My post was in response to the "Balance" issue. Due to V engines have exessive shear loads on the crank shaft they use counterbalances to compensate. I, Boxer, Rotary, and Radial engines do not have the same high shear loads inherant in their design. They each have their own design issues. All things being equal Vs make more torque, and breath better other designs, but can't rev as high due to the loads on the crankshaft.

 

Also, the best FI applications have been I-6 or Flat 6 designs. The Skyline GTR (2.6 L I-6) and the Supra (I-6) are notorious for their strong internals. I've never seen a V6 FI that is known for its ability to withstand high levels of boost (probably due to its inherent lack of stability).

 

F1 is all about speed, the higher the Revs the higher your top speed will be. Therefore Flat or I engines work best for that application, but you will not see a Boxer engine on a Top Fuel Dragster either. If your interested in Boost try an 11:1 supercharger.

 

Well, if you include the RX8's rotary engine (an entirely different beast, of course), you're getting 238hp from 1.3L of displacement, or 183hp/L. I think that pretty much steals the record for naturally-aspirated engines.

 

But it sucks gas...

The Corvette's LS6 produced 405 HP while getting 19city/28highway per the EPA.

And my LS1 Camaro gets virtually the same mileage as my new Accord V6 while producing ~ 1/2 again the drive wheel power.

 

http://www.ukcar.com/features/tech/E...smooth%206.htm

 

Speed and "revs" don't necessarily go hand in hand.

VELOCITY = POWER/FORCE

(horse)POWER= TORQUE*RPM/5252

Those formulas don't favor Torque or RPM (revs); the result (horsepower) is all that matters.

 

V engines feel smoother externaly because you have your mass moving in 4 different directions, cancelling much of the "vibrations" felt external to the engine. I engines mass moves in only 2 directions, all parallel in so the stresses on the crank are along one plane. Less of this vibration is absorbed internally and so you feel more. Flat engines mass moves directly opposed to the opposite bank, therefore nearly all of the stresses are cancelled internally. All thinks being equal a V engine "feels" smoother than an I and a flat smoother still. That being said, a better balanced engine is a smoother engine, and inherant configuration characteristics can be overcome through superior design and execution.

 

You're correct.

Check out this link:

http://www.ukcar.com/features/tech/E...smooth%206.htm

 

http://www.ukcar.com/features/tech/E...smooth%206.htm

 

That statement is no basis in fact.

 

http://www.ukcar.com/features/tech/E...smooth%206.htm

 

The transmision is mounted behind the engine an driven by a chain off the crank shaft...the transmission in the volvo is the same used in the Cadillac STS (a pre Ford buy out move, obviously)

 

E-mail Ron Dennis (CEO/F1 team manager of McLaren) and let him know that. They're running 72 degree angles in their V10 (common):

http://www.geocities.com/formula-fun/mclaren_car.html

In fact, show me ONE modern F1 engine that's running anything close to a "20 degree" angle:

http://www.f1db.com/car/part/engine/...on/season/2003

 

quote:
--------------------------------------------------------------------------------
Originally posted by flanagan
Modern F1 cars use a narrow angle V10 between 20 and 60 degrees in most cases.
--------------------------------------------------------------------------------




Ferrari (dominant for the past several seasons) runs a 90 degree cylinder angle on their V10:

http://www.formula1racing.com/NewFer...MM09142002.htm

 

Name ONE "flat or I engine" that is currently being used in Formula 1.

The most common configuration is a 72 degree V10.

Ferrari (dominant for the past several season) uses a 90 degree V10....

McLaren:
http://www.geocities.com/formula-fun/mclaren_car.html

Ferrari:
http://www.formula1racing.com/NewFer...MM09142002.htm

The reason you don't see Boxster engines in drag racing is attributable to the fact that it's still primarily an American sport and that most of them are still running engines that are (very loosely) based on old production Amercian engines (eg Keith Black V8 hemi, modeled after Chrysler's 426 Hemi).

