ArboristSite.com Sponsors
 
 



 
 


Page 1 of 12 12311 ... LastLast
Results 1 to 15 of 177
Like Tree8Likes

Thread: Porting the 361 Big Bore

  1. 01-06-2009, 05:25 AM #1
    blsnelling
    blsnelling is offline
    Site Sponsor
    Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation
    Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation     blsnelling's Avatar
    Join Date
    Nov 2006
    Location
    Franklin, OH
    Posts
    38,764
    Credits
    1,100

    Porting the 361 Big Bore

    Tonight I began the process of porting the 361BB prototype that I have. The P&C look as good as new upon disassembly. The goal of this saw is to be competetive at a GTG level. It will also be used as a firewood saw. I took measurements on the saw tonight and will post them here. I would appreciate any feedback you guys might have on what numbers I should go with. Here's where it stands right now.

    1. Squish = .017, no base gasket. That's how I've been running it.
    2. Compression was 185 cold after only a little run time. I forgot to check it tonight.
    3. Exhaust 105*
    4. Transfers 125*
    5. Intake 71*
    6. Blowdown 20*
    7. Exhaust width 1.00", can go to 1.25".
    8. Intake width 1.03", can go to 1.25".


    The exhaust seems aweful low, but this saw 4-stroked out to15,800. If I went to 98*, I would have to raise the roof .075"! To get to 95* would require raising it .115"! I can't imagine taking that much out. What numbers would you go with?

    The exhaust port shape is pretty nice the way it is. The intake floor is very round. A lot of improvement to be made there. As you can see, I've got room to widen quite a bit, nearly .250" on both sides.

    Whatcha think?

    Exhaust Port


    Intake Port


    Crown after running 15,800.
    Brad - Snellerized Saws

    Have a 201T that doesn't run like you expected? Need a new one that's already modded and ready to go? PM me for details.
    Reply With Quote Reply With Quote
  2. 01-06-2009, 05:30 AM #2
    blsnelling
    blsnelling is offline
    Site Sponsor
    Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation
    Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation     blsnelling's Avatar
    Join Date
    Nov 2006
    Location
    Franklin, OH
    Posts
    38,764
    Credits
    1,100
    I need a new circlip to put this thing back together. Getting a OEM Stihl part would be fastest. What saw has an .432" wristpin and uses a .040" thick wire circlip? The OEM 361 circlip uses only .030" thick wire.
    Brad - Snellerized Saws

    Have a 201T that doesn't run like you expected? Need a new one that's already modded and ready to go? PM me for details.
    Reply With Quote Reply With Quote
  3. 01-06-2009, 05:40 AM #3
    super3
    super3 is offline
    Arboristsite MVP
    Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation
    Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation     super3's Avatar
    Join Date
    Dec 2007
    Location
    indiana
    Posts
    2,013
    Credits
    272
    So much for coating the piston huh?
    Reply With Quote Reply With Quote
  4. 01-06-2009, 06:20 AM #4
    blsnelling
    blsnelling is offline
    Site Sponsor
    Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation
    Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation     blsnelling's Avatar
    Join Date
    Nov 2006
    Location
    Franklin, OH
    Posts
    38,764
    Credits
    1,100
    Quote Originally Posted by super3 View Post
    So much for coating the piston huh?
    I have to assume that the coating is only for break-in. It wears off right away.
    Last edited by blsnelling; 01-06-2009 at 06:59 AM.
    Brad - Snellerized Saws

    Have a 201T that doesn't run like you expected? Need a new one that's already modded and ready to go? PM me for details.
    Reply With Quote Reply With Quote
  5. 01-06-2009, 06:59 AM #5
    blsnelling
    blsnelling is offline
    Site Sponsor
    Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation
    Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation     blsnelling's Avatar
    Join Date
    Nov 2006
    Location
    Franklin, OH
    Posts
    38,764
    Credits
    1,100
    How about these for numbers? Do these look good for a torqey GTG saw?

