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Author Topic: Ringed engine stuck with goo  (Read 1406 times)

Offline Tim Wescott

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Ringed engine stuck with goo
« on: December 18, 2018, 11:09:54 AM »
I almost revived this thread, but it's about lapped engines stuck with goo, and I've never had a problem with those.

I've got a bunch of SuperTiger 46's and a couple of bigger ones that have been exceedingly well taken care of, but which have then sat for 20 years.  If they were ABC or OS-style engines I'd just hit them with heat or fuel or alcohol and go -- but I have no experience with ringed engines.  I'm worried that if I do that with these the last thing that'll get freed up will be the ring, and that the stuck ring will do damage to itself or the cylinder before it's freed up.

Am I right to be worried, or can I treat them exactly the same as I would an OS LA or FP engine?
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Online Brett Buck

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Re: Ringed engine stuck with goo
« Reply #1 on: December 18, 2018, 12:18:54 PM »
Quote from: Tim Wescott on December 18, 2018, 11:09:54 AM

Am I right to be worried, or can I treat them exactly the same as I would an OS LA or FP engine?

   More or less the same. The difficulty usually revolves around fishing the wrist pin out of the hole. I drill and tap the aluminum end plug for a 2-56 screw and thread that in and use it to pull on. But otherwise, mild heat, penetrating oil, etc.

    Brett
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Offline Tim Wescott

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Re: Ringed engine stuck with goo
« Reply #2 on: December 18, 2018, 12:53:06 PM »
Quote from: Brett Buck on December 18, 2018, 12:18:54 PM
   More or less the same. The difficulty usually revolves around fishing the wrist pin out of the hole. I drill and tap the aluminum end plug for a 2-56 screw and thread that in and use it to pull on. But otherwise, mild heat, penetrating oil, etc.

    Brett

Does one need to disassemble the engine, or if it seems free can one run it with confidence?
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Online Brett Buck

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Re: Ringed engine stuck with goo
« Reply #3 on: December 18, 2018, 02:59:07 PM »
Quote from: Tim Wescott on December 18, 2018, 12:53:06 PM
Does one need to disassemble the engine, or if it seems free can one run it with confidence?

   Depending on what was required to get it loosened up, I would be a little concerned that the wrist pin is stuck to the rod and rotating in the piston instead of the little end. How bad that is and how long it would take to have it come loose on its own volition, I don't know. It would *probably* be OK to run it and let it loosen itself up, but I was faced with more-or-less exactly the same issue recently and completely disassembled the engine and cleaned and oiled everything (with Singer sewing machine oil). It took a lot of work to get the wrist pin out, because this engine had never been apart and so didn't have the end cap threads.

  This was a nearly perfect engine, and extremely powerful by ST46 standards, I loaned it to someone, they put it up without oiling it, and didn't give it back to me for about 20 years. Bearings were rusted and it was as locked up as they ever get. And I didn't get my venturi set or SST muffler back.

    Brett
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Offline Dane Martin

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Re: Ringed engine stuck with goo
« Reply #4 on: December 18, 2018, 03:14:28 PM »
On a less severe note than Brett's borrowed engine anecdote....

Bill Ervin had his cobra sitting for 3-4 years. It has an ST51 in it. He brought it out and tested it. It was gutless and didn't sound right. We came to the educated guess the ring was stuck. He pulled it apart, cleaned it up (I think crock pot? ) and brought it out like a week later. Bada bing.
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Offline EddyR

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Re: Ringed engine stuck with goo
« Reply #5 on: December 18, 2018, 06:26:53 PM »
 Having worked on hundreds of ST .46 motors I will agree with what Brett says about the wrist pin being frozen to the piston. They will run that way but the power will be down and they get to hot. One of the most common problems with the 46 over the years was the wrist pin fit  to tight from the factory. Many new in the box motors show up but every one I have taken apart has had the wrist pin to tight. When I use to do reworks on them I set them up with very loose fitting pin to piston fit. I used a straight reamer to get the hole in the piston perfectly round and straight.  I have seen new looking 46's that had rusted rings and bearings. I do not know of any good source for rings today.  Before I sold my house this spring I built two motors from all new parts. Sold one and kept one. The Brian Gardner  ABC setup is the way to go if you must run a ST/46
EddyR
 
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Offline Air Ministry .

