Another Engine Tale - TD .020

Tee Bee Wed Mar 07, 2018 3:42 pm

At the same time that I purchased the Thermal Hopper from the other thread, I had the opportunity to rescue this poor TD .020. It was in the original blister pack which excited me to no end since I had never had one of those boxes, but the poor engine was in terrible shape when I got it home. The tank was rotted worse than any I had ever seen and the carb body disentegrated as soon as I tried to remove it from the engine. No problem since I had some replacement plastics on hand. Turns out that the crank was seized in the case! I soaked it in oil, baked it, torched it, tried to tap it out with a hammer, etc with no luck. I reluctantly resorted to putting pliars on the prop driver, mauling it as I went. The splined teeth stripped smooth on the crank! Finally, I gripped the crank spline in some needle nose and with constantly applied heat and force, it finally broke free. The crank was toast. Turns out that the piston also was seized in the cylinder, causing me to recreate much of the same grunting noises to get it free. Seems someone had previously burred the cylinder(probably with the Cox tool) as is a common occurance. I ordered some new shiny bits such as prop driver from Cox Int and a crankshaft from EX Model Engines. When I get it all reassembled, it's going to get one of those awesome aluminum backplates for sale over at the RC Groups 1/2A forum. Since I had already recently refurbished a couple of TDs with new plastic bits and such, I put one of those in the display box. I ended up with a neat display for one of my refurbished engines and another old neglected TD .020 is getting the attention it deserves and will soon be breathing fire once again. Fun stuff!

Kim Wed Mar 07, 2018 4:37 pm

Kinda looked like a shark....

Tee Bee Wed Mar 07, 2018 5:48 pm

Looks that way, Kim. A spot of duct tape should hold it tight, right?

Jason_WI Wed Mar 07, 2018 7:28 pm

That’s a serious case of tank rot!

Kim Wed Mar 07, 2018 7:36 pm

Jason_WI wrote:That’s a serious case of tank rot!

Been running that sucker on Hydrazine....

Jason_WI Wed Mar 07, 2018 7:58 pm

Kim wrote:
Jason_WI wrote:That’s a serious case of tank rot!

Been running that sucker on Hydrazine....

and LOx apparently...

Please store it with the fuel pickup tube removed from the tank or tank rot will strike again in the future.

Tee Bee Wed Mar 07, 2018 8:49 pm

The worst case of tank and carb rot I've ever seen! The carb literally crumbled when I touched it. The line was very hard and brittle. That new tank and line has never seen fuel.

MauricioB Wed Mar 07, 2018 8:52 pm

hello Tee Bee, the way it looks, it is possible that someone has used gasoline to wash the engine, you may have dipped it in gasoline. I do not see any other way for it to become rotten by nature like that.
It is (I think) that the plastic was altered by some cleaning element used by another previous owner.

Tee Bee Wed Mar 07, 2018 9:07 pm

Yep. It's safe from such treatment now.

MauricioB Wed Mar 07, 2018 9:11 pm

Tee Bee wrote:Yep. It's safe from such treatment now.

I hope that whoever did that if he has false teeth, do not use the same method, I do not think he recommends it, hahaha

Jason_WI Wed Mar 07, 2018 10:14 pm

Tank rot is caused by the chlorine in the PVC tubing leaching out and damaging the Delrin tank. This is why it always rots out by the fuel nipple on the tank. Store your plastic tanked TDs without the fuel line connected to the tank.

https://www.coxengineforum.com/t1342-i-have-a-bad-case-of

Chemical compatibility of delrin. Chlorine is rated poor resistance.

https://www.calpaclab.com/acetal-polyoxymethylene-chemical-compatibility-chart/

Tee Bee Wed Mar 07, 2018 11:00 pm

Once again, this forum is great. I'm always learning something new here. I will promptly remove the lines from my stored tanks. Thanks for the heads up, again. I Love This Forum!

Tee Bee Wed Mar 07, 2018 11:06 pm

So, is the risk of rot eliminated with the use of silicone fuel lines? That's what I've been replacing the old OEM lines with on my runners.

MauricioB Thu Mar 08, 2018 4:49 am

This is very interesting, but I do not understand something ...
When I translate to my language, I read that chlorine damages plastic, what I do not understand is, where it is produced or where chlorine exists?
The original hose of the engine produces that effect ?.
I would like to understand this topic well.
Thank you

balogh Thu Mar 08, 2018 5:03 am

I do not think that extensive tank rot as seen in the pictures was just because of the plastic fuel tube, that we know often caused rotting but only around the fuel nipple area...after the nipple has rotten away, and direct contact with the plastic tube was detached,what would have continued the rotting into almost half of the tank?

Maybe the previous owner - who may not have been a prudent and cautious one, also burring the cylinder - may have experimented with a flammable material for fuel, that was incompatible with the delrin tank material? Maybe common gasoline, acetone, or similar?

Mauricio I read somewhere that the stock fuel tube put on TD-s in the factory had chlorine emitted when ageing, and that was detrimental to the delrin material...but to such an extent as seen here????

MauricioB Thu Mar 08, 2018 5:21 am

balogh wrote:I do not think that extensive tank rot as seen in the pictures was just because of the plastic fuel tube, that we know often caused rotting but only around the fuel nipple area...after the nipple has rotten away, and direct contact with the plastic tube was detached,what would have continued the rotting into almost half of the tank?

