engine size debate
#1
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Thread Starter
engine size debate
having trouble telling guys about the size of the engine, few guys persume is a 1.3L but on my reg docs it says 2.6L i no each rotor has cubic copasity of 1.3 x2 as 2 rotors correct ?
#4
no sleep til it spools
If it was 2.6, that means that you'd have a 26b, which means that you have a 4-rotor, which means that I would try to convince you to come state side so that I could....."borrow" your car
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#7
40th anniversary Edition
By designating it as 2.6 in UK they can charge a higher fees. There was a RX8 club post this past year where a group of RX8 owners on the island of Crete, I think, won a year-long battle to defeat that island from raising the designation from 1.3l to 2.6l (the island wanted to raise the use fees and taxes to a higher category). The RX8 owners prevailed in court and it was correctly kept at 1.3l.
#8
Registered User
Thread Starter
so it is 1.3 then lol i think ive got 2 rotors i got 4 plugs multi port lol
£250 road tax 04 plate 06 plate £450 thats yearly lol.
how can a 1.3l engine use so much god dam fuel then so strange
£250 road tax 04 plate 06 plate £450 thats yearly lol.
how can a 1.3l engine use so much god dam fuel then so strange
#9
Registered
Probably because it has four spark plugs. Take two out and it won't use any. ![Smilie](https://www.rx8club.com/images/smilies/smile.gif)
FWIW, I had fun registering my 8 as having no cylinders. Property tax here in Virginia is by the book value of the car, so as long as they have the make and model, and a copy of KBB, they don't care about displacement.
Ken
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FWIW, I had fun registering my 8 as having no cylinders. Property tax here in Virginia is by the book value of the car, so as long as they have the make and model, and a copy of KBB, they don't care about displacement.
Ken
#10
no sleep til it spools
#11
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wasn't there some controversy over how Mazda figured the rotary displacement? In a piston engine it is easy because you add up the displacement of each cylinder. some argued that in a rotary, instead of the 2 "combustion chambers" mazda calculates (the displacement of one face of the rotorx2), you actually have 6 combustions chambers (the displacement of each face of each rotor), which would give youa 3.9 liter engine. which would explain our fuel economy.
Last edited by usnidc; 09-26-2011 at 01:29 PM.
#12
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you actually have 6 combustions chambers (the displacement of each face of each rotor), which would give youa 3.9 liter engine. which would explain our fuel economy
Fuel economy (or lack thereof) is explained by the shape of the combustion chamber and all the surface area involved through the strokes.
Ken
#13
Uncontrollable drifter
By designating it as 2.6 in UK they can charge a higher fees. There was a RX8 club post this past year where a group of RX8 owners on the island of Crete, I think, won a year-long battle to defeat that island from raising the designation from 1.3l to 2.6l (the island wanted to raise the use fees and taxes to a higher category). The RX8 owners prevailed in court and it was correctly kept at 1.3l.
Really? Think so? Cooooome on....
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#15
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Because it produces so much hp and performance for it's displacement it is considered a very efficient engine in power to displacement ratio. For that reason I can forgive the fuel economy which is a little worse than a 265 hp piston 3x it's ci. The fun factor, comfort and handling easily make up for it. High performance engines use more gas. Some more than others. The greedy oil companies and the price at the pump are what bothers me. I hate giving into them, even filling my 90mpg scooter feels like I'm getting screwed by big oil.
#16
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Because it produces so much hp and performance for it's displacement it is considered a very efficient engine in power to displacement ratio. For that reason I can forgive the fuel economy which is a little worse than a 265 hp piston 3x it's ci. The fun factor, comfort and handling easily make up for it. High performance engines use more gas. Some more than others. The greedy oil companies and the price at the pump are what bothers me. I hate giving into them, even filling my 90mpg scooter feels like I'm getting screwed by big oil.
now a 1.3L rotary engine is equivalent to a 2.6L inline 4 four stroke engine looking at firing order, or 1.3L inline 4 two stroke engine AT maximum load.
so really, if you talk about power/displacement efficiency it all comes down to how they use the displacement.
#17
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you cant compare displacement vs power in different engine type. say if you have a 1.3L two stroke and a 1.3L four stroke, the two stroke will make twice as much power and burns twice as much gas at maximum load (assume same efficiency), because power comes from burning gas.
now a 1.3L rotary engine is equivalent to a 2.6L inline 4 four stroke engine looking at firing order, or 1.3L inline 4 two stroke engine AT maximum load.
so really, if you talk about power/displacement efficiency it all comes down to how they use the displacement.
now a 1.3L rotary engine is equivalent to a 2.6L inline 4 four stroke engine looking at firing order, or 1.3L inline 4 two stroke engine AT maximum load.
so really, if you talk about power/displacement efficiency it all comes down to how they use the displacement.
