Swaging pushrod tubes on the O-300 engines

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DMACJR
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Swaging pushrod tubes on the O-300 engines

Post by DMACJR »

Going to ask a simple question of this group....who has had experience in swaging the pushrod tubes on the 0-300 engine and what level of success had you achieved at doing it, plus I have heard coupling that process with the addition of certain wicking loctite products gives a much better result..... I'm not looking for negative input or some ones "expert opinion" that it's like legal vs not legal.....looking at options....and no I am not seeking the pushrod kit replacement as an option, just trying to solve a problematic oil leak as a short term fix.....
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Bruce Fenstermacher
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Re: Swaging pushrod tubes on the O-300 engines

Post by Bruce Fenstermacher »

I've done it with some success for a limited time. I replaced about half the tubes with new as they actually had holes rotted in them. All the tubes where completely remove from the cylinders and either reinstalled or replaced with new. All cylinders were degreased well. All the tubes where coated with a high temp gasket silicone before insertion in the cylinder and swagged. All where then let to cure.

Compared to the quart an hour I was leaking from the rotted tubes and the swagged areas of the tubes, the engine was very dry after the procedure and stayed that way till I no longer owned the plane. There was some seeping however. It was not perfect.
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GAHorn
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Re: Swaging pushrod tubes on the O-300 engines

Post by GAHorn »

I've done it on several different engines with varying results. The best results were obtained on those that 1- had never been re-swaged previously, 2- that had OEM/Continental cylinders. The one ECI cyl I (attempted) to do it on would not accept the standard tool without machining the tool to an undersize... and I did not want to alter the tool so gave up on it.
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Bruce Fenstermacher
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Re: Swaging pushrod tubes on the O-300 engines

Post by Bruce Fenstermacher »

As George noted, this might be a once, or if your lucky, twice and done on a tube, procedure. First, most swaging tools I've seen are a type that us a round bar with 3 ball bearings held captive and pushed out with a threaded cone shaft inside. There is only so far those bearing can be pushed out of the tool. Second, if your a tool maker/modifier :roll:, the cylinder housing can only be pushed so far out you will never get the tube tight inside it.
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170C
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Re: Swaging pushrod tubes on the O-300 engines

Post by 170C »

I too experienced that the tool George lent me would not fit inside the ECI push rod tubes. My mechanic had two of them, neither of which would fit. He turned one of them on his lathe and it worked as designed. Unfortunately when he passed, I didn't get the one that would work. That was 10 yrs ago and seemed to work. George and others cautioned against swaging too agressively as you can actually cut the tube if not careful. (Don't all Continental O-300's leak somewhere after a few hundred hours? Keeps the tail spring from rusting :mrgreen: )
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Re: Swaging pushrod tubes on the O-300 engines

Post by GAHorn »

170C wrote:I too experienced that the tool George lent me would not fit inside the ECI push rod tubes. My mechanic had two of them, neither of which would fit. He turned one of them on his lathe and it worked as designed. Unfortunately when he passed, I didn't get the one that would work. That was 10 yrs ago and seemed to work. George and others cautioned against swaging too agressively as you can actually cut the tube if not careful. (Don't all Continental O-300's leak somewhere after a few hundred hours? Keeps the tail spring from rusting :mrgreen: )
I'm bringing a show-and-tell item to convention that was the trouble-maker of a nasty oil leak on the O-300 installed on the 172C we bought last year. That oil leak was a beast to fix... and I'll bet it's not all that uncommon. (I'll reveal the detail here later...I don't want to spoil the interest at convention.)
Anyway... to my complete surprise...it's now the only mid-time O-300 I've ever seen that stays absolutely dry from any oil leaks. 8O
(And only umpteen hours labor to achieve.) :cry:

Maybe it's because it has no tailwheel mainspring that needs lubrication? :lol:

One contributing-reason may be that the pushrod oil rubbers are made of blue, silicone-rubber instead of the traditional black/hard-rubber TCM part. I've yet to find who made them.
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
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170C
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Re: Swaging pushrod tubes on the O-300 engines

Post by 170C »

Or maybe you don't have that leaky pull-start !
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