Author Topic: Port timing.  (Read 5974 times)

0 Members and 27 Guests are viewing this topic.

Offline Al Smith

  • Moderator
  • Nitro Hotsaw
  • *******
  • Posts: 2779
  • Karma: 181

  • Total Badges: 34
    Badges: (View All)
    Tenth year Anniversary Nineth year Anniversary Eighth year Anniversary Level 6 Seventh year Anniversary Sixth year Anniversary
Re: Port timing.
« Reply #30 on: February 16, 2013, 07:43:25 pm »
You know come to think about it if you want 25 thou all you need to do is get a set of micrometers and start measuring paper thickness .Most printer paper is a tad less than 3 thou ,Some is close to 5 thou .An old fashion IBM type punch card is 7 thou .Lots of possibilities here .

Offline jmester

  • Global Moderator
  • Nitro Hotsaw
  • *******
  • Posts: 2106
  • Karma: 171
  • Location: MD

  • Total Badges: 36
    Badges: (View All)
    Tenth year Anniversary Nineth year Anniversary Eighth year Anniversary Seventh year Anniversary Sixth year Anniversary Level 6
Re: Port timing.
« Reply #31 on: February 16, 2013, 07:47:59 pm »
I measured the gasket at .020 that came off the saw. Have a new one on the way. Will have to measure it to make sure. Is your .015 mill spec with or with out a gasket. I might check out some different stuff. I have been saving some different thickness of paper and card stock for a while.
FEAR NO TREE. FEAR GOD.

Offline jmester

  • Global Moderator
  • Nitro Hotsaw
  • *******
  • Posts: 2106
  • Karma: 171
  • Location: MD

  • Total Badges: 36
    Badges: (View All)
    Tenth year Anniversary Nineth year Anniversary Eighth year Anniversary Seventh year Anniversary Sixth year Anniversary Level 6
Re: Port timing.
« Reply #32 on: February 16, 2013, 07:56:11 pm »
I just found a index card that is .007 thickness. Should give me a squish of .027 which I can live with. I guess now I need to work on my porting work.
FEAR NO TREE. FEAR GOD.

Offline jmester

  • Global Moderator
  • Nitro Hotsaw
  • *******
  • Posts: 2106
  • Karma: 171
  • Location: MD

  • Total Badges: 36
    Badges: (View All)
    Tenth year Anniversary Nineth year Anniversary Eighth year Anniversary Seventh year Anniversary Sixth year Anniversary Level 6
Re: Port timing.
« Reply #33 on: February 17, 2013, 08:26:18 pm »
Will you get an accurate squish reading if the rings are removed. Or because the piston rocks back and forth it gives you the wrong reading. I ask because, I cut out my index card gasket of .007 thickness. And bolted the cylinder back up and got a squish of .035. It should be around .027 now with removing the factory base. That measured .020.
FEAR NO TREE. FEAR GOD.

Offline aclarke

  • Nitro Hotsaw
  • *******
  • Posts: 1676
  • Karma: 172

  • Total Badges: 25
    Badges: (View All)
    Fourth year Anniversary Third year Anniversary 1000 Posts Second year Anniversary Level 5 500 Posts
Re: Port timing.
« Reply #34 on: February 17, 2013, 08:53:33 pm »
Put the solder at 90 degrees to exhaust.  I.e. if exhaust is 12:00 put the solder at 9:00 and 3:00  the rocking is minimized at the axis

Offline jmester

  • Global Moderator
  • Nitro Hotsaw
  • *******
  • Posts: 2106
  • Karma: 171
  • Location: MD

  • Total Badges: 36
    Badges: (View All)
    Tenth year Anniversary Nineth year Anniversary Eighth year Anniversary Seventh year Anniversary Sixth year Anniversary Level 6
Re: Port timing.
« Reply #35 on: February 17, 2013, 08:57:59 pm »
So the rocking does have an effect. I will try it  that way and see what I get.
FEAR NO TREE. FEAR GOD.

