Flat Plane Crankshaft

[loungin112]

I never gave it much thought before, but came across this discussion on BAT: https://bringatrailer.com/2019/03/25/so ... vette-z06/

That said, it seems like old tech that never really caught on to become mainstream. I like the idea that these style of cranks - and the associated changes to ignition - are claimed to be more efficient than traditional/current designs.

Just curious what everyone's thoughts were. Also, did Datsun/Nissan ever dabble in flat plane crankshafts? I could only imagine how such tech could change the behavior of an L20b or a KA24DE...or even one of the higher revving straight 4s (I'm looking at you SR and CA).

I don't imagine this part will ever be made for today's Nissan/Datsun engine builders as it would likely be a pricey part that would see very slow sales.

But, interesting nonetheless.

[datzenmike]

Yes they did. All of their 4 cylinder engines are flat plane. Here is my flat plane or 180 L20B and Z22 crankshafts.

[defdes]

....and once they're knife edged, you REALLY have something!

crank5.JPG (165.94 KiB) Viewed 3578 times

[510rob]

https://forums.autosport.com/topic/9159 ... ibrations/

https://www.eng-tips.com/viewthread.cfm?qid=401468

[loungin112]

Yes they did. All of their 4 cylinder engines are flat plane. Here is my flat plane or 180 L20B and Z22 crankshafts.

Palm----->Forehead

Sometimes, an idea seems so interesting, I go searching for information without doing research. In this instance, the realm was my go-to for info. Cool that Datsun had already explored and utilized this concept. I'll have to go out and take a look at my KA crank to see if it is the same...I think it would be.

Pretty cool about knife-edging the crank. I'll have to remember that.

[datzenmike]

All 4 cylinder cranks will be 'flat plane'. As they are all 4 cycle engines (compression, fire, exhaust and intake) and there are only 4 cylinders, I don't think you could do it any other way really.



Don't bother. Here's my KA crank wearing a girdle.

[gooned]

It’s slimming!

[510rob]

All 4 cylinder cranks will be 'flat plane'. As they are all 4 cycle engines (compression, fire, exhaust and intake) and there are only 4 cylinders, I don't think you could do it any other way really.

Mike, you had to know that Japanese engineers would challenge that thinking sooner or later...

https://www.youtube.com/watch?v=eNph5Q9j1mE

https://www.youtube.com/watch?v=sqNi7TMSICs

[icehouse]

All 4 cylinder cranks will be 'flat plane'. As they are all 4 cycle engines (compression, fire, exhaust and intake) and there are only 4 cylinders, I don't think you could do it any other way really.

Mike, you had to know that Japanese engineers would challenge that thinking sooner or later...

https://www.youtube.com/watch?v=eNph5Q9j1mE

https://www.youtube.com/watch?v=sqNi7TMSICs

I don't get it. they fire evenly apart, what is the point? Going to have to think about it a bit longer.

[datzenmike]

"Sometimes I sits an thinks.... sometimes I just sits"

I meant most all are flat plane 1342 firing order as cheaper to make and for balance.