BMW approved 0W-20 for N20 turbo four cyl.

[CATERHAM]

Originally Posted By: SilverC6
I thought the 1977 Civic was Honda's most glorious, shining moment.

Many could not see them for the achievement that they were due to the oil smoke from their tailpipes.

At the time BMW was just tinkering around with their 2002tii model.

But we all know how collectors covet those early Civics.

And covet the early Bimmers like the 2002 tii if not much more so.

 

[SilverC6]

There was a bit of satire in my discussion on the early Civic.

But I can certainly remember my insurance agent's BMW 2002tii in 1975.

It was green, almost a British racing green but a bit darker, over tan leather, with a set of Minilites shod with Pirelli CN36s.

I bought my first issue of Road and Track that same week.

I'd write a check for $20,000 for that little BMW right now.

 

[A_Harman]

Originally Posted By: Blue_Angel
KEY points here:

- A 2.6L V6 displaces 2600cc per every two crankshaft revolutions, just like a two rotor Wankel.

That video proves nothing, and if you pay attention the rotary in that car is a THREE rotor... or equivalent to a 3.9L nine cylinder engine.

Its Brake Specific Fuel Consumption (BSFC) isn't much different than other car engines, which means it's burning roughly the same amount of fuel and consuming about the same amount of air per horsepower generated as other engines.


Almost everything you said up there is true, except:

A 2600cc piston engine displaces 10400 cc's of volume in two crankshaft revolutions. But because of the valves controlling air flow, it will only have the opportunity to displace 2600cc of whatever fluid is residing in the intake manifold when the intake valves open.

A three-rotor Mazda rotary makes 3 power strokes per crankshaft revolution, so it would be equivalent to a 3.9L six-cylinder engine.

Judging by the poor fuel economy rating of the RX8, I would say that the Wankel's BSFC is not about the same as 4-stroke piston engines.

And here is an interesting read about Wankel engines:
http://www.personal.utulsa.edu/~kenneth-weston/chapter7.pdf

 

[Garak]

Originally Posted By: SilverC6
There was a bit of satire in my discussion on the early Civic.

I got it.

My neighbour had one of them. I wonder if there's one left on the planet that isn't a bunch of powdered rust surrounded by a cloud of blue smoke.

 

[jrustles]

Originally Posted By: SilverC6
I thought the 1977 Civic was Honda's most glorious, shining moment.

Many could not see them for the achievement that they were due to the oil smoke from their tailpipes.

At the time BMW was just tinkering around with their 2002tii model.

But we all know how collectors covet those early Civics.

haha! Check this out, I actually wanted that era of Civic to do a VTEC engine swap in, back in high school. We had an 81 wagon growing up, so that's probably why

Originally Posted By: Blue_Angel
Once again, a piston engine is also conducting all of its strokes simultaneously, exactly like a rotary. It just uses more parts to do exactly the same thing.


Correct, including three times the intake/exhaust port area, three times the runner paths, three times the combustion space. Forgot to carry the two

Again, one cannot just sum-up the individual, stroke-dedicated rotor chambers as equivalent to an individual cylinder where all strokes occur. To discuss displacement in this regard can make logical sense, but is arbitrary to this discussion.

We are discussing displacement for VE purposes as in 'the ability to fill a displaced volume with charge', not the ability to work a total sum of displaced volume in all strokes, only the intake stroke matters in this discussion.

Multi-Piston engines conduct their strokes 'simultaneously', sure, in dedicated cylinders using their own valves, ports and runners or in other words, three-times it's flowing valve, port and runner area vs the Wankel rotor. The Wankel truly conducts strokes simultaneously for one rotor, port set, combustion chamber and manifold runner, thus each dedicated stroke chamber repeats it's OWN respective stroke consecutively.

Piston cylinder does all four strokes in place, in one cylinder, sequentially. Wankel does all four strokes in 4 separate chambers (incl. combustion chamber) simultaneously and the charge itself is moved from one chamber to the other between each stroke. TOTALLY DIFFERENT. Not just the way power is transmitted to the "crank" output shaft.