Offline Al Smith

  • Moderator
  • Nitro Hotsaw
  • *******
  • Posts: 2779
  • Karma: 181

  • Total Badges: 34
    Badges: (View All)
    Tenth year Anniversary Nineth year Anniversary Eighth year Anniversary Level 6 Seventh year Anniversary Sixth year Anniversary
Re: Port timing.
« Reply #36 on: February 17, 2013, 09:10:15 pm »
You have to remember two things .First it's a hemi domed piston plus it's a off set chamber .You're going to have to get that solder where it hits the machined face  around  the chamber pretty square which is going to be tough being off set and a rounded surface of the piston face.

That same deal I might add is why and how I screwed up cutting down the base of an 038 Av and made a head knocker out of it which I had to correct with a thicker gasket .The whole concept  of what I just said had completely slipped my mind when I made my preliminary mesurements .Chit happens.


While on the subject I'm not certain if the chamber is milled perpediculer to the bore or angled .You could probabley check it with a depth micrometer from the cylinder base .Geeze what a fine kettle of fish this is .
.

Offline jmester

  • Global Moderator
  • Nitro Hotsaw
  • *******
  • Posts: 2106
  • Karma: 171
  • Location: MD

  • Total Badges: 36
    Badges: (View All)
    Tenth year Anniversary Nineth year Anniversary Eighth year Anniversary Seventh year Anniversary Sixth year Anniversary Level 6
Re: Port timing.
« Reply #37 on: February 17, 2013, 09:14:28 pm »
I will check it in a couple of different places tomorrow and see what I get.
FEAR NO TREE. FEAR GOD.

Offline man of stihl

  • Nitro Hotsaw
  • *******
  • Posts: 1219
  • Karma: 71
  • NW PA
  • Location: nw pennsylvania

  • Total Badges: 31
    Badges: (View All)
    Level 6 Fourth year Anniversary Spammer 25 Posts in one day Karma Good 1000 Posts Third year Anniversary
Re: Port timing.
« Reply #38 on: February 18, 2013, 08:42:19 pm »
This is how i check squish.
Ron

Offline Al Smith

  • Moderator
  • Nitro Hotsaw
  • *******
  • Posts: 2779
  • Karma: 181

  • Total Badges: 34
    Badges: (View All)
    Tenth year Anniversary Nineth year Anniversary Eighth year Anniversary Level 6 Seventh year Anniversary Sixth year Anniversary
Re: Port timing.
« Reply #39 on: February 18, 2013, 08:58:03 pm »
Well geeze you usually knock the carbon off first . ;D

I've been racking my brain on this hemi domed piston business becuse it would not be the same with an offset combustion chamber .About the only way or one way might be to squeeze wax and measure with a  good set of calipers from the piston skirt .

I don't know if it would work or not .You'd have to have the piston face clean enough the wax would stick and oil the head deck so it wouldn't stick .

Macdizzy mentioned using some kind  of wax or clay but exactly what kind or how to slips my mind .

 

Related Topics

  Subject / Started by Replies Last post
8 Replies
1252 Views
Last post May 12, 2012, 09:30:03 pm
by Al Smith
5 Replies
633 Views
Last post January 22, 2014, 02:46:36 pm
by danders
17 Replies
2508 Views
Last post February 14, 2014, 10:46:23 am
by 660magnum
6 Replies
566 Views
Last post November 02, 2015, 07:43:33 pm
by Al Smith
2 Replies
1790 Views
Last post March 20, 2016, 01:15:19 pm
by 660magnum
0 Replies
805 Views
Last post April 07, 2016, 01:41:04 pm
by Cut4fun .
5 Replies
506 Views
Last post July 20, 2016, 07:33:47 pm
by 1manband
21 Replies
6850 Views
Last post October 17, 2016, 08:19:31 pm
by dannyupsolate
0 Replies
335 Views
Last post October 12, 2016, 02:12:43 pm
by Cut4fun .
4 Replies
922 Views
Last post April 18, 2018, 01:10:06 am
by 660magnum