Please explain th 3.9 theory as posted below. Which is more correct yours or his?
some argued that in a rotary, instead of the 2 "combustion chambers" mazda calculates (the displacement of one face of the rotorx2), you actually have 6 combustions chambers (the displacement of each face of each rotor), which would give youa 3.9 liter engine. which would explain our fueleconomy.
#18
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Please explain th 3.9 theory as posted below. Which is more correct yours or his?
some argued that in a rotary, instead of the 2 "combustion chambers" mazda calculates (the displacement of one face of the rotorx2), you actually have 6 combustions chambers (the displacement of each face of each rotor), which would give youa 3.9 liter engine. which would explain our fueleconomy.
some argued that in a rotary, instead of the 2 "combustion chambers" mazda calculates (the displacement of one face of the rotorx2), you actually have 6 combustions chambers (the displacement of each face of each rotor), which would give youa 3.9 liter engine. which would explain our fueleconomy.
now, we looking at a four stroke engine. it takes a single four stroke engine two crank shaft rotations to do a combustion, so two pistons give you one combustion per rotation. now a 654cc single rotary engine combusts 654cc per eccentric shaft rotation, for a twin cylinder engine to do the same, it needs TWO 654cc combustion chambers to satisfy combusting 654cc per crank shaft rotation. that gives you 1.3L. now two 654cc rotary engine, equals two 1.3L twin engines, that gives you a 2.6L inline 4.
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Please explain th 3.9 theory as posted below. Which is more correct yours or his?
some argued that in a rotary, instead of the 2 "combustion chambers" mazda calculates (the displacement of one face of the rotorx2), you actually have 6 combustions chambers (the displacement of each face of each rotor), which would give youa 3.9 liter engine. which would explain our fueleconomy.
some argued that in a rotary, instead of the 2 "combustion chambers" mazda calculates (the displacement of one face of the rotorx2), you actually have 6 combustions chambers (the displacement of each face of each rotor), which would give youa 3.9 liter engine. which would explain our fueleconomy.
I threw that out as something I had seen discussed in various places a long time ago where some people were debating how to compare the rotary to other engines. the arguement was each rotor has 3 "combustion faces" so that is 6 x 650cc = 3.9L. But that doesn't go into the differences with how the rotary combustion cycle/eccentricshaft rotation works vs. a 4 stroke recip engine.
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i researched the engine a little more in regards to displacement. The displacement is 1.3 by volume but breaths like a 2.6 piston for the reasons you stated. So the rotary breaths twice as efficient as a piston engine the same displacement but also sucks more gas for the reasons stated. Insurance companies are wrong to call it a 2.6 for rate hikes. Here in wisconsin my 8 is rated as a 1.3 four cylinder familiy sedan by state farm. I love it. My insurance rates are lower than 4 banger accord I had 10 years ago. kinda makes up for the lower gas mileage.
#21
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i researched the engine a little more in regards to displacement. The displacement is 1.3 by volume but breaths like a 2.6 piston for the reasons you stated. So the rotary breaths twice as efficient as a piston engine the same displacement but also sucks more gas for the reasons stated. Insurance companies are wrong to call it a 2.6 for rate hikes. Here in wisconsin my 8 is rated as a 1.3 four cylinder familiy sedan by state farm. I love it. My insurance rates are lower than 4 banger accord I had 10 years ago. kinda makes up for the lower gas mileage.
lucky you. how come mine is listed 1.3L "sport" coupe and I am paying almost twice as much as I paid for a 3.5L four door sedan?
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maybe cuz I totalled two motorcycles. oh well.
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Last edited by jasonrxeight; 09-28-2011 at 11:46 AM.
#23
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They do it because of the related power to a cylinder engine and for tax purposes. 1.3L cars are typically under 100 HP. So they classify the Rotary as a 2.6L so they can steal more money when the tax man comes. I agree though should be taxed as a 1.3L not our fault we bought a wankel engine.
#24
Senior Member
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They do it because of the related power to a cylinder engine and for tax purposes. 1.3L cars are typically under 100 HP. So they classify the Rotary as a 2.6L so they can steal more money when the tax man comes. I agree though should be taxed as a 1.3L not our fault we bought a wankel engine.