How to lighten a stock cast iron flywheel



Start with your stock flywheel, In my case, 2.3L Turbo Ford



Its weighs in at 20.5Lbs

Lets see how much weight can be cut off….



Next is to remove the clutch plate alignment pins….



A slide hammer works well



Mount the flywheel upside down, on the flywheel grinder



Start buy cutting the excess cast iron down to the ring gear..


Once that was flush, I weighed the flywheel again, that reduced the weight by .75 lbs (12 oz) now 19.75 lbs

Time to thin the fat from behind the ring gear…



each pass, this machine cuts only .005-.008 off…




the final weight is now 17.75 Lbs

I removed a total of 2.75lbs…. This should help the engine rev a bit faster, with out giving up too much torque..

They are the thickness they are for a reason. It is like a brake rotor, once you take too much off, they don't function properly.

I don't recommend this.

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"The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government."

He didn't remove any material from the friction surface, so no affect on the functionality. The reason they are as thick as they are is weight. A heavy fly wheel gives the engine more inertia, and makes your starts and shifts smoother, but having to move all that weight slows you down. For go-fast applications, it is quite common to lighten a flywheel. In fact, super light weight aluminum flywheels are quite common in racing applications. My Ghia was running a 8lb flywheel, and I had no issues, any more than you would expect with a light flywheel and grabby clutch.

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If it is a 4 wheel drive, you actually want that inertia spinning for slow speed crawling...in fact, Jeepers add an inertia ring to ADD weight...

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2001 Ranger XLT SuperCab 4dr Flareside 3.0 V6

yup.

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this flywheel is in a 85 Thunderbird Turbo coupe, it hits the strip from time to time.

yes you do have to be carefull of where the material is removed. but where I have removed weight should not make it frature.. but allow the engine to rev a bit sooner so I can get the turbo to spool sooner

what about balance??

the balance was still close, some stock flywheels I have checked have been up to 10- 15 grams off with an avarage of 7g (I checked 6 stock used flywheels)

this one when I had it balanced was off by 12g

This wasn't a very good how to. More of a look what I can do. Don't get me wrong, I like what you did and for the application, it is a good idea. The problem is that not many people have direct access to specialized machining equipment. If the average person reads this how to, they would still have to take it to a machine shop and have them do the work.

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2003 Ranger FX4 level II. 3" BL, 33x12.50 GT Radial Mud Claws, Custom front and rear bumpers with winch hookups, custom flatbed, with hi-lift, and full size spare mount, 12,000 lb winch mounted under bed, Electric fan, and of course a flowmaster.