Then that makes the VR6 detuned too... Running the engine to the limit as we do would have ensured non complience for the manufacturer in various certification tests before the vehicle or powertrain could be sold.
The 1ZZ-FE is an economy engine found in many everyday econoboxes. The emphasis here is low CO2, low emissions, low to mid range torque response and good fuel economy. In addition to the undersqaure dimensions of the short engine the cylinder head carries a 22.5 deg cant between valves and the intake cam is driven be a scissor gear from the exhaust cam. These engines also carry a close coupled catalyst. A smaller 1500cc varient to this is called the 3ZZ-FE, found in the JDM Corolla Fielder. 2ZZ-GE is a bit different. in addition to the near perfect square dimension the 'G' type head allows for TIVCT and at least a 45 cant between valves. Essentially this engine can rev torque quite high by increasing valve overlap electronically and when operated at lower speeds reduce overlap and increase VE to improve low speed torque. These engines can be found in the Corolla, Celica, MR-S and JDM Corona ( Avensis ) Toyota has been building engines with this format for ages and examples that come to mind are the Corolla 4A-FE vs the GTi/Levin 4A-GE or the Celica 3S-FE vs the 3S-GE This is just another addition to what influences the marketed power and torque figures used to sell the vehicle.
Daved's workings earlier on in this thread got me thinking, so I wrote up a program in Matlab which produced these graphs. The displacement, velocity and acceleration shown are all VERTICAL components of the piston's motion. In the first three, the blue lines represent a 144 rod and the red lines represent a 159 rod, both with a stroke of 92.8. The displacement is the vertical distance from the top of the rod to the centreline of the crank. However, I have shifted the curve for the long-rod down the graph by the difference between the 2 rod lengths. (Sorry if I'm being confusing, but I did it so we can focus on how long the piston takes to travel over TDC, rather than height of block.) And for the purpose of this thread, the next three graphs still have a stroke of 92.8, but rod lengths of 100 (blue) and 300 (red), just to exaggerate (massively) the differences in motion. So we can see how the longer rodded engine takes longer to pass over TDC, but the shorter rodded engine falls away from TDC faster. I'm no expert on the behaviour of engines, but I hope some of you will find the graphs interesting and might be able to interpret them better than me... Of course, there's plenty of assumptions etc... if I find myself trying to dodge more exams-revision later this week, I might start considering forces
Nice work. I'm now going to sit back whilst others make more sense of this (!). Thanks for the superb contribution.
Toyotec, I'm suggesting Toyota achieved very different torque characteristics from sibling engines through major changes to ancillaries rather than architecture - - at (presumably) far greater lifetime cost than simply increasing the deck height and rod length whilst retaining common ancillaries (of course, another option is to substitute a longer rod within the same deck height by decreasing the piston compression height, but it appears contemporary engine designs already exploit that option) Again assuming identical 1ZZ and 2ZZ deck heights, Toyota's action seems at odds with those who promote rod/stroke ratio change as a panacea for manipulating torque production - - or perhaps it suggests Toyota can, within reason, ignore that principle as a similar effect is available through ancillary substitution? Perhaps ever improving materials, heat treatments, and surface finishes mean, despite increasing rev limits, previously imprudent ratios no longer threaten piston and bore integrity to the same degree, thereby encouraging shorter rods and compact engines as desired for less frontal area and lower wind resistance? Apart from the long rods of high rpm engines (spot the exception!), there seems few patterns in the following rod/stroke ratios (please correct if certain of your sources) Ford Zetec R 1.55 Honda B16 1.73 Honda B18 1.58 Honda F20C 1.82 Mazda FS-ZE 1.47 (seems extreme, but - - ) Mitsi 4G63 1.70 (minor variations with model changes?) Nissan SR20DE 1.58 Renault F4R730 1.55 Rover 3500 2.02 Suzuki Hayabusa 1.90 Toyota 1ZZ 1.60 Toyota 2ZZ 1.65 VAG 9A 1.55 VAG ABF 1.72 And fishnchipsx2's welcome contribution graphically demonstrates how fuel combustion characteristics don't seem influential either, as designers do not appear to have specified long rod engines in order to exploit the suppressed ignition characteristics of leaded fuel - - and neither does combustion chamber efficiency appear influential - - Ideas/suggestions?
Please advise, which rod length do I need when stroking the ABF to TDI Crank? The pistons um gonna use is the one on auto tech http://www.autotech.com/prod_engine_engkit.htm
If you are fitting the stroker crank, you will be over 2000cc. Is that permitted? Are you considering the 'Knife Edge' crank? Check out Brain G's thread, if so!
Check out his thread regarding combustion chamber clearance! http://www.clubgti.com/forum/showthread.php?t=157590
Cetainly true when considering the low tech truck lumps in this link. http://victorylibrary.com/mopar/rod-tech-c.htm
Cheers i thought my name would be dragged into this conversion at some point. Regarding the question above with building a stroker Engine from an ABF using a 1Y 95.5mm Crank. The crank and block will need to be machined to allow correct fitting to prevent clearance issues. Pistons will have to be custom deck height which are available but you will probably need 159mm rod with a 20mm pin. Wossner ABF 9032D Piston comp height 31.6mm Wossner 9A 9031D Piston comp height 30.6mm
Good work with the trig, not sure about your force diagram. As the piston rod angle changes so does the rod crank angle which cancels it, leaving torque the same for both. Also you say "Power will be higher in the 144 rod engine as with the same force applied it will have travelled further in the same time" Will it be the same time though. It's your force F that dictates h that makes the angle, not the other way around. What i'm trying to say is that if the force acting on the piston, and the time it acts, are the same then h will be equal and the angle of the shorter rod engine will be less. For the angles to both end up at 45 either F would have to change, or more likely the time F acts.ie the ABF would cover the first 45 deg more quickly than the 9A (over simplified). Not sure if this is any help or not as I've forgotten more of this stuff than I know.
It has to be the same time, cos. they are both travelling at the same RPM! I understand what you say, but although 144 accelerates more quickly, it has to do so to get to 45 deg at the same time as 159. Force F will be less on the 144 rod cos. P1V1 = P2V2 (See post #52) The resultant force R, on the 144 rod, will be less cos. in forms a larger angle with the cylinder. The only saving grace for the 144 rod, is that the lever arm will be longer than for the 159 rod. Approx 39.41 mm vs 38.86 mm. Just did a quick calc: Lever Arm x Instantanious Load @ 45deg (post #52) x cosine (Angle between Rod and Cylinder) 159 ; 38.86 x 0.158 x 0.9785 = 6.008 144 : 39.41 x 0.147 x 0.9737 = 5.64 159 > 144 PLease re-calc and post if I have cocked it up!
But RPM only takes in to account the average over many whole revolutions. They will both travel around the 360 deg in the same time, but may not cover the 45 segments at the same rate.
I agree with you on all this. But, while the 144 forms a larger angle with the cylinder, it forms a 'better' angle with the crank, which cancel eachother out.