    Exhaust 100* / Duration 160*
    Transfers 120* / Duration 120*
    Intake 75* / Duration 150*
    Blowdown 20*

    Or would you leave the tranfer timing alone for a longer blowdown of 25*?
    Last edited by blsnelling; 01-06-2009 at 07:17 AM.
    Brad - Snellerized Saws

    Have a 201T that doesn't run like you expected? Need a new one that's already modded and ready to go? PM me for details.
    Reply With Quote Reply With Quote
  6. 01-06-2009, 09:23 AM #6
    epicklein22
    epicklein22 is offline
    ArboristSite.com Sponsor
    Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation
    Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation     epicklein22's Avatar
    Join Date
    Feb 2007
    Location
    Mantua, Ohio
    Posts
    3,252
    Credits
    702
    Wasn't this thread in the Hot Saw section? Hopefully some of regular mod guys come and give you answers about the durations. You know most of the people here are in the dark when it comes to modding. Me included.
    ~Andrew~
    Reply With Quote Reply With Quote
  7. 01-06-2009, 09:30 AM #7
    Lakeside53
    Lakeside53 is offline
    Stihl Wrenching
    Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation
    Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation     Lakeside53's Avatar
    Join Date
    Dec 2004
    Location
    Woodinville, WA
    Posts
    24,831
    Credits
    103
    Quote Originally Posted by blsnelling View Post
    I have to assume that the coating is only for break-in. It wears off right away.

    Why would you need a coating for "break-in"? The RVR of a modern cylinder is correct when made, and the piston isn't supposed to wear except over a long time. Only the rings bed slightly.

    Moly-coating is supposed to prolong the life of the pistion... and stop the skirts skirts wearing. Is it advertised as moly-coated, or what do they call it?

    Your pic of the intake port:
    Is it just the pic or do you have a bunch of vertical wear lines? And.. that "crosshatch" looks "odd", almost like it was done with hand held hone, and not carefully. It is hard to get a decent pics of the crosshatch as the lighting tend to pic up on only a few surfaces, but compare it to your oem.
    Last edited by Lakeside53; 01-06-2009 at 09:37 AM.
    Any sufficiently advanced technology is indistinguishable from magic."
    --Arthur C. Clarke,
    Reply With Quote Reply With Quote
  8. 01-06-2009, 09:33 AM #8
    timberwolf
    timberwolf is offline
    Arboristsite MVP
    Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation
    Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation     timberwolf's Avatar
    Join Date
    Aug 2002
    Location
    Ontario
    Posts
    3,811
    Credits
    166
    If the coating is a thou thick as soon as it's gone your already starting to eat away and having a nice tight fitting piston.

    Skirts are showing quite a bit of wear low on the skirts both front and back. This is odd for a saw with little time on it.

    The bore looks very rough and there is something odd about the placement of the pulse inlet.
    Reply With Quote Reply With Quote
  9. 01-06-2009, 09:35 AM #9
    epicklein22
    epicklein22 is offline
    ArboristSite.com Sponsor
    Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation
    Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation     epicklein22's Avatar
    Join Date
    Feb 2007
    Location
    Mantua, Ohio
    Posts
    3,252
    Credits
    702
    Quote Originally Posted by Lakeside53 View Post
    Why would you need a coating for "break-in"? The RVR of a modern cylinder is correct when made, and the piston isn't supposed to wear except over a long time. Only the rings bed slightly.

    Moly-coating is supposed to prolong the life of the pistion... and stop the skirts skirts wearing.
    When you gonna try the prototype 441 BB kit for Baileys? I think you would be an excellent candidate to help get these kits perfect.
    ~Andrew~
    Reply With Quote Reply With Quote
  10. 01-06-2009, 09:40 AM #10
    blsnelling
    blsnelling is offline
    Site Sponsor
    Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation
    Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation     blsnelling's Avatar
    Join Date
    Nov 2006
    Location
    Franklin, OH
    Posts
    38,764
    Credits
    1,100
    Quote Originally Posted by timberwolf View Post
    If the coating is a thou thick as soon as it's gone your already starting to eat away and having a nice tight fitting piston.

