Results 1 to 9 of 9

Thread: Head question?

  1. #1
    r33pwrd's Avatar
    Join Date
    Mar 2006
    Location
    Sammamish Washington
    Posts
    4,216
    +1
    360

    Head question?

    Currently I have the riva heads on my ski and have thought about having lowell or someone rework my stock head to 150psi (same as the rivas) is this worth it? Stock reworked better / worse / same as aftermarkets? I do NOT have the girdle kit. Also can i go higher compression than 150? I can only get 92 octane gas and want to do the 3 deg. timming key. Or can I go higher compression and forget the key?? any ideas? thanks


  2. #2

    Join Date
    Apr 2006
    Location
    panama city beach 'fl
    Posts
    1,846
    +1
    9

    Cool

    I like the thought of tying all cylinders together using stock head.150 will be fine, tell who ever doing head about adv key, they should be able to stager compression

    I used Lowell for mine

    later cd

  3. #3
    Happily Self-Employed WFO's Avatar
    Join Date
    Nov 2005
    Location
    Houston, Texas
    Posts
    12,800
    +1
    449
    I am with Chip, 150 is plenty for your boat. 160 is the highest I would go.

    The great thing about the stock head is its strong and the compression for #3 is lower.

  4. #4
    r33pwrd's Avatar
    Join Date
    Mar 2006
    Location
    Sammamish Washington
    Posts
    4,216
    +1
    360
    Quote Originally Posted by WFO View Post
    I am with Chip, 150 is plenty for your boat. 160 is the highest I would go.

    The great thing about the stock head is its strong and the compression for #3 is lower.

    If they take a straight cut on the head is the compression still lower in #3, should be! or do they remove some material from the dome are?

  5. #5
    Happily Self-Employed WFO's Avatar
    Join Date
    Nov 2005
    Location
    Houston, Texas
    Posts
    12,800
    +1
    449
    Larger chamber in #3.

  6. #6
    2000 GPRXP 4tec shooter98xpl's Avatar
    Join Date
    Dec 2005
    Location
    Charleston SC
    Posts
    2,717
    +1
    3
    Jim at Jim's performance did my stock 06 head. I paid $100 shipped back to me. I had it back within days. Works great on my 06 motor.
    SHOOTER

  7. #7

    Join Date
    Oct 2006
    Location
    UNITED KINGDOM
    Posts
    160

    Cool stock head

    if you take 0.030"off of a standard head .what compression will it give and do you use the standard gasket or just one of the three layers??how about squish???

  8. #8
    Mongoose's Avatar
    Join Date
    Aug 2005
    Location
    Wales
    Posts
    665
    +1
    6
    30 thou off will give you a cranking comp of about 140-145 psi.
    That is with a standard non modified head gasket.
    30 thou off is ok without having to alter the squish angle.
    any more than 30 thou, and you will have to re cut the domes at a different angle.

  9. #9
    Shooter, what psi did that bring yours up to? did he cut the domes or straight deck? Im planing to do the same Just not sure who im sending it to yet.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. JS440/JS550 head question
    By delagem in forum Kawasaki Open Discussion
    Replies: 1
    Last Post: 02-09-2007, 11:34 AM
  2. Pro 785 head question
    By absentx in forum Polaris PWC Performance
    Replies: 8
    Last Post: 09-05-2006, 04:23 AM
  3. Another Head Question (or 3!)
    By washingtonrider in forum Yamaha PWC Performance (2-stroke)
    Replies: 9
    Last Post: 08-08-2006, 02:24 PM
  4. Riva head question
    By shooter98xpl in forum Yamaha PWC Performance (2-stroke)
    Replies: 12
    Last Post: 12-19-2005, 10:24 PM
  5. head question
    By shooter98xpl in forum Yamaha PWC Performance (2-stroke)
    Replies: 7
    Last Post: 12-13-2005, 11:22 AM

Posting Permissions

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