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Z06 ME To Have This?

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  • John
    started a topic Z06 ME To Have This?

    Z06 ME To Have This?

    We keep hearing, and those of you with great hearing have supported that the C8.R testing at night at Sebring, has a motor with a flat plane crank (FPC). As reading Ford forums has shown, there have been more than a few complaints, alleged massive warranty issues due to the flat plane crank Ford has in some of their top powered Mustangs, grenading themselves from NVH consequences of the FPC. Whether that is fact or not, it is fact that a flat plane crank produces more NVH issues than a typical crank. Those issues have to be dealt with, though here to fore use of counterbalancing weights has created secondary issues, especially if used in a sports car.

    Although the exhaust music from a FPC is fantastic!

    For those who never listened to the C8.R test at Sebring (or can not get enough of it), here is that thread, with the video inside of it.


    What is interesting is the increasing rumors of late that the Z06 version of the Corvette mid engine will have a flat plane crank. If so, the vibrations (of course the harshness too) has to be also dampened. Which leads to the following potential use of engine mount solenoids in the Z06 C8.

    GM is using engine mount solenoids in its soon upcoming 3.0L new diesel, so might we be seeing a future component of the C8 Z06 first used in the GM diesel (that motor, BTW, coming as an option in the 2019 Silverado and Sierra 1500)?

    Originally posted by gmauthority
    GM 3.0L Duramax To Reduce Vibrations Via Engine Mount SolenoidsSponsored Links

    Over the past few weeks, GM Authority has exclusively brought you the very first images of the upcoming GM 3.0L Duramax LM2 turbo-diesel engine for the 2019 Silverado 1500 and 2019 Sierra 1500. We also told you that the new diesel mill will use an advanced cooling system and that, despite rumors to the contrary, it is on track to launch in the first half of 2019. Today, we have more new information on the forthcoming motor related to how it will be mounted.

    According to insiders familiar with the matter, the Silverado and Sierra light duty trucks will use an engine mount solenoid valve system to cradle the new 3.0L Duramax. The variable viscosity technology is essentially an adaptive shock absorber that actively controls engine vibration, reducing a significant amount of vibration from the engine and contributing to lower NVH levels.

    Various German and Japanese luxury automakers have been using advanced solenoid valves for mounting engines for the exact purpose of reducing vibration and harshness levels. The practice originally started out with diesel engines in Europe. For its part, GM currently uses engine mount solenoids for its all-new, turbo-charged 2.7L L3B gasoline motor in the 2019 Silverado and Sierra.
    Audi Engine Mount Solenoid Valve
    Febi Bilstein engine solenoid valve for Audi vehicles

    Besides pre-announcing the 3.0L Duramax when unveiling the 2019 Silverado and Sierra light duty trucks at the end of 2018/beginning of 2019, GM has remained very tight-lipped about the diesel engine. Leaks from late last year have pegged the engine as making 282 horsepower and 450 pound-feet of torque in the 2019 Silverado 1500 and 2019 Sierra 1500. Today’s information about the motor’s advanced mounting system gives us a bit more intel that we did not have before.

    The new 3.0L Duramax is scheduled to become available in the first half of the 2019 calendar year. Stay tuned to GM Authority for more GM LM2 engine news as well as ongoing GM news coverage.

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    Last edited by John; 03-12-2019, 02:20 PM.

  • conmax
    i doubt that chevy will risk a FPC in the C8. the engineering challenges appear to be significant, especially for larger displacements. since the performance models will be charged of some sort, it is not necessary to rev into the 8000 rpm range. most boosted cars perform best when shifting around the peak torque range. at Spring Mountain, chevy recommended shifting the Z06 at 5500. this was to keep engine temps down, yet the instructors claimed it was just as fast short shifting.

    if the C8 were a smaller, lighter car, a small displacement FPC engine in the 4L range might make sense, but i don't think they are planning a Lotus size car for the masses.

