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Author Topic: Has anybody (else) had a OS .40LA or .46LA throw a rod?  (Read 3651 times)

Offline Steve Helmick

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Has anybody (else) had a OS .40LA or .46LA throw a rod?
« on: August 25, 2014, 07:57:34 PM »
Just today got pics from Old Harley Guy (who no longer has any mo'sickles) of his .46LA that split the bottom end of the rod. He said it was new this year, never crashed, no reason for it to puke. But it's pretty much trashed, with damaged piston and cylinder. I was just wondering if anybody else has had this happen, because I have not seen or read about this sort of thing happening. There's a 2 year warranty, which should cover it. Let's hope this is a rare deal!  y1 Steve
"The United States has become a place where professional athletes and entertainers are mistaken for people of importance." - Robert Heinlein

In 1944 18-20 year old's stormed beaches, and parachuted behind enemy lines to almost certain death.  In 2015 18-20 year old's need safe zones so people don't hurt their feelings.

Offline Mark Scarborough

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Re: Has anybody (else) had a OS .40LA or .46LA throw a rod?
« Reply #1 on: August 25, 2014, 08:10:16 PM »
thats a new one,, I have pealed the chrome on the liner,, never broken any parts and trust me,, my LA 46s have been given every oppurtunity to break stuff

Old Harley guy,, Mike Fitzgerald?
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Offline Chris Wilson

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Re: Has anybody (else) had a OS .40LA or .46LA throw a rod?
« Reply #2 on: August 26, 2014, 03:44:52 AM »
Define 'split' Steve - did it emanate from an oil hole, bronze bush pushed in too tight perhaps?
MAAA AUS 73427

You have enemies? Good. That means you've stood up for something, sometime in your life.
 Nothing in life is so exhilarating as to be shot at without result.  It's not enough that we do our best; sometimes we have to do what's required

Offline Steve Helmick

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Re: Has anybody (else) had a OS .40LA or .46LA throw a rod?
« Reply #3 on: August 26, 2014, 12:36:48 PM »
Mark...Yup, the other Fitzgerald!

Chris...Well, it split across the lower end of the hoop...parallel to the crankpin, in line with the rod centerline.
Picture showed no sign of a bushing, as I recall. I would guess that too much press would be a good explaination for the problem. Since the hole in the rod would be reamed, my guess is that the bushing was o/s from the CNC lathe that probably made them. Likely was the last bushing turned before the insert was changed. I'd think those things would go through some sort of high-tech semi-automatic gauge, but I don't know much about what the current technology is. Wouldn't expect a micrometer to be applied to each bushing, anyway. Maybe some sort of go/no go gauge?   

Maybe Mike will post the picture, because I didn't save it. Like y'all, I was totally shocked when Mike said it was a .46LA.  I was kinda expecting it was a Chinese Super Tigre G.51, because he runs those also.  D>K Steve 
"The United States has become a place where professional athletes and entertainers are mistaken for people of importance." - Robert Heinlein

In 1944 18-20 year old's stormed beaches, and parachuted behind enemy lines to almost certain death.  In 2015 18-20 year old's need safe zones so people don't hurt their feelings.

Offline Balsa Butcher

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Re: Has anybody (else) had a OS .40LA or .46LA throw a rod?
« Reply #4 on: August 30, 2014, 08:44:39 PM »
I'm curious is he runs the world renown NW LA-46 set-up, that being relitively low rpm on a big 'ol 12.25x3.75 prop? Not being critical here, just it seems to me that that set-up may put more stress on the engine than a smaller prop running at a higher RPM.  8)
Pete Cunha
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Offline Mark Scarborough

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Re: Has anybody (else) had a OS .40LA or .46LA throw a rod?
« Reply #5 on: August 30, 2014, 09:08:09 PM »
I'm curious is he runs the world renown NW LA-46 set-up, that being relitively low rpm on a big 'ol 12.25x3.75 prop? Not being critical here, just it seems to me that that set-up may put more stress on the engine than a smaller prop running at a higher RPM.  8)
I fly all my 46 LAs on that setup,, its not really low rpm,, I launch at 9800 typically,,