Maybe the previous owner - who may not have been a prudent and cautious one, also burring the cylinder - may have experimented with a flammable material for fuel, that was incompatible with the delrin tank material? Maybe common gasoline, acetone, or similar?

Mauricio I read somewhere that the stock fuel tube put on TD-s in the factory had chlorine emitted when ageing, and that wasdetrimental to the delrin material...but to such an extent as seen here????

Ahhh now I understand András, the tube itself generates chlorine over time and that affects the nipple of the tank basically. That is what I learned now.
Now judging by the comment of Tee Bee and observing the engine, where the Carb Body is even shrunk, I think that that could never have made the effect of the original hose, it is too much. I tend to think, as I mentioned earlier, that some previous user, I try to clean the engine with some agent that attacked the plastic.
It is possible that there is the sum of situations, but I argue that the Carb Body, is very extropeado to think about the effect of the original hose of the engine. At least it's my opinion.
I have marked with colored arrows what I think is related:
Yellow arrow: it may be the cause of the chlorine generated by the original engine tube (according to comments)
Green Arrow: In my opinion and according to my experience, that hose appears to have been attacked with gasoline, given its color and apparent crystallization.
Celestial arrows: here you see the carb body totally attacked and even shrunk, I think something outside could have done that damage so important.
It is good to be able to determine the real causes of the damage, in order to avoid unnecessary worries.
Thank you András for your clarification. Thumbs Up

rsv1cox Thu Mar 08, 2018 7:23 am

I'm sure a six hour boil in anti freeze would have loosened your TD's engine components sufficiently to separate them without resorting to pliers. But by doing so the quality of the anodized parts would be compromised.

Either way Mauricico your engine turned out great.

Bob

Tee Bee Thu Mar 08, 2018 8:13 am

Yeah, I keep an old crock pot of antifreeze for old glow engine projects but elected to sacrifice the crankshaft and prop driver instead of losing the case anodizing. Matt at EX has new cranks to sell and needs me to keep sending a steady supply of my dollars. Smile

MauricioB Thu Mar 08, 2018 9:51 am

rsv1cox wrote:I'm sure a six hour boil in anti freeze would have loosened your TD's engine components sufficiently to separate them without resorting to pliers. But by doing so the quality of the anodized parts would be compromised.

Either way Mauricico your engine turned out great.

Bob

Hello Bob! .... the engine is not mine, it's from Tee Bee, it looks like new thanks to his work done on it! Thumbs Up

rsv1cox Thu Mar 08, 2018 10:41 am

MauricioB wrote:
rsv1cox wrote:I'm sure a six hour boil in anti freeze would have loosened your TD's engine components sufficiently to separate them without resorting to pliers. But by doing so the quality of the anodized parts would be compromised.

Either way Mauricico your engine turned out great.

Bob

Hello Bob! .... the engine is not mine, it's from Tee Bee, it looks like new thanks to his work done on it!

My mistake Mauricio, I even spelled your name wrong.... Sad

....I meant to type Tee Dee. I must have had you on my mind.

Bob

rsv1cox Thu Mar 08, 2018 10:44 am

Tee Bee wrote:Yeah, I keep an old crock pot of antifreeze for old glow engine projects but elected to sacrifice the crankshaft and prop driver instead of losing the case anodizing. Matt at EX has new cranks to sell and needs me to keep sending a steady supply of my dollars.

I'm joining you in that effort. Smile

I'm running a tab there trying to complete a bunch of "parts" Cox engines.

Bob

MauricioB Thu Mar 08, 2018 3:11 pm

rsv1cox wrote:
MauricioB wrote:
rsv1cox wrote:I'm sure a six hour boil in anti freeze would have loosened your TD's engine components sufficiently to separate them without resorting to pliers. But by doing so the quality of the anodized parts would be compromised.

Either way Mauricico your engine turned out great.

Bob

Hello Bob! .... the engine is not mine, it's from Tee Bee, it looks like new thanks to his work done on it!

My mistake Mauricio, I even spelled your name wrong.... ....I meant to type Tee Dee. I must have had you on my mind.

Bob

Hey Bob, there is no problem, the way of writing names in another language is complicated, even I am helped by a translator to be here, so I always say, I hope you can convey what I really want to say!
If you have me in mind, that's good, it's good for people to have it in mind!

Sponsored content

Another Engine Tale - TD .020

Another Engine Tale - TD .020

Re: Another Engine Tale - TD .020

Re: Another Engine Tale - TD .020

Re: Another Engine Tale - TD .020

Re: Another Engine Tale - TD .020

Re: Another Engine Tale - TD .020

Re: Another Engine Tale - TD .020

Re: Another Engine Tale - TD .020

Re: Another Engine Tale - TD .020

Re: Another Engine Tale - TD .020

Re: Another Engine Tale - TD .020

Re: Another Engine Tale - TD .020

Re: Another Engine Tale - TD .020

Re: Another Engine Tale - TD .020

Re: Another Engine Tale - TD .020

Re: Another Engine Tale - TD .020

Re: Another Engine Tale - TD .020

Re: Another Engine Tale - TD .020

Re: Another Engine Tale - TD .020

Re: Another Engine Tale - TD .020

Re: Another Engine Tale - TD .020

Re: Another Engine Tale - TD .020

Re: Another Engine Tale - TD .020