News:


  • April 27, 2024, 12:53:20 AM

Login with username, password and session length

« previous next »
Pages: [1]   Go Down

Author Topic: "trick" for rear intake engines  (Read 773 times)

Offline bill bischoff

  • Trade Count: (0)
  • Admiral
  • ******
  • Posts: 1704
"trick" for rear intake engines
« on: October 09, 2011, 12:48:12 PM »
In recent posts I have mentioned that rear disc valve engines can be made to run backwards by assembling them "incorrectly". I just came across an article I published in the NCS newsletter in 2000. I thought it might be of interest.
Logged

Offline Wayne J. Buran

  • AMA Member
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 1096
Re: "trick" for rear intake engines
« Reply #1 on: October 09, 2011, 02:31:28 PM »
Bill, I knew of the rear intakes being reversed however it was the standard front intakes that drove my question.
Thanks for the article.
Wayne
Logged
Wayne Buran
Medina, Ohio
AMA 14986 CD
USAF Veteran 35 TAC GP/ 6236 CSG, DonMuang RTAFB, Bangkok, Thailand 65-66 North Coast Controliners   "A fine is a tax for doing wrong. A tax is a fine for doing well!

Offline john vlna

  • 21 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 1353
Re: "trick" for rear intake engines
« Reply #2 on: October 09, 2011, 06:42:01 PM »
Wayne
Some Front intakes can be reversed in the same way, the K&B with a bolted front end for example. Mounting the engine can get weird though
John
Logged

Offline Wayne J. Buran

  • AMA Member
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 1096
Re: "trick" for rear intake engines
« Reply #3 on: October 10, 2011, 04:32:36 AM »
I understood that also, its the one piece case engines I was questioning. No source around here for that crank work.
Thanks
Wayne
Logged
Wayne Buran
Medina, Ohio
AMA 14986 CD
USAF Veteran 35 TAC GP/ 6236 CSG, DonMuang RTAFB, Bangkok, Thailand 65-66 North Coast Controliners   "A fine is a tax for doing wrong. A tax is a fine for doing well!

Offline john vlna

  • 21 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 1353
Re: "trick" for rear intake engines
« Reply #4 on: October 10, 2011, 11:45:28 AM »
Wayne,
Yeah if it is a one piece case you have to have a LH crank, What motor is it?
John
Logged

Offline Wayne J. Buran

  • AMA Member
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 1096
Re: "trick" for rear intake engines
« Reply #5 on: October 10, 2011, 06:04:31 PM »
Irvine .36 ABC Red Case
Wayne
Logged
Wayne Buran
Medina, Ohio
AMA 14986 CD
USAF Veteran 35 TAC GP/ 6236 CSG, DonMuang RTAFB, Bangkok, Thailand 65-66 North Coast Controliners   "A fine is a tax for doing wrong. A tax is a fine for doing well!

Offline bill bischoff

  • Trade Count: (0)
  • Admiral
  • ******
  • Posts: 1704
Re: "trick" for rear intake engines
« Reply #6 on: October 10, 2011, 09:08:17 PM »
Wish I knew a source of custom crankshafts. Anybody know anybody who makes cranks?
Logged

Offline Mike Greb

  • Trade Count: (0)
  • Commander
  • ****
  • Posts: 333
Re: "trick" for rear intake engines
« Reply #7 on: November 16, 2011, 04:14:01 PM »
I have made LH cranks for my own use. What a PIA.  I think i counted 15 setups to make a crank.
Logged

Offline Tim Wescott

  • 2016 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 12808
Re: "trick" for rear intake engines
« Reply #8 on: November 16, 2011, 07:08:06 PM »
Quote from: Mike Greb on November 16, 2011, 04:14:01 PM
I have made LH cranks for my own use. What a PIA.  I think i counted 15 setups to make a crank.

??

1: Chuck stock in 3-jaw, turn & polish bearing surface, prop mount, prop shaft (or hole for same), and front face of crank
2: Turn, wrap beer can around bearing surface, drill hole for intake
3: mount in offset holder, put holder in chuck (maybe swap to 4-jaw to dial in the stroke), turn pin and counterweight (thunkity thunkity thunkity)
4: Mount on V-block, carefully align crank pin, drill/mill/whatever the intake hole.  Mill flat on prop mount if that's what floats your boat.

If you're not going to heat treat and a D-shaped prop drive is enough -- you're done and I'm confused.  Even if you are heat treating then I come up with two more setups (one to finish grind the bearing, and one to finish grind the pin), and I'm still confused.

Granted, as wannabe machinists go I'm a lot more "wanna" than "be".  So I'm not criticizing -- I'm wondering what the other 11 (or 9) setups are?
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 Mike Greb

  • Trade Count: (0)
  • Commander
  • ****
  • Posts: 333
Re: "trick" for rear intake engines
« Reply #9 on: November 17, 2011, 04:52:05 PM »
It was a long time ago when I made my cranks. I rough turned the shaft and crankpin on my cranks because I was going to heat treat them. I think the way I did the counterweight took a couple, a couple for the intake timing port. These were produced on clunky machines and required a lot of messing around to get the parts finished . Maybe not quite 15, but a bunch.  If these had been more that one off projects, I might have become more efficient.   

I don't know if they are still available, but os made a left hand version of their 40 sf. That crank fit the os 40 and 46 sf and fx, and maybe some of the china os clone motors. Again that was a long time ago.  One time I bought one of those cranks and a os 46 sf and had the crank installed before I left the hobby shop. Talk about voiding the warranty in a hurry!
Logged

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


Advertise Here