Go Back  RCU Forums > RC Airplanes > ARF or RTF
 Engine Mounting Question >

Engine Mounting Question

Community
Search
Notices
ARF or RTF Discuss ARF (Almost Ready to Fly) radio control airplanes here.

Engine Mounting Question

Thread Tools
 
Search this Thread
 
Old 01-31-2009 | 03:40 PM
  #1  
Korps's Avatar
Thread Starter
Senior Member
 
Joined: Oct 2008
Posts: 438
Likes: 0
Received 0 Likes on 0 Posts
From: Wellington, SOUTH AFRICA
Default Engine Mounting Question

I'm building an Edge 540 .46

After I have mounted the engine too the brackets which is attached too the firewall...The engine is skew, it turns down too the right at an angle - I know they talk about the thrust etc. Is this "skewness" correct or should the engine be straight towards down the middle of the plane. I just don't want too maiden the plane and have an incorrect mounted engine.

Any help would be greatly appreciated
Old 01-31-2009 | 03:59 PM
  #2  
 
Joined: Feb 2005
Posts: 2,102
Likes: 0
Received 3 Likes on 3 Posts
From: Zephyrhills, FL
Default RE: Engine Mounting Question

Korps : I'm not familuar with that Edge but I think you are going to have to give MORE information as to how the engine sits in the mount and how it lines up with other parts of the plane. Sorry I can't help. ENJOY !!! RED
Old 01-31-2009 | 04:10 PM
  #3  
dan4466's Avatar
My Feedback: (68)
 
Joined: Jan 2002
Posts: 588
Likes: 0
Received 1 Like on 1 Post
From: perry, Lansing MI
Default RE: Engine Mounting Question

I had the Great Planes Extra 300 .40 size that had the cylinder head angled down at about the 8 o' clock position. If this is what you mean, it is so the muffler on a 2-stroke can be positioned at the bottom so it looks better than coming out the side of the cowl. My Decathlon is the same. The engine mount was already attached in the position for this. You are good to go.
Old 01-31-2009 | 07:03 PM
  #4  
Zippi's Avatar
My Feedback: (10)
 
Joined: Jun 2004
Posts: 4,977
Likes: 0
Received 1 Like on 1 Post
From: Evansville, IN
Default RE: Engine Mounting Question


ORIGINAL: Korps

I'm building an Edge 540 .46

After I have mounted the engine too the brackets which is attached too the firewall...The engine is skew, it turns down too the right at an angle - I know they talk about the thrust etc. Is this "skewness" correct or should the engine be straight towards down the middle of the plane. I just don't want too maiden the plane and have an incorrect mounted engine.

Any help would be greatly appreciated
Korps,

Most planes have some right and down thrust (normally about 2%) built into the firewall. If you were looking down on the plane the engine should look like its angled to the right. If you were to draw a straight line from the tail of the plane past the front, the end of the crank shaft should be right on the center line. The engine being at an angle is to help with the torque of the engine.
Old 02-01-2009 | 03:02 AM
  #5  
Korps's Avatar
Thread Starter
Senior Member
 
Joined: Oct 2008
Posts: 438
Likes: 0
Received 0 Likes on 0 Posts
From: Wellington, SOUTH AFRICA
Default RE: Engine Mounting Question

Thanks a lot guys - I'll quickly check the line from the tail again too the crank and post some pictures aswell. Just need a minute or two.
Old 02-01-2009 | 04:14 AM
  #6  
Korps's Avatar
Thread Starter
Senior Member
 
Joined: Oct 2008
Posts: 438
Likes: 0
Received 0 Likes on 0 Posts
From: Wellington, SOUTH AFRICA
Default RE: Engine Mounting Question

Okay here are some pictures so that you know what I'm talking about in more detail.

I checked the line up from the tail - it seems too be in a line - perhaps half a mm out.

Attached Thumbnails Click image for larger version

Name:	Fd90790.jpg
Views:	25
Size:	58.2 KB
ID:	1124666   Click image for larger version

Name:	Fa87346.jpg
Views:	27
Size:	51.5 KB
ID:	1124667   Click image for larger version

Name:	Pu52423.jpg
Views:	26
Size:	45.0 KB
ID:	1124668  
Old 02-01-2009 | 08:05 AM
  #7  
Senior Member
 
Joined: Oct 2005
Posts: 1,993
Likes: 0
Received 1 Like on 1 Post
From: Deland, FL
Default RE: Engine Mounting Question






Is that engine mount stock ? did you build
or assemble the mount ? The reason I ask is,
that first pic looks like alot of right thrust.