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  • meyerweb
    The C7.R uses a 5.5 liter "LT5" engine. Related to, but not the same as the 6.2 Liter LT1. Just as a smaller displacement flat plane crank engine could be related to, but not the same as, the LT2 engine expected for the C8. There has been some speculation Chevy could even race a version of the ME with a twin-turbo V6, similar to what's in the Ford GT. I find that unlikely, but the rules would allow it.

    As for having to have the C8 on the market first, exceptions to that rule are allowed, and have been granted in the past.

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  • SheepDog
    Originally posted by meyerweb View Post

    The current C7.R racecars don't use the same engine as the production car. No reason to think the C8.R will, either.

    The C7-R seems to use "essentially" the same engine, they had to reduce the horse power output. Same Badic Engine however :

    1. Therefore , whatever is being tested in the C8R will end up in the C8 production car.
    2. That thing sounds like a FPC in the night test C8R video.
    3. DonSherman Says "flat Plane Crank.
    Three pieces of evidence.

    Furthermore, the production car that is the basis of the C*R race car must be released and marketed before the race car may be raced with the "whatever " engine.. Therefore the flat plane crank production ar will be released "sooner than later", if they are to race it and sold before before the race it.. It being whatever engine is in the C8R.

    Scott KoleckiSCOTT KOLECKI JANUARY 4, 2018
    Pratt & Miller

    The Corvette C7.R was conceived, designed and constructed by Pratt & Miller Engineering based on the C7 Corvette Stingray developed by Chevrolet.

    Based in New Hudson, Michigan, with an additional engineering division located in North Carolina, Pratt & Miller partnered with Chevrolet to develop the Corvette Racing program in 1999. The company, which was founded a decade earlier by Gary Pratt and Jim Miller in 1989, had already developed an incredible reputation for building high-performance cars for both the race track and all-terrain racing. Working together with Chevrolet, Pratt & Miller have developed purpose-built Corvette race cars since 1999, and have become recognized for building some of the winning-est race-edition Corvettes in recent history. The 2016 C7.R at the starting grid of the Petit Le Mans in Braselton, Georgia.
    The C7.R Corvette was developed in 2013 as a replacement for the out-going C6.R Corvette race car, whose retirement from racing mirrored the end of its commercial counterpart’s production run at the end of the 2013 model year. Interestingly, while the 2014 C7 Corvette is an almost entirely new production vehicle, early variants of the C7.R Corvette actually incorporated properties of the outgoing C6.R. That is not to say that the C7.R is the evolution of the C6.R, exactly, but rather that “lessons learned” while racing the older car were utilized in development of the newest racer.

    As Corvette Racing program manager Doug Fehan descibes it, the C7.R benefited from “cascade engineering.” Says Fehan, “You build a great road car, homologate it and make a great race car. You learn things in that race car, and it gets moved into the next-generation road car and then you homologate that (for racing). Look at the progression from C6, C6.R, Z06, ZR-1 and now C7, C7 Z06 and (the) C7.R. In each of those model years, production-wide, you saw more and more racing content.” Under The Hood

    The 5.5 liter engine of the Corvette C7.R produces 491 horsepower at 6,000 RPM.
    At the core of the C7.R Corvette is a direct carry-over from its predecessor – the same 5.5 liter engine that was developed during the C6.R’s successful tenure in both the American Le Mans series and at The 24 Hours of Le Mans. Sure, Chevrolet had developed a 630 horsepower, supercharged LT4 small-block V8 engine for the Z06 Corvette (the production variant upon which the C7.R presently shares the most DNA), but racing rules require that the engine architecture must be de-bored and de-stroked to 5.5 liters to be eligible for competition. Nobody, not the engineers at Pratt & Miller and Chevrolet, nor Doug Fehan felt that the time and expense to re-work the new LT4 engine made any economic sense when they already had a proven winner with the current 5.5-liter engine platform.

