lightened flywheel

[karlncas]

Hi all,

Saw an article on t.v the other day about the lightened flywheel and was
interested if anybody has one, how much are they?, where from? And if I am
able to remove the gearbox am I able to install it or is it a technical job
best left to an expert ( x being an unknowen quantity and spert being a drip
under pressure).


Cheers

Karl and Cassandra Blumenthal

[Ian]

Hi Karl...

Autotek in Carlyle St ChCh (Prop. Peter Cunliffe) Ph 03 372 9595,
info@autotek.co.nz sell a light flywheel for $550 incl gst. I don't have any
details of weight etc.
I believe, with the right tools, your flywheel will come off without hassle
and engine in place...

Cheers, Ian Wooster

From jifjif@gmail.com Fri Apr 27 16:57:51 2007
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Date: Mon, 11 Jul 2005 17:29:54 +1200
From: ~Jeff~ <jifjif@gmail.com>
To: MX5List <mx5list@mx5club.org.nz>
Subject: Re: lightened flywheel
In-Reply-To: <20050711045601.A28851A504B@mail.inspire.net.nz>
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If you're doing the clutch anyway, it's not much more labour, so it's
just the extra cost of the FW ($500 in my case).

briefly (cos I'm going home ):

PROS:
- revs faster
- faster acceleration (in theory)
- cool factor

CONS:
- revs drop faster than the synchros match up, requiring a lot of
blipping the throttle, esp when cold (grumpy synchros)
- noisier; tho mine is pretty quiet so I forgot about this but still
thought I had engine bearings going south for the next week (see the
"warning")... http://www.flyinmiata.com/index.php?dep ... r=08-26000
- $$$
- ring gears need to match the starter motor teeth, otherwise nastiness results
- easier to stall when stopping for the lights.
- no point chrome plating it, doesn't come with flashy stickers


In practise the "pros" listed above aren't really noticeable (esp #2,
with a turbo)...
this is a cro-moly steel one, not a super lightweigt Alu unit. A nice
Mazdaspeed one can be ordered from your friendly Mazda dealer, but is
~$1k !

If you can remove the 50kg transmission from under the car then the FW
should be easy-peasy. There's a writeup on miata.net/garage too.

HTH !
Jeff


On 7/11/05, Karlncas <karlncas@inspire.net.nz> wrote:
[...]

[Mikkels]

If you can remove a gearbox you can install a flywheel but
you will need a torque wrench to do up the six flywheel
bolts and a clutch alignment tool to align the clutch plate.
Actually you can get way without a clutch alignment tool as
you can feel the clutch plate around the side of the cover
plate and get it right that way.

I'm just about to get an aluminium flywheel on my trip to
the USA in a weeks time. $400 US. I will install when I
get back

I'll let you know how it all goes.

Don
[...]

[Ian]

Does anyone know of a source for a Jacson Racing cold air intake (for an NA
1800)?

Ian

[poison]

Make one, looks better and sounds better...
http://www.mx5club.org.nz/downloads/gazza_cai_1.jpg

zorruno has one, maybe he will sell it.

Gazza

"PO1SON"

[EricW]

Hi Karl,

These comments are general, to give you some idea of what you are looking at,
they will relate to the MX5 in principle, but as I have never taken one apart,
they are not specific to the MX5

The job is pretty similar to changing a clutch, and I think we all agreed
that, lacking the tools and facilities, that is a job best left to the
experts.

Basically, you go one step further and having removed the gearbox and clutch
assembly, you can unbolt the flywheel from the back end of the crankshaft,
(The bolts are quite often locked with tabs which you flatten out with a small
cold chisel or punch, the tabs, if any, should not be re-used). Preventing the
crankshaft from turning, while you swing on these bolts, can be a real issue.

Once you get it off, you can then simply re-assemble the whole thing again
using new components. Note that you cannot usually assemble the clutch onto
the flywheel before you put the flywheel back, as the clutch cover covers the
flywheel bolts

Doing a flywheel necessitates replacing the clutch friction plate, as the
flywheel constitutes one of the pressure faces of the clutch, and the old
clutch plate will have scored to match the old flywheel. (You would not
install old brake shoes on new drums, or would you? It's essentially the same
thing).

Since you are going that far, you would probably replace the entire clutch
assembly, you should at least reface the clutch pressure plate (same issue as
the flywheel, it's a pressure surface, which will be scored, not good on a
nice new friction plate). Replacing it would not cost a lot more and makes the
best economic sense. You would certainly also replace the clutch thrust
bearing, they are never the same after they have been disturbed.

