We had this topic about lightened flywheels recently.
Some time ago I decided not to use the engine of my racing car anymore, and put that engine after doing some modifications into my EFI powered road car, to have some fun on the road.
After taking the engine out, I checked most of it and it is still in perfect condition, good honing pattern and a real great burning pattern on top of the pistons.
The fist modification what had to be done is changing the full race steel flywheel / 7" clutch combination, (only 6.5KG) for a mildly lightened standard combination.
This time I took a different route, not simply machine the standard flywheel thinner, but removed quite some material, CNC form the outside to keep the center rigid and still get less inertia.
An other very simple and effective way to remove weight, is using a modern made clutch cover like this on from Luck, you save over a pound against a Borch and Beck one, or using a QH what even save almost 2 pounds.
Last Monday I had an appointment with van Giersbergen Motoren revisie a company I use for these kind of work, and checked and balanced 3 sets crank, flywheel/clutch and front pouly.
This one, and 2 sets for racing engines so with the steel flywheel and 7" Quarter master clutches, all balanced under 1 gram.
Now talking about cranks, I still had 2 brand new STR cranks, a few weeks ago I checked them before using and found out they run out more tan I like it 0.07mm, so the message is NEVER simply use new or reconditioned parts before thoroughly check them yourself.
For an other engine I had already picked a good standard sise X drill crank what have first to be nitrated and polished, and damm that crank also run out 0.06mm, so these guys will straighten 3 cranks next week within 0.03mm or less.
You start to pick it up again, and within a eye blink over my ears into a lot of work.
Hans
A few more pictures and films below.
http://sprint.smugmug.com/Cars/Forum/11 ... 3834_GwjBg