Go Back  RCU Forums > RC Airplanes > Questions and Answers
Reload this Page >

Question: Prop shaft too short and fueling a cowled engine

Notices
Questions and Answers If you have general RC questions or answers discuss it here.

Question: Prop shaft too short and fueling a cowled engine

Old 10-12-2007, 08:01 PM
  #1  
K2MIT
Junior Member
Thread Starter
My Feedback: (4)
 
Join Date: Apr 2004
Location: Scarsdale, NY
Posts: 8
Likes: 0
Received 0 Likes on 0 Posts
Default Question: Prop shaft too short and fueling a cowled engine

I am finishing a Great Planes Cosmic Minnow .60 2C / .91 4C ARF and I have two problems/questions.

I have an O.S. 91 with a pump mounted on an O.S. engine mount. When I put the propeller on, the cowl prevents
it from resting on the back groved plate of the engine so the prop won't go on. Trimming the Cowl will not work
because I would have to take material off the back side and it would not be flush anymore.

1. Does anyone make a space peice that you can put in between the back plate and the prop?

2. How do you know when the tank is full in a cowled engine?

In my PT-40, I would disconnect the fuel line at the fuel filter for fill and disconnect at the muffler. When I had enough
fuel, the fuel would come out the disconnected mufler tube. But, that's not possible ( A) it has a pump unit and B) the whole
thing (or nearly the whole thing is under the cowl).

Thanks in advance for any help.
Old 10-12-2007, 09:40 PM
  #2  
KI8FR
Senior Member
 
KI8FR's Avatar
 
Join Date: Feb 2004
Location: Ovid, MI
Posts: 976
Likes: 0
Received 1 Like on 1 Post
Default RE: Question: Prop shaft too short and fueling a cowled engine

fuel line. one way to do it is put a t in the line and a plug and put it in a place that you can get to it. take out the plug fuel the plane. when the fuel comes out of the line put the plug back in. good to go.

With the prop. I do not think there is a spacer for that but you can make one to go from the engine mount and the fire wall. That is the best way. Some how you need to move the engine

Paul
Old 10-12-2007, 10:28 PM
  #3  
Campy
Senior Member
My Feedback: (1)
 
Campy's Avatar
 
Join Date: Jan 2002
Location: Baltic, CT
Posts: 3,613
Likes: 0
Received 1 Like on 1 Post
Default RE: Question: Prop shaft too short and fueling a cowled engine

ORIGINAL: Jeffreys48

I am finishing a Great Planes Cosmic Minnow .60 2C / .91 4C ARF and I have two problems/questions.

I have an O.S. 91 with a pump mounted on an O.S. engine mount. When I put the propeller on, the cowl prevents
it from resting on the back groved plate of the engine so the prop won't go on. Trimming the Cowl will not work
because I would have to take material off the back side and it would not be flush anymore.

1. Does anyone make a space peice that you can put in between the back plate and the prop?


>Fox engines make adaptors for engines. They are available in different lengths up to about 3/4" (if I remember correctly )

2. How do you know when the tank is full in a cowled engine?

>With a fuel dot (or 3rd line) the fuel will come out the muffler. Another option is to run the fuel line
>outside the cowl to a short length of brass tube. Disconnect the brass tube to fill. I think Tower
>has a commercial setup for this. When full, fuel will come out the muffler.

In my PT-40, I would disconnect the fuel line at the fuel filter for fill and disconnect at the muffler. When I had enough
fuel, the fuel would come out the disconnected mufler tube. But, that's not possible ( A) it has a pump unit and B) the whole
thing (or nearly the whole thing is under the cowl).

