M10 Flywheel lightening

[Deadskittles]

Has anyone ever done this? if so how much did you take off?

[E30_Pare]

http://www.millersmule.com/MillersMu...-flywheel.html

Tada

[petrolhead]

Has anyone ever done this? if so how much did you take off?

I had a bit over 1 kg machined off my flywheel, including balancing it together with the pressure plate. I would not do this on a cast flywheel (found in "new" M10's). Mine was/is steel..

[thebutterson]

I would not do this on a cast flywheel (found in "new" M10's). Mine was/is steel..

Don't take this as me calling you out, I'm just trying to gather info, but can you ellaborate or provide some links on why it's not wise to do this with a cast flywheel? I've heard this before, but couldn't find any real evidence other than forum talk that it wasn't safe.

[E30_Pare]

"Flywheel material composition. Beware that cast flywheels typically have voids in them. This is why minimum thickness rules cannot be applied across all different flywheels. Never say “I’ve seen this done on other flywheels,” every flywheel design and manufacture should be evaluated individually. The material quality is vastly different between Fiat and BMW flywheels, even between different model flywheels of the same company."

[petrolhead]

Don't take this as me calling you out, I'm just trying to gather info, but can you ellaborate or provide some links on why it's not wise to do this with a cast flywheel? I've heard this before, but couldn't find any real evidence other than forum talk that it wasn't safe.

No, I can not elaborate or present an argument against having a cast flywheel machined. I am simply repeating what the big boys seem to agree on. However, I've seen many many (cast) brake disks broken for various reasons, none of them really because of exessive wear. Forces acting on a brake disc are perhaps somewhat similar to those that a flywheel experiences. Of course flywheels rev much higher and thus see much higher centrifugal forces.

In my part of the world, a steel flywheel is about 200€, and having it balanced with pressure plate is less than 100€. You'll be putting it to a tuned engine anyway where average revs are much higher than stock right? BTW, I would absolutely have the package balanced, no matter if parts are OEM or expensive 'n shiny aftermarket ones. They can be far off balance. Vibration forces put enourmos stress on your crank/driveline.

[TobyB]

The 215mm flywheel can go down to 14 lbs pretty easily and safely- the back side has
a 'pudge' that can come off.

After that, you need someone who knows what they're doing- the area behind
the ring gear can be thinned, etc, but it gets a bit scary.

I've taken 2 to 13-14 lbs, and spun both into a 7600 rev limiter. Other things broke,
but the flywheels were fine.

t

[Smelser]

I havent had my engine trans apart. but are the 84/85 steel or cast, or is it a crap shoot?

[E30_Pare]

Cast. Older is steel

[petrolhead]

I havent had my engine trans apart. but are the 84/85 steel or cast, or is it a crap shoot?

If you're uncertain about the material, hit it with a (small) hammer. Steel says dingg! and cast goes "bonk". :D
Anyway.. E30 flywheels are cast.

[jeffnhiscars]

I'm fond of my 8lb JB Racing aluminum flywheel

[Smelser]

2.0 – ENGINES
 2.1 - Three (3) or Four (4) cylinder engines only, must be stock for make, model and
year.
 2.2 - Track Management has the right to make a weight rule to equal out the
competition.
 2.3 - Engines no larger than 2.5 liter (2500 cc.)
 2.4 – 16 valve engines allowed single cams only. 250 lbs. added to minimum weight.
 2.5 - No V-Tec or variable valve timing.
 2.6 - No dual cams.
 2.7 - No Rotary.
 2.8 - 2 spark plugs per cylinder allowed.
 2.9 - No performance or truck parts of any kind allowed.
 2.10 - No engine modifications to enhance performance are allowed.
 2.11 - No porting or polishing allowed.
 2.12 - Valve size must be stock for that engine.
 2.13 – Milling of head allowed. Must not exceed 190 psi compression.
 2.14 - Maximum 0.040 overbore.
 2.15 – 8 and 12 valve camshaft must have stock lift any duration. 2.3 Ford OHC
maximum .2437 lobe lift .400 valve lift. Valve springs can be higher pressure. Multi
index timing gears or adjustable sprockets are allowed on 8 and 12 valve engines
only.
 2.16 – 16 valve engines must have stock or stock replacement camshaft only. Lift
and duration must be stock. Valve springs must be stock.
 2.17 - Cranking compression must not exceed 190 lbs on any cylinder .No
exceptions.
 2.18 - No after market or performance ignitions allowed. Must remain stock.
 2.19 - No mass air modifications. Must remain stock.
 2.20 - No intake modifications. Must remain stock.
 2.21 - Engine size must be placed on the hood in CC or CID.
 2.22 - Must remain stock stroke.
 2.23 - Stock connecting rods and rod caps. No grinding or polishing.

18.0 - REAREND, TRANSMISSIONS, CLUTCHES, FLYWHEELS
 18.1 - Any stock transmission for make, model. No modifications allowed.
 18.2 - All gears must be in working order.
 18.3 - Must have two (2) safety hoops 2” x ¼” within 6” of either end or drive shaft.
 18.4 - Driveshaft must be painted white.
 18.5 - Locking of rear ends or differentials allowed.
 18.6 - Stock unaltered rear end for that make, model and year and must remain square
in car.
 18.7 - Clutch pedal must remain stock for make, model and year.
 18.8 – 100 pound weight break for automatic transmission.


so, Where do you get this nice lightweight flywheel??
any suggestions besides dumping the p/s to gain the 20 hp that the Fords have over me??

[thebutterson]

IE sells an aluminum flywheel as well as valve springs, an adjustable cam gear, and various crank pulleys.

I'm thinking you could use the springs to increase the reliability of the head at the top end, and use the adjustable cam gear to move power to whatever range you are usually in. The pulleys can be used to underdrive your accessories for a small gain.

[jeffnhiscars]

I got mine from Bavauto, but

http://jbracing.com/flywheels.php

[Smelser]

Know this started as a flywheel lightening thread, but just a quickie question, is the M10 an interferance engine? (valves drop into the path of the piston) example, Could I spin the crank and move the pistons with no timing chain on, leaving the cam in one place and not bend a valve?