Doug,
All the lightened flywheels have their sizes tare taken off the manual
flywheel. I assume because the lightened flywheels are used in
performance
vehicles with manual gearboxes. Remembering lightened flywheels are NOT
turned down cast manual flwheels but turned steel flywheels to preset
weights. Many can be purchased off the shelf ( or ordered) for many
different model engines.
All manual flywheels are smaller than the Auto flex-plates.
I believe all manual flywheels are the same diameter 298mm OD and all
flex-plates are the same diameter 320mm OD.
I can't for the life of me wonder why the RX8 would be different - but I
haven't checked. Perhaps someone is confusing the manual and flex-plate
OD.
I believe the Ross PSRU's used the manual diameter for their lightened
flywheels. This also tends to provide more room in an auto bellhousing.
Their wouldn't be a problem making a lightened flywheel in either
aluminium
or steel in either diameter - as Richard Sohn has done with the single.
It
would require the engine to be balanced OR make it the same weight as
the
combined flex-plate and counter weight. Understanding the weight must be
in
the correct place. Richard achieved this with lightening holes, however
this
is an assumption on my part. As flex-plates become more scarce, perhaps
this
will be only course available to new builders.
I think a flat plate would be easier to mount Tracy's type dampers but
would
recess the starter ring more toward the engine, requiring a starter with
a
longer snout- probably not too big a deal as their are other ways around
this as well.
Hope that helps !
George ( down under)
Doug,
I checked the difference between depth of the flex-plate at the rear face
(that Tracy recommends), it's only 5mm - that's 5mm difference because of
the recessed centre.
If using aluminium for a flat plate, that 5mm would be the back side of
the
turned recess, as in the manual flywheel which holds the ring gear-
problem
of the depth of the starter solved!!
The builder that has a RX8 flex-plate, could he quote the OD please!
George ( down under)
George,
Thanks for your input. The challenge is fitting the CVT into a robust
Bell
housing with sufficient depth and width. My old RX-4 semi automatic bell
housing is a little too old to be trusted and is not as robust as the
RX-8.
Also the starter motor comes from the front and interferes with the PSRU
housing. Worst of all it looks clunky. The automatic bell housing looks
good and if I can find some dimensions for it I'll pick one up.
Cheers mate
Doug
Here are some pictures of Doug's old RX-4 semi automatic bell housing.
Don't chop it up Doug. It is probably a collectors item.
Paul Lamar
Doug,
What a coincidence, I just had a Cosmo Auto BH in my hands on the weekend. I
needed to check the extra bolt hole placement and the young chap up the road
( neighbour) has two of them.
I know Don Dunbar in Western Australia is using one for his development and
wondered if it was up to the task. Well I can honestly say this is a well
made BH and appears very strong indeed. The reversed starter would suite
your purpose as well.
What dimensions would you need - I noted the front face bolt pattern, which
is 214mm (8 3/8") Dia and depth of 168mm (6 3/8"). Just from looking at the
RX8, I would say it was equally well made with the extra bolt hole in the
same place as the Cosmo ( perhaps) at 101.25 degrees, just left of the top
centre. However I would say it's much longer, by just looking at the Photo
Paul has shown.
I guess it boils down to, if you need more than 6 3/8" of depth!?
George (down under)
Gidday George,
Thanks for your fast response. I think the Cosmo is out because the Bell 47
diameter is definitily over 214mm. It is excellent for use with Tracy's unit
though. I'm heading to the office now to check. I would be interested to
know the dimension of the front face and depth of the RX-8 housing if you
come across one. I am busy putting ALL parts into Rhino now as Paul has
repeately stated, it does make it a lot easier to design the total engine
layout. I know this but it doesn't make it less painful:)
Doug
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