News:



  • June 15, 2024, 01:13:37 PM

Login with username, password and session length

« previous next »
Pages: [1]   Go Down

Author Topic: Cub .074 diesel 0-rings  (Read 2095 times)

Offline Larry Renger

  • 21 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 4002
Cub .074 diesel 0-rings
« on: June 19, 2010, 12:06:04 AM »
Smallparts.com being who they are, I had to order 100 o-rings for my Cub .074 diesel to get one.  They are Viton elastopolymer, and resistant to heat and chemical stress.

 If anyone wants one, a self-addressed, stamped envelope will net you one (or more, let me know) in return.  The 100 only cost $8 with shipping, so this is a freebie!
Logged
Think S.M.A.L.L. y'all and, it's all good, CL, FF and RC!

DesignMan
 BTW, Dracula Sucks!  A closed mouth gathers no feet!

Offline Tim Wescott

  • 2016 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 12832
Re: Cub .074 diesel 0-rings
« Reply #1 on: June 19, 2010, 10:17:04 PM »
What size?
Logged
AMA 64232

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

Offline Jim Thomerson

  • Trade Count: (0)
  • Admiral
  • ******
  • Posts: 2087
Re: Cub .074 diesel 0-rings
« Reply #2 on: June 20, 2010, 07:43:19 AM »
I use the black O rings from the local hardware store.  They seem to work fine, and they will sell you as few as you want.
Logged

Offline Larry Renger

  • 21 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 4002
Re: Cub .074 diesel 0-rings
« Reply #3 on: June 20, 2010, 12:33:44 PM »
1/2" OD, 1/16" cross-section.

How long do the hardware store o-rings last in a diesel head?
Logged
Think S.M.A.L.L. y'all and, it's all good, CL, FF and RC!

DesignMan
 BTW, Dracula Sucks!  A closed mouth gathers no feet!

Offline Jim Thomerson

  • Trade Count: (0)
  • Admiral
  • ******
  • Posts: 2087
Re: Cub .074 diesel 0-rings
« Reply #4 on: June 20, 2010, 02:59:52 PM »
I don't know.  I've never had one fail or leak.  If I have occasion to take the contrapiston out, I replace the O ring because it is compressed looking.  Crossection D instead of O.   :o
Logged

Offline GGeezer

  • Trade Count: (0)
  • Commander
  • ****
  • Posts: 241
    • Gizmogeezer Products
Re: Cub .074 diesel 0-rings
« Reply #5 on: June 20, 2010, 06:33:48 PM »
I use standard nitrile "O" rings on the contra pistons in my home-made diesels. They seem to work fine in these long-stoke cool running engines. I haven't tried them in my hotter engines (Cubs & McCoys) where I use the Viton versions.

Orv.
Logged

Offline Bill Adair

  • 21 supporter
  • Trade Count: (0)
  • Captain
  • *
  • Posts: 882
  • AMA 182626
Re: Cub .074 diesel 0-rings
« Reply #6 on: June 20, 2010, 10:12:38 PM »
Hi Orv,

I'd like to try Viton O-rings in my McCoy 049 diesels, because the hardware store Bunna-N rings don't seem to last very long.

Do you happen to know what size rings the McCoy 049 uses? I just took my engine to the hardware store, and found the rings that fit about right. Should have paid more attention to the sizes.

Bill
Logged
Not a flyer (age related), but still love the hobby!

Offline Larry Renger

  • 21 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 4002
Re: Cub .074 diesel 0-rings
« Reply #7 on: June 21, 2010, 10:48:11 AM »
I have a Cub .049 diesel, and will measure it.
Logged
Think S.M.A.L.L. y'all and, it's all good, CL, FF and RC!

DesignMan
 BTW, Dracula Sucks!  A closed mouth gathers no feet!

Offline Bill Adair

  • 21 supporter
  • Trade Count: (0)
  • Captain
  • *
  • Posts: 882
  • AMA 182626
Re: Cub .074 diesel 0-rings
« Reply #8 on: June 21, 2010, 12:04:51 PM »
Thanks Larry,

Just found measurements that I jotted on the back of the ACE small parts envelope, so I did note the size after all.

If my McCoy .049 takes the same size rings as your Cub, we could split a bag of Niton rings if you like.

Measurements are: (Dia X ID X O/D)

1.6mm X 7.1mm X 10.3mm, or 3/32" X 1/4" X 7/16".

Bill
Logged
Not a flyer (age related), but still love the hobby!

Offline Tim Wescott

  • 2016 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 12832
Re: Cub .074 diesel 0-rings
« Reply #9 on: June 21, 2010, 08:33:30 PM »
Quote from: Bill Adair on June 20, 2010, 10:12:38 PM
I'd like to try Viton O-rings in my McCoy 049 diesels, because the hardware store Bunna-N rings don't seem to last very long.

Do you happen to know what size rings the McCoy 049 uses? I just took my engine to the hardware store, and found the rings that fit about right. Should have paid more attention to the sizes.
O-rings come in even-inch sizes (unless they're metric -- let's not go there).  They're probably either 3/8 (0.375") OD 1/16" thick or 7/16 (0.437") OD.  Measure the bore that they go into (or a fresh hardware store O-ring) with a ruler and see.

If you know what size, both Smallparts (www.smallparts.com) and McMaster-Carr (www.mcmaster.com) stock many different O-rings in many different materials -- don't get lost and chances are you'll find what you want.
Logged
AMA 64232

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

Offline Larry Renger

  • 21 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 4002
Re: Cub .074 diesel 0-rings
« Reply #10 on: June 23, 2010, 11:02:13 AM »
The Cub .049 uses a 7/16" OD x 1/16" cross-section ring.  I guess they aren't compatible.   :-\
Logged
Think S.M.A.L.L. y'all and, it's all good, CL, FF and RC!

DesignMan
 BTW, Dracula Sucks!  A closed mouth gathers no feet!

Offline Bill Adair

  • 21 supporter
  • Trade Count: (0)
  • Captain
  • *
  • Posts: 882
  • AMA 182626
Re: Cub .074 diesel 0-rings
« Reply #11 on: June 23, 2010, 01:38:07 PM »
Larry,

Thanks for checking the Cub O-ring size. Looks like they are much thinner than the McCoy rings, but about the same outer diameter.

Bill
Logged
Not a flyer (age related), but still love the hobby!

Offline Robert Mathison

  • Trade Count: (0)
  • Lieutenant
  • ***
  • Posts: 76
Re: Cub .074 diesel 0-rings
« Reply #12 on: June 26, 2010, 02:35:28 PM »
Larry,the O K cub diesel's came in two sizes , .049 & .075 and the .075 was a very good diesel we used the one we had for years.
     Bob
Logged

Offline Larry Renger

  • 21 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 4002
Re: Cub .074 diesel 0-rings
« Reply #13 on: June 28, 2010, 10:16:12 AM »
Oddly, Cub never turned their .099 into a diesel.  Wonder why.

Oh, yes, looking in my diesel box, I found I have a couple of extra .049 0-rings in Viton that I picked up years ago.  I went to an aviation O-ring supplier, and asked to buy one or two rings.  The guy laughed (You want 1 or 2 THOUSAND, kid?) and gave me several for free.
Logged
Think S.M.A.L.L. y'all and, it's all good, CL, FF and RC!

DesignMan
 BTW, Dracula Sucks!  A closed mouth gathers no feet!

Advertise Here
Pages: [1]   Go Up
« previous next »
Tags:
 


Advertise Here