Dr. Paul Engine? 5

[mcspeed]

What's the concensus on the 'Dr. Paul' Opposed Piston engine talked about in this Youtube video:

part1:

http://il.youtube.com/watch?v=Fz8Z9geyOkk&feature=related

part2:

http://il.youtube.com/watch?v=K6ahbdkJTN8&feature=related

part3:

http://il.youtube.com/watch?v=hTnxsqX9FhE&feature=related

part4:

http://il.youtube.com/watch?v=ihR1fCeEobQ&feature=related

part5:

http://il.youtube.com/watch?v=y6OuUN2LlV8&feature=related

It was briefly referenced in this thread by someone who seemed to have been involved with the DARPA work on it:

http://www.eng-tips.com/viewthread.cfm?qid=237389&page=8

It sounds too good to be true of course, but it also sounds like too much development went into it for it to be worthless.

What's the deal?

 

[mcspeed]

Wow thanks for the firsthand info tbuelna!
Do you think the design is any more promising 20 years later? Or is it just a novel approach that has run its course?

 

[tbuelna]

mcspeed,

I took a quick look at the first video. It looks like the same engine from 15 or 20 years ago, except that there are now a pair of rotary valves.

The engine had lots of basic issues regarding combustion efficiency, heat transfer and tribology. It doesn't appear that those issues have been addressed, so I'd say the engine does not appear to be any more promising now than it was back then.

Regards,
Terry

 

[mcspeed]

Much appreciated! Have a great weekend

 

[gruntguru]

Professor Fred Major!
If you developed something that was any good, the last thing you would do is get this turkey to publicise it on YouTube. Those videos contain about 5 fallacies or engineering inaccuracies per minute - eg. "Muscle car engines of the 60's were more efficient than today's engines. The reason today's car achieves good fuel economy is weight reduction" BALDERDASH! It is the exact opposite. Current engines are the most efficient ever and cars today are much heavier. I don't know what he is supposedly a Professor of, but it sure isn't engineering.

 

[WhizzMan]

I commented on the blog, lets see what happens.

 

[HRHtex]

Grunt - I agree with your comments on engine efficiency - but are today's cars heavier? I thought that with thinner higher-tensile steel in the bodies and plastic bumpers etc. that they were lighter on average than the older cars.

 

[MikeHalloran]

The bodies are thinner and lighter, but there's a lot of additional crap to be carried within them, like airbags, evaporative emission systems, fuel return lines, ABS plumbing, lots more wires, etc. Additionally, frames (or structural body parts) with crumple zones must be heavier than simpler straight-ish frames.

I suggest that weight reductions implemented at considerable effort and investment in pursuit of better fuel economy have been mostly offset by mandatory safety equipment, and additional doodads installed by default as market pressures and/or manipulation by marketing operations has pushed up the amount of stuff installed on a 'base' car.



Mike Halloran
Pembroke Pines, FL, USA

 

[gruntguru]

Two graphs at the following link say it all.

http://www.epa.gov/fueleconomy/fetrends/420s07001.htm

Since 1980:
- Fuel efficiency is up
- Performance (acceleration) is up
- Mass is up

 

[patprimmer]

It might vary from region to region, but cars here are heavier. While they use lighter materials, the increased power, requires beefier axles, drive shafts, transmissions and brakes.

Wheels tyres and suspension are heavier, air conditioning and power steering are std on base models, air bags and ABS are also very common now and crash performance requirements are ever increasing as is torsional rigidity and control over suspension and chassis compliance on bumps and curves

Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers &

http://eng-tips.com/market.cfm

for site rules

 

[BrianPetersen]

A 1970's Honda Civic was a 1600 lb car. A new one is 2700 lbs.

A 1970's VW Golf was an 1800 lb car. A new one is 3000 lbs.

Both of those have grown substantially in size ... the current Civic is bigger than the 2nd-generation Accord, nevermind the 1st-generation. A Honda Fit is bigger than the 2nd-generation Civic, and it weighs more.

A Chevrolet Aveo is a 2500 lb car.

 

[WhizzMan]

I drive Alfa Romeo, in Europe. The average alfa 33, considered a small midsized car here, weighed less than 900 kilo when first on the market. It could be bought with a 1.5 liter engine with over 100 bhp. Fuel economy was about 1 liter in 12 km. The replacement I own is a 145, 2 liter, 1250 kilo car. It does about 1 liter in 11 km, has 155 bhp and is just as fast to drive on the road. It does have way more crumple zones, safety beams, air conditioning sound padding and is emitting substantially less CO, NOx and HC than the 33. Fuel efficiency is up, the engine is cleaner, but most of it is offset by the extra safety and luxury indeed.

In Europe, where the focus already was on small, efficient cars, this is the trend. I think that in the USA, where technology wasn't pushing towards smaller, more efficient cars, people were buying trucks with large, gas guzzling engines. Only recently, when economics started demanding people to size down, the market has been going towards smaller cars. This may be the explanation that sales and car population have shown a different trend than engineering trends world wide have been.

 

[GregLocock]

How much bigger and heavier are the tires wheels and brakes on your new Alfa?

How many more gears does it have?

How much quieter is it?

How much stiffer is the body?

I bet the old Alfa didn't have as many electric motors to do all those tiresome jobs like moving the seat and the windows and the mirrors.

Even silly things like the number of speakers affect the weight - you have to reinforce the panels to make up for the holes the speakers go in.

