Community Forums

ScoobyDoo · 08-10-2019, 08:57 AM

Quote:

Originally Posted by tuffr2

That is 4 gallons to go up those 8 miles but going down makes up for a tiny bit. Probably use .5 gallons going down so 4.5 gallons to go 16 miles ... Still not good.

It is still interesting to me that for 120 years pistons going up and down turns a crank shaft. Seems the Mazda Rotory engine would be the way to go but they just can't get that engine design to work as well as they want. The Rotory engine has 12 or 15 moving parts (I forget) and the engine is spinning the right direction.

Looks like we will go right to electric motors and forget about the Rotory engine.

Pretty easy to make a ring to seal between piston and cylinder. The edge of something spinning in a round bore would be harder. But in a round bore it would not be compressing the air, so they are trying to seal around something spinning in a irregular shaped bore.
Now if you want to get into a turbine...

Mekanic · 08-10-2019, 09:10 AM

I’m sure you will see 450HP/500TQ in the not so distant future.
The aftermarket will be at that level Vdry quickly

sirtate · 08-10-2019, 09:28 AM

Quote:

Originally Posted by ScoobyDoo

Pretty easy to make a ring to seal between piston and cylinder. The edge of something spinning in a round bore would be harder. But in a round bore it would not be compressing the air, so they are trying to seal around something spinning in a irregular shaped bore.

Now if you want to get into a turbine...

Ah, yes... The old apex seal quandary...

In order to get a decent compression ratio, you need serious eccentricity.

With serious eccentricity, you need strong apex seal springs.

With strong springs, you have high friction.

High friction means low fuel economy and high wear on the seals...

Good luck getting a Wankel to last beyond 80k miles, and get above 20mpg...

Nevermind the emissions...

My 1990 RX7 Turbo, had a redline of 8000rpm, a buzzer at 8200, and fuel cut-off at 8500. It would keep pulling right through until fuel cut.

Those numbers weren't for the longevity of the engine but for the *accessories*!
Apparently the water pump and the A/C compressor clutch didn't like spinning that fast.

It was a neat motor... Apex seals failed at 85000miles... instant rebuild...

Wouldn't want one for daily transportation today...

dcaresio · 08-10-2019, 11:24 AM

Hard to beat Chevy's 8.1 with a 6 speed Allison behind it.

tuffr2 · 08-11-2019, 08:25 AM

I would like to see that 8.1 GM engine in a modern truck. Those old trucks were small. I drove my friends early 2000's Chevy 2500 with the 8.1 engine. That truck was small compared to today's Chevy 2500.

Was it EPA emissions that caused GM to stop making that engine?

dcaresio · 08-11-2019, 08:56 AM

I like the 8.1 because it never gets close to overheating, always stays at half on the gauge. Had that engine in my 2500 and now in my motorhome. Love it. Glad Ford is getting rid of the V10.

bross · 08-11-2019, 09:05 AM

Quote:

Originally Posted by tuffr2

I would like to see that 8.1 GM engine in a modern truck. Those old trucks were small. I drove my friends early 2000's Chevy 2500 with the 8.1 engine. That truck was small compared to today's Chevy 2500.

Was it EPA emissions that caused GM to stop making that engine?

Who Killed the Big-Block V8?

TourNut · 08-11-2019, 11:31 AM

Quote:

Originally Posted by sirtate

Ah, yes... The old apex seal quandary...

In order to get a decent compression ratio, you need serious eccentricity.

With serious eccentricity, you need strong apex seal springs.

With strong springs, you have high friction.

High friction means low fuel economy and high wear on the seals...

Good luck getting a Wankel to last beyond 80k miles, and get above 20mpg...

Nevermind the emissions...

My 1990 RX7 Turbo, had a redline of 8000rpm, a buzzer at 8200, and fuel cut-off at 8500. It would keep pulling right through until fuel cut.

Those numbers weren't for the longevity of the engine but for the *accessories*!
Apparently the water pump and the A/C compressor clutch didn't like spinning that fast.

It was a neat motor... Apex seals failed at 85000miles... instant rebuild...

Wouldn't want one for daily transportation today...