    Skirts are showing quite a bit of wear low on the skirts both front and back. This is odd for a saw with little time on it.

    The bore looks very rough and there is something odd about the placement of the pulse inlet.
    Do you have any suggestions on the port timings?
    Brad - Snellerized Saws

    Have a 201T that doesn't run like you expected? Need a new one that's already modded and ready to go? PM me for details.
    Reply With Quote Reply With Quote
  11. 01-06-2009, 09:42 AM #11
    Lakeside53
    Lakeside53 is offline
    Stihl Wrenching
    Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation
    Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation     Lakeside53's Avatar
    Join Date
    Dec 2004
    Location
    Woodinville, WA
    Posts
    24,831
    Credits
    103
    Quote Originally Posted by blsnelling View Post
    I need a new circlip to put this thing back together. Getting a OEM Stihl part would be fastest. What saw has an .432" wristpin and uses a .040" thick wire circlip? The OEM 361 circlip uses only .030" thick wire.
    None that I'm aware of... My packets of clips around that size are all the same wire. Maybe Husky?
    Any sufficiently advanced technology is indistinguishable from magic."
    --Arthur C. Clarke,
    Reply With Quote Reply With Quote
  12. 01-06-2009, 09:44 AM #12
    Lakeside53
    Lakeside53 is offline
    Stihl Wrenching
    Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation
    Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation     Lakeside53's Avatar
    Join Date
    Dec 2004
    Location
    Woodinville, WA
    Posts
    24,831
    Credits
    103
    Quote Originally Posted by epicklein22 View Post
    When you gonna try the prototype 441 BB kit for Baileys? I think you would be an excellent candidate to help get these kits perfect.

    lol...
    Any sufficiently advanced technology is indistinguishable from magic."
    --Arthur C. Clarke,
    Reply With Quote Reply With Quote
  13. 01-06-2009, 09:58 AM #13
    blsnelling
    blsnelling is offline
    Site Sponsor
    Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation
    Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation     blsnelling's Avatar
    Join Date
    Nov 2006
    Location
    Franklin, OH
    Posts
    38,764
    Credits
    1,100
    Quote Originally Posted by Lakeside53 View Post
    None that I'm aware of... My packets of clips around that size are all the same wire. Maybe Husky?
    Thanks Andy. I'll give Gregg a call.
    Brad - Snellerized Saws

    Have a 201T that doesn't run like you expected? Need a new one that's already modded and ready to go? PM me for details.
    Reply With Quote Reply With Quote
  14. 01-06-2009, 09:59 AM #14
    spacemule
    spacemule is offline
    Banned
    Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation
    Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation     spacemule's Avatar
    Join Date
    Apr 2003
    Location
    the sideways 40
    Posts
    17,732
    Credits
    1,455
    Quote Originally Posted by epicklein22 View Post
    When you gonna try the prototype 441 BB kit for Baileys? I think you would be an excellent candidate to help get these kits perfect.
    It'd be fun watching Andy turn gray overnight.
    I'm not the pleasant pheasant plucker
    I'm the pleasant pheasant plucker's son,
    I'm only pleasantly plucking pheasants,
    Till the pleasant pheasant plucker comes.
    Reply With Quote Reply With Quote
  15. 01-06-2009, 10:23 AM #15
    Lakeside53
    Lakeside53 is offline
    Stihl Wrenching
    Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation
    Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation Reputation     Lakeside53's Avatar
    Join Date
    Dec 2004
    Location
    Woodinville, WA
    Posts
    24,831
    Credits
    103
    Better hurry - looking like bald before gray...
    Any sufficiently advanced technology is indistinguishable from magic."
    --Arthur C. Clarke,
    Reply With Quote Reply With Quote
Page 1 of 12 12311 ... LastLast
« Previous Thread | Next Thread »

Thread Information

Users Browsing this Thread

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

Bookmarks

Posting Permissions

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

Forum Rules

Page generated in 0.28235 seconds with 43 queries [Server Loads: 2.28 1.65 : 1.40]