NEVER had this hapen though like I said,, my one 15$ ebay special motor did peal the liner,, after about 350 or 400 flights
For years the rat race had me going around in circles, Now I do it for fun!
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Offline Balsa Butcher

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Re: Has anybody (else) had a OS .40LA or .46LA throw a rod?
« Reply #6 on: August 30, 2014, 11:41:33 PM »
That is relatively high RPM-myth busted. When I tried that prop on the one I am running, did not run it that high. Maybe a second experiment is in order. 8)
Pete Cunha
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Offline Brett Buck

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Re: Has anybody (else) had a OS .40LA or .46LA throw a rod?
« Reply #7 on: August 30, 2014, 11:52:28 PM »
That is relatively high RPM-myth busted. When I tried that prop on the one I am running, did not run it that high. Maybe a second experiment is in order. 8)

  The engine is designed to run 14000 rpm all day long. 9800 isn't  very fast compared to that.

    Brett

Offline Motorman

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Re: Has anybody (else) had a OS .40LA or .46LA throw a rod?
« Reply #8 on: August 31, 2014, 06:35:32 AM »
I would guess more than likely a fuel problem.


MM

Offline Chris Wilson

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Re: Has anybody (else) had a OS .40LA or .46LA throw a rod?
« Reply #9 on: August 31, 2014, 02:33:45 PM »
We are talking about the relatively unstressed 'lower' end of the rod here and as such stress shouldn't really cause this.
My bet is on a metallurgical fault that has been brought to light by the large inertial load.
« Last Edit: August 31, 2014, 03:34:48 PM by Chris Wilson »
MAAA AUS 73427

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 Nothing in life is so exhilarating as to be shot at without result.  It's not enough that we do our best; sometimes we have to do what's required

Online Lauri Malila

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Re: Has anybody (else) had a OS .40LA or .46LA throw a rod?
« Reply #10 on: August 31, 2014, 03:01:36 PM »
  The engine is designed to run 14000 rpm all day long. 9800 isn't  very fast compared to that.

    Brett

Unless lubrication fails, engines rarely break because of high rpm, more often due to too much load.

L

Offline Steve Helmick

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Re: Has anybody (else) had a OS .40LA or .46LA throw a rod?
« Reply #11 on: September 12, 2014, 05:49:51 PM »
 I would not be surprised if it wasn't the only one, probably due to o/s rod bushing. Or, maybe the hole was drilled but not reamed? Mucho press, anyway.

This just in!  "Hey Steve...I sent that engine with the thrown rod back to Tower...They sent me a new engine... :0)  Mike"
« Last Edit: September 23, 2014, 08:50:19 PM by Steve Helmick »
"The United States has become a place where professional athletes and entertainers are mistaken for people of importance." - Robert Heinlein

In 1944 18-20 year old's stormed beaches, and parachuted behind enemy lines to almost certain death.  In 2015 18-20 year old's need safe zones so people don't hurt their feelings.

Offline Steve Helmick

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Re: Has anybody (else) had a OS .40LA or .46LA throw a rod?
« Reply #12 on: September 23, 2014, 08:42:59 PM »
Here's the picture. Pretty complete rod failure, IMO. Where's that bushing? LL~ Steve
"The United States has become a place where professional athletes and entertainers are mistaken for people of importance." - Robert Heinlein

In 1944 18-20 year old's stormed beaches, and parachuted behind enemy lines to almost certain death.  In 2015 18-20 year old's need safe zones so people don't hurt their feelings.

Offline Dane Martin

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Re: Has anybody (else) had a OS .40LA or .46LA throw a rod?
« Reply #13 on: September 23, 2014, 09:06:18 PM »
dude! that's a neat failure. it's great tower warrantied the engine. must have been a descent pop!