Since there is only one induction set per rotor (3 virtual cylinders), we discuss now how effectively that induction set can fill it's demanded displacement (654cc @ 270 degrees output rotation, not 180).

To further distinguish piston and Wankel engines from each other, we know that each Wankel stroke completes in 270 degrees while the reciprocating piston 4 stroke completes in 180. The Wankel requires 90 more degrees output shaft rotation to "displace" 654cc, so @ 180 for 180, the Wankel displaces 436cc (or some other derivative accounting for the non linear rate of displacement) per rotor chamber, not even the full 654

The only way one could as easily and comprehensively as you've tried to, equate one Wankel rotor to a three cylinder reciprocating piston motor for VE purposes is if that three cylinder engine was capable of running all three cylinders with only oneintake/exhaust portset and one combustion chamber, otherwise the comparison is always fundamentally flawed. The simple fact that only one third of the gas-flowing and combustion engine anatomy can be worked three times as hard actually makes a great case for Wankel VE. a-whoops.

 

[HTSS_TR]

Originally Posted By: OVERKILL
So I guess when BMW powered the McLaren F1 they had to learn their engineering from Honda? It was 102HP/L, that's 12HP/L more than the NSX, in 1992. And of course the LM version (street version of the car used in LeMans) had 680HP, putting it at a healthy 112HP/L. In 1995.

So I guess it was Honda who was having a HP/L war with BMW that BMW didn't know about then eh? I mean Honda didn't best BMW's power density in the McLaren F1 until several years later

In 1964 Ford released an engine (we had one in a Thunderbird) called the 427 SOHC. Nicknamed the "Cammer", in dual quad configuration the engine made 657HP (94HP/L). Gee, that's also more than the NSX!

I'm talking about engines for mass product every day cars that normal people can buy at normal car dealers, not race engines.

You should compare apple with apple, not apple with orange. Mass product engine sold in public with reliability requirement and complying with emission law compares with one-off race engine without emission controlled is not the valid comparison. Same for non-emission era engine with heavily emission controlled engine.

Do you remember the mid '70 till mid '80 ? When emission control became law the engine power dropped like a rock, some 5 liter engines made less than 200 HP ? Some was as low as about 30 HP per liter.

Show me any normally aspirate piston engine in any standard BMW car that people can buy at any BMW dealer in North America that makes more than 90 HP per liter before 1995. There was none.

Tell me why 1991 Porsche 911 with 3.6L only make 247 HP, if they can design their engine to make only 85 HP per liter then it should generate 306 HP, 59 HP more than Porsche could do in 1991. With 90 HP per liter that Porsche 3.6 liter engine should generate 324 HP, a whopping 77 HP more than it could in 1991. Do you what was that 247 HP from 3.6 liter represent ? a paltry 69 HP per liter and this was from one of the best engine producers in Germany.

A full 5 years later that same 3.6 liter engine in 1996 911 makes 282 HP for 78 HP per liter. It took Porsche another 5 years to develop a decent engine, 2000 911 with 3.4 liter engine makes 300 HP for 88 HP per liter.

I said "Pioneer is difficult, copy cat is easy". But I was wrong, it isn't as easy as it should be. Porsche needs 10 years to catch up and some more years to surpass the benchmark Honda set in 1991.

Foot note: Porsche and other German makers need special/qualify oil to keep their engines in good working condition, while NSX and S2000 engines only need API spec'ed dino oil.

 

[KrisZ]

Originally Posted By: mcrn
I bet last week.....nobody went from my living room to my bathroom faster than me.


I know, the twisted logic used by some is borderline juvenile.

What started as HP/L bragging and was shot down, quickly evolved into HP/L bragging but the engine cannot have more than 4 cylinders, then it had to be 4 cylinders and 2L or less, then it cannot be a wankel because despite officially published and accepted numbers, a methodology used in racing (where the original argument was for production engines) was used to argue against it. Now the engine has to be made in 1999 as well.

