10/15/2014 - Tech Talk - Engine Series: Part 1

[Hog]

In a press release words and context are very important. I dont think it is going too far to parse this release carefully. As others point out, "finally" can mean different things to different people (and it is intended to do just that), and the 'prototype' engine as 'assembled' is important also. I think they (Elio) understand there is some , shall we say, anxiousness, over the engine development, and this release is primarily designed to alleviate some of that.
If you are the pessimistic type, you could see it as a stall, if overly optimistic, as engine progress, but taken at face value, it is simply a status PR report.

 

[Jeff Porter]

So true!
As Goofyone commented, EM is aware that every bit of information is heavily scrutinized and (my opinion) over analyzed.

You are right, we will have multiple posts on the use of the word "finally". lol

 

[Jeff Porter]

Anyone want to take a shot at explaining the graphs, to those of us who don't know nuttin' about:

• Time Distribution %
• Engine-TC
• BMEP [bar]
• Brake Torque
• Torque [N-M]

Por favor and gracias!

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Elio Motors Tech Talk v38
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Why We Went with a New Engine Design: Finding the Balance Between Fuel Efficiency, Power

The Elio Motors project has had three main goals for the powertrain team:

1. Up to 84 MPG for the highway drive cycle
2. The powertrain needs to be low cost
3. The powertrain needs to be comparable to current automotive quality standards.

Looking at these independently, each are not difficult to achieve, but together this is quite the challenge.

The original engine concept was to take the Geo Metro engine and create a template for the Elio engine. Overall it is compact, perceived to be efficient, has the correct power requirements, and is relatively inexpensive to produce. As the team began to dive into some of the details and changes to meet the desired Elio targets, one thing became apparent: the Geo Metro engine would not meet the fuel efficiency targets to enable the vehicle fuel economy goal of 84 MPG highway.

After running computer simulations, it was apparent that a new engine design was needed to work with the Elio vehicle to achieve this goal and still maintain a top speed of more than 100 MPH with a goal of 0-to-60 MPH in less than 10 seconds.

Figure 1: Geo Metro operating load on the highway drive cycle in an Elio.

Since the Elio is considerably lighter than anything else on the market today, a suitable existing engine was not available. This included the Geo Metro engine since it was optimized for running at the higher load used in a heavier and larger vehicle. The conclusion was clear – to meet the vehicle performance, economy, and cost objectives, a new engine would be necessary.

Figure 2: Geo Metro operating torque on the highway drive cycle in an Elio.
With the decision to design a new engine for the Elio, the program focused on determining the technical features needed to achieve the targets. The team looked at the Geo Metro design to see if modernizing the 30-year-old strategy would make it more efficient. The outcome was to maintain the three cylinder architecture, but update the cylinder block, cylinder heads, CAM cover, front cover, oil pan, crankshaft, camshaft, valvetrain, pistons, connecting rods, bearings and water pump to Elio specifically designed components. This allowed the engine development team the flexibility to keep the design simple, efficient and easy to manufacture while enabling all of the major fuel economy related attributes – combustion system, friction and pumping energy – to be enhanced. Many parts were identified as cost and risk reductions to be sourced as currently produced off-the-shelf components. All of the sensors, alternator, A/C compressor, oil filter, air filter, electronic throttle body and the engine control system are all currently produced and available at your local service center.

Over the next couple of weeks, we will share some additional details about the Engine Control Unit (ECU), show nearly all of the components that have been machined to date and finally show the prototype Elio engine fully assembled. In doing so, the powertrain Tech Talk series will answer many of the questions you, our Elio fans and supporters, have been anxiously anticipating.

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Copyright © 2014 Elio Motors, All rights reserved.

 

[outsydthebox]

You are right, we will have multiple posts on the use of the word "finally". lol

Yes!...Should "finally" go on the left side or right side of the Elio?

 

[wheaters]

Anyone want to take a shot at explaining the graphs, to those of us who don't know nuttin' about:

• Time Distribution %
• Engine-TC
• BMEP [bar]
• Brake Torque
• Torque [N-M]

The first two aren't terms I'm used to. However....