    From Wikipedia:
    24 Heures Le Mans 2016 (27190307204).jpg
    WeatherTech SportsCar GTLM
    24 Hours of Le Mans LMGTE Pro
    United StatesChevrolet / Pratt & Miller Engineering
    Tadge Juechter
    Chevrolet Corvette C6.R
    Aluminium monocoque
    Short/long arm double wishbone, fabricated steel upper and lower control arms, coil over adjustable shock absorbers
    As front
    4,496 mm (177 in)
    2,050 mm (81 in)
    1,151 mm (45 in)
    2,708 mm (107 in)
    Chevrolet Corvette LT5.5 5.5 L(336 cu in) V8 90° naturally aspirated, front engined, longitudinally mounted
    Xtrac 6-speed semi-automaticgearbox
    491 hp (366 kW) @ 6000 RPM
    1,110 kg (2,447 lb) (excluding driver, fluids and fuel)
    1,245 kg (2,745 lb) (including driver, fluids and fuel)
    VP Racing Fuels Ethanol C85 E85 (2014-2015) later MS100 E20 (2016-present) (WeatherTech SportsCar Championship)
    Esso Ethanol E10 (24 Hours of Le Mans)
    Mobil 1, Motul and Valvoline
    BBS forged magnesium wheels
    United StatesCorvette Racing
    FranceLarbre Compétition
    Last edited by SheepDog; 03-14-2019, 08:30 PM.

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  • Meldoon
    Personally, I love my Grand Sport. It is nicer than anything I ever thought I could own. I love the looks of it, the smell of it, and the performance of it. I think Chevy does an awesome job creating a car of this performance at this price. If I can afford the C8 I’ll get one. I don’t care what plane crank it has. I’ve always been a Chevy guy, not sure I want my Corvette to sound like a Ferrari. If it does, I’m sure I’ll love it too.
    I wonder how development costs compare between a Corvette and a’s obvious those costs are recouped in different ways.

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  • John
    Koenigsegg is cutting edge, beyond smart and top quality craftspersons. GM’s brilliance is creating for fractional cost of not just Koenigsegg but also fractions of the cost of the mid tier exotic OEMS, yet a super sports car that performs in that same realm.

    Tadge et all dream of being able to develop a finished Corvette at a cost of $300,000, let alone 5 to 10 times that.

    Good point meyerweb.

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  • meyerweb
    Originally posted by Meldoon View Post
    GM should buy Koenigsegg. He Could teach them a thing or two about building high performance engines.
    The technology development in his latest creation is pretty impressive.
    Putting high tech in your car is easier when you can sell them for $1 to $2 million dollars each.

    Leave a comment:

  • meyerweb
    Originally posted by SheepDog View Post

    What to make of the C8 Night Testing at Sebring video? The sound is like a FPCrank.
    The current C7.R racecars don't use the same engine as the production car. No reason to think the C8.R will, either.

    Leave a comment:

  • John
    Thank you. I was unaware of that difference and I have a WRX.

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  • Meldoon

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  • Meldoon
    • 72
    The engine architecture of V8 machines

    Powerful eight-cylinder engines have been as much a part of the Porsche story as the traditional at-six engine for decades. Porsche Engineering also develops V8 engines—for customer orders. The reasons for the popularity of this engine type are revealed by the fundamental properties of the engine architecture of the V8 machine.Panamera Turbo: 4.0-litre V8 biturbo engine, 2016, Porsche AGLuxury sedans and sports cars, SUVs and pickup trucks—in each of these vehicle categories, the eight-cylinder combustion engine in the V configuration enjoys an outstanding reputation. Depending on the use, it embodies either luxury and comfort or sportiness and emotion. The reason for the popularity of the V8 compared to other engine configurations is its fundamental advantages. The V8 is only slightly longer than an inline four-cylinder engine with the same cylinder spacing. The slight increase in required structural length is due to the offset of the two cylinder banks. So the V8 is also a promising option for hybrid drivetrains with an additional electric motor on the crankshaft flange, as the Porsche 918 Spyder demonstrates.

