ArboristSite.com Sponsors
 
 


squishey squishey

Discussion in 'Chainsaw' started by muddstopper, Jan 27, 2019.

  1. muddstopper

    muddstopper Addicted to ArboristSite

    Joined:
    Nov 20, 2011
    Messages:
    3,652
    Likes Received:
    6,595
    Location:
    mountains of nc
    I got a 55 husky practice saw. Practice as in, trying get a little bit more out of a bunch
    of junk. Split the case and installed new bearing and seals and bolted the chinese cyl on it and measured the squish, .055 no gasket Not the worse china cyl I have measured, but bad enough. This will be my first attempt to cut the base on a cyl, which is why I am using cheap china parts. Just looking for a good target number, thinking .020, but is that cutting to much for a 53cc saw. I plan on trying a little porting once I get the squish where it needs to be. The ports on that china cyl look a lot smaller than a oem so even a little bit of grinding should help.
     
  2. Ketchup

    Ketchup Smells like 2-stroke.

    Joined:
    Nov 7, 2017
    Messages:
    261
    Likes Received:
    195
    Location:
    Boulder, CO
    0.025-0.018" is good. Lots of people target 0.020".

    The plating in chinese jugs tends to delaminate after port work. Some people say if you grind carefully (right direction, sharp burrs, finer grinding heads) it's less of an issue.
     
  3. blsnelling

    blsnelling Site Contributor

    Joined:
    Nov 8, 2006
    Messages:
    53,417
    Likes Received:
    31,741
    Location:
    Franklin, OH
    .055"?!!! That's atrocious! Wow! I would shoot for .016"-.020".
     
    mikerudder likes this.
  4. muddstopper

    muddstopper Addicted to ArboristSite

    Joined:
    Nov 20, 2011
    Messages:
    3,652
    Likes Received:
    6,595
    Location:
    mountains of nc
    Not as bad as the AM closed port I bought once, it had over .080. That one got sent back.
     
  5. Jasonrkba

    Jasonrkba ArboristSite Guru

    Joined:
    Jul 25, 2015
    Messages:
    753
    Likes Received:
    429
    Location:
    Stokesdale NC.
    Where are you buying from? I wonder how consistent they are.
     
  6. drf255

    drf255 BAD CAD

    Joined:
    Nov 3, 2014
    Messages:
    3,205
    Likes Received:
    4,357
    Location:
    Socialists Republic of New York
    Not sure how you checked, but it’s helpful to have a few different diameters of solder around for it.

    I sent a saw that was a dead nuts accurate .018 squish that was measured by the end user to be .038. He was using plumbing solder that was over .100 thick to measure. I was using .024 solder.

    To get an accurate squish now, I turn the saw over with a drill for around 15 seconds and insure I cannot feel the solder at all when I pass TDC. If you can still feel the piston hitting the solder, youre not at an accurate measurement yet.

    The solder you use should be close in diameter to suspected/intended squish.
     
  7. muddstopper

    muddstopper Addicted to ArboristSite

    Joined:
    Nov 20, 2011
    Messages:
    3,652
    Likes Received:
    6,595
    Location:
    mountains of nc
    I am using solid solder and its pretty large dia. I will try something smaller. I assembled the rest of the saw, except for p/c, today. That should make it easier to spin and squish the solder. I'll have to head down to the shop and see what else I have on hand. Thanks for the tip.

    Edited to add, The solder I first used measured .110, advertised as 1/8. I
    had some rosin core that measured .060. I tried the small dia solder and it measured .051 squish. couldnt hardly tell the pistion had hit it.I spun the engine with the pull rope several times. I put .110 solder back in and spun the motor a few times and got the same .051 squish. The AM p/c is a warhawk brand. The cheapest one HL sales.
     
