News:


  • March 28, 2024, 01:47:36 PM

Login with username, password and session length

Author Topic: Crazy four stroke question  (Read 4126 times)

Offline Clancy Arnold

  • 2015
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 1453
  • I am 5 Ft. 8 In., the Taube is 7 Ft. 4 In.
Crazy four stroke question
« on: November 14, 2010, 02:40:53 PM »
I have reviewed the owners manual and have many years experience working on car engines but I can not find the answer!

How does the lower end of the OS FS91 SII-P engine get lubricated?

The only thing I see is that there is a line from the lower crankcase to the intake manifold.  The only instruction in the manual is to put after run oil in the glow plug hole.

Clancy
Clancy Arnold
Indianapolis, IN   AMA 12560 LM-S
U/Tronics Control
U/Control with electronics added.

Offline Bob Reeves

  • 2016 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 3415
    • Somethin'Xtra Inc.
Re: Crazy four stroke question
« Reply #1 on: November 14, 2010, 02:47:08 PM »
Not positive about the OS but Saitos get lubed by what blows by the ring when they are running. Would put money on the OS being the same.

Offline Tim Wescott

  • 2016 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 12804
Re: Crazy four stroke question
« Reply #2 on: November 14, 2010, 02:47:21 PM »
My understanding is that it depends on blow by.
AMA 64232

The problem with electric is that once you get the smoke generator and sound system installed, the plane is too heavy.

Offline Clancy Arnold

  • 2015
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 1453
  • I am 5 Ft. 8 In., the Taube is 7 Ft. 4 In.
Re: Crazy four stroke question
« Reply #3 on: November 14, 2010, 04:30:24 PM »
Thanks
I had not taken that into consideration.
I am not used to rings having that much blow by, but then I am used to pistons with three or four rings.

I was expecting something along the line of the crankcase filling with fuel/air mix during the compression stroke through the crankcase breather tube.
Clancy
Clancy Arnold
Indianapolis, IN   AMA 12560 LM-S
U/Tronics Control
U/Control with electronics added.

Offline Dick Pacini

  • 24 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 1628
Re: Crazy four stroke question
« Reply #4 on: February 21, 2011, 10:13:52 PM »
I have pondered that too, but never asked the question.  After all, how can you have suck, squeeze, bang and blow without a crankcase full of oil? ???
AMA 62221

Once, twice, three times a lady.  Four times and she does it for a living.  "You want me on that wall.  You need me on that wall."

Offline Air Ministry .

  • Trade Count: (0)
  • Admiral
  • ******
  • Posts: 4978
Re: Crazy four stroke question
« Reply #5 on: May 19, 2011, 02:41:05 AM »
Yep , NO Oil Control Ring .

Offline Jim Kraft

  • 2015
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 3411
  • AMA78415
Re: Crazy four stroke question
« Reply #6 on: May 21, 2011, 07:56:47 AM »
They do get oiled from blowby. I have one of the original OS 60 FS engines with the open rockers, and it blows quite a bit of oil out of the crankcase breather. You do have to oil the rockers before a days flying, as they do not get oiled any other way. I also have one of the old original OS 90 FS engines, and it also blows out quite a bit of oil from the breather. The 90 is a very powerfull engine, and will swing a 16-6 prop. The 60 is a sweet runner, but not great on power, although it will swing a 14-6 very well. I also have an old Saito 90 twin that uses a vane pump in the rear to blow out excess oil, as it has both rods connected to the same crankpin, and therefore does not scavange the oil from crankcase pressure. It is actually more of a 2 cyl. radial than a twin. Saito makes them both ways.
Jim Kraft

Offline Clancy Arnold

  • 2015
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 1453
  • I am 5 Ft. 8 In., the Taube is 7 Ft. 4 In.
Re: Crazy four stroke question
« Reply #7 on: May 21, 2011, 08:32:16 AM »
Thanks Jim
Should I oil them before each days flying or before each flight give them a drop or two?  I have several oils to choose from:  Marvel Mystery Oil, 3 in 1, Singer sewing machine oil, WD-40.  I use the Marvel Mystery Oil as an after run oil in all of my engines.

I fly the OS FS91 SII-P engine at 1/3 throttle most of the flight.  It is swinging a 15 x 6 prop and doing 7.5 second laps on 65 Ft. lines.

Is this a good idea, bad idea or recommendations?
Clancy
« Last Edit: May 22, 2011, 06:51:52 AM by Clancy Arnold »
Clancy Arnold
Indianapolis, IN   AMA 12560 LM-S
U/Tronics Control
U/Control with electronics added.

Offline Jim Kraft

  • 2015
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 3411
  • AMA78415
Re: Crazy four stroke question
« Reply #8 on: May 22, 2011, 02:05:26 PM »
As far as the rockers on the OS 91, you should be fine as they are oiled up the pushrod tubes. I sure would use an after run oil in it, and my preference would be Marvel Air Tool oil, or Rislone. I have used both, and they both do well. I would not use WD-40 in any engine, as it has a bad habit of building up a residue on the cyl. walls that is real hard to clean off. I usually give mine a shot of rislone in the breather nipple after a days flying, and flip it a few times to distribute the oil. There are other after run oils that work well also, but my experience has been with these two.

The Rislone I use is the one in the quart bottle that is used as an additive, not the concentrate. Marvel Mystery oil is okay for short term, but no good for storage as it will dry out and leave your engine stuck with a red residue. Just about any air tool oil should work and not dry out.
Jim Kraft

Offline Clancy Arnold

  • 2015
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 1453
  • I am 5 Ft. 8 In., the Taube is 7 Ft. 4 In.
Re: Crazy four stroke question
« Reply #9 on: May 22, 2011, 06:05:08 PM »
Thanks Jim
I will still give the rocker arms some oil before each day's flying.  I will use the 3 in 1 oil as it will wick into the small spaces.

This is not the first time I have heard about Marvel Mystery Oil drying out but the can I have is over 20 years old and even the spillage around the top of the can does not dry out.  I heard that they changed the formula some time back.  I have engines that were treated with Marvel Mystery Oil and have not been run in years that still turn over freely.  I guess that when this can runs out I will have to switch to Rislone!
Clancy
Clancy Arnold
Indianapolis, IN   AMA 12560 LM-S
U/Tronics Control
U/Control with electronics added.


Advertise Here
Tags:
 


Advertise Here