1300 or 2600 ???

[johnf]

First off I\'ve just paid up and become a full member

This question has been raised before and I\'m not sure what to do. My car\'s log book says 1300 but the information included in the \'Club Welcome Pack\' says that the DVLA does\'nt like it. So what should I do, tell them it\'s 2600 or carry on regardless ?

[J4P RX]

Id carry on if thats what its listed as.  Cheaper tax.  Im going to try and get mine registered as a 1.3

Plead ignorance if they complain, but then it is a 1.3 anyway so whats the issue !

Cheers
Lee

[t2rew]

i agree, your one of the lucky one\'s

[Adam]

Just registered mine at the dvla office.  I let them fill in the forms from the de-registration documents......1300cc   thankyou very much!   just play stupid if they start asking questions.

cheers

adam

[boltoa]

Forgive the ignorance, but how is the displacement of a rotary defined anyway? For a normal engine, its the swept volume of the piston times the number of pistons. For a rotary, is it the swept volume of one "combustion space" (don\'t know the proper term for it) or all 3 per rotor? Times 2 rotors, obviously. I\'ve been confused for some time by some sites that quote 2*653cc rotors, and some that say it\'s a 2.6l engine. Surely it\'s either 1.3 or 3.9???

Confused of Newark

Andrew

[g11ary]

I have one reg as 1300 and 2 as 2600 which I am gona try and get changed.

[richrx]

Originally posted by boltoa
Forgive the ignorance, but how is the displacement of a rotary defined anyway? For a normal engine, its the swept volume of the piston times the number of pistons. For a rotary, is it the swept volume of one "combustion space" (don\'t know the proper term for it) or all 3 per rotor? Times 2 rotors, obviously. I\'ve been confused for some time by some sites that quote 2*653cc rotors, and some that say it\'s a 2.6l engine. Surely it\'s either 1.3 or 3.9???

Confused of Newark

Andrew

baisicly the rotary is a 1300cc but it is classed by insurance as a 2600cc for higher premiums. i think its a 2600cc for mot too but im not sure. Also some people class it as a 2600 because they cant believe that you can get 250bhp from a 1.3

the reason is simply that because there are two rotars each carrying out their own power stroke that equals the same as a combustion engine of twice the capacity.

i.e 2 intake strokes, 2 combustions, 2 exhaust strokes = 2 power strokes

i have it clear in my head but i cant seem to put it down too easily, any more clarification would be helpful for all i think

[MikeLMR]

each chamber (3 per rotor) has a change in volume (capacity) of 654cc\'s (for a 13b or a 20b)

As the rotor spins ONCE for every THREE revolutions of the crank shaft 1 chamber of the three sided rotor will deliver power (while the other 2 are in the intake an exhaust phases)

therefor the capacity is 1308cc\'s as the rotor turns 1/3 of a revolution in one rotation of the ecentric (equivilent of the "crank") shaft

BUT

the government see fit to double this value for taxation purposes

Mazda have always quoted their engine sizes as 2x654cc or 2x573cc\'s etc. which I think is a better way of describing them

[boltoa]

I\'ve just read the howstuffworks article on the rotary. I thought I understood them, but I didn\'t realise the crank was internally geared in each rotor (but of course it must be now I think about it). There is effectively one power stroke in each rotor per revolution of the crank, which I guess vaguely justfies doubling the apparent capacity as a normal 4 stroke piston engine has a power stroke for 2 revolutions of the crank for each piston.

Still, typical of government to screw more tax out of us .

Andrew

[Grizzly]

Ok, How about a T2 (Gen 2) that has 2.4 on the Log book and has a 13b fitted?

For some funny reason the second gens where always classed as 2.4lt? Puzzling.

Chris