Considered one of the most famous BMW models, the 750Li V8 has been praised for its impeccable performance and add-on features.
Nevertheless, questions regarding its engine speed and quality persist to this day for some beginners – especially when the topic of engine firing disorder is brought up.
In this article, Bryan’s expert team will discuss the engine 750li BMW V8 firing order in more detail. Keep scrolling to learn our take on the matter!
What Is An Engine Firing Order?
An “engine firing order” refers to the sequence that your engine cylinders ignite/fire.
In spark ignition (petrol/gasoline) engines, firing orders often correspond to the sequence of spark plug operations.
Meanwhile, for diesel engines, engine firing orders correlate with which order the fuel is pumped to each cylinder.
Even four-stroke tanks must time their valve openings with firing orders – since these valves do not close and open upon every stroke.
Regardless of your chosen engine, its firing order strongly influences power evenness, sound, vibration, and crankshaft structure.
How about the cylinders’ numbering system? In most cases, it’s based on the increased cylinder numbers from the engine’s front point to the endpoint.
Nevertheless, certain differences are noted among different engine types and manufacturers:
Straight engines: The cylinders are numbered from the front (cylinder #1) to the rear.
Radial engines: The numbers go in a circle (clockwise), with cylinder #1 on top.
V engines: (like those used in BMWs): The frontmost cylinders are often #1. Other than that, two popular approaches are identified:
- Sequentially numbered cylinders for each engine bank (ex: 1/ 2/ 3/ 4 along your left bank; 5/ 6/ 7/ 8 along your right)
- Numbered cylinders based on where they are along the crankshafts (ex: 1/ 3/ 5/ 7 for right engine banks; 2/ 4/ 6/ 8 for the left)
What Should You Know About The Engine 750Li BMW V8 Firing Order?
Like other V engines, the 8-cylinder firing order relies on its spark plug/ attachment arrangement. It never stays fixed by solely following the spark-plug directions from your motor cylinders.
That’s why motors in a typical 8-cylinder bank do not fire in the stereotypical sequence (1/ 2/ 3/ 4/ 5/ 6) to avoid breaking or disfiguring the driving rods.
Instead, their firing order is 1/ 5/ 4/ 2/ 6/ 3/ 7/ 8 (in normal cases) and 1/ 3/ 7/ 2/ 6/ 5/ 4/ 8 (for small aluminum block designs).
In all firing orders, the #1 cylinder always seizes the biggest role at the engine’s front, on the passenger/traveler side of every back tire truck or vehicle.
Plus, whenever the cylinders are on target at the top above pressure strokes, their internal rotors must align with your main spark plugs.
Note that the firing order may also fluctuate across certain model years, so do your research carefully!
Another interesting fact is that the above orders also apply to some other non-V8 models and engines, such as:
- 5.4L
- 5.0L EFI
- Ford 351
Why Is The Firing Order of An 8-Cylinder Engine Important?
Correct and appropriate firing orders are extremely important; mixing up your spark and plug wires will keep the engine from immediate starts. It might backfire and run poorly (or worse, not run at all!).
Such dilemmas may cause severe crossfires among your plugs, as magnetic fields made by one spark plug will fire the nearby plug prematurely.
Your car engine might run roughly as a result and misfire at unexpected timing!
A great tip to prevent that disaster is to criss-cross two adjacent plugs and plug wires, which cancel out their magnetic induction.
Still, not every driver has the technical skill to do that – all the more reason to learn your engine firing disorder from the get-go!
What Are Factors That Determine The Firing Order Of The Engine?
Firing orders are decided by the engine’s cylinder amount and offset/crankshaft alignment for every crank journal during manufacturing/design.
Each manufacturer puts in painstaking effort during production to ensure the engine runs as smoothly and efficiently as possible.
Other critical factors, such as the pistons’ exerted loads and forces and required counterweight, also play a part in the calculation.
They are plugged into a dynamic balancing equation to aim for minimum car vibrations, fostering a seamless driving experience.
Long story short, the designing parameters for are:
- Cylinder amount (how many cylinders?)
- Exposure honing /Heat distribution
- Torsional vibrations
- Cylinder arrangement
- Crankshaft journal
- Exhaust manifold
- Offset/intake camshaft alignment.
What Are The Authentic Firing Order For 8-Cylinder Engines of Other Brands?
Enough about the BMW V8 models from the BMW 7 series; let’s look at other famous car brands and engines!
- Old Chevy and Mopars: “1-8-4-3-6-5-7-2” firing order
- Ferrari GT 456M V12: 1/ 7/ 5/ 11/ 3/ 9/ 6/ 12/ 2/ 8/ 4/ 10
- Lamborghini VT Diablo: 1/ 7/ 4/ 10/ 2/ 8/ 6/ 12/ 3/ 9/ 5/ 11
- Caterpillar 3412E: 1/ 4/ 9/ 8/ 5/ 2/ 11/ 10/ 3/ 6/ 7/ 12
- Audi VW W12 Bentley: 1/ 12/ 5/ 8/ 3/ 10/ 6/ 7/ 2/ 11/ 4/ 9
- Rolls/ Royce Merlins: 1/ 12/ 7/ 6/ 3/ 10/ 11/ 2/ 5/ 8/ 9/ 4
- Lamborghini Aventador: 1/ 12/ 4/ 9/ 2/ 11/ 6/ 7/ 3/ 10/ 5/ 8
FAQs
Is Every V8 Cylinder Firing Order Similar?
No. V8 engines have different engine firing order – even engines of the same brand!
What Is The Firing Order for Other BMW Engines?
- V6: 1/ 5/ 3/ 6/ 2/ 4
- V12: 1/ 7/ 5/ 11/ 3/ 9/ 6/ 12/ 2/ 8/ 4/ 10
- V10: 1/ 6/ 5/ 10/ 2/ 7/ 3/ 8/ 4/ 9
Is BMW 750Li Reliable?
There were admittedly some issues with the earlier models of this vehicle line, such as engine cooling, transmission, and electrical systems.
Thankfully, the latest years have shown outstanding improvements, garnering more positive feedback from experts and car owners.
What Are The Possible V8 Firing Orders?
Refer to the previous section (about V8 orders from other brands) for more info!
Conclusion
Our expert guides have discussed the engine 750Li BMW V8 firing order in great detail and even brought other brands and engine models to the table!
Understanding how they work will help you identify and tackle technical issues (ex: cylinder wall damage) much more efficiently.
Contact us if you still need help or technical updates on the BMW V8 firing order!