John Leidle

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Re: Has anybody (else) had a OS .40LA or .46LA throw a rod?
« Reply #14 on: September 23, 2014, 10:32:56 PM »
   Point of interest Steve,
  Several of my Magnum .53s have the same bushing elongate & knock like an old Dodge.
  John

Offline Steve Helmick

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Re: Has anybody (else) had a OS .40LA or .46LA throw a rod?
« Reply #15 on: September 25, 2014, 06:15:02 PM »
What sort of fuel & oil, John?  ??? Steve
"The United States has become a place where professional athletes and entertainers are mistaken for people of importance." - Robert Heinlein

In 1944 18-20 year old's stormed beaches, and parachuted behind enemy lines to almost certain death.  In 2015 18-20 year old's need safe zones so people don't hurt their feelings.

Offline Jim Kraft

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Re: Has anybody (else) had a OS .40LA or .46LA throw a rod?
« Reply #16 on: September 25, 2014, 06:46:08 PM »
I have seen this happen before on R/C pattern engines. It was caused by the bearing being fit to tight on the shaft and galling the bearing from heat. They tend to go down hill from there. We use to take new YS 60's and open up the bushing a bit. That seemt to take care of the problem. We were running 12-9 and 12-10 props that does put a pretty good load on the bottom end.
Jim Kraft

Offline Chris Wilson

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Re: Has anybody (else) had a OS .40LA or .46LA throw a rod?
« Reply #17 on: September 25, 2014, 08:41:11 PM »
It is a contentious point that bushings are of value in a model engine due to the amount of support material around the rod eye that it removes - add oil holes and it could be "tear along the dotted line."

Oil holes on an overhung crank are a mistake in my opinion.
MAAA AUS 73427

You have enemies? Good. That means you've stood up for something, sometime in your life.
 Nothing in life is so exhilarating as to be shot at without result.  It's not enough that we do our best; sometimes we have to do what's required

Offline Steve Helmick

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Re: Has anybody (else) had a OS .40LA or .46LA throw a rod?
« Reply #18 on: September 27, 2014, 12:47:58 PM »
More info from Mike. The fuel used was PowerMaster GMA 5% x 22% 50/50 castor/synthetic. That's certainly good enough, it easily meets the manufacturer's suggestions.  H^^ Steve
"The United States has become a place where professional athletes and entertainers are mistaken for people of importance." - Robert Heinlein

In 1944 18-20 year old's stormed beaches, and parachuted behind enemy lines to almost certain death.  In 2015 18-20 year old's need safe zones so people don't hurt their feelings.

John Leidle

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Re: Has anybody (else) had a OS .40LA or .46LA throw a rod?
« Reply #19 on: September 30, 2014, 11:53:37 PM »
  Hi Steve,  I have used all synthetic for 15 years add a dash of castor in all my engines,  the Magnum .53s are the only ones that knock,,

Offline Mark Scarborough

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Re: Has anybody (else) had a OS .40LA or .46LA throw a rod?
« Reply #20 on: October 01, 2014, 12:18:25 AM »
John point of reference,, the Magnum in my Avenger uses GMA 10 - 22 ( 10 castor and 11 synth,,)
I have never heard mine knock,,
For years the rat race had me going around in circles, Now I do it for fun!
EXILED IN PULLMAN WA
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John Leidle

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Re: Has anybody (else) had a OS .40LA or .46LA throw a rod?
« Reply #21 on: October 03, 2014, 09:23:03 PM »
 I hope yours holds together Marc, most of mine knock even when I used GMA 10% never had another engine knock & for those who know me know I have run many brands of engines more than most. Only the Magnum .53s have knocked for me but none have blown.
  On one of them I replaced the rod & opened the oil hole when I had it apart.
  Marc , how can yours know you never run them ,,, at least that's what you told me... LL~
  Will I see you in Salem tomorrow?


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