Why did the yanks think that FPV were going over the top with a red line set at 6000rpm when the engine we've developed it from (the all alloy 5.4L Mustang Cobra-R) has a redline near 7000rpm.
A bit funny don't you think???
Cobra Stats.
Type: V8
Displacement cu in (cc): 330 (5409)
Power bhp (kW) at RPM: 390(287) / 6250
Torque lb-ft (Nm) at RPM: 385(522) / 4250
Redline at RPM: 6600
Let me explain a little bit about over and undersquare engines and the impact on an engines ability to rev - better still go and read this article in the Tech Forum and then you will understand why.
The Mustang Cobra R engine has upgraded internal components.
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The ford-tech article regarding piston acceleration is incorrect.
The author has applied the Windsor rod length when performing the calculations for the Boss290, Mustang 4.6 and BarraI6. Sorry to spoil the fun.
Originally posted by Colow The ford-tech article regarding piston acceleration is incorrect.
The author has applied the Windsor rod length when performing the calculations for the Boss290, Mustang 4.6 and BarraI6. Sorry to spoil the fun.
Its mentioned above the Cobra motor has hardened internals.
The FPV sales info states the Boss motor in 290 kw form has all sorts of different internals eg G pins, pistons, etc. (can't remember the full list, but if you read the sales info, its all stated there).
Does this mean, in the above members opinions, the FPV replacement parts, which have been made out publicly as being the way to performance, are not as they seem?
The way I have read the info, the Boss 290 is something special, work upon and a desireable motor.
On another point, I've noticed Motor, Wheels, and NZ Autocar all bleat about 'only 6000rpm limit' when comparing the Boss with Gen III/LS1 standard production motors (please, no comments like "I knew an LS1 that went to 9000rpm", I'm talking standard, off the shelf motors). Who's looked at what the opposition redlines at? All under 6000rpm. So really its an issue thats really a non issue. Except maybe the Boss could have been developed better, with some redundancy (assuming public statements are correct that the Boss power is 'it' and can't be developed further, easily) so it could have been tweaked easier later. Maybe the only issue with the 6000rpm limit is that the engine revs so quickly, the motoring journo's have been used to driving slugs that take longer to rev, so the 6000rpm limit takes longer to get too, so seems to be a higher reving motor? (must admit, I haven't driven a Boss, as am waiting on GT-P and no one has offered me an XR8 test drive to see what to expect, however, have driven an XR6Turbo and does that redline come around fast!)
The way these stat read (and being Ford, they must know their product better than anyone else), the Boss motor is, in fact a very good motor and doesn't actually need to rev above 6000rpm.
The block is cast-iron which makes it exceptionally rigid. It is three times stronger than aluminium for extra durability reserves and refinement under high horsepower and torque loads and maintains tolerances better. Cast-iron is more stable over a wider range of temperatures and there is less movement at critical sealing points for superior resistance to oil and coolant leaks. Ultimately, it's what we use for V8 Supercar engines. Enough said.
The engine has an under-square bore and stroke ratio that delivers the flexibility, fast response and strong pulling power from low engine speeds expected from a high-performance V8.
A forged steel crankshaft maintains strength and refinement under high power and torque loads.
Each crankshaft undergoes a special balancing process at Ford Performance Vehicles prior to assembly to match the special Boss 290 piston and conrod combination for exceptional refinement and reduced stress on components at all engine speeds.
Locally-sourced high-performance tri-metal main and big-end bearings are specified for extra durability under higher engine speeds and peak power and torque loads.
Each main bearing cap is precisely located by two cross-bolts, two vertical bolts and two vertical locating dowels for superior location over six bolts. That means superior durability and refinement under high performance loads.
Each conrod is re-engineered to match the stronger pistons and floating gudgeons.
The conrod big-ends are separated by a controlled cracking process before main bearing insertion. When reconnected, this creates a multi-ridged join unique to each conrod that is exceptionally strong and virtually invisible.
Locally-supplied high-performance pistons with domed tops lift the compression ratio to 10.5:1 on 96 RON PULP for improved engine response, efficiency and fuel economy under light throttle loads.
The oil pump is driven directly off the crankshaft. So when the engine is running, the oil pump is too. And that eliminates one serious potential for engine failure (for example, when a separate oil pump drive breaks and the engine continues to run).
Extra components are;
FPV Hi Comp pistons and Piston ring pack
FPV Re-engineered Conrods with fully floating Gudgeon pin (assume XR8 Boss 260 doesn't have these)
FPV High lift Inlet camshaft (13mm lift), Outlet (12mm lift)
FPV Valves, Valve Springs, Finger Followers, Balanced Camshaft, Heavy duty bearings, Hi Flow Air Intake System, Long Runner Intake Manifold, Stainless steel Exh manifolds, Hi Cap fuel pump.
Is this 'hardening' or just sale gumpf? I read it as hardening and it is an exceptional motor. Over and above that, Ford Aust told the press the Cobra motor was made from rudementry rough castings that lasted only 3000 times then had to be thrown away (because of poor quality?), and the FPV product was well above that in quality.
The only confusing thing above- how many bolts does the big end actually have - 2, 4 , 6 8 or 12, if dowels are counted as 'bolts'. Even taking 'dowels' out of the calculation, the way it reads is 10 bolt mains. Haven't seen these used - heard of 2 bolt, 4 bolt.
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