Turbo V-6

Ya know, I just went and dug up the old mains from a V6 rebuild I did and I only counted five... so there are 6 crank throws and it WOULD be possible to have a 7 main V6 block but I don't know if anyone makes one.

as to inline sixes, they are pretty much THE best engine design out there. Internally balanced with 120 degree spaced crank throws, seven main bearings, six inline cylinders make good smooth power with minimal friction losses, and the single cylinder bank means the block cannot split along a lifter valley and is much simpler in design and easier to work on.

spanky442 said:

yeah but more people are saying bye to V-8 and going for cars with turbo V-6.

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Really what would those cars be? Turbo Supra and Turbo 300ZX are both extinct! So I'm not sure what Turbo 6 cylinder models your are talking about?
Maybe there is a higher demand for 6 cyclinders nowadays but since the only TT 6 cylinders that come to mind are high priced Audi's I guess they must have a corner on that "High Demand", and I dont really see any of those as major competitors to any current or future mustang models. A turbo 6 mustang would be interesting but needless with affordable lightweight V8's.

Forget the Falcon XR6, I'll take the XR8 Boss 260 (5.4L DOHC) or better yet any of the awe inspiring Falcon GT, GTP, and Pursuit GT produced by Ford Performance Vehicles (FPV) of Austrailia!!!

Ford should seriously look into importing or building these here to battle the CTS-V and GTO!!!!!!! But that would be a cold day in Hell!


Check these links out: http://www.fpv.com.au/index.asp?link_id=2
http://www.ford.com.au/home/home.asp

Oh and FPV also built a 5.6L (347ci) derivative of the old pushrod 5.0L in '02 I believe before dropping the pushrod in '03 for the 5.4L DOHC motors. If I rember right it was hand built by FPV.

I've been a big fan of Austrailian Ford muscle ever since I discovered these Falcons a few years back. I got some awesome wallpapers from these sites of the 5.6L, 5.4L and Falcon models check out their downloads and history areas, also got a few pics of the '02 Aussie Mustang Cobra.

Ray III said:

60 degree V6 engines are a good design with much greater strength than a V8 engine. Each piston has its own crank throw, with more iron between cylinders and seven main bearings. The crank throws are offset by 120 degrees in groups of three, which means the engine is internally balanced. No wonder these motors are used for high specific outputs at high speeds, like the 3 liter 320 horsepower twin turbo that was previously built by Mitsubishi.

Still, while the V8 design is no better than a weak four-cylinder with double pistons, you can't argue with the sound and displacement and smoothness of power production.

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The V8 design has much better balance than an inline four, or a V6 for that matter. Also, the only thing that would make a V8 inherently weaker than a V6 is the extra length.

The trend in new cars seems to be towards V8's, not away from them. Audi dumped their TT I6 for a V8 in the S4, rumors of a revived Supra put a V8 in it - also in the next gen M3, IIRC. A V8 simply allows car makers to fit more displacement in the same engine bay.

I think that a forced induction V6 is not something Ford should do. The only FI V6 we have in the sates that I can think of is the SC 3800 - I'll bet it costs as much to build as the 4.6 for less HP.

Check out http://autozine.kyul.net/technical_school/engine/smooth1.htm for some good analysis of the common engine layouts.

(As for the TT Mitsubishi 3.0 V6 - Ugh. 'Nuff said.)

Thanks Ray, I knew they were good for a (or a couple of) reason(s).

GT5oh, we do have a 5.0, it's called the Windsor here over 5.0. I'd rather call it 5.0 but oh well.

Oh yeh, I think I'd rather the turbo 6 over the boss motor, because the boss adds so much weight, and not all that much more power (except in GT form, 290kW), boost can be cranked up, and fair economy can be acheived by keeping it out of boost. Plus it's the first REAL engine with a turbo on it from Ford that I know of. (Real meaning worthwhile size lol)

Here's a go at the advantages and disadvantages of various engine types.