  8. muddstopper

    muddstopper Addicted to ArboristSite

    Joined:
    Nov 20, 2011
    Messages:
    3,652
    Likes Received:
    6,595
    Location:
    mountains of nc
    Another question. My plans are to take .030 off the cyl base. This should give me a squish of .020. .030 is almost 1mm. I dont have anyway to to know or measure stock port timing on a good oem cyl. Well I could take a good running saw apart, but dont really want to. I realize lowering the base by milling should cause the exhaust to be lower and to open later and could increase compression and might increase power. While I do intend to widen the ports, I had not planned to raise the exhaust. Without any numbers to go by, anybody have any suggestions as to what degree's the exhaust port should open.
     
  9. muddstopper

    muddstopper Addicted to ArboristSite

    Joined:
    Nov 20, 2011
    Messages:
    3,652
    Likes Received:
    6,595
    Location:
    mountains of nc
    Cyl is a Warhawk brand. I have been doing a little more measureing, trying to figure out why a replacement p/c would be so far off of oem. I have a couple of bad oem cyl/pistons to measure off of. A few things I have found is the total lenght of piston, from bottom of skirt to top, the Am is shorter than oem. From piston pin to top of piston is also shorter. The piston would loose compression, even with a oem cyl. I then started measureing the transfers in the cyl. I found that the Am cyl is .030 longer from base to top of transfer than oem. Cutting the base .030 would bring the AM cyl just back to oem spec. The bottom of the AM cyl walls, the part that sets in the case, is also longer than OEM. Whether it will be a problem once I mill the base, I dont know. I will probably just go ahead and cut this too when I cut the base. I tried to measure the top and bottom of the ports, but with just slide calipers, I couldnt get a consistant reading. They look different so I assume they are. My guess is that the saw would run with nothing done to the AM parts, but it would fall short of the performance of a stock oem saw.
     
  10. DSW

    DSW ArboristSite Guru

    Joined:
    Jul 18, 2016
    Messages:
    768
    Likes Received:
    1,186
    Location:
    TheWoods
    Why did he measure it at all?
     
  11. drf255

    drf255 BAD CAD

    Joined:
    Nov 3, 2014
    Messages:
    3,205
    Likes Received:
    4,357
    Location:
    Socialists Republic of New York
    AM jugs can have drastically different numbers than their oem counterparts.

    I used a Hyway jug (a premium AM brand) on an 028S and it ran like shít. I pulled jug and timed it. Got 108/136/72. I changed that to 103/120/78 and tightened squish to 20 and the saw came alive.

    For your saw, I’d say a 105* ex roof would be perfect.

    OCD. I check everyone else’s work at least once before installing on any saw. I check my own work twice. The last guy to touch a saw is “it”.
     
    CJ Brown, Dahmer and Need2Saw like this.
  12. muddstopper

    muddstopper Addicted to ArboristSite

    Joined:
    Nov 20, 2011
    Messages:
    3,652
    Likes Received:
    6,595
    Location:
    mountains of nc
    Just a few weeks ago I put a warhawk jug on a 028 and it ran like a stock saw. Nothing special, but not bad either. I didnt measure anything or change anything. I would have to say the warhawk parts might not be to consistant.
     
  13. drf255

    drf255 BAD CAD

    Joined:
    Nov 3, 2014
    Messages:
    3,205
    Likes Received:
    4,357
    Location:
    Socialists Republic of New York
    Not even oem fully consistent, but way more so than AM. No matter how you slice it, the OEM parts will always be better in some way over AM.

    Squish, port design and timing, port size, plating quality, casting alloy, etc...
     
    sunfish likes this.
  14. drf255

    drf255 BAD CAD

    Joined:
    Nov 3, 2014
    Messages:
    3,205
    Likes Received:
    4,357
    Location:
    Socialists Republic of New York
    Don’t take 30 off jug base btw. My guestimometer says start with 23 and recheck squish. For some reason the larger the squish, the less consistent the measurement.

    You may be right on target with 30 off, but if you’re not, you can’t put it back.
     