Gee, in essence, a manufacturer would have to make exactly the same engine in exactly the same time frame as Honda did, use exactly the same oil in order to satisfy the fan boys. And I bet, that even then they would not be satisfied and claim that the said manufacturer simply copied Honda

The whole "pioneers and copycat" nonsense.

Yeah, Honda is such a pioneer that even to this day the valves have to be adjusted, their ignition system for the longest time matched the ones from 70's, they adopt DI for mass production a decade after GM, they knock like crazy on cold starts, but that’s a feature on a Honda and the list can go on

 

[Blue_Angel]

Originally Posted By: A_Harman
A 2600cc piston engine displaces 10400 cc's of volume in two crankshaft revolutions. But because of the valves controlling air flow, it will only have the opportunity to displace 2600cc of whatever fluid is residing in the intake manifold when the intake valves open.


Correct. I was assuming the displacement during only the intake stroke.

Originally Posted By: A_Harman
A three-rotor Mazda rotary makes 3 power strokes per crankshaft revolution, so it would be equivalent to a 3.9L six-cylinder engine.


Correct. A two rotor would be equivalent to a 2.6L four cylinder. I was off by one and made the mistake early on.

Each rotor is doing the work of two cylinders in a piston engine.

Originally Posted By: A_Harman
Judging by the poor fuel economy rating of the RX8, I would say that the Wankel's BSFC is not about the same as 4-stroke piston engines.


I just did a quick Google on BSFC for rotaries and came up with 0.60 at WOT. This is very rich by naturally aspirated engine standards, and would be more in line with a turbo or super charged piston engine.

I said "about" the same to make the point that the Renesis rotary (the most advanced design to date) was not doing anything exceptional WRT power output or efficiency. You are correct, the rotary is not a very efficient engine at all unless you are considering power/weight/size of the engine. It is relatively compact for its power output.

 

[Blue_Angel]

Originally Posted By: jrustles
The only way one could as easily and comprehensively as you've tried to, equate one Wankel rotor to a three cylinder reciprocating piston motor for VE purposes is if that three cylinder engine was capable of running all three cylinders with only oneintake/exhaust portset and one combustion chamber, otherwise the comparison is always fundamentally flawed.


Clarified above (thanks A Harman) I should have been equating a single rotor with two cylinders, not three.

The Renesis actually uses three intake ports per rotor, one more than the equivalent two cylinder engine.

Originally Posted By: jrustles
The simple fact that only one third of the gas-flowing and combustion engine anatomy can be worked three times as hard actually makes a great case for Wankel VE. a-whoops.


The efficiency and emissions of a Wankel rotary are sub-par compared to a piston engine. The Wankel has a few things going for it, but when judged on the most important criteria for a passenger car engine, it falls short.

On the topic of specific output, the Renesis was originally rated by Mazda at 247hp. After its release it was re-rated to 238hp. Chassis dyno tests indicate that it is probably making about 215hp. A 2.6L engine making 215hp is 83 hp/L.

 

[A_Harman]

Yes, I have a warm spot in my heart for Wankels. They pack a lot of displacement into a small engine volume. But their inherently poor combustion due to the high surface to volume ratio of the combustion chamber, and the practical limitation on compression ratio in a structurally sound design makes them less efficient than 4-stroke piston engines.

 

[mcrn]

Originally Posted By: HTSS_TR
Originally Posted By: OVERKILL
So I guess when BMW powered the McLaren F1 they had to learn their engineering from Honda? It was 102HP/L, that's 12HP/L more than the NSX, in 1992. And of course the LM version (street version of the car used in LeMans) had 680HP, putting it at a healthy 112HP/L. In 1995.