I-4 -
Advantages
Compact and easy to package for a wide variety of applications. Strong block. Basic design is simple.
Disadvantages
Natural imbalance requiring counter shafts. Larger displacements magnify the effects of the imbalance. Difficult to tune for both low end torque and high horsepower. Can be tune for either, but not typically both.
I - 6
Advantages
Naturally balanced. Strong block. Good torque production and better horpower than I-4s. Basic simple design.
Disadvantages
Displacement is tipically limited due to engine length and height restrictions. There seems to be some limits to attainable horspower with reliability. BMW had to install V8s in their 3-Series ALMS GT racers a few years back to remain competitive.
V -6
Advantages
At roughly half the length of the I6, you get the same displacement and horspower.
Disadvantages
Naturally imbalanced and requires counter shafts to be truly smooth. Typically produces less torque than the I-6.
V-8
Advantages
Similar packaging advantages as the V-6, for an overall length slightly greater than an I-4 you get twice the displacement. Can be naturally balanced(90°) or balanced externally(60°). Good power and torque production.
Disadvantages
Typically heavier. Typically more complex, if all engines are equipped with similar head designs for example all engines compared have either 2 valve per cylinder, 3V, 4V, etc.



Turbos, superchargers, variable timing/lift, etc can make I4, I6, and V6 engines more comparable to a V8. However, using those same tools on a well designed V8 puts everything back in its normal order.

To add a couple of things.

More cylinders = higher friction losses.

#1 advantage of I4 & I6 engines = lower manufacturing cost.

There is a practical displacement limit for any # of cylinders. A very large displacement I4, or even an I6 can be a rough running engine simply due to the large individual masses of the reciprocating parts.

More cylinders usually equates to a smoother running engine. The old straight 8's were the smoothest engines of their day. But the real long crankshafts and camshafts presented other problems which limited their RPM range.

Back in the days of carburators, one of the problems with I6's was getting equal and efficient distribution of the intake air fuel mixture to all cylinders especially when a single carb was used. This was still a problem with throttle body fuel injection (single injector). Port EFI has pretty much solved this problem, but intake manifolds can still present some design challenges.

A 60 degree block V6 gives an even firing order, which smooths out a V6. The narrow 60 degree angle helps to make the V6 compact and easier to fit into small cars. But the 60 degree angle limits the space available for the intake manifold and plenum, forcing it to be located outside the V between the cylinders. This can add to the height requirements. On some engines the intake manifold has to be removed to change the spark plugs on one of the cylinder heads.

What really says it all is that V8 engines have dominated most forms of racing since the mid 1950's when they pushed I6's aside. BMW has been one of the few manufacturers to successfully race I6's in recent years, but as 63 Fairlane said the BMW I6's are no longer really competitive against V engines. Yes there have been other succesful race engines, V6's, V10's and V12's but note they are all V engines.

After all these years, the V8 still seems to be the best compromise between performance, refinement and complexity.

for me at the moment it's V8 or nothing. I don't want anymore 4 or 6 cyl cars. I haven't had a V8 car since my 75 Monte Carlo (which was a dog where performance was concerned) before that 77 Olds Cutlass (even worst, but incredible gas mileage for a 8 cyl) and before that...ahhhhh my old 1968 Mustang Coupe. I miss that car so much.

I would love to have a V8 by fall of 05 but if my income stream does'nt increase i might have to get a 6 shooter. whether 6 or 8, both are fun to mod. ford wont make turbo 6'ers here and even the aftermarket for FI is 90% supercharged not turbocharged on V6 stangs.
i would love to have deep roaring exaust and a tire smoking engine of a V8 straight from the factory, but it may not be practical for me, expecialy with a g/f and her daughter moving in next month.

They won't build a forced induction V6 because it will cost too much for ford to do it.Who wanna buy a 25k+ v6 mustang? Not me. Remember the mustang was made with one thing in mind, good performance for the buck aspect.

351CJ said:

To add a couple of things.

More cylinders = higher friction losses.

#1 advantage of I4 & I6 engines = lower manufacturing cost.

There is a practical displacement limit for any # of cylinders. A very large displacement I4, or even an I6 can be a rough running engine simply due to the large individual masses of the reciprocating parts.

More cylinders usually equates to a smoother running engine. The old straight 8's were the smoothest engines of their day. But the real long crankshafts and camshafts presented other problems which limited their RPM range.

Back in the days of carburators, one of the problems with I6's was getting equal and efficient distribution of the intake air fuel mixture to all cylinders especially when a single carb was used. This was still a problem with throttle body fuel injection (single injector). Port EFI has pretty much solved this problem, but intake manifolds can still present some design challenges.

A 60 degree block V6 gives an even firing order, which smooths out a V6. The narrow 60 degree angle helps to make the V6 compact and easier to fit into small cars. But the 60 degree angle limits the space available for the intake manifold and plenum, forcing it to be located outside the V between the cylinders. This can add to the height requirements. On some engines the intake manifold has to be removed to change the spark plugs on one of the cylinder heads.

