Porsche needs to be sued
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From: Bay Area, CA
Originally Posted by carrera4,Aug 21 2007, 10:15 AM
AP2 has more than 237/240 HP. Just like the NSX has more than 276.
Honda didn't want to obsolete the AP1 for the rest of world markets.
Just look at dynos of AP1 and AP2. AP2 is consistently 10+ whp greater.
Honda didn't want to obsolete the AP1 for the rest of world markets.
Just look at dynos of AP1 and AP2. AP2 is consistently 10+ whp greater.
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From: Palm Harbor, FL
Originally Posted by ZDan,Aug 21 2007, 03:23 PM
A rotary is not a two-stroke, and even if it were, two-stroke displacement is measured the same as 4-stroke displacement. 250cc two-strokes are not referred to as being 500cc.
Applying the FIA's arbitrarily chosen "equivalency" factor does not mean that a 1.3 liter rotary is *really* a 1.3*1.75 = 2.275 liter.
The fact that they have an equivalency factor is because rotaries DO make way more power/displacement than piston engines.
In the case of RX-8 vs. S2000, that would be 178hp/liter vs. 108hp/liter (120hp/liter for the AP1).
178hp/liter is, I believe, a record not only in the rotary world, but for all naturally aspirated production cars.
But 600cc sportbikes make more like 190/liter...
Applying the FIA's arbitrarily chosen "equivalency" factor does not mean that a 1.3 liter rotary is *really* a 1.3*1.75 = 2.275 liter.
The fact that they have an equivalency factor is because rotaries DO make way more power/displacement than piston engines.
In the case of RX-8 vs. S2000, that would be 178hp/liter vs. 108hp/liter (120hp/liter for the AP1).
178hp/liter is, I believe, a record not only in the rotary world, but for all naturally aspirated production cars.
But 600cc sportbikes make more like 190/liter...
http://en.wikipedia.org/wiki/Pistonless_rotary_engine
A Wankel engine has no empty stroke like a reciprocating four stroke engine, therefore a Wankel engine needs only half the volume of a reciprocating four stroke engine.
From wikipedia: http://en.wikipedia.org/wiki/Mazda_W...engine#Renesis
It won International Engine of the Year and Best New Engine awards 2003 and also holds the "2.5 to 3 liter" size award for 2003 and 2004, where it is considered a 2.60 L engine
Joined: Feb 2007
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From: Pawtucket, RI
It's somewhat arbitrary to say the 1.3 liter rotary is "equivalent" to a 2.6 liter engine. BTW, plenty of other "experts" continue to refer to it (more correctly imo) as a 1.3 liter.
IMO, it would be more appropriate to label a 2.0 liter 4-stroke piston engine as a 1.0 liter engine, because it only aspirates 1.0 liters per crank revolution.
Rotary aspirates 1.3 liters per crank revolution.
250cc 2-stroke piston engine aspirates 250cc per crank revolution.
You are right that they aren't comparable in terms of specific output. Rotaries and 2-strokes KILL 4-strokes in this regard!
IMO, it would be more appropriate to label a 2.0 liter 4-stroke piston engine as a 1.0 liter engine, because it only aspirates 1.0 liters per crank revolution.
Rotary aspirates 1.3 liters per crank revolution.
250cc 2-stroke piston engine aspirates 250cc per crank revolution.
You are right that they aren't comparable in terms of specific output. Rotaries and 2-strokes KILL 4-strokes in this regard!
Joined: Feb 2007
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From: Pawtucket, RI
Originally Posted by overst33r,Aug 22 2007, 07:18 AM
My question to you is, how does a 2.0L only have 1.0L of displacement when the crank rotates half way for the outside two cylinders to complete half a stroke, at the same time the inside two complete half a stroke. When one revolution of the crank is completed, ALL 4 cylinders have fully displaced the engines rated displacement.
If you looked at a 2.0 liter (4x500cc) four-cylinder starting at TDC prior to intake stroke on cyl1, one complete crank revolution goes like this:
Cyl1:
piston goes down, intake stroke
piston goes up, compression stroke
Cyl2
piston goes up, compression stroke
piston goes down, power stroke
Cyl3
piston goes up, exhaust stroke
piston goes down, intake stroke
Cyl4
piston goes down, power stroke
piston goes up, exhaust stroke
Note that only cylinders 1 and 3 have an intake stroke in this one crank revolution, and cylinders 3 and 4 have an exhaust stroke. i.e., only 2x500cc has gone into the engine, and only 2x500cc has gone out. 1 liter.
Next crank revolution, Cylinders 2 and 4 have an intake stroke, and cylinders 1 and 2 each have an exhaust stroke, another liter cycled.
Two crank revs required to aspirate 2.0 liters.