>>> How would one go about Raising a rotary's compression ratio?
>>>
>>> For the same compression ratio as a piston engine does a rotary engine
>>> require more, less or equal octane?
>>> Thanks,
>>> Brent Hasty
>>
>>
>>
>>> Requires changing the depression depth in the rotor flanks.
>>>
>>> Paul Lamar ...No rotor no motor.
>>
>>
>> I can see it would be easy to lower compression by removing
material, to
>> raise
>> you would have to fill in the depression, typically how? with weld?
>>
>> Thanks,
>> Brent Hasty
>>
>> You might try screwing in a curved steel plate.
>> Or braze it in.
>>
>>
>> Paul Lamar ...No rotor no motor.
>
> Paul,
> That could be a bit risky - might try the RX8 10:1 rotor with 3mm apex
> seals! Which is what I'm using on the single development.
>
> George ( down under)
>
> The RX8 rotors are having cracking problems. I don't know if Mazda
> fixed it yet.
>
> --
> Paul Lamar ...No rotor no motor.
NOW you tell me!!
George ( down under)
----------------------------------
So are we now saying that stock RX-8 engines have
problems with cracking on the rotors?
Or has this only an off chance, and that this has
shown up in the cars under certain circumstances
That concerns me as I have I have 2 of these targeted
for aircraft use. one 6 port and a 4 port.
Regards David
It is showing up in Star Mazda spec formula road racing racing.
Usually the rotary engines last up to three 10 race season. It is
happening after several races. The red line is 8500 RPM. Most of
the time is spent near red line. Piston engines under the same
circumstances last as little as one race and maybe three or four
races at the outside. The fix is minor for Mazda. Merely a small
change to the rotor casting patterns. The crack happens at a machined
notch that locates the rotor bearing shell.
Paul Lamar ...No rotor no motor.
-------------------------------------
So, Should I need to strip these engines down they are in
extremely good condition and I have run both of them up for
a few hours a piece now, They were two of the "test motors"
from rupert. It is unlikely that they will see more 7500RPM
at a pinch they might see max rpms at high altitude maybe
that will be a while away yet at the moment.One of the engines
is slated for a 2 seat side by side Gyro.
I don't mind, if I it has to be striped and modified then so be
it in which case I'll get "extreme rotaries" just down the road
from me in Melbourne to do one of their "stud kits" and they can
put it back together at the same time.
Or leave them alone?
Your opinion?
Regards David
Leave them alone for now David. I would tear them down after
500 hours and do a magnaflux inspection however.
You don't really need the stud kits for NA use. Mazda beefed
up the end housings around the two dowel pins about 1991. The turbo
engine end housings were cracking due to detonation when
people jacked up the boost over 10 psi. The stud kit is for people
running 30 or 40 psi boost. However it does fix the tension
bolt resonant problem in the bargain. Since Tony is missing
the point perhaps you can talk Guru into making them out of
titanium to cut the weight as the bigger steel studs required
in the stud kit are heavier.
Paul Lamar ...No rotor no motor.
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