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Re: Ringed engine stuck with goo
« Reply #6 on: December 18, 2018, 09:25:19 PM »
More than likely the pins stuck in the piston , as well . in my limited experiance .

C R C / Crock Pot , Heat . 22 G wire hooked at the end , a small ( thin ) allen key
& check , or get , the rod fore & aft-ing on the wrist pin , is a start .

Engines that have been sitting about , the wrist pin is usually gungy.
Can take repeated attempts / heat cycles etc to free off & remove .

Found the HEAT GUN is vastly superior to boiling water , so getting that aimed up in there might save a good deal of aggravation .
Brett'll have a fit , but I put a wire thru the pin , degunge briefly with spinning across 320 paper , then polish on 600 S paper .
some'd use 1200 etc .The green 3 M pot scourers are good , A bit used & theyre softer for polishing ,
Cut in say 3/16 strip & pull / screww thru gudeon ( wrist ) holes in piston - to delacquer the build up there .

Obviously if youve got a good cleaner set up , and the patiance to wait it out , it'll save a good deal of hand work  .
the object is clean & delacquered, everywhere . (in Ring groove too ) .

Deburring , polishing etc is the fancy pants stuff . If youve got a polishing wheel , the crank & pin , wrist pin etc , could go ' mirror finish ' .
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Offline RandySmith

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Re: Ringed engine stuck with goo
« Reply #7 on: December 19, 2018, 08:15:15 PM »
Quote from: EddyR on December 18, 2018, 06:26:53 PM
Having worked on hundreds of ST .46 motors I will agree with what Brett says about the wrist pin being frozen to the piston. They will run that way but the power will be down and they get to hot. One of the most common problems with the 46 over the years was the wrist pin fit  to tight from the factory. Many new in the box motors show up but every one I have taken apart has had the wrist pin to tight. When I use to do reworks on them I set them up with very loose fitting pin to piston fit. I used a straight reamer to get the hole in the piston perfectly round and straight.  I have seen new looking 46's that had rusted rings and bearings. I do not know of any good source for rings today.  Before I sold my house this spring I built two motors from all new parts. Sold one and kept one. The Brian Gardner  ABC setup is the way to go if you must run a ST/46
EddyR

I have most all parts for the  ST 46 , including rings ,  and some for the  ST 60

Randy
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Offline Bill Ervin

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Re: Ringed engine stuck with goo
« Reply #8 on: December 20, 2018, 03:32:55 PM »
Quote from: Dane Martin on December 18, 2018, 03:14:28 PM
On a less severe note than Brett's borrowed engine anecdote....

Bill Ervin had his cobra sitting for 3-4 years. It has an ST51 in it. He brought it out and tested it. It was gutless and didn't sound right. We came to the educated guess the ring was stuck. He pulled it apart, cleaned it up (I think crock pot? ) and brought it out like a week later. Bada bing.

Dane, yes, that’s exactly what happened.  I even had to soak (Crock Pot) the piston after extracting it from the sleeve with the ring still glued in the groove.  Once the dried castor was soft enough the ring was removed and the ring and piston received yet another soaking followed by scrubbing with a toothbrush.  Once everything was spic and span the engine was reassembled and all was well with the world again.
« Last Edit: December 20, 2018, 04:21:06 PM by Bill Ervin »
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Online Brett Buck

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Re: Ringed engine stuck with goo
« Reply #9 on: December 20, 2018, 10:24:34 PM »
Quote from: Bill Ervin on December 20, 2018, 03:32:55 PM
Dane, yes, that’s exactly what happened.  I even had to soak (Crock Pot) the piston after extracting it from the sleeve with the ring still glued in the groove.  Once the dried castor was soft enough the ring was removed and the ring and piston received yet another soaking followed by scrubbing with a toothbrush.  Once everything was spic and span the engine was reassembled and all was well with the world again.

   We were always able to loosen up the ring just by running it on the 46, but unfortunately, you had to get pretty good at taking it apart and putting it back together, so cleaning it is probably a better approach. Unfortunately the mere act of taking it apart also creates issues, and from what I have seen, this is almost as bad as the original issue for many people.

    I *do not* miss the supposed Good Old Days, at least in this regard.
 
    Brett
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