HPV KPV First Build- Spec Review

This topic has 4 replies, 2 voices, and was last updated 11 years, 1 month ago by Andres Malovos.

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- July 3, 2015 at 8:58 am #50931
  
  Walt Gifford
  Participant
  
  Flex hone is the fastest way to ruin a 2 stroke cylinder I know of.
  
  Port timing is usually measured in piston travel from TDC. I would get a WKA rule book and use those specs.
  
  Ignition timing is mild, you could go to .085 no problem. Might help it run cooler.
  
  I would jack up the head clearance to .035″ for a trouble free practice engine.
  
  Gif
- July 3, 2015 at 9:07 am #50932
  
  Andres Malovos
  Participant
  
  Thanks Walt,
  
  That’s why I went with the Wiesco one.
  
  I don’t yet have 2″ dial indicator and bridge to measure in piston travel “.
  I’ll likely get one at some stage.
  
  OK, so what impact will expanding the squish have in terms of longevity, combustion stability.
  
  I should also mention I have HPV 3/4 pipes, and am in California, so usually running our pump 91.
- July 3, 2015 at 9:05 pm #50952
  
  Walt Gifford
  Participant
  
  Wiseco flex hone, says it’s safe for 2 strokes but you will need sand paper to put in the cross hatch. What does it do if it won’t even put in a cross hatch?
  
  If you want to fit pistons to cylinders you need something like an Ammco 3950 small cylinder hone.
  
  Gif
  - July 3, 2015 at 9:34 pm #50953
    
    Andres Malovos
    Participant
    
    Well, I wasn’t looking to hone to size, that I’d leave to the machine shop. Instead I was looking to de-glaze and prep for new rings in a more even way that a scotch bright job would provide, without the risk of damage of a dingle berry hone. Given that, it did it’s job.
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