You would also factor in a new ring gear, unless the new flywheel has one
machined in. (Not a great idea, replacing the ring gear then means a new
flywheel, thus a new clutch and away we go again . There are also stress
issues for a flywheel with an integral ring gear, unless it is "stress
relieved" after machining, (specially heat treated), and it could come apart.
Integral ring gears are best left to racing cars where they can throw the
flywheel away after each race or two).

The ring gear is usually expansion fitted to the flywheel, you get the gear
glowing a nice cherry red with a Gas torch then quickly slip it on. When it
cools down, it contracts very tightly onto the flywheel. You need to know what
you are about, you generally only get one shot at this.

(There's the answer to that old brain teaser about "if you heat up a circle,
does expansion make the hole in the middle bigger or smaller")

A lightened flywheel will give you faster engine acceleration/decceleration,
due to the reduction in inertia and momentum, but the engine will probably
need to idle faster and will not idle as smoothly.

It would seem to me, and I can only speak in general terms as I have never
done this job on an MX5, that it would be essential to dynamically balance the
new flywheel. That's a specialist job, but the idea of a dynamically
unbalanced flywheel, at 7000 rpm, frightens me!. This is done on a special
balancing machine and is akin to balancing wheels, but much more critical due
to the much higher rotational speeds.

As a guestimate, I think you would get little change from $1200 to $1400, all
up, to professionally do the flywheel with a new clutch, flywheel etc.

However, to answer your question directly, if you have the gear and skill to
remove and replace the gearbox and clutch, getting the flywheel off, and back
on, should be relatively simple.

Good Luck

Eric

[Mike Jolley]

Gaz, Dont wof nazis get funny about this type of induction threw
firewall>>>>mike
looks good thogh.

From jifjif@gmail.com Fri Apr 27 16:57:26 2007
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Date: Tue, 12 Jul 2005 16:39:01 +1200
From: ~Jeff~ <jifjif@gmail.com>
To: MX5List <mx5list@mx5club.org.nz>
Subject: alignment in Auckland? (Panmure-ish)
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Someone recommended a good place around here (Panmure, Greenlane
vicinity) a while ago, could they please list it again? I'm the
finicky type ...

thanks!
Jeff

[karlncas]

Eric,


WOW that was more than informative, thanks for taking the time to write all
of that down, it has answered my question and some.

I think I will go and see Autoworks here in palmy and have them source the
part and put it in for me when I have saved a bit more, best done right the
first time as they say.

Thanks heaps again


Karl and Cassandra Blumenthal


_____

From: e-admin@mx5club.org.nz [mailto:e-admin@mx5club.org.nz] On Behalf Of
Eric & Ann West
Sent: Monday, 11 July 2005 10:14 p.m.
To: MX5List
Subject: Re: lightened flywheel


Hi Karl,


These comments are general, to give you some idea of what you are looking
at, they will relate to the MX5 in principle, but as I have never taken one
apart, they are not specific to the MX5


The job is pretty similar to changing a clutch, and I think we all agreed
that, lacking the tools and facilities, that is a job best left to the
experts.


Basically, you go one step further and having removed the gearbox and clutch
assembly, you can unbolt the flywheel from the back end of the crankshaft,
(The bolts are quite often locked with tabs which you flatten out with a
small cold chisel or punch, the tabs, if any, should not be re-used).
Preventing the crankshaft from turning, while you swing on these bolts, can
be a real issue.


Once you get it off, you can then simply re-assemble the whole thing again
using new components. Note that you cannot usually assemble the clutch onto
the flywheel before you put the flywheel back, as the clutch cover covers
the flywheel bolts


Doing a flywheel necessitates replacing the clutch friction plate, as the
flywheel constitutes one of the pressure faces of the clutch, and the old
clutch plate will have scored to match the old flywheel. (You would not
install old brake shoes on new drums, or would you? It's essentially the
same thing).


Since you are going that far, you would probably replace the entire clutch
assembly, you should at least reface the clutch pressure plate (same issue
as the flywheel, it's a pressure surface, which will be scored, not good on
a nice new friction plate). Replacing it would not cost a lot more and makes
the best economic sense. You would certainly also replace the clutch thrust
bearing, they are never the same after they have been disturbed.


You would also factor in a new ring gear, unless the new flywheel has one
machined in. (Not a great idea, replacing the ring gear then means a new
flywheel, thus a new clutch and away we go again . There are also stress
issues for a flywheel with an integral ring gear, unless it is "stress
relieved" after machining, (specially heat treated), and it could come
apart. Integral ring gears are best left to racing cars where they can throw
the flywheel away after each race or two).


The ring gear is usually expansion fitted to the flywheel, you get the gear
glowing a nice cherry red with a Gas torch then quickly slip it on. When it
cools down, it contracts very tightly onto the flywheel. You need to know
what you are about, you generally only get one shot at this.


