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Project Cosmo - Finished (nearly)

B-Man

By B-Man,
in New South Wales

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Abo Bob Grand Master

Abo Bob

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none of this hopefully :nyaanyaa:

Haha, that's funny.

I've always thought that it was a bit disingenuous to claim that a 13B is a 1.3L and a 20B a 2L. I say there are 3 chambers in each rotor, not 1, so a 13B is 3.9L and a 20B is 6L. Power output seems to be more commensurate with this theory but the rotary still has the weight and physical dimensions advantage when compared to other engines of the same size.

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B-Man Grand Master

B-Man

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In a standard piston engine (an Otto or Diesel engine), displacement is calculated by multiplying the number of cylinders in the engine with the area of a piston and the length of the stroke. With circular pistons, displacement can be calculated from the bore diameter and stroke using the following formula:

displacement = pi /4 * bore^2 * stroke * number of cylinders

Displacement in a Wankel engine is much more complicated. For instance,Mazda's 13B is a two-rotor engine with combustion chambers of roughly 0.65 liters in displacement (difference in max vs. min combustion chamber volume). At 100% volumetric efficiency, 0.65 liter per rotor face * 3 faces per rotor * 2 rotors gives a total displacement of 3.9 liters. It takes 3 rotations of the eccentric shaft to complete one engine cycle, however. In 2 rotations of the eccentric shaft, comparable to 2 crankshaft rotations on a 4-stroke piston engine, the 13B would displace 2.6 liters. Mazda advertises the 13B as a 1.3 liter engine, which is the volume displaced during a single rotation of the eccentric shaft.

lingeringsoul Grand Master

lingeringsoul

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the funny thing is, they are pretty much dirt cheap these days.....i saw guy had a beautiful yellow one for sale for around 10-13 grand?? seriously, lux interior + 20b....what more can you ask for

i putst my hand up for a ride in the bmanmobile

B-Man Grand Master

B-Man

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I know - they are sooo cheap now - I can't beleive that they are so hard to sell that the price has come down that much. Doesn't bother me cause I am keeping my baby for ever.

You know - the early Cosmos - the 12A ones - are fetching BIG $$$ now - Hoopefully in 20 years time mine will be worth a bit .... ha ha ha !

B-Man Grand Master

B-Man

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Car started today - no issues at all. According to Race Solutions it sounds 'tough'

Matt has tuned it - run in tune - no idea if they have put it on the dyno - I expect not, until it has been run in and proper tune.

Maroun is finishing off the air box and I pick up tomorrow ! Yay !

B-Man Grand Master

B-Man

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YAY !

Got the Cosmo back today. It's running a very safe run in tune and RPM is limited to 4500 - I don't think they trust me - ha ha ha

First thing I noticed was that it was way louder than it was before - all the twin turbo junk off and with the nice big single, free flowing dump etc makes a hell of a difference. Before - it sounded like a straight six - now it sounds like a rotor. Bigger ports helps too. Its sounds tuff - Nice.

The boys at Race Solutions & Hit Man did a fantastic job - they wouldn't let me take it until everything was just right.

And Nick (Blitz) - guess what the wastegate dumps to ------- did someone say screamer ???

Had a small problem with the Bosche 044 - doesn't go in the tank - it's an external one - my bad. Not to worry - the boys are ging to knock up a dual Walbro in tank system. I don't need the extra fuel yet. This will happen after its run in and gets a final tune.

Boost is limited to 5 PSI at the moment - and I get that at 2500RPM

Very happy with the result and will be even more happy in a couple of weeks :D

legend01 Experienced

legend01

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The running in bits the pain ,only got 270k's on mine, did first service today and of to Newcastle via the putty and back down through gosford on the old road tomorrow rough figgers gives me near another 500k's close to second service .Matt did a runin tune on mine fortnight ago .Maroun showed me your car and told me what they had done to it lot of custom work in thet manifold

Peter

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