Welcome to Club Hot Rod!  The premier site for everything to do with Hot Rod, Customs, Low Riders, Rat Rods, and more. 

  •  » Members from all over the US and the world!
  •  » Help from all over the world for your questions
  •  » Build logs for you and all members
  •  » Blogs
  •  » Image Gallery
  •  » Many thousands of members and hundreds of thousands of posts! 

YES! I want to register an account for free right now!  p.s.: For registered members this ad will NOT show

 

Thread: What are boring oversize limits?
          
   
   

Reply To Thread
Page 1 of 2 1 2 LastLast
Results 1 to 15 of 19
  1. #1
    Ralph Moore's Avatar
    Ralph Moore is offline CHR Member Visit my Photo Gallery
    Join Date
    Jan 2006
    Location
    North Pole
    Car Year, Make, Model: 1932 5W, Flathead Powered
    Posts
    87

    What are boring oversize limits?

     



    Update on my 46 flathead, The only cracks(other than the guaranteed stud to water jacket) were in two valve seats which have been repaired. The machinist here found my .040 cylinders were tapered about .022-.025 from top to bottom, so an .060 oversize bore will not quite cover the wear. He recommends .080 or .100 oversize, but I cannot find any pistons in these sizes. Speedway sells some 4-ring .125 pistons, but is this going too far?
    This guy has worked on a lot of flatheads and says they have plenty of meat on them, but I don't want to go out any more than is necessary.
    Any ideas? Or sources for .080 pistons?
    Thanks,
    Ralph

  2. #2
    HWORRELL's Avatar
    HWORRELL is offline CHR Member Visit my Photo Gallery
    Join Date
    Oct 2003
    Location
    ST.LOUIS
    Car Year, Make, Model: 31 FORD 5 WINDOW,69 442, 305 sprint car,
    Posts
    1,410

    I'm by no means a flathead expert,But that sounds way too much for my taste. I kinda understand that flatheads always ran hot and 80 over is gonna compound that problem I would think...

  3. #3
    Ralph Moore's Avatar
    Ralph Moore is offline CHR Member Visit my Photo Gallery
    Join Date
    Jan 2006
    Location
    North Pole
    Car Year, Make, Model: 1932 5W, Flathead Powered
    Posts
    87

    I was thinking the same thing, but he seems to know his stuff and also why would they make them in .125 over?
    Ralph

  4. #4
    R Pope is offline CHR Member Visit my Photo Gallery
    Join Date
    Jun 2005
    Location
    Eston
    Posts
    2,270

    Lots of 59a flatties were bored 3/16 over. True, some were water heaters, but 1/8" was considered mild. A good sound block is too hard to find to chuck it because of bore wear. Flathead Jack sells pistons for it.

  5. #5
    Matt167's Avatar
    Matt167 is offline CHR Member Visit my Photo Gallery
    Join Date
    Jan 2004
    Location
    Prattsville
    Car Year, Make, Model: '51 Chevy Fleetline and a Ratrod project
    Posts
    4,990

    if your not comfterble having it bored .100 over, have .066 over pistions made by EGGE this will cover what you need. he only deals with Cast pistions but will make anything you want, and he's resonable
    You don't know what you've got til it's gone

    Matt's 1951 Chevy Fleetline- Driver

    1967 Ford Falcon- Sold

    1930's styled hand built ratrod project

    1974 Volkswagen Super Beetle Wolfsburg Edition- sold

  6. #6
    techinspector1's Avatar
    techinspector1 is offline CHR Member Visit my Photo Gallery
    Join Date
    May 2003
    Location
    Zephyrhills, Florida, USA
    Car Year, Make, Model: '32 Henway
    Posts
    12,423

    Sonic check the block. You need minimum 0.130" wall after boring and honing.
    PLANET EARTH, INSANE ASYLUM FOR THE UNIVERSE.

  7. #7
    HWORRELL's Avatar
    HWORRELL is offline CHR Member Visit my Photo Gallery
    Join Date
    Oct 2003
    Location
    ST.LOUIS
    Car Year, Make, Model: 31 FORD 5 WINDOW,69 442, 305 sprint car,
    Posts
    1,410

    Quote Originally Posted by techinspector1
    Sonic check the block. You need minimum 0.130" wall after boring and honing.
    there ya go, I'd take what Techie says as gospel....

