I may be completely off beam here but is there any reason why a Mazda rotary engine would be unsuitable, aside from the fear of the unknown? That and rotor tip wear. They do seem to be very powerful for their physical size and the noise is awesome!
Are there particular problems associated with their fitment in a T25?
Brooky.
Mazda rotary?
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Brooky
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Mazda rotary?
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toomanytoys
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toomanytoys
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Brooky
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Hmmm. Yeah but what a gorgeous noise! A bus that sounds like an F1 car!
There are other considerations. Only 3 moving parts; crank and two rotors, no valves, no camshaft, no cambelt or chains, virtually no constraints at all on revs and as every trainee mechanic is taught, making an engine rev faster is one of the four ways to increase power output. The others are; make it run hotter (better thermal efficiency), fill the cylinder better (better volumetric efficiency) and.....I can't remember the fourth!
So a turbo'd rotary engine fulfills two of those criteria. I'll have to try and find out how tall they are from centreline to top of plenum chamber.
Brooky.
There are other considerations. Only 3 moving parts; crank and two rotors, no valves, no camshaft, no cambelt or chains, virtually no constraints at all on revs and as every trainee mechanic is taught, making an engine rev faster is one of the four ways to increase power output. The others are; make it run hotter (better thermal efficiency), fill the cylinder better (better volumetric efficiency) and.....I can't remember the fourth!
So a turbo'd rotary engine fulfills two of those criteria. I'll have to try and find out how tall they are from centreline to top of plenum chamber.
Brooky.
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toomanytoys
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So a turbo'd rotary engine fulfills two of those criteria.
Very poor in basic thermodynamic cycle, in some respects worse than a reciprocating engine, the way it compresses gas, the 'lost volume', high surface area to volume ratio, and lack of full gas expansion...
Horrendously complex way of making a rotary engine though, took nearly 50 years for Wankel to get it working then another what, 20 or 30 for Mazda, a big shame, if Mazda had chosen a rotary with a better gas cycle to start with, having their great engineering abilities, might be throwing all our piston engines away now.
but yes, they rev well of course, their saving grace
Oh porting limitations too... limiting volumetric efficiency
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Also, don't rotary engines lack torque? You would have to rev the nuts off it to get it moving off the lights. Nice idea, but not suited to a bus. I still reckon the new Scooby boxer diesel engne is the way forward....
Couldn't agree more slamdunk, though if someone got their act together and developed the quasi-turbine it'd have so much torque you'd only need about 2 gears - that would be a proper rotary engine!
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fisher4772
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Rotary!!!
Ive owned a few rx7 s and disagree with most of your opinions,i found that the engine is very torquey even at low revs very quiet and the newer rx7 twin turbo very powerfull and reliable and costing under a thousand pounds for a full engine rebuild... I think it would make a good transplant engine and prefer the Type rb from the rx7 which produces more torque and bhp per cc compared with the factory restricted rx8 unit.
I think the only gripe would be mpg generally producing 25mpg on a carefull run but under 10mpg when your having fun......but just think 300 bhp standard what a smile....
I think the only gripe would be mpg generally producing 25mpg on a carefull run but under 10mpg when your having fun......but just think 300 bhp standard what a smile....