w8ye

My Feedback: (16)

The Teflon buttons on the ends of the wrist pin would not be damaged by immersion in a crockpot

The Raven

I agree, but the heat from a heat gun/paint stripper might be enough to do some damage if care is not taken.

Campgems

The TT doesn't use the Teflon buttons, but has spring clips to hold the wrist pin in check.

Don

proptop

My Feedback: (8)

I don't think you could get things hot enough with a heat gun to damage a Teflon button (if it did use them) unless you used an industrial heat gun?
They use Teflon (how do ya do the "trademark" thing?) for coating frying pans, aye!? I think they sometimes get hotter than 4-500 degrees if you get a bit over zealous with the cooking heat?

One thing I would be careful of though, is by prying hard on the upper end of the rod, you could damage the "E" clip groove in the piston by (accidently ) shoving the wrist pin out of the piston, if the rod doesn't want to let go.



I went through this cleaning/cussing process with an O.S. FS .61 that had been dunked in a lake, and not completely dried out inside, before storage. It then sat for close to 20 yrs. before I got it...and the rust inside was unbelieveable![X(][:'(] (brown/orange/dark gray, all sorts of different colors)
The steel parts are a little pitted, but not too bad...so I put new bearings in it and test ran it...(runs great!)
I used a heavy duty jewelry cleaner liquid to remove the rust (some blue stuff that smells like the home perm solution that my mom and sisters used to use back in the 70's ) and some 1000 grit wet/dry paper and light oil to polish the wear surfaces like the crank pin, wrist pin, etc.

Sneasle

I actually do have an industrial heat gun.. hehe.. It is great for shrinking covering..

I will check to see if anything is loosening up. The antifreeze has turned a nice brown, so I think it is time to change it out for some fresh stuff.

Jazzy

Wow!
I never made it this far (time-wise that is). When I got frustrated with a con rod I grabbed it with a pair of pliers and worked the sucker till it came off.
Yeah, I know. Everyone who just read that is cringing and shaking their heads.
I looked at it this way: it is gonna take a whole lot to bend that rod and a few nicks in it won't hurt anything. Who is gonna see it? After the cleaning was complete I filed off the nastiest of the nicks and put it back together.
All's well that ends well.

Working the rod towards the back of my TT 91 piston took some colorful expletives but it came off without much trouble.

Sneasle, if it is rust that is preventing the rod from sliding on wrist pin and you force it over the rust, both pieces may need to be replaced. A rusty wrist pin, even if cleaned up, will no longer have the proper finish on it and it will chew up a bronze bushing.

Good luck,
Jeff

Sneasle

Oh I hope not. I don't think I will be able to find parts for this engine if I need them.

proptop

My Feedback: (8)

You might get away with using the original wrist pin, even if it's rusty/pitted. The pitting will most likely be in between the rod and pin bosses in the piston...unless it's really bad (like that O.S. I described above ) but it takes quite a while to wear out the hard bronze bushing.

One thing though...if you do finally get it apart, clean the wrist pin bushing area in the rod real good because the rust particles will get into the lube hole. (or slot, whichever it uses )

proptop

My Feedback: (8)

There are a couple of places that sell TT parts...
Don't have the addresses right off hand...but maybe someone will chime in with them...(or I'll look 'em up if ya need 'em )

Sneasle

I know of Thunder Tiger 4U, and ace hobby. I don't know if either has them in stock. It is possible that the parts are a close enough clone of something else that I can jump between brands.. but that will be a last resort. It was basically a free engine, but the plane it came with was expensive, so I am using it to justify the plane price and I don't want to put too much into it.

TimC

Here's another source for Thunder Tiger parts. I've dealt with Paul and received my order in just a few days. There is a toll free number to call for part availability at his web site.
Paul's Model Supply in Fargo , ND: http://paulsmodelsupply.com

Sneasle

Looks good. I will keep him in mind if I end up needing parts.

Jazzy

Sneasle, I didn't mean to dishearten you.
My first ball bearing 46 ended up sitting overnight with fuel filling the crank case. (Don't ask-long story) By the time I found it the bearings were cruchy and there was some surface rust on the crank pin not to mention every other steel surface inside. (I do not think there was any on the wrist pin though...) Point being that it wasn't terribly long before the bushing on the bottom end of the con rod wore out and the rod started scraping the inside of the case on the down (power) stroke. The top bushing is still fine.
Maybe some other factors contributed to its wearing out, I don't know for sure. She was rode pretty hard over the years.

Heck, maybe proptop is right and the only nasty stuff is on the sides of the pin not covered by the rod bushing. Either way you'll still be able to run the engine if you get it back together. Just make sure you clean out every speck of loose rust. And mark the orientation of the parts before disassembly so that they go back together in the same position.

If you get fed up with wasting your time trying to be gentle, try the plier method. You can put a couple wraps of electrical tape (or whatever suits your fancy) on the plier jaws so as not to mar the rod too much. It really doesn't do much damage. I don't think you can get enough leverage in there to do any serious harm. Try to force the piston end of the rod more than the crank end though.
I kinda like the bent flat-blade screwdriver idea as a lever. That is a good option too.

Let us know what happens

Jazzy

OOps, double post.

Sneasle

Will do Jazzy. You haven't disheartened me. Just dealing with the beginning of a new school term right now, so time is limited. I need to change the fluid in the crock pot. Maybe after doing that and a bit more soaking it will have worked itself a bit more loose.

I would think that you would need to pull on the rod a bit to get it off. If the rod could slide easily on the wrist pin and the crank pin, I would think it would be too likely to pop off while in use.

Jazzy

The back plate prevents the rod from sliding off the crank pin. It basically self-centers itself in the piston and on the crank pin.

Where are you going to school? (Or are you teaching...?)
I just got my engineering degree from Penn State, May 19th. Keep at it!

TimC

Sneasle, I've had good luck with stuck parts using a penetrating oil called "Kroil" and a heat gun. Warm up the stuck parts a bit and then give them a shot of Kroil. It works pretty quick.

Sneasle

Auburn University down here in Alabama. Double major in Electrical Wireless Engineering and Physics. I am like, 4 hrs away from being a junior.



TimC:

I will look and see if I can find it and give it a shot.

DarZeelon

Mazal-Tov, Jazzy!

Cheers.

jimcork1

My Feedback: (4)

Correct this engine does not use the Teflon. BTW,, I got my Engineering Degree in May 1969.


The first model motor I disassembled was a Cub .049 1952 or there about

Jim

Jazzy

Thanks Dar! At 37 I fully appreciate every congrats I get!
Education never ends... nor should it.

Jim: Gee, I was born in 1969.

Sneasle, Sounds like you have your hands full! Focus and succeed!
Best of luck to you.


Jeff

blw

My Feedback: (3)

War Damn Eagle, Sneasle.

Sneasle

Damn Skippy.

You in Auburn currently blw?




Ok, so no Teflon washer. Didn't think there was one. Now to find the time around the massive amount of homework and studying for tests to finish working on the engine.. I have a Diff Eq test every week. Joy.

blw

My Feedback: (3)

Sneasle,

Just sent you a PM.

Sneasle

Got it, responded.