    The distribution of the total displacement among many cylinders results in uniform torque output and thus smooth running. So in a four-stroke V8, there are four power strokes per crank-shaft revolution. Larger numbers of cylinders offer smoother running and therefore greater comfort, but their greater structural length and higher weight are drawbacks in terms of the vehicle’s architecture and the axle-load distribution. In sports cars, for example, this can be compensated for through a midengine configuration or, in the case of front engines, by resolutely shifting the ten- or twelve-cylinder engine towards the center of the vehicle. For drivers and passengers, however, this results in space constraints—which is not a viable route for luxury sedans. Here, the structural length of the engine is completely incorporated into the longitudinal geometry of the vehicle, which with a V12, for example, results in a longer wheelbase or overhang and thus disadvantages in terms of vehicle agility. Special designs such as the W12 compensate for this disadvantage of the classic V12, albeit with a higher degree of technical complexity. So the classic V8 represents a good compromise, offering small structural space requirements with a simple engine architecture, high power-to-weight ratio and extremely smooth running characteristics. The basics of V engines

    Conventional V engines have a special characteristic: The two piston rods of the respective opposing cylinder pair connect to a shared crank pin of the crankshaft.

    V motor 90 degree profile, Porsche Engineering, 2017, Porsche AG
    V engine with 90° bank angle

    The bank angle of the V is immaterial, because even with some engines with horizontal, opposing cylinders, two connecting rods connect to a shared crank pin. Engines such as that of the Porsche 917 are therefore grouped not with the at engines but with the V engines—albeit with a 180° bank angle. With the at engine characteristic of the Porsche 911, by contrast, the connecting rods of the opposing cylinder pairs run to separate crank pins offset from each other by 180°. For this reason, the at engine in modern architecture has more main crankshaft bearings than a comparable V engine. The usual number of main bearings today is:

    > for V engines = (number of cylinders: 2) + 1
    > for at engines = number of cylinders + 1

    This in turn results in a further difference in the offset of the two cylinder banks: in a V engine, the bank offset is determined by the width of the connecting rod, while in a at engine it amounts to half the distance between cylinders. Bank angle

    The bank angle of a V engine influences the engine height and width as well as the position of the center of gravity in the vertical axis. Ideally, in a V engine it is selected so as to produce an even ignition interval. For a four-stroke V8 engine, that means: 720-degree cycle angle, i.e. two crankshaft revolutions for a complete working cycle, divided by the number of cylinders (8) yield a 90° bank angle or a whole-number multiple thereof. Derivative with a trick up its sleeve: V6 engine

    The usable construction space, or when vehicle platforms are offered with V engines with different numbers of cylinders, can necessitate deviations from this rule. One example of this is the V6 engine: to achieve a regular firing order, this four-stroke, six-cylinder engine requires a bank angle of 120°, which is associated with an unfavorably large structural width. Moreover, in most cases the mounting space for a V8 variant with a 90° bank angle is predetermined. The V6 is then also implemented with a 90° bank angle.

    V6 split-pin-crankshaft, Porsche Engineering, 2017, Porsche AG
    V6 split-pin-crankshaft

    To compensate for the resulting irregular firing order, engineers fall back on a trick of sorts: the “incorrect” bank angle is compensated for through an additional crankpin offset on the crankshaft. This requires split-pin crankshafts or even flying arms (see figures to the right of page 50) with an angle offset making up the difference. For a V6 with a bank angle of 90°, the requisite angle offset is then 30°.

    V6 crankshaft with flying arms, Porsche Engineering, 2017, Porsche AG
    V6 crankshaft with flying arms

    Design of the crankshaft

    In the basic design of a V8 engine, designers have another important bit of room for maneuver: the configuration of the crank throws on the crankshaft. This has a crucial influence on the principal characteristics of the engine—whether sporty/aggressive or with comfort-focused smoothness and low vibrations.

    The decision regarding the arrangement of the crank throws is shaped by the dichotomy between maximum power potential and optimal balancing of the free inertia forces and torques. Due to the kinematic coupling in the crankshaft drive, the inertial forces are produced by the oscillating motion of the piston and connecting rod masses. Depending on whether these inertial forces are produced one or two times per crankshaft revolution—for example through the upward or downward motion of the piston—we speak of primary and secondary forces in relation to the engine speed. If for the free inertial forces there is also a moment arm with respect to the engine center, this produces free inertia torques.

