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  1. #1

    Milling Riva Heads

    I've got a set of 41cc heads I've had on my riva stage 3, 2006 gpr for awhile now, and am thinking about shaving them to eek-out ~10 more psi. I've got .075 thou squish clearance with them currently. Thinking about taking .020 off and running 1 gasket. Anyone shaved a Riva/R&D head? Other thoughts?


  2. #2

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    I would pull one gasket and check it first. Might give you about 7-8 psi. You can shave the head, as long as you don't change the diameter of the chamber much. I think on the riva heads you can get away with taking 0.020 off. If I remember correctly that's what I did on mine years ago. Had about .050 squish with 155-160 psi

  3. #3
    Hey thanks ronn, really appreciate it...

    Oh, btw, how's ur 1390 working out? Did you convert from a 1200 66v motor? What's your compression on that one? What kind of head u running?

    I'm thinking , down the road, doing that to my xlt.

  4. #4

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    1390 is great. Yes, it was a 1200. R&D heads, around 175+ I will be putting triples on it soon. I miss my old triple piper haha.

  5. #5
    Quote Originally Posted by Ronn25 View Post
    1390 is great. Yes, it was a 1200. R&D heads, around 175+ I will be putting triples on it soon. I miss my old triple piper haha.
    Unbelievable Wow ronn, I can't imagine a 1390 in a gp hull with 175 compression and triples too boot! OMG! I need to get with the program!

    What kind of prop will you turn with that horsepower!!???

  6. #6

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    Quote Originally Posted by jim mcgreehan View Post
    Unbelievable Wow ronn, I can't imagine a 1390 in a gp hull with 175 compression and triples too boot! OMG! I need to get with the program!

    What kind of prop will you turn with that horsepower!!???
    I had one back in 2007, near same setup. Also had a 1456cc. Will run 88mph+ A triple doesn't turn that big of prop. 14/23 to 14/25 but at 7800rpm+

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