Advances in the auto industry

[rocketmanpete]

I promise after this paragraph I will get on topic,this dose have to do with the topic in a way.The link to the vid was removed but I heard the broadcast.Last week in the Senate this is what Sen. Dianne Finestien of CA. said (as best as I can remember) "Mr President we are elected to the Senate for a six year term because we have to make tuff decisions in the best interest of the nation. Mr. President my office recieved 91-K phone calls and e-mails,85-K citizens of CA. are aganist the bailout,these citizens do not understand, are misguided, or uinformed about how serious this is.There for Mr President I agree to the proposal." I think she just insulted 85-K people, Hey wait a minute I want there phone numbers,I have 85-K beach front lots to sell in Hadly NV.

OK to the topic,Something the rest of the idiots in DC really don't see.
Way back in the early 70s I took auto mechanics in high school. It was a trade and tech school. I went through a 3 year program. One of the related course's was Related Science and Theory.Don't ask for all the terms it was 30 years ago. however it gose like this. It takes a certian amount of energy to move an object a certian distance in a certian amount at a given speed.

Back then DCs idea of economy was to put the infamous Vega 4 banger in a Fleetwood Caddy

Here is my report on progress.

#1) 1970 F-100 with a 300 cu in six cyl. with a three speed on the colum.
11 MPG 29 years later 99 F-150 super cab long bed,4.6 L with a 5 speed
23 MPG
#2) 1970 C-20 (this was my baby) fully loaded custom camper BB 396 cu in auto 8 MPG but boy I could smoke them tires
2000 C-20 5.7 L (small block 350) auto
17.5 MPG
All of the above I owned one time or another, I do not believe the people in DC have really looked at this on ground level. Unless we all start driving smart cars or we use lighter alloy's or composites it still takes energy to move an object. I think we have refined the internal combustion to run as efficiently as we can get with the technology we have. OK thats my two bits

[CraziFuzzy]

Re: Advances in the auto industry

You are correct, in that the internal combustion is getting to the point where it won't really get any more efficiency by itself, because it has to run as a car engine (meaning it has to work well over a HUGE range of conditions, varying RPM's and throttle loads). An internal combustion engine COULD be much more thermally efficient, if it's operating parameters could be more narrowed down. It could be optimized to run at a set power band, and at the most efficient throttle. THIS is the benefit of the Series Hybrid platform (such as the upcoming volt, and some large busses). Where the Ups and Down of the car are handled in a very efficient way (via an electric motors, whose efficiency is pretty constant, regardless of conditions), and the batteries are maintained by a small ultra-optimized generator.

[Wellarmed]

Re: Advances in the auto industry

Old threads needs fresh comments. I am not a Californian, but I do spend a significant amount of time in the state. I personally will plead to every Californian I know that this woman needs to be removed from office. Wellarmed isn't just a handle, it is factually representative. Any elected official that puts barriers in the way of excercising rights of birth, deserves to be looking for a new job! She took an office with the responsibility to uphold the Bill of rights, and there was no picking or choosing when she repeated that oath. On the other matter Crazzyfuzzy is correct in that choosing a fixed operating RPM allows one to further refine the efficiencies of the ICE. The main objective to extracting the greatest thermal efficiency is to have the entire combustion cycle occur within no more than a 20 degree (10 degrees before and 10 degrees after TDC) window at all operating rpms. This is nearly imposible to achieve because the time for these events to occur can be measured in nano seconds at higher revolutions. It has always been my understanding that the flame speed will increase exponentially in relation to greater inputs of induced turbulance. The real question that I would like to see addressed is, at what point if any does the turbulance wipe away the boundry layer? This test should idealy be performed in a single cylinder engine to eliminate any variablities that could occur in variation from air/fuel composition or incomplete homogenization. I would also be curious as to what the ignition energy requirements would be under these circumstances, and if ignition can even be maintained. Coil saturation time would be virtually non-existant. Many questions, very few answers?

[cowboy]

Re: Advances in the auto industry

I to had a 70 300 six and 3 spd and a2.73 rear that I put in and it got 20 to 22 mpg I drove it back an forth to fla from md every week everyone seems to look at the wrong end for mpgs as I have improved the mileage on many cars and trucks with a rear change I also have a home made chevy pu with a549 int diesal and a2 to 1 od with a 4.11 rear gets 28 best and 24 most of the time gear fast run slow get great mpg

[larrycng]

Re: Advances in the auto industry

I'll have to disagree on one point, Wellarmed, burn time for a given fuel is relative constant; yes there are slight variation in burn time. For gasoline and natural gas it is about 1 to 3 ms. Yes octane rating and mixtrue will affect the burn time.

