Results 1 to 9 of 9

Thread: Milling heads for more Compression

  1. #1
    Arctic Art
    Join Date
    Oct 2010
    Location
    Manley Hot Springs Alaska
    Posts
    140

    Talking Milling heads for more Compression

    Got some spare heads,am sending them out for dual plugging and am considering milling for higher compression.Have R100 at 8.2;1 considering .025 off for 8.7;1 or .040 off for 9.0:1.Any problem w/valve to piston clearence.Please speak from expearence. Thank you

  2. #2
    DoktorT
    Join Date
    Jan 2010
    Location
    Spokane
    Posts
    247
    I have only enough experience to offer, without knowing the year and model that R100 head came on no one can be certain of your questions. Check part nos and MAXBMW to verify what you got, then report to any guru for specifics. Will say sounds like a very good plan with those low comp heads. I got an earlier 9.5 and thinking about dropping that just a bit to be rid of the last bits of ping. But I get super mpg and don't want to give up a bit of that as well.

  3. #3
    DoktorT
    Join Date
    Jan 2010
    Location
    Spokane
    Posts
    247
    Quote Originally Posted by 140008 View Post
    Got some spare heads,am sending them out for dual plugging and am considering milling for higher compression.Have R100 at 8.2;1 considering .025 off for 8.7;1 or .040 off for 9.0:1.Any problem w/valve to piston clearence.Please speak from expearence. Thank you
    If I was you, I would talk to Ted Porter. As much as anyone he knows the variations through the Airhead years. One of the top US Airhead suppliers for heads rebuilding and refining. He will be doing mine likely next winter.

    Just a happy customer, but I might buy stock if he went public.

  4. #4
    Registered User RINTY's Avatar
    Join Date
    Nov 2005
    Location
    Calgary, Alberta
    Posts
    4,238
    I had .030 taken off my '82 R100RS with no issues. This gives a compression ratio of 8.7 to 1.

    I used to own one of the most highly modded airheads around, and IMHO, if you're after more chassis and/or engine performance, you're better off to put your money into an Oiler. Airheads are just fine as they come out of the crate. At most, I would replace the triple tree with a thicker unit and brace the swingarm.

    Anyway, have fun.
    Rinty

    "When you don't know where you're going, any road will get you there."

  5. #5
    Arctic Art
    Join Date
    Oct 2010
    Location
    Manley Hot Springs Alaska
    Posts
    140
    The bike is a 1983 R100 and I'm using it with sidecar.Changing final to 37;11 and am looking for a little more power in 4th and something in 5th.Pistons are 8.2;1

  6. #6
    Airhead #85 mymindsok's Avatar
    Join Date
    Jan 2009
    Location
    65 Mi North of Frisco
    Posts
    719
    You could always install a set of higher compression pistons...

  7. #7
    Registered User
    Join Date
    Dec 2007
    Location
    Reno, NV
    Posts
    1,933
    Quote Originally Posted by mymindsok View Post
    You could always install a set of higher compression pistons...
    Will those clear the 1983 heads?

  8. #8
    Registered User lkchris's Avatar
    Join Date
    Mar 2003
    Location
    Albuquerque, NM
    Posts
    4,610
    Quote Originally Posted by jforgo View Post
    Will those clear the 1983 heads?
    Absolutely--there's no difference in cylinder heads and the 9.5 pistons are not domed.
    Kent Christensen
    21482
    '12 R1200RT, '02 R1100S, '84 R80G/S

  9. #9
    Registered User RINTY's Avatar
    Join Date
    Nov 2005
    Location
    Calgary, Alberta
    Posts
    4,238
    ...using it with a sidecar...140008
    Ah.
    Rinty

    "When you don't know where you're going, any road will get you there."

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •