Notices
Gas Engines Questions or comments about gas engines can be posted here

G62 idles but won't do much more

Old 10-26-2011, 05:07 AM
  #51  
spaceworm
 
Join Date: Mar 2009
Location: Guilford, CT
Posts: 3,950
Received 2 Likes on 2 Posts
Default RE: G62 idles but won't do much more


ORIGINAL: Lightning Fan

The pics Super08's last post ARE NOT MY ENGINE!! [img][/img]
Not even ... close ....

The only difference is the magic that Antique puts on the G62. Also notice the thick carb insulator/twister on Antique's conversion; I think it is available from him separately.

Good luck, I am happy you seem to have found your problem.

Sincerely, Richard
Old 10-26-2011, 06:35 AM
  #52  
Super08
My Feedback: (2)
 
Super08's Avatar
 
Join Date: Dec 2007
Location: Fort McMurray, AB, CANADA
Posts: 4,121
Received 0 Likes on 0 Posts
Default RE: G62 idles but won't do much more

Dan he found the problem back in post 43.
Old 10-26-2011, 10:05 AM
  #53  
tkg
My Feedback: (1)
 
Join Date: Jan 2002
Location: Riverton, WY
Posts: 3,114
Likes: 0
Received 0 Likes on 0 Posts
Default RE: G62 idles but won't do much more

Well that figures, I start to post then, spend 20 min fumbling around in the shop looking for a g-62 cylinder to confirm my suspicion and by the time I finish the post, Rikk has already figured it out. Anyway that thin piece of plastic is part of the Zenoah manifold. The stock manifold is about 1"+ thick and someone bandsawed off a slice to make the engine narrower to fit in the cowl, Guess they forgot about the other engie or needed it thinner.
BYW Vogelsang Aeroscale in NC sells the Tony Clark 90 deg intake for the G-62 that will make it even narrower.
WME
Old 10-26-2011, 11:53 AM
  #54  
Lightning Fan
Thread Starter
My Feedback: (17)
 
Join Date: Nov 2002
Location: Hartland, WI
Posts: 277
Likes: 0
Received 0 Likes on 0 Posts
Default RE: G62 idles but won't do much more

Well, that explains the bandsaw marks on the plastic.  I was wondering why a person would go to the trouble of making a large block and then shave it down ... I assumed the original owner made it.
So, if I want to make these things, I assume fiberglas reinforced plastic, like G10 composite is OK.  I have some Delrin as well.  I'll look into the other commercial suggestions you guys put up.

I got this plane for song, so I got what I paid for, and I've had to replace a lot of stuff.  It has definately been a learning platform, which is good too.  You gotta love RC ... if you think you got it all figured out, it will do what is necessary to humble you again.

Give me a week, and I'll try to post some P-38 music for you guys.
Old 10-26-2011, 01:11 PM
  #55  
Antique
Senior Member
My Feedback: (4)
 
Antique's Avatar
 
Join Date: Jul 2002
Location: Somewhere, DC
Posts: 9,825
Likes: 0
Received 0 Likes on 0 Posts
Default RE: G62 idles but won't do much more

B&B was selling Bennettbuilt G62s with the stock insulators cut down to move the carbs in closer...If someone copied on of those they didn't get it right....I ASSumed the insulators were the black ones that come with Horizon G62s....
Old 10-27-2011, 12:14 AM
  #56  
Lightning Fan
Thread Starter
My Feedback: (17)
 
Join Date: Nov 2002
Location: Hartland, WI
Posts: 277
Likes: 0
Received 0 Likes on 0 Posts
Default RE: G62 idles but won't do much more



My curiosity has overwhelmed caution, so I have to ask this question of Antique ...

As an authority not only on G62's, but the history of the engine, can you tell me why the pulse port holes on the carb and engine cylinder do not align? Fixing it is easy with the insulator, but one has to wonder why such a critical port is configured for failure by being offset. Is it because the two devices the engine and the carb were designed separately for other mating components, and they have been adapted as we see it in the G62? Or is it simply that there was no room in either component to locate the port exactly where it needed to be, so the problem was addressed in the insulator?
It's not critical for me to know this, but I'm an engineer by trade and I find that interfaces are where designs usually get into trouble. They require two people or groups to communicate, which it is occasionally rumored that we engineers are not so good at. This appears to me to be a classic interface failure (the mating holes are in the wrong places), but often there are extenuating circumstances that force complication into an interface (like the need for an insulator with a wormhole to connect the two holes).

