Lightened Flywheel and Crank pulley

[Hjulen]

In a few months I will be converting my spider over to the Ford EDIS ignition system to compliment an upgrade to the Megasquirt computer already in the car...

...in order to get the EDIS in I have to get a crank pulley machined to fit a 36-1 sensor wheel ect ect...

The question is, since I am thinking about getting this machined out of alluminum, what should I look about for as far as engine balancing?

What are peoples experiences with lightened flywheels as wheel?

[So Cal Mark]

the TC motor is balanced internally, so the crank pulley isn't an issue. For spiderrey's crank fired system we modified a stock pulley, mounting the trigger wheel on the back of it.

You should read Crofts' book about flywheel lightening, too much material removal will result in a much-shortened life.

[Hjulen]

Alas, I have been trying to get my hands on the book for about a year now. Unfortunately, its hard to grab for under 200 $

[So Cal Mark]

ahh, maybe someone with a book would make it available to be read from this site.
We've had several flywheels lightened, but have been pretty conservative with it. Especially when they're running without a scattershield!

[Site Owner]

Mark -
I have Guy's book as well as another spider specific book, can't remember the name of the other book off-hand. Guy's book is outstanding. He used to come in here from time to time. Maybe he will show up again. I think before anyone posts any portions of his book online though, they should get Guy's permission to do so. Wouldn't want to offend him, but even more important I wouldn't want to have any copyright issues.

=e=

[pastaroni]

I've hacked out quite a bit of material from the stock flywheels, they are plenty safe with >12mm thickness. Don't take any more from the stock flywheel though. Here is a link to a file on my site with different comparisons as far as lightened flywheels.

http://www.millersmule.com/File%20Libra ... arison.pdf

Have a look to learn more

Happy motoring,
-Jason Miller

[pastaroni]

btw, I prefer not to copyright my work, but please don't make me change my mind.

[mdrburchette]

If you want to go extreme, you can get a steel flywheel and clutch assy made. The whole setup weighs about 11 pounds and sure frees up the engine. Just got mine installed this weekend and am real pleased with it.

[So Cal Mark]

Guys' book is out of print, that's the only reason I suggested posting sections of it. After all, most of the tech sections use copywrited material from factory manuals. I wouldn't do it without his permission though.

[pastaroni]

no worries, I just don't want people to claim my work as their own or steal my ideas without asking =]

[Hjulen]

Since the primary job of the flywheel is to "store" inertia or smooth out the revs, if too much of the flywheel weight is removed it could cause fast "dereving of the engine" and make street driving a little more finicky.

[124JOE]

im thinking on this subject

[maytag]

Since the primary job of the flywheel is to "store" inertia or smooth out the revs, if too much of the flywheel weight is removed it could cause fast "dereving of the engine" and make street driving a little more finicky.

I don't really see the down-side to this.
What IS a factor that should be considered is the ramifications to the potential engine-braking, or compression-braking.

But all-in-all, I've never heard of anyone lightening their flywheel and then wishing they hadn't.

[124JOE]

i have a flywheel in the garage
not sure it will fit
a buddy took one look and said"junk"
but again im not sure of that ether

[baltobernie]

the TC motor is balanced internally, so the crank pulley isn't an issue...

Are you sure about this? I've seen several crank pulleys off Spiders, and they all have varying numbers of 5mm drilled depressions on the back side of the innermost pulley. Sure looks like a factory balancing technique.