  8. #8
    Ralph Moore's Avatar
    Ralph Moore is offline CHR Member Visit my Photo Gallery
    Join Date
    Jan 2006
    Location
    North Pole
    Car Year, Make, Model: 1932 5W, Flathead Powered
    Posts
    87

    Just a bit over an 1/8th huh! I would have thought there was more than that. So how thick are sleeves? I guess if you were going back to STD that would give alot more room for a sleeve. Now the problem, I live in North Pole, Alaska. Sonic testing hasn't even been invented up here yet! Is there another way to measure it, say at the base of the cylinder?
    Ralph

  9. #9
    techinspector1's Avatar
    techinspector1 is offline CHR Member Visit my Photo Gallery
    Join Date
    May 2003
    Location
    Zephyrhills, Florida, USA
    Car Year, Make, Model: '32 Henway
    Posts
    12,423

    Sleeves are 0.125"
    I suspect that you'd have to move up the cylinder to get to the water jacket to find the wall thickness, but then....whoops....too late....now what??

    I wonder if it's possible to get in touch with the folks who manufacture these sonic tools and find out if you could rent one for a short period. I assume they have mail service up there????????
    PLANET EARTH, INSANE ASYLUM FOR THE UNIVERSE.

  10. #10
    Ralph Moore's Avatar
    Ralph Moore is offline CHR Member Visit my Photo Gallery
    Join Date
    Jan 2006
    Location
    North Pole
    Car Year, Make, Model: 1932 5W, Flathead Powered
    Posts
    87

    Of course we have mail! It arrives by dogsled once every six months. Now that you mention it, are the tools your talking about the same as say a paint thickness gage? I think eastwood sells them to tell how many layers of paint (or Bondo) you have.
    Ralph

  11. #11
    Flathead4d is offline CHR Member Visit my Photo Gallery
    Join Date
    Dec 2002
    Location
    The Motor City
    Car Year, Make, Model: 50 Ford Custom
    Posts
    47

    The general consensus is you can bore and 8-BA block to 3-5/16" without any problems. I have mine at 3-3/8" but the block was sonic tested beforehand. The bad news is that the machinist who did it is no longer in business. Try the motorcityspeedequipment.com web site.

  12. #12
    Ralph Moore's Avatar
    Ralph Moore is offline CHR Member Visit my Photo Gallery
    Join Date
    Jan 2006
    Location
    North Pole
    Car Year, Make, Model: 1932 5W, Flathead Powered
    Posts
    87

    Yea, I know what you mean, the guy that's doing mine is losing his shop soon due to a construction right of way. He said after they buy him out he will probably retire and he is the only guy in town I would trust with a fathead. What would the Cubic inches be at 3-5/16" bore with a 3-3/4" stroke. Thanks for all the info.
    Ralph

  13. #13
    nitrowarrior's Avatar
    nitrowarrior is offline CHR Member Visit my Photo Gallery
    Join Date
    Mar 2007
    Location
    Mesa
    Posts
    1,385

    How soon is he losing it? CID would be approx 258 for an 8 cyl. 6 cyl will aprox be 194.
    Last edited by nitrowarrior; 05-26-2007 at 09:36 AM.
    What if the "Hokey Pokey" is what it's really all about?

  14. #14
    Ralph Moore's Avatar
    Ralph Moore is offline CHR Member Visit my Photo Gallery
    Join Date
    Jan 2006
    Location
    North Pole
    Car Year, Make, Model: 1932 5W, Flathead Powered
    Posts
    87

    I'm not sure exactly when, but it's been in the paper as a proposed street change. One thing about Alaska there are only two seasons, winter and construction. I checked with EGGE as Matt167 suggested and they carry the .080 pistons I need which will keep me .040 under maxing the cylinders out. And after reading the motor city web site it sounds like I won't have any trouble going the .080 over.
    Ralph

  15. #15
    techinspector1's Avatar
    techinspector1 is offline CHR Member Visit my Photo Gallery
    Join Date
    May 2003
    Location
    Zephyrhills, Florida, USA
    Car Year, Make, Model: '32 Henway
    Posts
    12,423

    I think Don Shillady still has a 4" Mercury crank for sale. Email him and ask.
    PLANET EARTH, INSANE ASYLUM FOR THE UNIVERSE.

Reply To Thread
Page 1 of 2 1 2 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
Links monetized by VigLink