Home › Forum › Ask A Member › Are Ruddertwin flywheels cast Iron or cast steel? › Reply To: Are Ruddertwin flywheels cast Iron or cast steel?
For what its worth, I have been in contact with the gentleman who had the question. It was never stated specifically what the flywheels were made of originally. It would take spectrometer testing to verify the actual elements contained in a given sample of flywheel metal. That being say-ed, I would suggest that a flywheel cast in ductile iron is as good a replacement as you will find. It doesn’t have to spin much over 1200 RPM.
With respect to the eccentric orientation (its not really an eccentric – it’s an offset circle is what it is), a good pattern maker can build whatever you want. I’ll make some assumptions here and wager that if the conversation has gotten as far as considering the use of a good original part as a pattern to cast a fresh one that the methodology has been discussed and decided upon. I’d just volunteer that there should be some additional material present in the casting that allows for shrinkage and also to accurately machine the new casting. Spraying wax on the pattern part is one way to do this in a uniform manner. The key thing is to duplicate the circular off-set orientation in the reproduction part to make it the same as the original. Its perfectly round so as long as you duplicate the orientation and diameter of the original, your timing should be fine.
If you want to be daring and add some pep to her step – machine the off-set in such a way that you advance the timing a couple of degrees. I’m only kidding – don’t actually do it. But that is part of how the Speedsters generate their higher revs and additional power… and its why a Ruddertwin flywheel won’t work worth a damn on a Speedster.
Regarding shipping parts overseas – I’ve had a bad experience with a person in the land Down Under ripping me off, so that activity is off my list of things to ever do again.
Best,
PM T2
He's livin' in his own private Idaho..... I hope to go out quietly in my sleep, like my grand-dad did..... and not screaming, like the passengers in his car...