Turbulence will generally provide for more complete combustion the lean burn CNG engines, Cummings and Deere are good examples. When combustion is disruppted, not a smooth burn across the cylinder, such as in detonation or preignition, then the boundry layer is distrubed and you will melt down the pistons and cylinder heads. As for too much turbulence, I don't believe that would be a problem because "swirl" and "tumble" determined by combustion chamber and piston design are not random and disruptive as would be the affect of detonation or pre-ignition because of the two separate flame fronts.

As was brought out by Cowboy if you can keep the rpms low you can get better miliage. As a mentor once said keep the throttle open and engine turning slow for good miliage. The slow speed is generally understood. The wide throttle opening reduces pumping loss making for more efficiency; less power required to operate the engine and therefor more power available for the output shaft.

Had and '86 Cougar, 5.0 with 2:73 and AOD for a final drive 2:20, about 1600 rpm@ 72 mph --31mpg between LA and Joshua Tree -- consistantly. This brings up one other important point, the engines "sweet spot". There is a speed where and engine will give it best miliage. It is generally around the top of the torque curve. It also depends on where the power valve tips in on a carbureted engine or if the system is in closed loop (14.7:1 AF mix) or in open loop (usually a richer mixture). Some of the new wide band sensors and computer software will allow the engine to lean out for better MPG

enough for now

Larrycng

[Wellarmed]

Re: Advances in the auto industry

Hi Larry, It's like I am in your class again! I sure do miss arguing these points with you and Collin. I will have to respectfully disagree with you on the affects of flame speed in relation to turbulance inputs, and cite an example to support my conclusions. I remember watching the report of the airplane that went down off of the east coast (I believe off the shore of NY), and there was a lot of suspicion that a US battle ship had inadvertantly shot down this aircraft. I was very interested in this report from the FAA in determining the causes of that horrible crash. One of the best visual displays that I have ever seen on the effects of turbulance on increasing flame speed was displayed in that report. The point of ignition occured in the center fuel tank and was the result of a short circuit in the wiring in the tank itself. Consequently all similar aircraft are now required to be upgraded as a result (currently the Pilot is to remember to shut the center fuel tank circuit off after the fuel level drops below a failsafe point).Either way, if you pull up the footage from that report, the FAA investigation created a Working blueprint of how the event transpired. It showed an amazing sequence of events with the explosion in the center tank blowing out the bottom of the fuselage and also entering into the passenger compartment. Watch the footage of the flame speed spreading exponentially INSIDE the cabin. This exponential increase in flame speed had occured due to the turbulance that was created (from the seating arrangement) as the flame front traveled towards the front of the aircraft. I can only assume that this flame front had exceeded the speed of sound before it blew the front of the aircraft completely off. It is my understanding that all fuels are subject to the same affects of increasing flame speed if (controlled) turbulance is induced into an expanding flame front. I drilled Don Bass on this issue, as he has had the most hands on experience with the subject. The conditions in that Aircraft created the perfect storm for that advancing flame front. Please see if the footage is still available from the congressional report and review the footage. It is truly amazing and horrifiably scary. The typical flame speed of a natural gas if I remember is around 55 mph, and is significantly slower than gasoline. This is the basis for requiring greater lead time during the ignition process with all other things being equal. Ignition lead time can generally be reduced in forced induction applications due to the affects of increased turbulance which affect the flame speed. When using Nitrous oxide or other forms of forced induction, a noticable increase in power occurs when ignition lead time is reduced and moved closer to this optimal operating window. I will cite another example such as porting cylinder heads. If done properly cylinder head porting will also generally net a visual benefit in power when the ignition lead time is reduced, even in naturally aspirated engines. Thanks for chiming in Larry.

[Wellarmed]

Re: Advances in the auto industry

I unfortunately miss stated the Federal Agency in charge of investigating the crash of TWA flight 800. It was the NTSB not the FAA. The visual display is from a recreation of the events as was displayed before congress. The point I was trying to make is that much more can be done regarding ICE efficiency by focusing on what can or should be done before the combustion chamber. I feel that far greater homogenization and control of flame speed can occur if pre combustion chamber events are tailored to achieve mass efficiency at all operating RPMs and load conditions. I personally was very disapointed that electronic valves never came into fruition and wonder where the patent and the company went that designed them.