Surface grinding a new flywheel

I was advised by a knowledgeable GT40 enthusiast that I should have my new RF flywheel surface ground prior to fitting it to my engine. I was told that it makes for a better clutch engagement and a longer lasting clutch. That was all fine until I called my local machine shop, who wants to charge me $65 for the service (including removing and reinstalling the dowels). That was a bit more money than I wanted to spend.

So my question: is it worth it? What benefits come from a surface ground flywheel?

Hi Mark, (stop procrastinating). The reason they recomend it is the lathe leaves a finish that is not really ideal on the wear area. By using a surface grinder or cutter that leaves a radial pattern ( with reference to the flywheel) things will bed in and engage more smoothly. You could do a backyard job with a flap wheel on a 4" disc grinder if you have some means of spinning the flywheel (lathe- older type wheel balancer ) but with the counterbalance it will shake like hell if spun to fast. Another way would be to have the wear surface bead blasted.

Jac Mac.

Hi Mark: Save your money. It's true about the finish left by machining versus Blanchard grinding. As Jac says, you can accomplish the same thing for a whole lot less money. I use what I call a "dingle berry" hone fitted to a 3/8" drill motor to put a swirl finish on the friction surfaces of the flywheel and pressure plate.

Mark, I always get flywheels surface ground if possible ( costs me approx $15 ) and I can assure you it is beneficial if you can get it done, particularly if you have a steel flywheel. Frank

Planetry ground flywheels and brake rotors is good for a bit of initial "bite", after a few applications the wear marks will soon be radial -- so fine turning (radial machining) the surfaces won't be a problem -- been done that way for the last 30 odd years

Mark,

While it is unlikely that a new flywheeel would require grinding, it does depend somewhat on the friction material. With an organic disc, a smooth surface is usually not specified. If you have something aggressive like a bronze/ceramic, then a smoother finish is usually reccomended.

Andys