Friday type question...
Close

Friday type question...

This is a discussion on Friday type question... within the General forums, part of the Caferacer.net Forums category; Ok so i got a stuck 350 engine. head is off, pistons exposed. left side cyl, free. right side piston is holding on for all ...

Results 1 to 9 of 9
  1. #1
    Senior Member burntblacktoast's Avatar
    Join Date
    Mar 2008
    Location
    bellflower, il, USA.
    Posts
    204

    Friday type question...

    Ok so i got a stuck 350 engine. head is off, pistons exposed. left side cyl, free. right side piston is holding on for all it is worth. it is soking in PB blaster (not peanut butter), i scrape all loose crud from around the piston/cyl, whack a few times with a rubber mallet just to get some molecules moving, repeat a day later. what other types of voodoo spells have yall had to invoke to get pistons undid? heat, pressure, violence? i am up to suggestions

  2. #2
    Senior Member oneworden's Avatar
    Join Date
    Jul 2008
    Location
    franklin, WI, USA.
    Posts
    854
    personally i would try to heat around where the piston and wall meet, after warming then spray with peanut butter. there will be a lot of cool smoke you don't want to breath in, but it will get the blaster in there deeper.

    oh yeah then get a bigger hammer...
    Did you hear about the pirate with two wooden legs?

    They caught fire and burned his ass to the ground!

  3. #3
    Senior Member burntblacktoast's Avatar
    Join Date
    Mar 2008
    Location
    bellflower, il, USA.
    Posts
    204
    i like the way you think

  4. Remove Advertisements
    CafeRacer.net
    Advertisements
     

  5. #4
    FR
    FR is offline
    Senior Member FR's Avatar
    Join Date
    Nov 2004
    Location
    Essex Jct, VT, USA.
    Posts
    2,595
    How did it sieze in the first place? Rust, or mechanical "interference"? Do you think the crankshaft turns? You can apply heat to the cylinder, it's going to need a hone at the least, maybe a bore, so I guess you can't do too much more harm with heat and force...


    FR
    FR


    http://sidewaysnortheast.blogspot.com/

  6. #5
    Senior Member bmartin's Avatar
    Join Date
    Feb 2008
    Location
    Palmyra, NY, USA.
    Posts
    2,740
    If the oil treatment is not working and the piston is going to be replaced, you can try a cold chisel and take the piston out in pieces. Reverting to a blow torch might do more harm than good. Another way to whack it with force is to use a 2x4 on the piston and a steel mallet on the other end of the 2x4. Be careful - too much force might kill the lower bearing and or the rod itself.

    Unless the ring is embedded in the side wall of the bore, the oil treatment should work fine to free the piston given enough time. Thinking a little more about this - Is the piston cocked to one side in the bore??? If it is, you can try tapping the piston square again in the bore.

    good luck and keep us posted...
    Bob - Palmyra NY
    2 - 69 CB750, 1 Turbo
    1 - 71 CB750

  7. #6
    Senior Member burntblacktoast's Avatar
    Join Date
    Mar 2008
    Location
    bellflower, il, USA.
    Posts
    204
    Thanks for the replies so far, let me lend some more info. the engine was siezed when it came into my possesion. due to the looks of a cam lobe or two and some rocker faces, oil starvation may be the culprit, i have not inspected all of my passages yet. I do intend on a bore job and over sized pistons so a chisel is not a terrible idea. FR, the crank does rotate at least a little. it is stuck pretty darn near TDC because the cyl will only raise up a little when a turn on the crank. i think that if it were stuck closer to the middle the cylnder would travel further up and down both CW/CCW since the other piston is free. you know, as one unit. This brings me to bmartins suggestion not to apply too much force in regards to the rod or bearings being damaged. if the rod was at more of an angle any force i would use would be move the crank down and around. if it is as near vertical or TDC as i believe, most of that force would be going straight down, through the rod to the bearings....uhh, maybe i will stop wacking it as much

  8. #7
    Senior Member UngaWunga's Avatar
    Join Date
    Mar 2004
    Location
    Raymond, NH, USA.
    Posts
    8,388
    Block of wood on top of piston, very large hammer.




  9. #8
    Senior Member burntblacktoast's Avatar
    Join Date
    Mar 2008
    Location
    bellflower, il, USA.
    Posts
    204
    enablers

  10. #9
    Senior Member 2smokeTyler's Avatar
    Join Date
    Apr 2008
    Location
    Paducah, Kentucky, USA.
    Posts
    699
    marvels mystery oil...i have seen the stuff work miracles, though last time i used it, i let it sit in the bores for 3 days
    --Tyler
    1976 RD400
    Best Flattrack Site On The Net! www.fightfordirttrack.com

Sponsored Links

Posting Permissions

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

Similar Threads

  1. Got A New Scoot Last Friday
    By Midwest FZ Rider in forum General
    Replies: 8
    Last Post: 07-02-2012, 08:46 PM
  2. Hoping this will be mine by friday
    By wooda2008 in forum General
    Replies: 9
    Last Post: 09-09-2011, 11:44 AM
  3. Black Friday
    By Judeyramone in forum General
    Replies: 1
    Last Post: 12-03-2009, 02:51 PM
  4. WHAT TYPE OF PLUG FOR MY POTATO GUN?
    By ROSKO in forum General
    Replies: 5
    Last Post: 03-30-2005, 11:35 PM
  5. Friday practice
    By CHUCK in forum Vintage Motorcycle Racing
    Replies: 9
    Last Post: 07-30-2003, 04:48 PM