I just read that entire thread...interesting points on both sides. Seems like alot of quibbling over details.
I guess I have a couple questions.
Dan, are you saying that the 900 polaris or the 800r skidoo engine is NOT out of balance?? Balance being used to define a lack of adequate counter weight for the piston/rod weight?
Dan, It seems that in one of your statements you are saying that Perk is adding a round symmetrical weight too each end of the crank thus muffling the vibration with added rotating mass...that is not how I understand Perks balance system to work. As I understand it, he is using external counterweights to add enough additional counterweight too the engine to bring the motor a point of "balance"
What doesnt make much sense too me is that you state that the 900 polaris crank (for example) is too light. Too light on the counterweight side I assume. How is using Perks system not a remedy for this issue?
I understand that you differ on views of how to measure runnout and how runnout is caused. Thats fine. But if we are talking strictly balance here, how is Perks system wrong? Can you state with confidence that his system WILL NOT/CANNOT work? And why?
Gus, you state that NO ONE balances engines like this. I have been told and read an article many years ago that stated that GM used a system much like this. They turned the motor complete with the oil pan off, stopped the engine at a point, drilled the crank, re-spun and then it could leave the factory. In this case they are lightening the crank but the concept remains the same. Turn the engine complete, adjust counterbalance as needed. And there are plenty of motors in existence that are "externally" balanced that work just fine.
Now, dont take this the wrong way. Ive read posts from both of you guys and you are both extremely accomplished in the industry. I understand that you guys both have issues with the idea that this balance kit of Perks is being touted as the be all/ end all for engine problems and run out ect.
My questions are aimed solely at the actual operations of the service and what you see wrong with his methods.
It should also be noted that I have personal experience with an engine that Perk did the balance work on. Its a 950ish triple polaris in a 1/4 mile asphalt sled. The tuner is very precise, the sled had a track record of consistency and it was very well backed up over 3 years of racing what the sled would run. (Lots of runs, lots of time slips) 9.50 at 138?? we'll call it.
Immediatly after the balance work and NO OTHER CHANGES the sled ran a tenth quicker with an additional 4 mph.
Thanks for answering my questions.