    As the engine speed rises, free inertial forces and/or torques are felt in the form of increased vibration, which, particularly as primary and secondary forces, are perceived as unpleasant and can only be partially mitigated through the engine mounts. For the most part, conventional V8 engines feature one of two crank variants: the “ at-plane” crankshaft in which all crank pins are on a single plane, and the “cross- plane” crankshaft, in which the crank pins of the four cylinder pairs are arranged at 90° angles to each other.

    Cross-plane V8 crankshaft, Porsche Engineering, 2017, Porsche AG
    Cross-plane V8 crankshaft

    Flat-plane V8 crankshaft, Porsche Engineering, 2017, Porsche AG
    Flat-plane V8 crankshaft

    Emotional sound: cross-plane V8

    One typical feature of the cross-plane V8 engine is the characteristic sound, defined by the emotional sound often referred to as “burbling.” What sounds pleasant for enthusiasts, however, impacts the gas exchange in the engine. However, an efficient gas cycle is a fundamental prerequisite for the optimal utilization of the displacement in terms of cylinder charge and volumetric efficiency and therefore the potential output. The gas cycle can be impeded by two effects:

    > flow resistance in the inlet and exhaust path 

    > incomplete gas exchange and thus residual gas in the cylinder 

    In gasoline-powered engines, residual gas also promotes a tendency toward hard, explosive combustion after ignition—i.e. knocking. Persistent knocking leads inexorably to piston damage. In order to prevent this under any circumstances, a knock control system has to intervene—but then the ignition cannot take place at the thermodynamically optimal time, which in turn leads to compromised thermal efficiency. 

    A V8 engine with a cross-plane crankshaft experiences this problem in a particularly pronounced form. In spite of the generally even ring order in the engine as a whole, with a 90° bank angle there is still an uneven ring order in each cylinder bank. Two cylinders per bank always fire in direct succession (90° ignition interval). What that means in concrete terms is that the exhaust pressure pulse of the subsequent cylinder already occurs while the exhaust valves of the previously ignited cylinder are still open. As a result, exhaust is pushed back into these cylinders, which in turn adversely affects the quality of the gas cycle. Porsche Engineering has broken new ground

    In practice, heretofore this disadvantage could only be countervailed through greater complexity: for example, through accordingly great lengths of the individual exhaust manifold pipes—although here the limits are generally defined by the vehicle package—or through cross-bank exhaust manifolds for V engines in which the exhaust side is in the V angle. As part of a current V8 engine project, Porsche Engineering has now broken new ground in this context. With specific control times for each individual cylinder, the residual gas problem can be eliminated with minimal effort. This was demonstrated in impressive fashion both in the simulation and on the engine test bench.

    The cross-plane V8 engine typically earns high marks in two other important categories: smoothness and low vibrations. In terms of free inertial forces and torques, the cross-plane configuration is ideal. While there is a remaining primary free inertial torque, this can be relatively easily counteracted through balancing masses on the outer counterweights of the crankshaft. The result is perfect balance. The double four-cylinder: at-plane V8

    The crankshaft for the at-plane V8 engine looks like that of an inline four-cylinder engine—aside from the wide crank pins, which in a V have two connecting rods. The similarity to a four-cylinder is no coincidence. The at-plane V8 embodies the original idea that led to the development of V8 engines, i.e. combining two inline four-cylinder engines in an angled configuration. And this is what gives rise to the fundamental advantages and drawbacks of this configuration. The secondary free inertial forces of the four-cylinder are retained and combine vectorially in the V configuration. The gas cycle, on the other hand, is considerably more harmonious. The ring in a at-plane V8 jumps from one cylinder bank to the other, which eliminates the residual gas problem of the cross-plane V8. The even, alternating expulsion of the exhaust also produces a completely unique engine sound that sounds noticeably like that of two inline four-cylinder engines—penetrating and aggressive. Putting all of these characteristics together, the at-plane V8 suggests itself primarily for use in high-performance sports cars such as the 918 Spyder. Differing ring orders depending on the manufacturer