This is by no means urgent, and if you don't have time to reply, no problem.

Old 10-27-2011, 12:37 AM
  #57  
Antique
Senior Member
My Feedback: (4)
 
Antique's Avatar
 
Join Date: Jul 2002
Location: Somewhere, DC
Posts: 9,825
Likes: 0
Received 0 Likes on 0 Posts
Default RE: G62 idles but won't do much more

The G62 cylinder is also used in the Red Max chainsaw...All carbs need an insulator block to insulate the carb from the heat of the cylinder...the orientation of the carb to the cylinder was designed many years ago before the G62 was an airplane engine...Zenoah engineers put it there, than's the way it is...The G62 cylinder is the only one I can think of that has the pulse hole offset between the mounting holes..Because the throttle shaft is not parallel to the cylinder I made a rotator block about 24 years ago to meke connection to the servo a straight line..Been that way on mine and Horizon's engines..Mine was first and almost the only one ever since...
The HDA 48 carb and its 3 versions were made for the G62 airplane engine by Walbro, there is no other application..
The Red Max chainsaw uses the same cylinder and piston but a different carb....
The pulse port/insulator block is not the only way to connect the pulse, my earlier conversions blocked the pulse hole and used a fitting in the crankcase connected to another fitting in the case cover of the carb...The slot routed in the insulator removes a possible source of leaking...K I S S principle [8D]
Old 10-27-2011, 01:36 AM
  #58  
Lightning Fan
Thread Starter
My Feedback: (17)
 
Join Date: Nov 2002
Location: Hartland, WI
Posts: 277
Likes: 0
Received 0 Likes on 0 Posts
Default RE: G62 idles but won't do much more

Thank you, sir. Makes sense.
Old 10-27-2011, 08:07 AM
  #59  
tkg
My Feedback: (1)
 
Join Date: Jan 2002
Location: Riverton, WY
Posts: 3,114
Likes: 0
Received 0 Likes on 0 Posts
Default RE: G62 idles but won't do much more

On more than one engine I have used a dremel tool with a small ball mill in it and made a groove on the back of the carb to get things lined up.
Old 11-05-2011, 07:30 PM
  #60  
Lightning Fan
Thread Starter
My Feedback: (17)
 
Join Date: Nov 2002
Location: Hartland, WI
Posts: 277
Likes: 0
Received 0 Likes on 0 Posts
Default RE: G62 idles but won't do much more

Gents -
Thanks to your sage advice and expertise, I ran my G62's in my P-38 up today sucessfully.  What a great engine!  With both of them spinning 22x10's, the back of my legs hurt pretty badly holding her back.
I used some 1/8"G10 and heavy cardstock gaskets that I had to mount the carb, that allows the carb to clear the cowl.  I let them run for around 8 minutes, with no issues, and restarts were OK.   Hopefully, no vapor lock in real life. 
The lower cowls were not installed so the real test of whether this thin an insulator will work once the engine truly heat soaks has to be run, but at least I know where to look if there is a problem.
I checked the thermal conductivity coefficient for G10, and it is around 0.25 W/m/°K, where paper is 0.05.  Aluminum is around 250.  So, that G10 is a pretty darn good thermal insulator... I might be OK.

I have some Twinsync problems to sort out now, but they are all my fault ... RFI from poor sensor location.  I know what to do.

Thanks again to all you guys!
Old 11-05-2011, 09:02 PM
  #61  
Super08
My Feedback: (2)
 
Super08's Avatar
 
Join Date: Dec 2007
Location: Fort McMurray, AB, CANADA
Posts: 4,121
Received 0 Likes on 0 Posts
Default RE: G62 idles but won't do much more

Get us some pictures when you get that bad boy in the air. [8D]

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.