Flat plane crankshafts have been around for a long time, and they have both advantages and disadvantages over their cross plane counterparts. In this video, we look at the differences.

Comments

    • Joel M
      Joel M

      Yeah, flat plane cranks have been in use in Japanese cars (Toyota, Honda, etc) dating back into the 1960's, such as in the original 1965 Corolla.

      about 3 days ago
    • Bran Stark
      Bran Stark

      Someone at youtube deserves a raise and a bj. So happy this was in my recommended. Subbed.

      about 4 days ago
    • Mark Richards
      Mark Richards

      Very simple informative explanation

      about 9 days ago
    • badad0166
      badad0166

      Concise information delivered in a professional manner. Most satisfying Utube experience. Harumph.

      about 11 days ago
    • V. E.
      V. E.

      Sure can hear the Coyote Mustangs when they rev. Completely different than a standard cross plane V8 - angrier, perhaps. lol

      about 11 days ago
    • Runkization
      Runkization

      Do some cylinders underperforms in V4 and in Yamaha crossplane inline 4 too? Cause even these engines fire unevenly.

      about 11 days ago
    • Grahame Rex
      Grahame Rex

      Great explanation. I’m new to understating these mechanics. Recently purchased an Alfa Romeo Giulia which has a flat plane crank V6 at 90 degrees. I found your video very informative.

      about 14 days ago
    • Sean Murkidjanian
      Sean Murkidjanian

      The point that is missing from this technology other than performance is endurance. meaning pistons that fire off at the same area of aluminium block is sure to fail due to heat offset in the block as a whole. endurance of the bearing package of this engine will have failure where that bearing is hit twice per fire order. with regards to performance, you pedal a bike at 180 and two adjacent axis. get a bike for two and find peak performance and build your crankshaft around that. Now you understand when you have a feeling your mechanical counterpart goes through.

      about 14 days ago
    • John Douglass
      John Douglass

      This video was an outstanding informative and concise demonstration of the flat plane crank. Exactly what I was looking for. Great job!

      about 15 days ago
    • 88SC
      88SC

      Single plane crank. Or “flat” crank.

      about 17 days ago
    • Quiet Knight
      Quiet Knight

      In what universe is a cross plane crank traditional?? You state yourself that the flat goes back to the earliest days of motoring, it seems to me that cross planes are found almost exclusively in higher end euro machines.

      about 23 days ago
    • Rock Fisher
      Rock Fisher

      Its looks like a flat plane crank would get more vibration because it looks like a giant rocking couple (picture a bicycle crank) when in operation. Parallel twins get that, especially when the bores get bigger.

      about 24 days ago
    • Inazuma MR
      Inazuma MR

      Thx - very cool explanation. Now I know how it really works

      about 25 days ago
    • M535
      M535

      Better sound. No...

      about 27 days ago
    • Arno Kilianski
      Arno Kilianski

      Related question: Are there any v-8 cars that use fork and blade connecting rods, like a Harley v-twin?

      about 27 days ago
    • Nippon Nostalgic TV
      Nippon Nostalgic TV

      With cross plane cranks. Could you alter the exhaust runner length on the appropriate cylinder to prevent the pulses overlapping like in the animation? Also, cylinders with uneven performance, would there be any gains to be had to different cam profiles fine tuned for each cylinder to reduce this issue?

      about 28 days ago
    • Cyphrix101
      Cyphrix101

      Flat-Plane or Cross-Plane, it doesn't matter to me. Long live the V8!

      about 28 days ago
    • Raspian Kiado
      Raspian Kiado

      I'm planning on making a (viewed from the first crank, to the back) Y shaped Crank. Would it be worth it.

      about 1 month ago
    • twl197860
      twl197860

      Everyone forgets in the early 1900s everyone was using flat plane cranks even the model t had one as for a cross plane crank being more reliable that really depends on several factors and flat or cross plane crank isn't one of them . So tired of ppl using Google for their info go to school or actually read a book .

      about 1 month ago
    • A Christian
      A Christian

      Wow, they are using a Porsche design. All boxers use that crank. lol

      about 1 month ago
    • Rick Murray
      Rick Murray

      The secondary imbalance mentioned here was not explained. It's the same reason 4 cyl inline engines shake or buzz (depending on their size and mounting). In a flat plane crank V8, you have 2 4 cyl engines 90 degr from each other, both shaking. You don't see modern 4 cyl engines over 2.5 ltr that don't have balance shafts. The shake is just too much to put up with over that (the Porsche 3 ltr 924 engine has a balance shaft, for instance). This imbalance is the result of the fact that the pistons are accelerated differently at each end of the stroke. And that is because of rod angularity when the piston moves in a straight line and the big end of the rod moves in a circle. The point in the stroke at which the piston movement changes from accelerating to decelerating is when the rod center line is at right angles to a line between the rod bearing and the main bearing. That puts the piston a little higher than midpoint of its stroke. Longer rods reduce this effect (it affects breathing as well). So the piston has less distance to travel in its reversal of direction at the top of its stroke than it does at the bottom of the stroke. The big end has farther to travel during the lower swing. The piston reverses direction quicker at the top of the stroke than it does at the bottom. That means it changes direction quicker at the top than at the bottom. That difference in acceleration produces different forces at the top and the bottom as well. Remember F=MA? Force = mass x acceleration. The difference in force at the top and bottom is what causes the shake. "Balancing" the parts has nothing to do with it. It is a result in differences in acceleration. "Boxer" engines, by virtue of their opposed cylinders cancel these forces out.

      about 1 month ago
    • BakerOne
      BakerOne

      Superb explanation, thanks

      about 1 month ago
    • EightFiveZero Braxton
      EightFiveZero Braxton

      better explanation than engineering explained, I like the animations you did

      about 1 month ago
    • Lefty16Vek
      Lefty16Vek

      Great video like the explanation and the visuals

      about 1 month ago
    • Colin Bremner
      Colin Bremner

      Sadly electric engines yield this tech obsolete very soon

      about 1 month ago
    • Rick Murray
      Rick Murray In reply to Colin Bremner

      Electrics are motors. That's what motor means. Internal combustion devices are engines. Using the term Motor referring to engines is popular, but technically not correct.

      about 1 month ago
    • Colin Bremner
      Colin Bremner

      You explain so nicely. What a clear mind and talent you have

      about 1 month ago
    • lawyers9
      lawyers9

      In reference to the flat plane shorter life span, just how much shorter?

      about 1 month ago
    • DukeDalington
      DukeDalington

      Very interesting, thank you.

      about 1 month ago
    • Marko Uzelac
      Marko Uzelac

      IT IS NOT NEW TECHNOLOGY!!!!

      about 1 month ago
    • Tj930
      Tj930

      Great video

      about 1 month ago