What really says it all is that V8 engines have dominated most forms of racing since the mid 1950's when they pushed I6's aside. BMW has been one of the few manufacturers to successfully race I6's in recent years, but as 63 Fairlane said the BMW I6's are no longer really competitive against V engines. Yes there have been other succesful race engines, V6's, V10's and V12's but note they are all V engines.

After all these years, the V8 still seems to be the best compromise between performance, refinement and complexity.

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More cylinders, also = more efficient combustion characteristics. This is one of the reasons F1 engines manufacturers stettled on v10's, along with the better packaging charateristics compared to a v12 and more power/rev potential compared to a V8. This is also the reason you are seeing a lot of v10 truck engines in favor of large displacement v8's

Vibration is also the reason you don't usually see 4 litre I4's or 5 litre v6's. Mercury marine still uses GM's "iron duke" I4 for their lower cost stern drives. It is a cast Iron, pushrod I4 displacing 3 litres. That thing shakes like it's going out of style. They also used to have their own I4 that displaced 3.7 litres (224 cu. in.). It used a die cast aluminum block (because they do a lot of in-house die casting), a cast iron Ford 460 big block cylinder head assembly as well as the 460's pistons and connecting rods. The boat builders loved them because they were small, cheap, made a lot of power and had a ton of low end torque. I even heard that they got a following among off-roaders because of their power/torque and you could easily put them in an old jeep.

The main reason car makers are going away from I6's is packaging, with front impact standards becoming more of an issue, an I6 leaves less crumple zone at the front of the car. As I have never seen anything touting a 3 series bimmers performance in a frontal crash test, I would imagine it's average at best. There is also a height issue to deal with. I seriously doubt you could put an e46 M3 engine in a vette and still keep the hood as low as it is. You also couldn't put that engine in a miata, which has been done often using ford 302 v8's. I6's also don't have any natural valleys or spaces to package intake or exhaust, which you generally get with a v6 or v8, so by the time you add those things, the width advantage is diminished.

While 60 deg v6 or 90 deg V8 would be heavier than an inline 6 of comparable displacement, The I6's center of gravity is generally going to be located higher and farther forward.

While the V6 and V8 don't have the near perfect balance of the I6, their blocks have much higher torional rigidity. This is the reason M3's, with their high specific output, still use a cast iron engine block.

I have heard that BMW looking at the possibility of a V6 in the next 3 series. Packaging and front impact requirements are the main drivers behind this.

The degree offset of the cylinder banks of a V configuration engine affects its balance. 90 degree V6s are imbalanced, but 60 degree V6s run very smoothly with no balance shafts.

shatner saves said:

There is also a height issue to deal with. I seriously doubt you could put an e46 M3 engine in a vette and still keep the hood as low as it is. You also couldn't put that engine in a miata, which has been done often using ford 302 v8's. I6's also don't have any natural valleys or spaces to package intake or exhaust, which you generally get with a v6 or v8, so by the time you add those things, the width advantage is diminished.

While 60 deg v6 or 90 deg V8 would be heavier than an inline 6 of comparable displacement, The I6's center of gravity is generally going to be located higher and farther forward.

While the V6 and V8 don't have the near perfect balance of the I6, their blocks have much higher torional rigidity. This is the reason M3's, with their high specific output, still use a cast iron engine block.

I have heard that BMW looking at the possibility of a V6 in the next 3 series. Packaging and front impact requirements are the main drivers behind this.

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Actually, the fact is when you overcome the length issue of an inline 6, it has much more space to the sides and is no taller than a comparable V8. You forget that some of the height of a V engine is because it has to have its intake manifold sitting on top of the engine, whereas inline engines can have nothing above the valve cover. Manifolds are pretty straightforward with one intake and one exhaust manifold, usually located to opposite sides but they can be located to the same side of the block. If you look in an older 300 powered F-150 there is a huge amount of space in the engine bay. A 351 truck fills the bay up pretty good.

Can you explain some more about the torsional rigidity of V blocks? Never heard of such a thing being an issue in 2000 ft-lb torque inline engines.

Ray III said:

The degree offset of the cylinder banks of a V configuration engine affects its balance. 90 degree V6s are imbalanced, but 60 degree V6s run very smoothly with no balance shafts.