(There's the answer to that old brain teaser about "if you heat up a circle,
does expansion make the hole in the middle bigger or smaller")


A lightened flywheel will give you faster engine acceleration/decceleration,
due to the reduction in inertia and momentum, but the engine will probably
need to idle faster and will not idle as smoothly.


It would seem to me, and I can only speak in general terms as I have never
done this job on an MX5, that it would be essential to dynamically balance
the new flywheel. That's a specialist job, but the idea of a dynamically
unbalanced flywheel, at 7000 rpm, frightens me!. This is done on a special
balancing machine and is akin to balancing wheels, but much more critical
due to the much higher rotational speeds.


As a guestimate, I think you would get little change from $1200 to $1400,
all up, to professionally do the flywheel with a new clutch, flywheel etc.


However, to answer your question directly, if you have the gear and skill to
remove and replace the gearbox and clutch, getting the flywheel off, and
back on, should be relatively simple.


Good Luck


Eric

[karlncas]

I am in the process of dealing with the WOF Nazis over this exact thing, I
took my car to a garage whom in turn took it to onroad where the mechanic
was told it was not legal... his reply to the inspector was "don't be
ridicules". The mechanic was then showen a form pointing out the structural
area of the car and because the twit oh sorry inspector is unable to spot
the difference agreed to a letter from a panelbeater confirming what the
mechanic was trying to tell him.
Long story short as I have to get some rust cut out I will be getting a
letter from the panelbeater at the same time and will hopefully have a WOF
by the weekend and another piece of paper in the glove box ti keep any
pratts happy.

Karl and Cassandra Blumenthal

[DBM58]

In truth, I think that when the WoF police meet dodgy characters, just as with the real constabulary, they view all things with suspicion. Gazza took my suggestion (I think the definition of suggestion here is "stole") and made a shonky copy. Of course his back-yard hacking around was going to be challenged by those in the know. I, on the other hand, pass all warrants without question. Unless I have a miniscule brake fluid leak that is.


Regards

David Moughtin

[poison]

Funny you should mention that, must depend on the person doing the test, the
testing station was crap. The next WOF, all the mechanics went and looked at
it for a while and I thought 'oh no not again' then the guy came up and said
"wow that's an awesome cold air system, where did you get it?" so a WOF was
issued no complaints.

Gazza
"PO1SON"

[poison]

At least the Gazza can type in English, Mr "I have a from the area of where
the brake hose meets the rear wheel." Moughtin... ha ha ha.



Of course if you were a real bloke, you would give it "that extra little
half turn it always needed" thus stripping the thread or snapping it off
completely, turning into a major job

Gazza
"PO1SON"

[Mikkels]

The Flywheel bolts do not have metal tags on them but a fairly tight. The
easiest way to lock the flywheel while loosening the bolts is to use a large
screwdriver on the ring gear locked against the starter housing. You need
two people for this job. The ring gear will be part of a new flywheel. If
you are in there replacing the clutch then no parts need machining as you
will use a new pressure plate and of course the face of the flywheel will be
new. In any event unless serious problems exist with the old clutch the
flywheel will be unlikely to be worn worth worrying about.


One thing worth looking for is oil from the rear crank seal or the front
gearbox seal. This is something you don't want. There were no problems
with my car but the trough out bearing was shot.


My advice: If like to learn by experience and can read a manual and have
access to some reasonable tools. Have a go. Very rewarding stuff.


Cheers


Don


_____

From: e-admin@mx5club.org.nz [mailto:e-admin@mx5club.org.nz] On Behalf Of
Eric & Ann West
Sent: Monday, 11 July 2005 10:14 p.m.
To: MX5List
Subject: Re: lightened flywheel


Hi Karl,


These comments are general, to give you some idea of what you are looking
at, they will relate to the MX5 in principle, but as I have never taken one
apart, they are not specific to the MX5


The job is pretty similar to changing a clutch, and I think we all agreed
that, lacking the tools and facilities, that is a job best left to the
experts.


Basically, you go one step further and having removed the gearbox and clutch
assembly, you can unbolt the flywheel from the back end of the crankshaft,
(The bolts are quite often locked with tabs which you flatten out with a
small cold chisel or punch, the tabs, if any, should not be re-used).
Preventing the crankshaft from turning, while you swing on these bolts, can
be a real issue.


Once you get it off, you can then simply re-assemble the whole thing again
using new components. Note that you cannot usually assemble the clutch onto
the flywheel before you put the flywheel back, as the clutch cover covers
the flywheel bolts


Doing a flywheel necessitates replacing the clutch friction plate, as the
flywheel constitutes one of the pressure faces of the clutch, and the old
clutch plate will have scored to match the old flywheel. (You would not
install old brake shoes on new drums, or would you? It's essentially the
same thing).