Thanks in advance for any help.
Old 10-12-2007, 10:34 PM
  #4  
jetmech05
 
Join Date: Jul 2005
Location: Jacksonville, FL
Posts: 4,865
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Question: Prop shaft too short and fueling a cowled engine

your plans should have a measurement from the firewall to the thrust washer....if you can't move the engine on the mount..then you're going to have to move the mount with a hardwood spacer...the spacer goes between the mount and the firewall..just pick up the exsisting holes in your firewall and use longer screws...glue the spacer to the firewall with epoxy....use longer screws and don't forget the thread locker...
KI8FR has told you the best way to do the fuel line
Old 10-12-2007, 11:40 PM
  #5  
K2MIT
Junior Member
Thread Starter
My Feedback: (4)
 
Join Date: Apr 2004
Location: Scarsdale, NY
Posts: 8
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Question: Prop shaft too short and fueling a cowled engine

Thanks. Great ideas. I got the engine mounted. Now I got to rig up the fuel line.

I love this site!

KI8FR, I am K2MIT! I fly 50.2 Mhz.
Old 10-13-2007, 12:33 AM
  #6  
ho2zoo
My Feedback: (5)
 
Join Date: Mar 2002
Location: Louisville, KY
Posts: 1,102
Likes: 0
Received 2 Likes on 2 Posts
Default RE: Question: Prop shaft too short and fueling a cowled engine

As for filling the fuel tank, I prefer to use the Du-Bro filling valve. I know, a lot of people here will groan about that, saying that they leak, they get stuck, they break, they are expensive, etc. Well, I have used them on several planes for the last 10 or 12 years, and yes they do have some problems. I've not had one leak, but I have had them stick open (cutting off the fuel to the engine), but to fix that you only have to 'pick' at the center stud with a pin or small screwdriver, and the stud will pop back into place. I have also had to repair the valve on one plane after a couple years of use. And they do cost about 10 to 12 bucks each.

But on the plus side, they make a really neat, clean installation. They automatically close off the fuel line to the engine, so as to not let fuel run out your carburator. It just requires a small hole to mount, and it goes between the tank and the engine. Quite simple. With a 'T' connection, you need to clamp off the fuel line going to the engine, or the fuel will run out the carb.

To tell when the tank is full, you normally have a pressure line going from the tank to the muffler; when fuel comes out the muffler, it's full. If you have access to this pressure line, you can pull it off and connect it to a small container so as to catch the overflow, then put it back on the muffler to run the engine. Here's a link: http://www3.towerhobbies.com/cgi-bin...&I=LXD745&P=SM

Old 10-13-2007, 02:02 AM
  #7  
KI8FR
Senior Member
 
KI8FR's Avatar
 
Join Date: Feb 2004
Location: Ovid, MI
Posts: 976
Likes: 0
Received 1 Like on 1 Post
Default RE: Question: Prop shaft too short and fueling a cowled engine

I run 50 on all my glow but I do not run my 50 on gas now. I was just haveing alot ot trubble with gliches.

Nice to meet you.
Paul
Old 10-13-2007, 11:49 PM
  #8  
K2MIT
Junior Member
Thread Starter
My Feedback: (4)
 
Join Date: Apr 2004
Location: Scarsdale, NY
Posts: 8
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Question: Prop shaft too short and fueling a cowled engine


ORIGINAL: KI8FR

I run 50 on all my glow but I do not run my 50 on gas now. I was just haveing alot ot trubble with gliches.

Nice to meet you.
Paul
What kind of glitches? Nothing here yet, thank G-d.
Old 10-13-2007, 11:56 PM
  #9  
KI8FR
Senior Member
 
KI8FR's Avatar
 
Join Date: Feb 2004
Location: Ovid, MI
Posts: 976
Likes: 0
Received 1 Like on 1 Post
Default RE: Question: Prop shaft too short and fueling a cowled engine

For some reson the 50 mhz will have gliches with my gassers. From what I here is that the modual puts out a hormonic. (i cant spell sorry) The gasers with magnetos do not have much porbs but I run cdi initions and that are the planes that I stoped running the 50. but like I said all my glow and my gas/glow engines all have 50mhz in them. Love it.
Paul

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.