I had a '73 RX3 , Great Engine until 55 K miles . Water pump failed , it overheated fast on I-80, engine oil cooler line into radiator input , aluminum female thread on radiator cracked / oil even on windshield . Expanding aluminum engine layers were tied together with steel bolts that didn't expand as much , crushing aluminum , so that engine case oil & coolant seals couldn't make up the clearances in a cooler , retracted aluminum engine , Result was exhaust and oil in the coolant system that forced out the lower pressure coolant , replacing it with oil & exhaust that radiator couldn't cool engine as needed . Things got worse & worse . Engine got replaced under warranty with a rebuild - that only lasted about 12 K , same problems , it got replaced with another that only lasted 3 K - that jammed / locked up , on I-75 , Cincinnati . Replaced it with another & I sold the car immediately , as I had had enough !

sirtate · 08-11-2019, 11:52 AM

Quote:

Originally Posted by TourNut

I had a '73 RX3 , Great Engine until 55 K miles . Water pump failed , it overheated fast on I-80, engine oil cooler line into radiator input , aluminum female thread on radiator cracked / oil even on windshield . Expanding aluminum engine layers were tied together with steel bolts that didn't expand as much , crushing aluminum , so that engine case oil & coolant seals couldn't make up the clearances in a cooler , retracted aluminum engine , Result was exhaust and oil in the coolant system that forced out the lower pressure coolant , replacing it with oil & exhaust that radiator couldn't cool engine as needed . Things got worse & worse . Engine got replaced under warranty with a rebuild - that only lasted about 12 K , same problems , it got replaced with another that only lasted 3 K - that jammed / locked up , on I-75 , Cincinnati . Replaced it with another & I sold the car immediately , as I had had enough !

They really were great fun...

A kid at my high school had an RX-3 that he had redone the body and put a loud(er) exhaust on. (This was 1980, and already the RX-3s and B210s were rotting away)

It had a great grey metallic with huge flakes in it that sparkled like a Bass Boat. Plus that exhaust...

I asked my dad why it sounded different, and he explained the Wankel Rotary Engine. (Say that in a Sotto voice ala the Python bit about the words you can't say on the BBC)

When I could buy my 1990, I jumped on it...

It made all the same noises as that 3, and had a Turbo whistle too...

I traded it for a 4 door sedan in 1997... My life was 'over' at that point... I had stopped being cool...

tuffr2 · 08-11-2019, 12:10 PM

I had a friend that had the older 1982 I think. He loved that car while it lasted. Then he had a few other cars and then bought a 1993 and he loved that car as long as it lasted. Just about everyday he would come into work in a good mood and was eager to talk about how much fun that car was.

Mtn. Lion · 08-11-2019, 04:22 PM

Quote:

Originally Posted by tuffr2

Was it EPA emissions that caused GM to stop making that engine?

I think it was a lack of customer demand for it. I had one back in 2005 in my 2005 2500 HD Silverado long bed extra cab 4X4. It was a pain to sell the truck because of the low gas mileage and people wanted the diesel for better MPG or for towing. At that time, gas was hovering around $5 a gallon.

tuffr2 · 08-11-2019, 07:34 PM

It will be very very interesting as to what the milage is on the 7.3 Godzilla engine. I did read where milage was taken into account...probably something GM did not do with the super duper gas guzzling beast.

I do like that as a code name for the 8.1. GGB. Gas Guzzling Beast.

I hope TFL can and will test the 2019 Boss engine milage vs the 10 speed Godzilla engine

ScoobyDoo · 08-12-2019, 06:50 AM

Quote:

Originally Posted by tuffr2

It will be very very interesting as to what the milage is on the 7.3 Godzilla engine. I did read where milage was taken into account...probably something GM did not do with the super duper gas guzzling beast.

I do like that as a code name for the 8.1. GGB. Gas Guzzling Beast.

I hope TFL can and will test the 2019 Boss engine milage vs the 10 speed Godzilla engine

I know some here do not like discussing it, but millions of trucks up to F 750 spend their whole life in one area, and parked in the same place every night. And many of these trucks are part of a fleet, with a bunch of trucks parked at the same place. If the new engine can get move the load with "good" mileage, and do it on say compressed natural gas, without the emission issues of diesels, there would be a market for the engine, and a big enough market to lower the cost of production. Maybe a RVer can buy cheaper.

tuffr2 · 08-12-2019, 08:37 AM

Scoopy - compressed natural gas had a good chance I think in the early 1990's to early 2000's but fell out of favor. There was a good enough push I think to get it started. It was a much cleaner burning fuel than gasoline with a much better natural octane rating. I think something like 103 octane.

But oil production increased and squashed natural gas like a bug. I do not hear anything about natural gas anymore.

I just checked the price of on a barrel of oil. It us $54.50 approx. I think compressed natural gas will make a comeback when a barrel of oil sells for $90 to $100.