What model Cox engine is this?

ebeneezer Sun Feb 16, 2014 4:33 pm

Hi guys what model TD 049 is this? I picked it up at a car boot sale today. Also why the brass scew in the backplate. Also how do get the backplate off it's siezed solid. It turns over great though. Once cleaned in my ultrasonic cleaner and the backplate replaced it will be as good as new

Cheers Mike

OVERLORD Sun Feb 16, 2014 4:42 pm

I'll have a guess. It's a TD with a QZ cylinder and muffler. A QZ engine also has the high compression head. The bolt probably replaces a nipple to use crankcase pressure for pressurizing a tank.

Lieven

G.O. Stang Sun Feb 16, 2014 4:43 pm

Looks like your run of the mill TD .049 with a QZ muffler. The screw is probably to close of a drilled and tapped hole for a pressure fitting. Like someone used to run bladder pressure and when the stopped, to continue running the engine, they had to plug the hole. That three fin high compression head is a nice find though. As for removing the backplate, try soaking the engine in fuel for a few hours. If that doesn't work, maybe a little heat on the engines will free it up.

Jason_WI Sun Feb 16, 2014 4:44 pm

It's a TD .049 with looks to be a pressure taped backplate that someone sealed with a brass screw.

Some heat on the backplate and it should come right off.

ebeneezer Sun Feb 16, 2014 6:04 pm

Thanks guys, I didn't think it was a standard issue
Mike

dckrsn Sun Feb 16, 2014 6:47 pm

Ebeneezer, I lifted this post by Rusty from this thread.
https://www.coxengineforum.com/t3568-removed-how-to-remove-td-051-back-cover-help
Tried this, and it works great.
Bob

RknRusty wrote:I usually clamp my Cox wrench in the vice so just the long edge is sticking out of the top. Wrap the engine in a rag so I can get a good grip, stick the slots on the edge of the wrench, press down on it with all of my weight(which ain't much) and turn the engine. If the slots are rounded out, I square them up with a file first. Show that sucker who's boss.

Or you could slot a couple of wood blocks so you can secure the engine in the vice, put the blade of a decent sized screwdriver in one of the slots and whack it with a hammer.

I'm a pretty experienced mechanic so I have a feel for things, so if you don't feel confident about how to secure it, how hard to whack it, what size hammer, screwdriver, etc., don't try too hard with that method. Those steps may sound excessive, but I don't mar parts. I do show them who's in charge in my shop.

Tinker Terry Mon Feb 17, 2014 2:07 am

I have one that is very much like yours. Mine has red plastic parts bought new in the 70s. Searching for info I found the instructions for yours in the Cox engine collection under Medallion. The pressure take off point is the nipple opposite the fuel inlet. Does it have a number engraved on the crank case?

ebeneezer Mon Feb 17, 2014 2:44 am

Thanks Tinker, I hope you enjoy the forum as much as I do, welcome

Mike RC Plane

Tinker Terry Mon Feb 17, 2014 4:12 am

Most definitely enjoying myself here. Back in 79 I clocked my Cox on CL at around 80 MpH on lines that were way too short. Hauled it down from the attic a few days ago and it still runs! Last time it ran. Was when my son was born in 79. I am looking forward to getting it back in the air. On RC. Planning to build a baby ringmaster RC conversion. Just not enough room to fly 80Mph on string. Should have some pics up in a few days of my engine. Been so long I can't remember which model it is but first loves are never totally forgotten. Seems like it has forgiven me for neglecting it all these 30 years or so cause it fires right up with a few flips of the prop. To bad I can't get proper fuel for my baby but us big kids will figure out a way to work around that. Castor oil available at drug store. Just gotta figure out how muchh to add.

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What model Cox engine is this?

What model Cox engine is this?

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Re: What model Cox engine is this?

what engine?

Re: What model Cox engine is this?

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Re: What model Cox engine is this?