    While the firing order determines the crankshaft rotation angle traveled between the ignition of two cylinders, the firing order defines the unique sequence of the cylinders in succession. As fixed geometric variables, the bank and crank angles only allow certain orders. The respective configuration defines which pistons reach their top dead center. The firing orders of flat- and cross-plane engines therefore differ in principle. Nearly all modern flat-plane V8 engines fire in identical sequences; in cross-plane V8 engines, by contrast, one generally finds manufacturer-specific firing orders. This takes into account a circumstance that can lead to slight confusion: worldwide there are different definitions as to which cylinder is counted first and how the other combustion chambers are numbered. This would seem to result in different firing orders. Removing the effects from the different cylinder counting methods, the variance in firing orders drops markedly.

    If one begins the cylinder count in each case with cylinder 1 according to DIN 73021, there are a total of eight theoretically possible ring orders for each rotational direction in a at-plane V8. With a cross-plane engine, the total is 16, as here the angle position of the center crank pin is interchangeable. However, not every theoretically possible ring order is implemented in reality. The objective is always the best-possible compromise between the following criteria:

    > Gas cycle 

    > Stress on the main crankshaft bearings 

    > Vibration stimulation of the crankshaft drive through deformation of the crankshaft under loads 

    > Rotational irregularities 

    Porsche Engineering carefully examined the question of the optimal ring order for both at-plane and cross-plane V8 engines. Nearly all at-plane engines reidentically, with alternation between banks always a possibility even with a deviating ring order. The result for cross-plane variants was likewise no surprise: particularly with a focus on maximum robustness of the crankshaft bearings, the ring order 1-3-7- 2-6-5-4-8 is the best choice in view of all characteristics — which is the ring order for all Porsche cross-plane V8 engines since the 928. Even so, the other implemented ring orders also have their justifications; here the objectives of the manufacturers in terms of their conceptual decision do vary. The results of the analysis also revealed another interesting point: There are certain ring orders that have never been implemented in reality but which also demonstrate exceptional balance in the fulfillment of the specified objective criteria.

    Crank Variants, Porsche Engineering, 2017, Porsche AG
    Theoretically possible firing orders for a given rotational direction in a cross-plane V8

    One thing is clear in any case: for all the competition between different drive technologies for future mobility concepts, the V8 will continue to have its place under the hoods of premium vehicles—not only as an icon of past glory, but due to the sum total of its technical characteristics.


    Text first published in the Porsche Engineering Magazin 1/2017.

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  • SheepDog
    Originally posted by Meldoon View Post
    GM should buy Koenigsegg. He Could teach them a thing or two about building high performance engines.
    The Chevrolet Indy V6 engine is a 2.2-litre Twin-turbocharged V6, developed and produced by Ilmor Engineering-Chevroletfor IndyCar Series. Chevrolet has been a highly-successful IndyCar Series engine supplier since 2012, scoring 33 IndyCar wins, 35 pole positions, 2 IndyCar Series driver's titles and 3 IndyCar Series manufacturer's titles. On November 12, 2010, Chevrolet confirmed their return to the IndyCar Series 2012 season after 6-year absence. They design, develop, and assemble the twin-turbo V6 Chevrolet IndyCar engine in partnership with Ilmor Engineering, and supply engines to A. J. Foyt Enterprises, Andretti Autosport, Dreyer & Reinbold Racing, Ed Carpenter Racing, Harding Racing, Juncos Racing, Lazier Partners Racing, and Team Penske teams.[1]

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  • Meldoon
    GM should buy Koenigsegg. He Could teach them a thing or two about building high performance engines.
    The technology development in his latest creation is pretty impressive.
    Last edited by Meldoon; 03-14-2019, 02:27 PM.

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  • Racer86
    A flat plane engine is not more expensive to build. It’s just a different crankshaft, and cam, ( cams). it’s very easy to machine a flat plane crank. And the different cam is necessary for the different firing order. Manufacturing costs would be the same as a cross plane engine if the manufacturer chose to built it in mass.

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  • 73shark
    After following the FPC discussion on the two threads, I'm wondering what the advantage is. It appears to have NVH issues, it's expensive, and the engine sound is not particularly desirable IMHO.

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