how many firing sequences for 90* V-8

[wyrmrider]

Javelin has same firing order as chevy
Our Javelin was one of the first to use x pipe- did sound different
Javelin heads were more efficient than chevy- fords more so at high rpm, low rpm less so

[swampbuggy]

Wyrmrider....what was the year your Javelin first used an X-pipe ? Mark H.

[peejay]

Do any engines fire two cylinders together? Would there be any advantage to this?

The VWAG ("Bugatti") W18 has eighteen cylinders firing in a 12 cylinder firing order, with every other firing being two cylinders at once. I haven't heard any particular reason why but my gut feeling is that it made the crankshaft simpler since it was three narrow-angle banks of cylinders. (So six actual banks sharing three cylinder heads, more or less three VR6 engines joined at the crank)

"Big Bang" four cylinder motorcycle engines often will fire cylinders in pairs. The idea is that by having a large dead time between firing pulses, the rear tire can regain traction. (Once traction is lost, the tendency is for the tire to keep spinning - think how easy it is to do a burnout once you lose hook)

This wasn't a pie-in-the-sky crazy idea, it was theorized as to why lower-horsepower V-twins could walk away from even-firing engines on loose tracks. Horsepower has increased to the point where the traction limitations show up on tarmac. The most extreme example I have to mind (on a STREET bike!) is an inline four that fires two cylinders, then fires the other two cylinders 180 degrees later, then there is 540 degrees of deadtime. Of course, this is one of those refinements that people argue endlessly about, and apparently people will take sound recordings of race bikes and analyze them to determine what firing angles the engines are using, and there has been a lot of thought put into it as regards to the elastic properties of the tire carcass being used and way more other factors than I care to think about.

[Truckedup]

My dual vintage engine Triumph land speed racer is a sort of Big Bang theory firing order...Both engine are twin cylinder with 360 degree cranks...The front left fires 5 degrees before the rear right,then 355 degrees later the right front fires 5 degrees before the left rear..This is done to lessen harmonics on the drive chains...
Modern 1000cc sport bikes have in excess of 150 HP at the rear wheel with bike and typical rider weight of about 650 pounds...I believe all the four cylinder engines have conventional firing orders? The few Italian twins have 90 degree cranks.. There are about 10 new production bikes costing less than 20 grand that are capable of high 9's and 150 MPH in the 1/4 mile, top speeds near 200, with an expert rider. and all stock equipment...Not traction problems so much as keeping the front down...

[peejay]

My dual vintage engine Triumph land speed racer is a sort of Big Bang theory firing order...Both engine are twin cylinder with 360 degree cranks...The front left fires 5 degrees before the rear right,then 355 degrees later the right front fires 5 degrees before the left rear..This is done to lessen harmonics on the drive chains...
Modern 1000cc sport bikes have in excess of 150 HP at the rear wheel with bike and typical rider weight of about 650 pounds...I believe all the four cylinder engines have conventional firing orders? The few Italian twins have 90 degree cranks.. There are about 10 new production bikes costing less than 20 grand that are capable of high 9's and 150 MPH in the 1/4 mile, top speeds near 200, with an expert rider. and all stock equipment...Not traction problems so much as keeping the front down...

IIRC most/all Japanese bikes are limited to 300km/h, although it is also somewhat trivial to bypass.

Also IIRC you won't see this on the large liter bikes, it's mainly the racing-class 500-600cc engines.

Really wish I could remember who made the engine I'm thinking of. Wiki says Kawasaki did it in the early '00s, but the one I am thinking of was much newer, and incorporated an electric motor that would drive the flywheel during the dead-time at low load and RPM for road pleasantness.

[Truckedup]

My dual vintage engine Triumph land speed racer is a sort of Big Bang theory firing order...Both engine are twin cylinder with 360 degree cranks...The front left fires 5 degrees before the rear right,then 355 degrees later the right front fires 5 degrees before the left rear..This is done to lessen harmonics on the drive chains...
Modern 1000cc sport bikes have in excess of 150 HP at the rear wheel with bike and typical rider weight of about 650 pounds...I believe all the four cylinder engines have conventional firing orders? The few Italian twins have 90 degree cranks.. There are about 10 new production bikes costing less than 20 grand that are capable of high 9's and 150 MPH in the 1/4 mile, top speeds near 200, with an expert rider. and all stock equipment...Not traction problems so much as keeping the front down...

IIRC most/all Japanese bikes are limited to 300km/h, although it is also somewhat trivial to bypass.

Also IIRC you won't see this on the large liter bikes, it's mainly the racing-class 500-600cc engines.

Really wish I could remember who made the engine I'm thinking of. Wiki says Kawasaki did it in the early '00s, but the one I am thinking of was much newer, and incorporated an electric motor that would drive the flywheel during the dead-time at low load and RPM for road pleasantness.

I believe Moto GP bikes, about 240 HP, use some sort of traction control..

[pdq67]

Stupid question, but still curious.

What would happen if you take a stock 1st Gen. SBC crank and split the rod journals 180 degrees and fire her off? In other words have 8 rod journals instead of 4, kinda like the weird V-6 engines.
.................l......l......l-----l......................................l-l----------l-l
Like this ------l-l----l-l----l-l----l-l---- instead of this -----l-l----l-l----l-l----l-l----
...................l......l......l.....l.............................l-l...........l-l

I hope my crude sketch make's since?

pdq67