Actually, the fact is when you overcome the length issue of an inline 6, it has much more space to the sides and is no taller than a comparable V8. You forget that some of the height of a V engine is because it has to have its intake manifold sitting on top of the engine, whereas inline engines can have nothing above the valve cover. Manifolds are pretty straightforward with one intake and one exhaust manifold, usually located to opposite sides but they can be located to the same side of the block. If you look in an older 300 powered F-150 there is a huge amount of space in the engine bay. A 351 truck fills the bay up pretty good.

Can you explain some more about the torsional rigidity of V blocks? Never heard of such a thing being an issue in 2000 ft-lb torque inline engines.

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A 90 degree v6 can be made to have good balance. It means you either have to add a balance shaft, as GM did on it's 4.3L vortec v6, or split the crank thows to get back to 60 degree firing intervals.

The vortc v6 engine essentially was a 350 cu in SB V8 with 2 cylinders lobbed off. It was a relatively large displacement V6 with bad primary balance so vibes weren't that good. I vaguely recall initial versions of that engine with a manual trans having bearing issues (or something). In the late '90's GM added a balance shaft, in the "V", right above the camshaft. This smoothed it out a lot, but I don't think they ever got it back to the smoothness of say, a 305 V8. Balance shafts also have the disadvantage of robbing a bit of power and they generally work best in a specific RPM range.

Splitting crank throws has the disadvantage of resulting in more expensive and weaker crankshafts. Lamborghini's new 5.0L v10 engine has a split crank, allowing even 72 degree firing intervals, but the lower CG of a 90 degree block. F1 engines have generally migrated to wide angle blocks but I think they are probably doing a combination of splitting crank throws to some degree and just figuring out how to handle the exess vibes. Renault's engine last year was 110 degrees. This year, with the "one engine rule" a lot of manufacturers are going back to 72 degrees.

As for "2000 lb-ft inline engines", I assume you are talking about highway truck engines. I can only make educated guesses:

1. These engines don't have to deal with High RPM/resonant frequencies you generally see in a high performance car engine.

2. These things aren't just heavy, they are F@#&ing Heavy. Here are the specs for a C15 CAT highway diesel.

Cylinders In-Line 6
Bore/Stroke 5.4 x 6.75 (137mm x 171mm)
Displacement 15.2 L (928 cu in)
Weight 2890 lb (1311 kg)
Horsepower 435 to 550 @ 2100 rpm
Torque 1350-1850 lb0ft @ 1200 rpm

This engine weighs more than most new cars.

3. These engines tend to have a more undersquare bore/stroke ratio and very long con rods. This contributes to a realtively tall deck, shorter length block, which would be much stiffer than a shallower, longer one.

So why won't they use V8s in highway tractors?

My point is, there is a good engine for different applications. The V8 design is not the end-all be-all.

yes I just happened to take a head off one of those yesterday and it looks like a good motor from what I can see, but it doesn't approach the output of 10-20 liter inlines. Plus it was a BITCH to work on, I had to jack the cab up to get at the bolts to the rear and god knows the deck will get all covered in crap before I wrestle that head back in.

GM electromotive diesels for trains on the other hand use a 60 degree V configuration because the height and length of an inline engine necessary to produce the staggering amount of torque would be a bit inconvenient even for the size of a locomotive. They are actually not too hard to work on as they have an engine room rather than bay and you can walk around it and there are many ports in the block that come off with a screw for inspection purposes.

Then when you get to diesel powered ships that like to have engines with upwards of a million ft-lb torque, inline motors are used because you have virtually unlimited room to work with...

Ray III said:

So why won't they use V8s in highway tractors?

My point is, there is a good engine for different applications. The V8 design is not the end-all be-all.

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I believe Cummins makes (or at least used to make) a 16L V8. Mmmmm 2L / cylinder.

I noticed in a service manual that Cat makes a 10.4L (the one I'm workin on) and an 18L V8 with everything else being an inline 6... so I guess they must make them for packaging reasons? I doubt an inline would fit in that stoopid azz shortbussed GMC, and an 18L inline would be pretty big even for a semi. Although the 18L had to be made in a 60 degree configuration for a narrower profile with the resulting balancer shafts and stuff. I do think the inline setup is better if you can work with the dimensions, and you rarely see these big assed diesel V8s around.

well that certainly went off topic... for my car I want to see a 302 or 351 under the hood. Sure, I would get a hardon over a turbo V6 but it's just not the same feeling.