BMEP = "Brake Mean Effective Pressure".
Brake Torque = the torque output of the engine, measured on a machine so called because it acts as a big brake.
Toque [N-M] = the engine torque measured in Newton Metres, which are metric units, as opposed to Imperial ones, e.g. lbs/ft (foot pounds).

 

[RKing]

You are right, we will have multiple posts on the use of the word "finally". lol

better than beating the dash some more I too think it is defining a sequence

On the data presented, note it is for the metro engine, only shown to demonstrate that a dedicated engine can improve on the metro results. Hopefully ,there will be simular data for the Elio engine showing the differences.
Wheaters covered all I know as well, not my area of knowledge

 

[Snick]

Anyone want to take a shot at explaining the graphs, to those of us who don't know nuttin' about:

• Time Distribution %
• Engine-TC
• BMEP [bar]
• Brake Torque
• Torque [N-M]

Por favor and gracias!

==============================================================================

Time distribution percent is just the (relative percent) amount of time they ran the engine at a particular load (BMEP) and at a particular rpm (how fast it rotates). This means that they have put an engine on a dynometer, which is a very positive development step, in my opinion.

BMEP is Brake, Mean Effective Pressure. It is a measure of how hard you are working an engine. Higher numbers means more work can be done. The adjective Brake in this context signifies how the pressure was averaged (mean)--as in by what ruler was used to measure it.

Torque is a "work like" quantity or the ability to do work, at a particular engine speed (RPM). In this context, they have chosen units of Newton-Meters, but torque is always a length vector *cross product* with a force vector. In simpler terms, if you hang your body weight off the end of a 3 foot crowbar, and let's say you weigh 200 lbs, to try and budge a huge boulder, you have exerted 600 foot-pounds of torque to that boulder.

I am not familiar with Engine-TC.

En

 

[Jeff Porter]

Dynamometer = device used to measure force, torque or power. I see.

For the first graph, what conclusions can we make? Same for the second graph?

They mention "after running computer simulations". So is it possible that they also put a Geo engine on a dynamometer?

Just wanting to understand so I can explain it to someone else.

 

[tonyspumoni]

This is exactly what I have been saying all along. It is most difficult to find investors to buy into a dream early on in the process however once you move further along it becomes easier. Elio Motors will soon have, or likely already have, a running engine in development and will also soon have a whole series of pre-production vehicles undergoing the final development development process. Combine the final engine and vehicle development program with a modern state of the art manufacturing facility and tens of thousands of reservations and you are no longer simply selling an abstract concept but a tangible product ready for production.

At that point Elio Motors will also have hard numbers as to what the fuel mileage will be and what it will cost to build this vehicle which will give them a final retail price point. With all that hard information lined up it does not matter if Elio Motors receives the government backed loan or not as they will be able to find the money they need to bring this vehicle to market.

G-

You are probably right, as are all those who hold the view that the engine is the critical rate-limiting step to further investment, but I'm not so sure. The Tesla team had to successfully design, build, integrate, and test a far larger array of new technologies - on their own no less - and they had no trouble convincing investors to flock aboard. Investment bucks flow towards the best (reward/risk) opportunities and with the market bouncing along at highs, it isn't hard to make money, reducing the incentives for VC guys to look hard for new ways to get good returns. Now with the market trending lower, I'm thinking Elio gets a lot more interest. I just don't see the engine as being so non-standard that it presents much of a challenge. Now if IAV wasn't involved and Elio Motors was doing this themselves from scratch, then I would totally buy into your views.

 

[Jay3wheel]

Anyone want to take a shot at explaining the graphs, to those of us who don't know nuttin' about:

• Time Distribution %
• Engine-TC
• BMEP [bar]
• Brake Torque
• Torque [N-M]

Por favor and gracias!

==============================================================================

Jeff even if you never get an Elio, I feel sure if you check with the local community college, you will certainly qualify for an assoc. degree in engineering.