Piston and rod size of the D14A3/A4/Z1/Z2

[saxophonias]

Very true Nick regarding the r/s ratio and the reliability issues!!take the d16s engines for example. if they rev 8000rpms like dodo does they won't last too long. The strains on the rods are great due to the bad r/s ratio. Take d12 and d13s for example. These engines lack rev limiter. Some people rev them @ 8000 stock and they keep working.
d13 engine is 75x76 and the jdm version scores 89hp

[mynameisowen]

hmm interesting. But there must be a reason why most engines arent designed to be as square as possible? For example Bseries is oversquare like you mentioned. Is this simply to increase torque?? Because if you have more torque then you dont really need to rev as high to create the same amount of power, as power=(torque x revs)/5252

????

[Dodo Bizar]

8100 rpm it is ...

I guess low rpm efficiency might improve from the under square setups? Just guessing now though.

[hondaNickx]

Under square engines with low R/S ratios always make more torque and visa versa for over square engines.
compare a B16 with a D16 that both put out 160Bhp.
The D16 will always have more torque then the B16.

[mynameisowen]

Just two ways of achieving the same goal then. But a D16 with 160hp and more torque will win a race over a B16 with less torque but has too rev higher to achieve 160hp.

[hondaNickx]

Just two ways of achieving the same goal then. But a D16 with 160hp and more torque will win a race over a B16 with less torque but has too rev higher to achieve 160hp.

Yes indeed torque is your friend.The B16 makes up (Cheats) for that with a very short tranny,which will put more torque at the wheels.

On a D14 you need to (cheat) a little too and take advantage of shorter transmissions like a D13b2 tranny for example.

[mynameisowen]

yea true. Its hard to compare engines because we only see them in cars and all cars have different trannys. It would be interesting to see a number of cars with different engines all with the same ratios and weight and see which beforms best.

[Dodo Bizar]

I once just laid the rpm/power curves of both my D14 and B16B on top of each other, same scales. Till 6000 rpm the D14 won (by a little)!

Btw since the new header the B16B wins overall, it got like 20Nm more torque in the low to mid rev for it.

Btw this brand new Honda JGTC car with the V8 or V10 ~3.5 litre and 500 bhp. It is enormously over square, 1.2 or 1.3 I think it was.

[mynameisowen]

its all very interesting. Id love to see some proper comparisons.

[NIO]

D14A4 pistons are different from D14Z2 pistons. I'm sorry that I can't provide pics but when I rebuild my D14Z2 engine I found the difference of the two pistons. D14A4 piston dish is deeper than D14Z2. D14Z2 is almost flat. The piston code was something like PXHG. But I will check it out again to be sure. Cheers.