So I guess it was Honda who was having a HP/L war with BMW that BMW didn't know about then eh? I mean Honda didn't best BMW's power density in the McLaren F1 until several years later

In 1964 Ford released an engine (we had one in a Thunderbird) called the 427 SOHC. Nicknamed the "Cammer", in dual quad configuration the engine made 657HP (94HP/L). Gee, that's also more than the NSX!

I'm talking about engines for mass product every day cars that normal people can buy at normal car dealers, not race engines.

You should compare apple with apple, not apple with orange. Mass product engine sold in public with reliability requirement and complying with emission law compares with one-off race engine without emission controlled is not the valid comparison. Same for non-emission era engine with heavily emission controlled engine.

Do you remember the mid '70 till mid '80 ? When emission control became law the engine power dropped like a rock, some 5 liter engines made less than 200 HP ? Some was as low as about 30 HP per liter.

Show me any normally aspirate piston engine in any standard BMW car that people can buy at any BMW dealer in North America that makes more than 90 HP per liter before 1995. There was none.

Tell me why 1991 Porsche 911 with 3.6L only make 247 HP, if they can design their engine to make only 85 HP per liter then it should generate 306 HP, 59 HP more than Porsche could do in 1991. With 90 HP per liter that Porsche 3.6 liter engine should generate 324 HP, a whopping 77 HP more than it could in 1991. Do you what was that 247 HP from 3.6 liter represent ? a paltry 69 HP per liter and this was from one of the best engine producers in Germany.

A full 5 years later that same 3.6 liter engine in 1996 911 makes 282 HP for 78 HP per liter. It took Porsche another 5 years to develop a decent engine, 2000 911 with 3.4 liter engine makes 300 HP for 88 HP per liter.

I said "Pioneer is difficult, copy cat is easy". But I was wrong, it isn't as easy as it should be. Porsche needs 10 years to catch up and some more years to surpass the benchmark Honda set in 1991.

Foot note: Porsche and other German makers need special/qualify oil to keep their engines in good working condition, while NSX and S2000 engines only need API spec'ed dino oil.



Can you at least see that there is a difference between having the ability to and desire to do it?

 

[OVERKILL]

Originally Posted By: HTSS_TR

I'm talking about engines for mass product every day cars that normal people can buy at normal car dealers, not race engines.

You should compare apple with apple, not apple with orange. Mass product engine sold in public with reliability requirement and complying with emission law compares with one-off race engine without emission controlled is not the valid comparison. Same for non-emission era engine with heavily emission controlled engine.


So I am not allowed to bring the McLaren F1 into the comparison because Joe blow couldn't walk into a local car dealer and buy one?

That's funny, given your statement earlier:

Originally Posted By: HTSS_TR
No company could do that, not Porsche, not Ferrari, not Lamborghini, not MB, not BMW and not Audi. All of them would think that it is impossible task.


So when YOU are the one trumping up unsubstantiatable statements like the above, it is fine to mention Ferrari and Lamborghini, but when I bring some actual facts to the table all of a sudden exotics are off-limits? Convenient

And BTW, the McLaren was not a "race car" and didn't have a "race engine", only the LM version of the car featured the race-style setup and powerplant. The car was also FULLY emissions compliant (even the LM version), no different than the NSX.

Originally Posted By: Wikipedia
The McLaren F1 is a sports car designed and manufactured by McLaren Automotive. Originally a concept conceived by Gordon Murray, he convinced Ron Dennis to back the project and engaged Peter Stevens to design the exterior and interior of the car. On 31 March 1998, it set the record for the world's fastest production car, reaching 231 mph (372 km/h) with the rev limiter enabled, and 243 mph (391 km/h) with the rev limiter removed.

