Best way to build a hybrid truck?

[Isaac Zachary]

Originally Posted by Piotrsko

Huh? What you talking about, Willis? Nict verstehe.

The derrailing topic of what engine configuration is the absolutely most efficient.

IMO it would be a single cylinder engine at low revs. But to get higher revs putting two pistons in the same cylinder and making it a 2-stroke would help. I'm not sure who may have made or thought of this before me. It just seems logical.

But maybe I should start another thread.

[Piotrsko]

Ok. Just had a problem with the 2 pistons in the same cylinder concept. Connecting that all together makes stuff really complicated and inefficient.

[Isaac Zachary]

Originally Posted by Piotrsko

Ok. Just had a problem with the 2 pistons in the same cylinder concept. Connecting that all together makes stuff really complicated and inefficient.

True.

The only thing it would help avoid is severe imbalance.

[freebeard]

I'm not sure who may have made or thought of this before me. It just seems logical.

https://en.wikipedia.org/wiki/Commer_TS3
Configuration: opposed-piston valveless, supercharged uniflow scavenged, two-stroke diesel engine

https://en.wikipedia.org/wiki/Napier_Deltic
Configuration: three-cylinder, six-piston opposed piston engine with rocker drive to a single crankshaft.

https://en.wikipedia.org/wiki/Free-piston_engine

A free-piston engine is a linear, 'crankless' internal combustion engine, in which the piston motion is not controlled by a crankshaft but determined by the interaction of forces from the combustion chamber gases, a rebound device (e.g., a piston in a closed cylinder) and a load device (e.g. a gas compressor or a linear alternator).

This is the one I documented at Permalink #35.

[Hersbird]

Originally Posted by S Keith

It depends on the goal. If the goal is to use the least amount of gas per kWh, then using the ICE for any charging is folly. Generators are designed for power production at constant rpm in mind. They have a near linear efficiency to power relationship. They are MORE efficient at 100% than they are at 50%. Propulsion ICE aren't. They are designed for efficiency while propelling a vehicle, and they have a variable mass/fuel flow, rpm and power relationship.

The ONLY way this would be viable is if you made the charging occur AT the peak efficiency point for power and rpm of the ICE. Under all conditions, the ICE would NEVER beat the generator in terms of fuel burned per kWh due to the larger mass and increase inefficiencies. Additionally, the battery would need to be VERY robust to handle this charge current as you'd likely be charging the 10kWh battery in under an hour.

The only place the propulsion ICE would beat the generator is in pollutants. Generators are dirty.

As far as robust charging ability, my Pacifica hybrid is nothing special but can recharge at up to about 85kw using the onboard motor generator although I don't know how long as that's what it allows max braking regen. The onboard charger can only go 6.6kw so if recharging with an external generator it would only need to be about a 14hp one but that's more a limitation to the size of the onboard charger installed which is reaching the limits of normal 240 outlets found in garages. Obviously if it can regen at over 10 times the rate, the battery is capable of a faster than 6.6kw recharge. So the 260hp inboard motor (or whatever it is, the non akitson versions like 285 hp) if able to constantly recharge at say 60kw would have that battery full in 15 mins. So why carry an extra $4000 300 pound generator in the bed to maybe save a gallon and take 6-8 times as long?

[cRiPpLe_rOoStEr]

Originally Posted by Isaac Zachary

In other words, if you need a 1, 3, 5 or 7 liter engine, just make one 1, 3, 5 or 7 liter cylinder.

[/QUOTE]

Sometimes the weight and physical volume difference between a thumper and some other engine with more cylinders, both ranging within the very same displacement, turns out to not be so much more favorable to the engine with fewer cylinders.

[Piotrsko]

Ok so "cylinders" does not relate to crankshaft. Got it.

[cRiPpLe_rOoStEr]

Originally Posted by Piotrsko

Ok so "cylinders" does not relate to crankshaft. Got it.

Even if a 2-stroke opposed-piston engine may feature 2 crankshafts instead of only one, it's still not so bad at all. Still usually involves fewer moving parts than a 4-stroke with its valvetrain. Well, there was also that Pinnacle Engines 4-stroke sleeve-valve design which looked quite promising...

[rmay635703]

I like how because the op crapped the bed and left it inspired more discussion in this thread than if he remained calm and kept posting

[Isaac Zachary]

Originally Posted by cRiPpLe_rOoStEr

Sometimes the weight and physical volume difference between a thumper and some other engine with more cylinders, both ranging within the very same displacement, turns out to not be so much more favorable to the engine with fewer cylinders.

Yes, a single cylinder engine could end up weighing more or being bigger than a multi-cylinder engine of the same displacement.

The benefit is that for the same displacement in a single cylinder engine you have less ring/piston wall area so less friction. You also have less combustion chamber surface area, so less heat rejection.

Of course the downside is vibration. A single piston engine would be terribly unbalanced. It would also get a power stroke once every 720⁰ making it even more shaky. So this limits speed (and longevity) and also limits power.