Bob
Old 02-01-2009 | 08:12 AM
  #8  
Zippi's Avatar
My Feedback: (10)
 
Joined: Jun 2004
Posts: 4,977
Likes: 0
Received 1 Like on 1 Post
From: Evansville, IN
Default RE: Engine Mounting Question

Korps,

Most of the time there are two vertical lines on the firewall. One is the center line and the other is the off set line for the thrust. Your motor mount should be set up on the off set line and as long as the end of the crank is on the center line your ok.
Old 02-01-2009 | 08:38 AM
  #9  
Korps's Avatar
Thread Starter
Senior Member
 
Joined: Oct 2008
Posts: 438
Likes: 0
Received 0 Likes on 0 Posts
From: Wellington, SOUTH AFRICA
Default RE: Engine Mounting Question


ORIGINAL: dignlivn






Is that engine mount stock ? did you build
or assemble the mount ? The reason I ask is,
that first pic looks like alot of right thrust.


Bob
I agree with that it looks like a lot of right thrust, that's why I'm a bit in the dark. I assembled the mount - mounted it onto the already installed firewall then mounted the engine on it. The holes drilled on the two mounts are right across from each other - so I know I didn't mount the engine wrongly on the mounts.
Old 02-01-2009 | 08:50 AM
  #10  
Senior Member
 
Joined: Oct 2005
Posts: 1,993
Likes: 0
Received 1 Like on 1 Post
From: Deland, FL
Default RE: Engine Mounting Question




Is there any mentioning in the manual about using
washers as shims, when mounting the mount to the
firewall ?


Bob
Old 02-01-2009 | 09:29 AM
  #11  
Korps's Avatar
Thread Starter
Senior Member
 
Joined: Oct 2008
Posts: 438
Likes: 0
Received 0 Likes on 0 Posts
From: Wellington, SOUTH AFRICA
Default RE: Engine Mounting Question

Nope none - the manual is very very vague.

It tells you too measure , drill holes for the mount then mount the engine - nothing further. It shows you to drill holes while the firewall is off the plane - but it's already glued too the fuselage so I don't know how they wrote the manual wrongly. They don't even tell you where too drill or how too get the places too drill.

I decided I'll take the plane too the hobby shop and see what they can figure out. This plane was suppose too be 96% build but it was more like a 90%.
Old 02-01-2009 | 09:41 AM
  #12  
Korps's Avatar
Thread Starter
Senior Member
 
Joined: Oct 2008
Posts: 438
Likes: 0
Received 0 Likes on 0 Posts
From: Wellington, SOUTH AFRICA
Default RE: Engine Mounting Question


ORIGINAL: Zippi

Korps,

Most of the time there are two vertical lines on the firewall. One is the center line and the other is the off set line for the thrust. Your motor mount should be set up on the off set line and as long as the end of the crank is on the center line your ok.
There is one horizontal line about a fifth or so from the top of the firewall then there is one vertical line going down. In the picture both dashed lines can be seen on the firewall.
Attached Thumbnails Click image for larger version

Name:	Ay74368.jpg
Views:	28
Size:	67.1 KB
ID:	1124769  
Old 02-01-2009 | 10:01 AM
  #13  
Senior Member
 
Joined: Oct 2005
Posts: 1,993
Likes: 0
Received 1 Like on 1 Post
From: Deland, FL
Default RE: Engine Mounting Question




Pic #3 in in your first post with pics. It looks
to be about right. I would do some taxing test
before trying to fly.

Bob
Old 02-01-2009 | 10:32 AM
  #14  
Korps's Avatar
Thread Starter
Senior Member
 
Joined: Oct 2008
Posts: 438
Likes: 0
Received 0 Likes on 0 Posts
From: Wellington, SOUTH AFRICA
Default RE: Engine Mounting Question

ORIGINAL: dignlivn
Pic #3 in in your first post with pics. It looks
to be about right. I would do some taxing test
before trying to fly.
Bob
What should I be looking out for while taxing too tell me the engine is mounted wrongly?
Old 02-01-2009 | 10:38 AM
  #15  
Senior Member
 
Joined: Oct 2005
Posts: 1,993
Likes: 0
Received 1 Like on 1 Post
From: Deland, FL
Default RE: Engine Mounting Question





I would think excessive pulling to the Right.