The car features numerous proprietary designs and technologies; it is lighter and has a more streamlined structure than many modern sports cars, despite having one seat more than most similar sports cars, with the driver's seat located in the centre (and slightly forward) of two passengers' seating positions, providing driver visibility superior to that of a conventional seating layout. It features a powerful engine and is somewhat track oriented, but not to the degree that it compromises everyday usability and comfort. It was conceived as an exercise in creating what its designers hoped would be considered the ultimate road car. Despite not having been designed as a track machine, a modified race car edition of the vehicle won several races, including the 24 Hours of Le Mans in 1995, where it faced purpose-built prototype race cars. Production began in 1992 and ended in 1998. In all, 106 cars were manufactured, with some variations in the design.


BMW made a production engine with more than 100HP/L that was fitted to a road car before Honda did. It doesn't matter if Joe Blow could afford the car or not. You claimed that no company COULD do it. And that's a massive steaming pile of fecal matter. BMW DID do it. They did it BEFORE HONDA, and if that causes you discomfort perhaps you need to figure out why.

 

[IndyIan]

Originally Posted By: mcrn

Can you at least see that there is a difference between having the ability to and desire to do it?

I think Honda did have some sort of technical advantage back then, they were making the best NA engine in F1 for many years in a row afterall, and had a program to take the R&D from racing to be used in their road cars. Also keep in mind, Japan did(does?) have increasing car taxes based on displacement, so HP/L was a real selling point too. So atleast the Japanese car makers had real incentive to match or surpass Honda.

While the S2000 motor is impressive, I think being able to produce the B16A2 with 100hp/L for Honda Civic money in the late 90's is quite an achievement too. In countries without displacement taxes it may not be worth spending the money to emulate, but there is quite a bit of the world market where it is significant.

 

[OVERKILL]

Originally Posted By: IndyIan
Also keep in mind, Japan did(does?) have increasing car taxes based on displacement, so HP/L was a real selling point too. So atleast the Japanese car makers had real incentive to match or surpass Honda.

While the S2000 motor is impressive, I think being able to produce the B16A2 with 100hp/L for Honda Civic money in the late 90's is quite an achievement too. In countries without displacement taxes it may not be worth spending the money to emulate, but there is quite a bit of the world market where it is significant.


You've touched on another key point here Ian and that was that in Japan, HP/L was a selling point. In Germany, it wasn't. Honda had a legitimate reason to spend the money and produce the engines in question, none of the German marques did.

When BMW was given an incentive to meet a power/displacement target (McLaren F1), they did. They actually bested the requested power output by 14%. But they would never go to the effort to develop a small N/A engine with a similar power density for their own vehicles because:

A) That's not what the target demographic wants
B) That wouldn't work well in other BMW cars. Even the S-prefix engines are derivatives of other production engines used in regular BMW vehicles.

So when downsizing on displacement they moved to forced induction to keep that target demographic happy with copious amounts of torque and retain the driveability characteristics that BMW owners expect.

 

[Blue_Angel]

Originally Posted By: A_Harman
Yes, I have a warm spot in my heart for Wankels. They pack a lot of displacement into a small engine volume. But their inherently poor combustion due to the high surface to volume ratio of the combustion chamber, and the practical limitation on compression ratio in a structurally sound design makes them less efficient than 4-stroke piston engines.


Cheers! I've always liked Wankels, if for no other reason than they're very different. I took great interest in the Renesis when it came out in the RX8, but was disapointed with the final product. The technical advances introduced showed great promise leading up to the product launch... there was a lot of buzz around that engine.

The RX8 is a cool looking car and everything I've read suggests it handles extremely well. Unfortunately its achillies heel was a lack of power, and Mazda never did follow up with a turbocharged version.

 

[SilverC6]

My son enjoys his RX8 and looks forward to future development by Mazda on that engine platform.

Mazda put a lot of engineering in the RX8.

You get a lot of driver satisfaction when you have that little rotary on 8 grand and you point it into a sweeping curve.

Of course I tell him I'm just taking it over to the car wash for a quick bath.

It does seem like its most recent PU fill.

 

[DBMaster]

I have two friends who purchased RX8's and subsequently didn't keep them long. One was an auto and the other manual. They were plagued with reliability issues and the 18 mpg overall fuel economy was pretty dismal for a car of that size.