The reason cars get bigger and heavier with time are based on trying to sell the same vehicle to the old customer (who is generally somewhat more affluent one model later) as well as the new customers for that model.



Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[WhizzMan]

Tires,wheels and brakes are bigger, mostly because the car is heavier. I compared the two top spec models to keep it fair and yes, the trend is that wheels are bigger and heavier. In fact, apart from this top model, the cars both have 254 disc brakes in front and drums in the back. The difference is that the newer model has ventilated brakes. As I said, it's much stiffer, mostly because of the safety regulations. There are exactly 2 more electric motors in the new one, for the wing mirrors. The rest is also present in the old one.

The car I picked to compare is maybe not totally representative of the european market, since Alfa already was putting quite a bit of features in their cars and kept it to "essential luxury" so the car would remain sporty. Power to weight ratio and suspension/brake features is rather good for a small midsized car and always has been with them. I picked it because it's the brand I've been driving for the last 11 years and I've been working on a lot of these cars, so I know the technology and features best.

If you look at for instance the VW golf, now in their sixth generation, the creeping featurism is much more defined. The first golf in the seventies curb weight started at 790 kilo's, the GTI at 836 kg being slightly heavier because of the bigger engine and brakes. The second generation already was at 120 kg more. The 3rd golf GTI was much slower than the first generation golf GTI and weighed 1088 kg.

These figures are quite a good representation of the trends in European cars. They got heavier, more features got added, engines gained power and efficiency, but in the end, the cars weren't going faster and fuel economy wasn't much better either. Only emissions of CO, NOx and HC are down because of the cleaner way the cars now burn fuel. CO2 is still roughly the same in real world use. The "euro test cycle" has been instated and altered a few times, but it's in no way representative for most of the driving done in the real world.

I live in the Netherlands and our government is traditionally taxing both ownership and usage of automobiles quite heavily. Purchasing a new car means that over 50% of what you pay is taxes, unless it's one of the "A label" cars that is environmentally friendly, then it's exempt from some of the taxes. The more a car pollutes (euro cycle used) the more tax you pay at purchase. You also have to pay road tax, based on the curb weight and the type of fuel used. Then there is fuel tax. Current prices for 95 ron, the most common fuel here (93 MON I believe) would be about 8.30 US dollar/gallon (1.54 euro/liter) The taxation on purchasing new vehicles based on pollution is new, it used to be a static percentage of the purchase price.

There's another phenomena here, but that's rather unique for the Netherlands, because of taxation, company lease cars. Quite a few people get a company provided lease car. They get to drive it as a personal car too, add a percentage of the catalog value of the car to their income (for tax) and usually don't have to pay for the first 10.000 km each year or so. For most, this is cheaper than buying a new car themselves so many companies offer this to their employees. They changed the tax rules for these cars as well, the A label cars get taxed 14%, the B labels 20% , and C and higher get 25% of the catalog value after taxes added to your income for tax reasons.

This means that a lot of the new cars sold here are in fact hybrids and "micro cars" as I call them, since they are the modern equivalent of the BMW Isetta in my eyes. We do see a few 3 cylinder turbo diesel cars that are slightly larger appear now, since they are very fuel efficient and the taxation criteria are only based on CO2 emissions per distance traveled.

A lot of governments are now trying to regulate what cars are being bought with tax and emissions regulations. Safety regulations seem to make meeting these emissions regulations hard, because you can't just put people inside a paper bag with wheels attached anymore.

 

[JayMaechtlen]

Yeah, the newer cars are absolutely marvelous, but it does cost weight and money to make it happen.
Air bags and guard beams and crumple zones, oh ####!
Actually, I bet the crumple zones add a lot more weight than the 'strength' / stiffness would otherwise require.

But - when something bad happens, you have a real good chance of surviving it.

My "Corvair" is almost 2500 lb, with its Iron 3.8 and no safety equipment to be seen. (well, it does have seat belts.) It encourages me to drive defensively.

Jay Maechtlen

http://www.laserpubs.com/techcomm

 

[izzmus]

Food for thought. A 2006 VW GTI (US spec) weighs within a couple dozen pounds of a 383ci '68 Dodge Charger.

Chargers are not small cars by any stretch of the imagination.

 

[tbuelna]

izzmus,

Maybe not a "couple dozen pounds", probably more like 200 to 300 lbs. But it's still an amazing statistic.

Both are unibodies by the way.

Terry

 

[izzmus]

The specs I found were ~3313 for the VW, ~3360 for the Dodge.

Multiple layers of carpeting and padding, sound deadener inside and out, and the complex wiring harness needed to control all of the modules and power everything do not come light.

People expect to drive cars with the silence and solidity of a tomb, though. Or, at least, the magazine reviewers expect it.

 

[DHambley]

I looked at the first video and quickly got bored. maybe not snake oil but, boring nonetheless. Clicking on some of the links on the right-hand column, within 3 links I was at the "Searl Engine". Oh man, what utter snake oil bull THAT is! Luckily, within 3 more links I was able to find two cute women having a pillow fight.

 

[gruntguru]

I looked at the first video and quickly got bored. maybe not snake oil but, boring nonetheless.

Have to disagree with you there. It's definitely snake oil!

Engineering is the art of creating things you need, from things you can get.

 

[L4189]

NAVISTAR just announced an agreement to further develop the OPOC engine.