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Search found 875 matches

by Brian P
Wed Jul 03, 2019 9:58 pm
Forum: Electric & Hybrid Vehicle ** NEW **
Topic: Booster Electric Motor between the auto transmission and tail shaft?
Replies: 8
Views: 1121

Re: Booster Electric Motor between the auto transmission and tail shaft?

... or you can skip trying to blend regen and friction brakes, and simply do one-pedal driving. Let off the accelerator pedal, and it regenerative-brakes (and some vehicles provide some method of having the driver adjust this). If that's not doing enough, the driver uses the normal brake pedal that ...
by Brian P
Tue Jul 02, 2019 7:42 am
Forum: Electric & Hybrid Vehicle ** NEW **
Topic: Booster Electric Motor between the auto transmission and tail shaft?
Replies: 8
Views: 1121

Re: Booster Electric Motor between the auto transmission and tail shaft?

The trouble with doing this in a home-grown way is the system integration. How do you interface with the driver's controls so that everything, and I mean EVERYthing, operates as it should, including safety? Drive-by-wire throttle; how do you intercept the signal (and do it safely). How do you synchr...
by Brian P
Mon Jul 01, 2019 5:30 pm
Forum: Electric & Hybrid Vehicle ** NEW **
Topic: Rivian discussion dumped to the cellar "General Discussion"
Replies: 29
Views: 5842

Re: Rivian discussion dumped to the cellar "General Discussion"

Electric and traditional combustion-engine powertrains can coexist for quite a while yet, probably longer than I'll be on this earth. I have zero interest in electric motorcycles, but it wouldn't trouble me one bit if the van that I use to carry my gasoline-engine motorcycle to and from the racetrac...
by Brian P
Sun Jun 30, 2019 8:57 am
Forum: Electric & Hybrid Vehicle ** NEW **
Topic: Here is how to do it
Replies: 111
Views: 15814

Re: Here is how to do it

Electromagnets can be turned on and off or reverse their polarity. A standard electric motor does that. Requires electrical energy to make it work ...
by Brian P
Sat Jun 29, 2019 10:24 pm
Forum: Electric & Hybrid Vehicle ** NEW **
Topic: I think I'm leaking?
Replies: 20
Views: 3077

Re: I think I'm leaking?

Would help to know make/model/year and how this apparent "loss of distance" is making itself known. Some EVs have battery temperature regulating systems that are active even when the "engine" is "off" in the interest of having the battery already in the optimum temperature range when you hop in the ...
by Brian P
Wed Jun 19, 2019 6:55 pm
Forum: Electric & Hybrid Vehicle ** NEW **
Topic: Here is how to do it
Replies: 111
Views: 15814

Re: Here is how to do it

*sigh* Internal combustion engines work because the combustion (heat energy input) leads to the pressure greatly increasing beyond what the initial mechanical compression achieved, and thus, the mechanical work extracted by expansion is greater than the work of compression. It didn't come out of now...
by Brian P
Wed Jun 19, 2019 3:51 pm
Forum: Electric & Hybrid Vehicle ** NEW **
Topic: Here is how to do it
Replies: 111
Views: 15814

Re: Here is how to do it

Sure. It's all well and good that you extract mechanical work from compressed air inside an air cylinder, except that once you've extracted that energy by expanding the air, you would have to put that mechanical work back into it to get your compressed air back. Whether that work of compression is d...
by Brian P
Wed Jun 19, 2019 7:57 am
Forum: Engine Tech
Topic: Why not?: Flywheel as crank position sensor
Replies: 47
Views: 3683

Re: Why not?: Flywheel as crank position sensor

That strategy isn't limited to diesel engines. I have a fuel-injected single cylinder Honda motorcycle engine, and a two-cylinder 180-degree-crankshaft Yamaha motorcycle engine (thus having an uneven firing order), which only have a crank sensor. Any engine with an uneven firing pattern - V-twins, D...
by Brian P
Tue Jun 18, 2019 12:24 am
Forum: Electric & Hybrid Vehicle ** NEW **
Topic: Here is how to do it
Replies: 111
Views: 15814

Re: Here is how to do it

Ohms law works just fine with AC. It requires understanding (and putting numbers to) additional time-related influences that are not relevant with DC - notably "capacitance" or "inductance" in addition to "resistance", which are gathered together as "impedance". The underlying physics is the same. T...
by Brian P
Mon Jun 17, 2019 4:42 pm
Forum: Engine Tech
Topic: All aluminum engine vs cast iron (Piston to head)
Replies: 14
Views: 1635

Re: All aluminum engine vs cast iron (Piston to head)

Based upon http://hyperphysics.phy-astr.gsu.edu/hbase/Tables/thexp.html or https://www.engineeringtoolbox.com/linear-expansion-coefficients-d_95.html Aluminum (nominally) has a coefficient of thermal expansion of 24 x 10^6 per degree C. (Could be 21 - 24, let's use worst case) Steel is around 12. Wh...
by Brian P
Thu Jun 13, 2019 2:20 pm
Forum: Engine Tech
Topic: Loss of torque with EFI?
Replies: 127
Views: 8550

Re: Loss of torque with EFI?

There are two ways that a "feedback carburetor" can work. Evidently that system works by relying on the base carb settings being lean, and then adding more fuel. The other way - the traditional one -relies on the base carb settings being rich, and then bleeding air in strategically (usually this was...
by Brian P
Wed Jun 12, 2019 8:00 am
Forum: Engine Tech
Topic: Loss of torque with EFI?
Replies: 127
Views: 8550

Re: Loss of torque with EFI?

From David Vizard's book "Chevy Big-Blocks - How to build Max-Performance on a budget": Port-injection systems are the way to go, but they’re not cheap. A fuel injector installed at a manifold location close to the cylinder head port seems like a big step forward over a carbureted system because it...
by Brian P
Tue Jun 11, 2019 10:39 pm
Forum: Engine Tech
Topic: For you with bike carb knowledge
Replies: 46
Views: 2831

Re: For you with bike carb knowledge

The individual "pod" filter is not stock on any bike built in the last few decades (I will grant that I know nothing of the 1960s-era British bikes). The OEM setup would have the carbs drawing from an airbox that stabilizes the airflow patterns, and the float bowl vents would be to atmospheric press...
by Brian P
Tue Jun 11, 2019 4:49 pm
Forum: Engine Tech
Topic: For you with bike carb knowledge
Replies: 46
Views: 2831

Re: For you with bike carb knowledge

Open carbs with no airbox (pod filters = same thing) ... It is fairly likely that air circulation around and past the bike is affecting the vacuum signal in the float bowls and/or disrupting airflow into the air filters themselves. It's not exactly clean undisturbed airflow ... Where are the float b...
by Brian P
Mon Jun 10, 2019 4:25 pm
Forum: Engine Tech
Topic: Loss of torque with EFI?
Replies: 127
Views: 8550

Re: Loss of torque with EFI?

Could it be Magazine propaganda, maybe that is why they made little mention of the torque loss. I agree with the previous poster if the correct carb had been chosen to begin with it could have been tuned in a couple of hours at worst. We tune all kinds of carbs and EFI and have even done some swaps...