Still, a very fun drive.

 

[Shannow]

Originally Posted By: OVERKILL
You've touched on another key point here Ian and that was that in Japan, HP/L was a selling point. In Germany, it wasn't. Honda had a legitimate reason to spend the money and produce the engines in question, none of the German marques did.

When BMW was given an incentive to meet a power/displacement target (McLaren F1), they did. They actually bested the requested power output by 14%. But they would never go to the effort to develop a small N/A engine with a similar power density for their own vehicles because:

A) That's not what the target demographic wants
B) That wouldn't work well in other BMW cars. Even the S-prefix engines are derivatives of other production engines used in regular BMW vehicles.

So when downsizing on displacement they moved to forced induction to keep that target demographic happy with copious amounts of torque and retain the driveability characteristics that BMW owners expect.


Oz car magazines had the results of that. Honda City (no bigger than an average shoebox) turbo, that would spin the fronts through to third (we got the Diahatsu Charade Turbo, and it had a quite large fan base)...Suzuki R13B is allegedly another engine the was thus manufactured, although I'm not quite sure which millisecond it was spawned in in relation to the Honda.

 

[jrustles]

Originally Posted By: Blue_Angel


Clarified above (thanks A Harman) I should have been equating a single rotor with two cylinders, not three.


That's a proportional distinction only based on 180 degrees of shaft rotation, which is an un-whole number of cycles in a Wankel. If by "cylinders" you mean 2 (or 1.66666?) combustion events in 360 degrees shaft rotation
Quote:

The Renesis actually uses three intake ports per rotor, one more than the equivalent two cylinder engine.


Just no.
On a multi-side port engine which is more emissions oriented, that would be 2 or 4 intake ports (depending on output), likened to a set of intake valves. On a peri-port ie non-MSP engine there is only one intake port, unless it's a custom built hybrid of peri- and side ports, common in racing.

Nevertheless, the ports in one intake chamber are in phase to the intake event of one rotor, the same way additional camshaft lift doesn't change the phase of each intake valve.

Quote:

The efficiency and emissions of a Wankel rotary are sub-par compared to a piston engine. The Wankel has a few things going for it, but when judged on the most important criteria for a passenger car engine, it falls short.


In what regard? Tooling a 4 door sedan around at part throttle crawling in rush hour traffic in LA? Absolutely. Driving to the corner store, you betcha!

But racing? Haha. No. The wankel has superior reliability in racing and other continuous high output situations (aircraft, watercraft) and even can be more fuel efficient than the racing piston engines! And with no catastrophic failure mode on a Wankel, some people favour them for aircraft where a serious failure will still allow a limp home.

To both points (particularly fuel economy), the 4-rotor 787B race car did consume the least amount of fuel during the 24HLM. That alone is no small thing, more power on less fuel is THE holy grail of rationed fuel racing.

This car


Quote:

On the topic of specific output, the Renesis was originally rated by Mazda at 247hp. After its release it was re-rated to 238hp.


Indeed, the North American emissions components and tuning took a penalty on the original output. Fairly easily recoverable to any owner

Quote:

A 2.6L engine making 215hp is 83 hp/L.


To be fair, that's a logical conclusion two-times removed from the last known fact

Wankels are fantastic in constant output modes. So long as they stay lubed, cooled and sans detonation, they'll keep going. Small, single rotor units are currently being developed for compact, virtually inaudible ICE range extenders for future EVs. 30KW in a briefcase; it's appealing

 

[Cujet]

Any of you in the South Florida area are welcome to come for a ride in my S2000 Turbo @ 19.5Lbs boost. Plenty of tire spinning torque!

In fact, the turbo setup does a great job of adding satisfying torque to an otherwise gutless "feeling" car. With the addition of a simple turbo setup, it goes from being "nothing spectacular" to "a whole lot of fun".