Author Topic: Who makes good cylinder, piston rings, for 372 and 390xp's?  (Read 793 times)

0 Members and 0 Guests are viewing this topic.

Offline alsled

  • Piped Saw
  • *****
  • Posts: 307
  • Karma: 18
Do these aftermarket companies keep the same port timing? or do they change things?

Offline 660magnum

  • Global Moderator
  • Nitro Hotsaw
  • *******
  • Posts: 6437
  • Karma: 249
  • For The Love Of Chainsaws
  • Location: NCO
They are pretty close
We should share what we know... someone may learn...
That knowledge can live after us... and that "Pays It Forward".
Be all that you can be . . .

Offline SawTroll

  • Nitro Hotsaw
  • *******
  • Posts: 1196
  • Karma: 68
  • Information collector
  • Location: Troms, North Norway
Do these aftermarket companies keep the same port timing? or do they change things?

Aftermarket cylinders tend to have ports that are narrower, which is a negative factor. I can't comment on the timing, but it likely varies.

Offline mdavlee .

  • Global Moderator
  • Nitro Hotsaw
  • *******
  • Posts: 1968
  • Karma: 171
Timing will vary on the cylinders. Some are as good and occasionally better. I would probably stick with OEM for the 390 since there's not many choices there. You can get an OEM cylinder from spike60 for a better deal than anywhere online. Be worth checking into. I think one of those aftermarket 390 pistons didn't last long for a member in BC. The 372 has a lot of choices and a lot of them seem to be fine. Check with weedeaterman.com for aftermarket parts.

Offline KilliansRedLeo

  • Nitro Hotsaw
  • *******
  • Posts: 2361
  • Karma: 80
  • Location: Rochester, NY
    • RoCHusqvarna
Whats the difference between the two pistons?

Both the BB kit piston and the Stihl 064 piston are 52mm. The Stihl 064 piston it taller by approximately 1.3mm and can be used to raise the CR to above 190PSI. I have done several for customers and the saws run well, with no problems so far.

The Stihl piston has the same 12mm pin as the Husky however a few thousandths must be removed from the inner sides of the piston pin boss in order to clear the small end of the rod and you must make sure that you have about 2mm clearance at BDC for the crank throws. A machine shop can remove the metal from the piston, my gunsmith does it for me, quicker and cheaper.
"When the people fear the government...you have tyranny....When the government fears the people....you have liberty"

Thomas Jefferson
1743-1826

Offline 660magnum

  • Global Moderator
  • Nitro Hotsaw
  • *******
  • Posts: 6437
  • Karma: 249
  • For The Love Of Chainsaws
  • Location: NCO
I have a 372 set up this way.
We should share what we know... someone may learn...
That knowledge can live after us... and that "Pays It Forward".
Be all that you can be . . .

Offline alsled

  • Piped Saw
  • *****
  • Posts: 307
  • Karma: 18
190 psi. Can you still run 91 octane pump gas on that?  I do a lot with snowmobiles and they would never live at  190 psi. Lots of detonation, like instantly.

Offline KilliansRedLeo

  • Nitro Hotsaw
  • *******
  • Posts: 2361
  • Karma: 80
  • Location: Rochester, NY
    • RoCHusqvarna
Never had a problem. I have customers who run 91 e10 with out a problem also others who run pure gas as well as SEF and no problems yet.
"When the people fear the government...you have tyranny....When the government fears the people....you have liberty"

Thomas Jefferson
1743-1826

Offline alsled

  • Piped Saw
  • *****
  • Posts: 307
  • Karma: 18
That's good to know. Just wondering, is there a huge difference in 190 and stock compression, as far as torque/ hp, plain old grunt feeling ?

Offline 660magnum

  • Global Moderator
  • Nitro Hotsaw
  • *******
  • Posts: 6437
  • Karma: 249
  • For The Love Of Chainsaws
  • Location: NCO
They sometimes build up more heat.
We should share what we know... someone may learn...
That knowledge can live after us... and that "Pays It Forward".
Be all that you can be . . .

 

Related Topics

  Subject / Started by Replies Last post
30 Replies
1914 Views
Last post October 09, 2015, 06:45:45 pm
by Cut4fun .
5 Replies
711 Views
Last post March 20, 2012, 09:04:51 pm
by Cut4fun .
8 Replies
498 Views
Last post July 30, 2013, 09:20:17 am
by farmboy
19 Replies
464 Views
Last post September 09, 2013, 09:51:10 pm
by doreadeal
54 Replies
1041 Views
Last post February 09, 2014, 05:37:39 pm
by wbhburn
3 Replies
586 Views
Last post November 06, 2013, 05:35:04 pm
by Captain Howdy
4 Replies
168 Views
Last post February 02, 2014, 07:51:15 am
by fossil
1 Replies
224 Views
Last post March 09, 2014, 03:41:36 pm
by stihls066
8 Replies
354 Views
Last post March 17, 2014, 09:07:10 am
by fordfairlane78
0 Replies
64 Views
Last post May 15, 2016, 04:28:51 am
by Eccentric