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Building Tips and technical articles. => 1/2 A building. => Topic started by: John Rist on March 10, 2014, 04:32:52 PM

Title: TD 049
Post by: John Rist on March 10, 2014, 04:32:52 PM: I picked up a TD 049 that is totally frozen up. I was able to get the head, back plate and carb off. The red plastic noise piece looks in bad shape (old and cracked). I have an aluminum replacement for this part, I just need to get it unstuck and dissembled. I am now soaking it in 10% fuel. Is there any advice to insure a good outcome? Other than frozen the engine look new.

#^
Title: Re: TD 049
Post by: Jim Roselle on March 10, 2014, 06:04:14 PM: I've put them in the oven to melt the old castor goop. I don't recall the exact temp but I would guess the 200 degree range would suffice.

Jim
Title: Re: TD 049
Post by: John Rist on March 11, 2014, 10:05:18 AM: Well between soaking in fuel and some heat My TD 051 is apart. It looks really good inside. The piston seems to have a good fit. However the piston/rod did need tightening. The red plastic front end piece was not usable but I have an aluminum replacement. Now for the question. The rod has a oiling hole drilled in the crank end. Never saw this before. Is this a Cox thing or was it done by the owner?
Title: Re: TD 049
Post by: Larry Renger on March 11, 2014, 11:44:59 AM: I don't recall there being a hole there.
Title: Re: TD 049
Post by: Jim Roselle on March 11, 2014, 12:24:19 PM: I have one like that as well.

Jim
Title: Re: TD 049
Post by: John Rist on March 11, 2014, 01:41:59 PM: I have a good runner!! She turns 19.5K with a Cox 5x3 3 blade prop. 25 % fuel and a balloon tank. Started instantly and ran the hole 3/4 oz fuel steady as a rock. This one will become the front engine for DO-335. I paid $10 for this one. Rollin Keszier picked it up at a swap meet for me. Wow - thanks Rollin!! #^ #^ #^
Title: Re: TD 049
Post by: kenneth cook on March 11, 2014, 06:46:08 PM: I have a few of the TD's with the oil hole as you describe. This is usually with the earlier thin walled cylinders. Ken
Title: Re: TD 049
Post by: John Rist on March 11, 2014, 09:47:42 PM: Quote from: kenneth cook on March 11, 2014, 06:46:08 PM
I have a few of the TD's with the oil hole as you describe. This is usually with the earlier thin walled cylinders. Ken

Ken, Is this a good thing? It seem to run strong.
Title: Re: TD 049
Post by: Larry Renger on March 12, 2014, 08:47:01 AM: Yes it is beneficial.
Title: Re: TD 049
Post by: kenneth cook on March 12, 2014, 08:12:50 PM: While I do like having the oil hole, I don't feel this is where the TD needs help. I've had a few break cranks at the square cutout and I also have had the entire web of the crank break off right where it meets the smaller portion of the crank. I've seen a few of the crank pins break off as well. This generally happens when the rpm's are about 23K. Seeing that my engines were being used for combat, I always wondered if some of the abrupt ground pounding was responsible for the breakage. The cranks never broke during a hit to the ground as it always happened when running. The later TD's don't have this oil hole and I never had a rod seize on the pin. I would like to think this is due to it receiving enough lubrication while running. The ball socket though is a very poor design in my opinion . I've had several failures with the ball socket. Many of my engines have had the ball socket break through the top of the piston. This happened even with resetting. If it doesn't punch through the top it breaks on the underside. Ken
Title: Re: TD 049
Post by: John Rist on March 12, 2014, 10:03:36 PM: So it looks like the 19-20K I will be running should be a safe level for this engine. As I said it is going in a scale. Easy starts and steady runs is all that counts. Will post how it works once I get the DO-335 airborne.