    CJ Brown, Dahmer, Jeff Lary and 2 others like this.
  15. muddstopper

    muddstopper Addicted to ArboristSite

    Joined:
    Nov 20, 2011
    Messages:
    3,652
    Likes Received:
    6,595
    Location:
    mountains of nc
    Well today I decided to work on the cyl. My lathe hasnt been used in a while so I had to do a lot of cleaning before fireing it up. My plans where to just chuck the cyl in the 4 jaw and cut the base, but after fooling with it for about a hour, I gave up. The base circle doesnt go all the way around which made it hard to center and the bolt holes around the base kept catching my indicator. Then to top it off, the fins on the cyl are not uniform, just to much work and time to get it right. I just happen to have a piece of aluminum that was just big enough to to turn down for the bore. Resized_20190207_205248.jpeg
    and here the finished base, Resized_20190207_205328.jpeg Not sure how that pulse hole is going to work out after the cutting the face, it sort of grew. I put the cyl on the case and it checked .0205 squish which is close enough to .020 for me. Tomorrow I am going to work on widening the ports. Not sure I have all the parts to put this thing together, so it might be a few days before I get to fire it up
     
    CJ Brown, Ketchup, sunfish and 2 others like this.
  16. muddstopper

    muddstopper Addicted to ArboristSite

    Joined:
    Nov 20, 2011
    Messages:
    3,652
    Likes Received:
    6,595
    Location:
    mountains of nc
    Got around to doing a little porting today. Didnt raise or lower just made them a bit wider and then blended to the size of the muffler gasket. Widen the intake by grinding the sides to match the outer dia. I know I could have made the exhaust a lot bigger than I did, but not knowing how much is to much, I went about a mm bigger than stock and tried to take the same amount off each side. After I run it, I might revisit the porting. Resized_20190208_200651.jpeg Resized_20190208_200622.jpeg
     
    CJ Brown, sixonetonoffun and Ketchup like this.
  17. rwoods

    rwoods Addicted to ArboristSite

    Joined:
    Feb 22, 2010
    Messages:
    5,746
    Likes Received:
    5,622
    Location:
    Tennessee
    ms, is there anything that you don’t DIY? Wish I had half your skills. Ron
     
    sixonetonoffun likes this.
  18. muddstopper

    muddstopper Addicted to ArboristSite

    Joined:
    Nov 20, 2011
    Messages:
    3,652
    Likes Received:
    6,595
    Location:
    mountains of nc
    I wouldnt call it skill, more like willing to take a chance. I dont show the stuff I mess up. I have done so much, for so long, with so little, I do feel qualified to do almost anything, with absolutely nothing. This is my first attempt to do more than just a basic rebuild on a chainsaw. If it runs, I'll probably give it away. If it doesnt work, I will be out $25 for the china kit and a bunch of junk I was going to trash anyways.
     
  19. Ketchup

    Ketchup Smells like 2-stroke.

    Joined:
    Nov 7, 2017
    Messages:
    261
    Likes Received:
    195
    Location:
    Boulder, CO
    That's the right attitude!

    There is one risk you may not have fully considered:

    You're probably going to get addicted to porting saws.
     
  20. muddstopper

    muddstopper Addicted to ArboristSite

    Joined:
    Nov 20, 2011
    Messages:
    3,652
    Likes Received:
    6,595
    Location:
    mountains of nc
    I do have a question for the real saw builders. 55ranchers come with 2 different carburetors, a zama and walbro. I have several of each, but they would all need to be rebuilt. Which does anybody think might be the best choice. I have read that the zama is actually a little smaller or has smaller jets than the walbro. Dont know if thats true. I also wonder if the pulse hole now being a little bigger because I milled into it, will this create more pulse to the carb causing tuning problems. The hole in the bulkhead wont be changed so I am thinking the bigger hole isnt going to make a difference. If I can get it to seal that is.
     
    sixonetonoffun likes this.

Share This Page