No-one to my knowledge has ever produced large displacement flat engines in any significant quantity. Since power ultimately comes down to the size of the air pump being uses (the engine), no-one ever bothered with (small displacement) flat engines.

 

Yep. I'm making no statement about fuel efficiency. Just saying that the RX8's power-to-displacement ratio is better than the S2K's and probably any other N/A production vehicle out there.

 

And I agree with you on that.

But I also argue that on the street (where their is no displacement-limiting sanctioning body is the case in most classes of racing), power, torque and MPG are what's "visible" to the driver.

It's true that my LS1 requires 5.7 liters to produce ~ 350 SAE NET HP. But so what? It was EPA rated @ 19 city/28 highway and makes big power throughout the rev range.

So while HP/liter might be interesting from a theoretical point of view, it's largely moot on the street.

I think HP/pound of engine mass is more meaningful unit of measure.

Again, let's look @ the LS6 (Z06 engine): 405 SAE NET HP from ~ 485 pounds worth of engine. I bet that's not far off from what Mazda is getting in from their RX8 engine.

 

IMHO, I think BMW gets more torque by using a longer stroke than Honda uses. I think that, for the same displacement, a longer stroke will result in more torque for each turn of the crank.

Also IMHO, a 60 degree V6 is smoother than a 90 degree V6 because 6 x 60 = 360 (360 degrees is a full circle). I believe V8's are smoother with a 90 degree bank (8 x 90 = 720, which is 2 x 360, or two fulll circles). Following that logic, 72 degrees should be a smooth angle for a V10.

 

Yep, you're right.

Remember though, that a longer stroke (via a longer crank) increases piston speed (measured in feet/sec), which reduces the limit on RPM.

Piston (and rod) speed is nearly always the ultimate limiting factor in most racing engine applications.

 

The displacement of a rotary is not the same as the displacement of a normal engine. I remember reading that there are twice as many combustions per revolution so you have to double the displacement so the 1.3 liter RX-8 is more like a 2.6 liter engine. Is this right?

 

That's a good point:

http://auto.howstuffworks.com/rotary-engine8.htm

"The neat thing about the rotary engine is that each of the three faces of the rotor is always working on one part of the cycle -- in one complete revolution of the rotor, there will be three combustion strokes. But remember, the output shaft spins three times for every complete revolution of the rotor, which means that there is one combustion stroke for each revolution of the output shaft."

 

harddrivin1le,

Thank you for nitpicking a single piece of information out of my 2 long paragraph post. So I was misinformed, shoot me. Please stop antagonizing. There is no need for three consecutive posts to prove someone wrong.

And now back to your regular scheduled programming.

To sum up, I-6 has been around for close to a century, V-6 is newer technology. BMW uses an I6, Honda uses a V6. I-6 is balanced, 60º V6 is balanced. 120º V6 is balanced, Boxer6 is balanced. I6 only works well with RWD or RWD based AWD, V6 works with all drivetrain layouts. Longer stroke gets more torque over a with lower potential rev limit, shorter stroke gets less torque with higher potential rev limit. A V7 is right out. A W16 has been delayed over a year from its original release date. Modern F1 engines range in angle from 72º to 110º and rev up to 18k and I want one in my car. I think that about covers it.

 

...the reason everyone is switching to V6 is that they are shorter and therefore offer more crash space. Additionally because they are more adapted to modular engine plans. For example, GM used to have a 4.3L V6 which was simply a 5.7L with two cylinders taken off.

I prefer inline 6's because they are much smoother than a V6, even in a Lexus or Mercedes. It is unfortunate that BMW and Mercedes (and Lexus for that matter) are ditching I6's because they have a special sound (like a turbine) and smoothness not found in a V6 no matter how well made they are.

 

Well, if you also include the Honda CBR600RR's 599cc inline-4 engine (yet another different beast, obviously), you are getting 117hp from merely 0.6L. That's a whopping 195hp/L. This one should really be the record for naturally-aspirated engines.

 

That's a motorcycle engine...

Most high performance motorcycle engines have MUCH smaller cylinder bores (and combustion chambers) than do car engines, and this speeds combustion by shortening flame travel. That allows them to run relatively high compression ratios, thereby producing more power.