Bob
Old 02-01-2009 | 02:20 PM
  #16  
Zippi's Avatar
My Feedback: (10)
 
Joined: Jun 2004
Posts: 4,977
Likes: 0
Received 1 Like on 1 Post
From: Evansville, IN
Default RE: Engine Mounting Question

Korps,

Even if you have no right thrust and you fly the plane it will just want to do a slight left turn under full power. Just cut the throttle back and fly it around. Once you get back home add a washer at a time until you get the flight path you want. New guys to Profile planes find this out very quick sinse there is no thrust built in and add washers to the back two engine bolts to get a couple of degrees of right thrust. Problem solved.
Old 02-01-2009 | 03:39 PM
  #17  
Korps's Avatar
Thread Starter
Senior Member
 
Joined: Oct 2008
Posts: 438
Likes: 0
Received 0 Likes on 0 Posts
From: Wellington, SOUTH AFRICA
Default RE: Engine Mounting Question

So if I understand correctly (sorry, I'm new too all this technical stuff) - if the engine isn't correctly aligned, which could be in my case, it will just tend too roll/turn too one side under power or could it result in more serious things?
Old 02-01-2009 | 04:11 PM
  #18  
Senior Member
 
Joined: Oct 2005
Posts: 1,993
Likes: 0
Received 1 Like on 1 Post
From: Deland, FL
Default RE: Engine Mounting Question





It may just not fly straight with out alot of
rudder input or it may be fine. Like zippi
said, try and throttle back at first. If you can
get it trimmed out and are happy with the
flight path once trimmed, your good to go.

We take it you do have flight experience ?


Bob
Old 02-01-2009 | 11:45 PM
  #19  
Korps's Avatar
Thread Starter
Senior Member
 
Joined: Oct 2008
Posts: 438
Likes: 0
Received 0 Likes on 0 Posts
From: Wellington, SOUTH AFRICA
Default RE: Engine Mounting Question

Yes I do have. I started flying with a Stick and still flew it up until now. The reason for going for the Edge and hanging up my Stick is because I got bored of the Stick a bit because you can't do a knife edge really etc

I just want too thank you guys a lot for the help - I really learned from you guys. I'll test it and take it from there.
Old 02-02-2009 | 09:04 AM
  #20  
Senior Member
 
Joined: Oct 2005
Posts: 1,993
Likes: 0
Received 1 Like on 1 Post
From: Deland, FL
Default RE: Engine Mounting Question





Let us know how it flys and enjoy !


Bob
Old 02-02-2009 | 09:05 AM
  #21  
Senior Member
 
Joined: Oct 2005
Posts: 1,993
Likes: 0
Received 1 Like on 1 Post
From: Deland, FL
Default RE: Engine Mounting Question

double post opps

Bob
Old 02-02-2009 | 09:25 AM
  #22  
Korps's Avatar
Thread Starter
Senior Member
 
Joined: Oct 2008
Posts: 438
Likes: 0
Received 0 Likes on 0 Posts
From: Wellington, SOUTH AFRICA
Default RE: Engine Mounting Question

The hobby shop owner picked up my plane this morning too take it too the shop. They are putting on a new muffler (the old one is giving problems with the fitting off the cowl. The engine was apparently anyway mounted too far forward. Will get the plane back in the week somewhere and this weekend I will take it up for some fun. Will probably have too sell my Stick too pay for the new muffler :P hehe.

I really hope it flys well and that you can do a lot with it. I haven't sworn so much in my life as the past week lol
Old 02-02-2009 | 11:59 AM
  #23  
opjose's Avatar
 
Joined: Nov 2005
Posts: 12,624
Likes: 0
Received 0 Likes on 0 Posts
From: Poolesville, MD
Default RE: Engine Mounting Question

In your original photo the engine mount is the problem...

Look at the photo and pay attention to the right arm of the mount... as seen by a pilot...

It is angled OUT at the engine. This means that the mount was set with the arms too close together at the base.
When you mounted the engine you effectively added more right thrust than that provided by the firewall.

You need to always make sure that the mount arms are parallel to each other and perpendicular to the firewall, before you drill the engine mount holes.


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
Trackbacks are Off
Pingbacks are Off
Refbacks are On



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

Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.