valves washed and lubed in certain circumstances ....this will allow hundreds of thousands of miles easily



All for naught.....

 

[sgtsandman]

With the 2.3, a catch can is in the cards. Unless Ford redesignes the engine for port injectors, not so much. I think all the latest versions of the Ford DI engines have gotten port injection now.

You and 85_Ranger could be right on the valves and the tune.

 

[85_Ranger4x4]

With the 2.3, a catch can is in the cards. Unless Ford redesignes the engine for port injectors, not so much. I think all the latest versions of the Ford DI engines have gotten port injection now.

You and 85_Ranger could be right on the valves and the tune.

No port injection for the 4 bangers as of yet.

 

[sgtsandman]

No port injection for the 4 bangers as of yet.

I think the four cylinders might be the only engines not fitted with them yet.

 

[bobbywalter]

Microsquirt your own system in.


MS overlay is how the 650 whp Taurus cars were getting done early on when bigger di injectors and hpfp we're not around yet

Now there are much larger hpfp so you can hack in alcohol tunes too.

 

[Chapap]

One thing to keep in mind with the smaller turbo charged engines being used to replace the larger naturally aspirated engines. Engine braking isn't as good.

The Accord had zero engine braking. It was amazing how little resistance there was at 4k rpm. It also took a solid 2 seconds for the engine to spool down when I turned it off.

 

[sgtsandman]

The Accord had zero engine braking. It was amazing how little resistance there was at 4k rpm. It also took a solid 2 seconds for the engine to spool down when I turned it off.

I had decent engine braking with the CR-Vs but they didn't have VTEC. They were old school dual overhead cams. So, between that and the manual transmission may be the reason why. The CR-Vs are a bit lighter than either Ranger as well. So, there is that...

 

[Chapap]

I had decent engine braking with the CR-Vs but they didn't have VTEC. They were old school dual overhead cams. So, between that and the manual transmission may be the reason why. The CR-Vs are a bit lighter than either Ranger as well. So, there is that...

Oh ya. My accord was manual. I guess that’s pretty pertinent. Our CX5 has quite a bit of engine braking. I’m thinking they can easily program it either way. I had an 85 or so Buick LeSabre that had ZERO engine braking. That was quite a car to drive.