And there are MANY other differences, not the least of which is their VASTLY shorter lifespan (as measured in miles driven prior to mandatory complete rebuild.)

Today's top Formula 1 racing engines (V10s, naturally aspirated) produce in excess of 900 HP from 3.0 liters.

That's 300 HP/liter, which makes that CBR engine look SICK in comparison.

Of course, that's not an "apples to apples" comparison. Then again, neither is yours.

 

A rotary engine works on a different priciple. At rest, the Renesis engine is 1.3 liters. In motion, it is an effective 2.6 liters. Thus, it has just under 100hp/l.

And for once I competely agree with harddrivin

 

My mistake. I forgot about the F1 3.0L V10 engines. I guess nothing can beat that one.

When someone threw in the rotary engine, it was already not an "apples to apples" comparison. It had become a Wankel engines vs piston engines comparison. So while everyone is having fun, I might as well throw in a motorcycle engine into the comparison.

 

I honestly believe that horsepower per pound of engine weight is a better indicator on the street. Some refer to that as power density (HP/POUND of engine weight).

Take the LS6 Corvette engine, for example: 405 HP (and 400 LB-FT of torque) from ~ 485 pounds of engine weight. Who cares if it takes 5.7 liters to do it? There's no racing sanctioning body dictating such things on the street. And it still gets 19 city/28 highway per the EPA.

So it makes big power, it's relatively light and relatively economical.

 

my grandpa has a Porsche 911 Twin Turbo (flat-6 cylinder TT) and its really really smooth. When you rev it it sounds like an airplane turbine but its smooth as butter.

 

if u don't notice, the mazda's rotary engine is rated as 2.6L comparing with an ordinary engine.

therefore it is not 1.83, but still an impressive 91hp/L

 

A few people have now said this because of the way the engine operates. Didn't know that, actually. Quite interesting for sure. Okay, so on production engines, back to the S2K's original 2.0L four banger, I guess!

 

talking about smooth

my buddy's 01 maxima SE with VQ30DE-K engine is one of the smoothest V6 i have even been, it's much smoother than our J32 engine and the VQ does SCREAM!!!

my friend's BMW 325i is soooo smooth too, but not as quiet as the lexus thou

 

yea, and honda is making the mark that can go more than 18000rpm!!!!

GO VTEC GO

 

Actually, Honda engines are NOT presently the highest revving in F1.

And I doubt they even use VTEC in their F1 application. (Maybe they do, but you'd have to show me that.) Those engines essentially "idle" @ 6,000 RPM

 

Actually, Honda engines are NOT presently the highest revving in F1.

They're not the most powerful, either.

And I doubt they even use VTEC in their F1 application. (Maybe they do, but you'd have to show me that.) Those engines essentially "idle" @ 6,000 RPM

 

The 3.0L VQ is much more smooth than the 3.5L. I say it was a fair trade off....smooth vs more power.

 

i know the BMW can rev up to 18000rpm too, but not too many can do that

Ferrari has at least 50 more hp than honda for sure, and so does mercedes...

i am not sure about now, but they used to have VTEC in F1 in the late 80s didn't they?

the VTEC was orginally came from F1

 

yes
i have driven the 3.5 altima, it's so rough and no where near smooth...not even as smooth as the new TL

the 3.0 is the smoothest of all

 

Towards the end of the 2003 F1 season, BMW's engine had been able to rev up to 19200rpm in qualify trim.
http://www.motorsport.com/news/artic...D=137713&FS=F1

However, the exact horsepower output s of the different engines were always the best guarded secrets for all the corresponding engine manufacturers.

But things are changing this season because of new engine rules. The max rpm has been reduced for all engine makes in return for reliabilty and longivity.

After the first two races, Ferrari is still the best package, and BAR-Honda has overtaken McLaren-Mecedeces. During last weekend's F1 race in Malaysia, Button's BAR-Honda easily pulled away from Raikkonen's McLaren-Mecedeces in the straights.