Since you are going that far, you would probably replace the entire clutch
assembly, you should at least reface the clutch pressure plate (same issue
as the flywheel, it's a pressure surface, which will be scored, not good on
a nice new friction plate). Replacing it would not cost a lot more and makes
the best economic sense. You would certainly also replace the clutch thrust
bearing, they are never the same after they have been disturbed.


You would also factor in a new ring gear, unless the new flywheel has one
machined in. (Not a great idea, replacing the ring gear then means a new
flywheel, thus a new clutch and away we go again . There are also stress
issues for a flywheel with an integral ring gear, unless it is "stress
relieved" after machining, (specially heat treated), and it could come
apart. Integral ring gears are best left to racing cars where they can throw
the flywheel away after each race or two).


The ring gear is usually expansion fitted to the flywheel, you get the gear
glowing a nice cherry red with a Gas torch then quickly slip it on. When it
cools down, it contracts very tightly onto the flywheel. You need to know
what you are about, you generally only get one shot at this.


(There's the answer to that old brain teaser about "if you heat up a circle,
does expansion make the hole in the middle bigger or smaller")


A lightened flywheel will give you faster engine acceleration/decceleration,
due to the reduction in inertia and momentum, but the engine will probably
need to idle faster and will not idle as smoothly.


It would seem to me, and I can only speak in general terms as I have never
done this job on an MX5, that it would be essential to dynamically balance
the new flywheel. That's a specialist job, but the idea of a dynamically
unbalanced flywheel, at 7000 rpm, frightens me!. This is done on a special
balancing machine and is akin to balancing wheels, but much more critical
due to the much higher rotational speeds.


As a guestimate, I think you would get little change from $1200 to $1400,
all up, to professionally do the flywheel with a new clutch, flywheel etc.


However, to answer your question directly, if you have the gear and skill to
remove and replace the gearbox and clutch, getting the flywheel off, and
back on, should be relatively simple.


Good Luck


Eric

[Ken McNoe]

Okay, I have held back for long enough, even tried to find out on the
net, what's a bl**dy flywheel???
=)

Ken McNoe

Phone: 09 483 8237
Mobile: 021 536 911

[r.v.boxall]

Ken,

The flywheel on a car is a disc of normally steel, fixed to the back of the crankshaft, in between the engine and gearbox. Its purpose is to provide some stored energy to take the engine from firing stroke to firing stoke of the cylinders. Do you know how a four-stroke engine works?That's why someone noted that the engine tickover would be changed with a an alloy flywheel. It doubles as one of the surfaces for the clutch friction disc to press against, and it is held in place by an outer plate, with strong springs in it. The middle of the clutch friction plate is splined onto the gearbox main shaft. When you press down on the cluch pedal, a lever overcomes the pressure of the sprung plate, allowing the engine to disconnect from the gearbox mainshaft by releasing the friction disc. That allows you to change gear without a huge crunch from the gearbox (the synchromesh is another help with that, another story!)

Is that clear? I could use more words if you like! So, the flywheel is actually a round weight!
[...]

[Robyn and Rich]

Ken...

in reply to "What's a bl...dy flywheel...?"...its a
device used on some mx5s... that arent white,, so therfore
slower,,, thus attracting flies...Its used to get rid of them.
Heavier fly wheels are sometimes used to kill blow flies and wasps.

R.& R.

[Ken McNoe]

RIGHT!!! Thanks for clearing that up, but obviously you are mistaken,
Red goes fast, white doesn't
For example fire is red, spreads fast, clouds are white, and move
slowly!!

You don't happen to own the white MX5 on the north shore do you, with
mx5 written on the side???

Makes perfect sense about the heavier wheels, the light ones might break
under the weight of a really big fly or bumble bee.

Ken McNoe

Phone: 09 483 8237
Mobile: 021 536 911

[DBM58]

Thanks for the link

Thank you for your help

Best regards

David Moughtin

[Robyn and Rich]

Nope... the white one that lives in Newmarket,,,, and white =
pure = chaste = Chased... but seldom caught... (your
turn)

[Greg and Shona Powell]

Jeff - thanks for the link to how stuff works. I'm having the clutch
replaced on my 91 V Spec and am looking at putting in a new lightened steel
flywheel. The mechanic tells me he has had the flywheel specially balanced
to the clutch plate which will make it freer running. Has anyone had any
experience of this and how noticable is it.

Greg

[Mikkels]

Hi

You won't notice a couple of pounds off a 18 pound flywheel.

Don

[...]