I was curious as to wether or not the stock GX200 clone cast iron flywheel is safe at high rpm's. I found this thread on the internet of a guy that sent it in to a place that does destruction tests. The bottom line is the stock flywheel and magnet seem to be fine and will not blow up at rpm's a street ride will ever see. I'll hold out on the billet flywheel for now. Here is the thread post:
"I sent a stock, cast flywheel from one of the yellow engines to The Balancing Company (
The Balancing Company Homepage ) for a spin to destruct test. This company's credibility to properly perform this sort of testing is well established and beyond reproach.
Balco does not verify the safety, suitability, use, or the fitness for a particular purpose, or unintended purpose of the flywheel.
I asked that they give me the RPM where the first failure occurs. I supplied them with a new flywheel, a starter cup, a standard flywheel nut, and a new crankshaft so they could chop off the mag side of the crank and use it as an arbor for their machine. This means the flywheel was mounted in the same manner as we would be using it on the engine.
They have completed the test and are sending the flywheel and the test results back to me. As I stated before I sent the flywheel, I intend to scan the letter from Balco into the computer and post it here for everyone to see.
If one of these engines is prepared according to AKRA's box stock rules, the max racing RPM will be below 5500 RPM. The front runners on 1/5 mile tracks are turning less than 5200 RPM.
The magnet came off the flywheel tested at 11,250 RPM which is more than double the RPM where most are turning them so...
I stand on my previous statement about this engine, which, contrary to some of the conspiracy theorists out there, has not changed one bit:
I am comfortable with the stock flywheel on the engines I sell when that engine is being raced according to AKRA's box stock rules.
That is a very specific statement that encompasses EXACTLY how I am racing this engine myself. Do not confuse my statement with ANYTHING outside of that statement. If you must switch to parts that have the potential to jack up RPM or horsepower, then you should run a billet flywheel. Racing is dangerous, and ANY racing engine part can fail under racing conditions. Failure of ANY engine part can injure, or even kill an individual within the vacinity. If you aren't willing to accept that risk, then you should not be racing or in the vacinity of racing vehicles. You should not race under uninsured circumstances and you should not be in the pits under uninsured circumstances.
End of "racing is dangerous" (duh huh) disclaimer.
And by the way, to assume that I had not personally tested the flywheel myself prior to this would be wrong.
Let the fur flying begin!"