RE: TT .46 Pro problem.
 

Hi!
When a bearing is hard to remove you must heat it repeatedly and in between cool the engine in water!! Then it will loosen!

The GX.40 belongs to 14year old newcomer in our club, Helped him to change the bearings in his engine.

RE: TT .46 Pro problem.
 

When I get my new bearings, do I need to do anything special to break them in? I'm already going to do a short re-breakin on the engine since it was all apart but is there a set time the bearings need or are they ready to rock? Hopefully the Jett pipe shows up this week so I can flog it a bit on the stand.

RE: TT .46 Pro problem.
 

If they seem OK to you after a short run - they are ready to go.

No break in. just a check to see if the engine is OK.

RE: TT .46 Pro problem.
 

Sounds good. Thanks.

RE: TT .46 Pro problem.
 

Okay fellas... I'm trying to get these new stainless bearings installed today but the prop hub is being a bugger. I used a torch on it and got it pretty hot, but it didnt budge. How hot do you have to get the hub before it'll come off? I doubt my pencil torch can get it hot enough to melt the aluminum, but I didnt want to get it too hot.

edit: I have the whole engine tore down. I figured for the heck of it, I'd put it in the oven at 315° for 15 minutes and try to get the hub off. I don't want to buy a puller if I don't have to. None of the other engines I have would need one.

RE: TT .46 Pro problem.
 

Hi!
You put a nut on the axle, then heat the drivewasher with a propane torch, then quickly tie an old leather belt around the drivewasher and grab it with a large plier...then hit the axle carefully with a copper hammer! -Simple as that!

RE: TT .46 Pro problem.
 

I have the stock prop nut on the crank, heated with a torch until I could smell the oil then held the drive hub with a pair of steel rods in the groove and hit the end of the crank with a block of wood. I do not have a copper hammer, nor do I feel comfortable in using one even if I had one. I like the wood mallet idea better. Perhaps I'm not getting it hot enough. In the oven for 15 minutes at 300° didnt do the trick, so I upped the heat to 320° and will try again in a few minutes. I'm hoping when the drive hub comes off the bearings fall out at the same time. If this doesnt work, I'll go back to the torch. I'm just worried about distorting the case from too much heat.

RE: TT .46 Pro problem.
 

Nevermind. I got it off finally. I just wasnt hitting it hard enough. I used a chunk of Birch as my mallet. I figured being that soft it wouldnt hurt anything. Back into the oven to get the bearings out. Does anyone put the crankshaft in the freezer to get the bearings out easier? This trick works great on car engines.

RE: TT .46 Pro problem.
 

Yes.

RE: TT .46 Pro problem.
 

The last thing you want to do is apply high heat to any area on an engine and then begin banging with any hammer of any sort! And, never ever use pliers for anything on a model airplane engine. This is the way to tear it up.

Here are the tools you should buy for the next time. They can be found either cheap or expensive. For our kind of work, the cheap ones will work every time. My set cost around $30.

Tighten the clamps under the outer lip of the drive washer. The 3 jaws of the puller then need to be fitted evenly under the clamps as you tighten it down. The washers sometimes come loose with a loud pop when they let go.

RE: TT .46 Pro problem.
 

Drive washers can be a PITA some times. That clamshell puller is a great idea but Ihave done the same as you on several occasions.

RE: TT .46 Pro problem.
 

I don't know if they've changed the hub design, but my engine has a brass collet that holds the hub to the crankshaft. I think someone earlier had said the hub is pressed onto the crank itself, but mine isn't.

RE: TT .46 Pro problem.
 

Ihave seen them with the brass collet , a key and or flat spot on the crank. .

RE: TT .46 Pro problem.
 

All of the TT .46's I have and friends engines I have worked on (about a dozen ) have tapered / split collets. The Alum. prop driver can really get stuck / jammed on there sometimes. (like most Saito's too )

You can also use a simple (and cheap ) 2 jaw battery terminal puller...or a larger version of the same type.
Some careful softening of the edges (w/ Dremel ) of the puller's jaws will lessen potential marring of the prop driver.


Some guys don't advocate the use of a Propane torch...but if you're careful, and "paint" the heat on evenly, like you were using an airbrush...(well...that's the way I do it )



As far as new bearing installation...
I put the crank in the freezer, and warm the rear bearing just a little (I set it on a pie pan on the burner of my electric stove for just a minute or so ) it will slip right on the crank. The R. bearing can still be picked up with bare fingers, so it it not all that hot...just good 'n warmed.

Then I put the crank w/ rear brg. installed, back into the freezer for 15-30 minutes.

Then warm the case....the chilled crank / R. brg. assy. will then virtually fall into place.

I am right handed...I wear a leather gardening glove on my left hand, holding the case with my index finger in the backplate opening pressing against the crank to keep it from falling back out...then...

Install the F. bearing quickly while the case is still warm and the crank is still cold.

Oil 'er up real good and finish assembling the rest of the engine.

RE: TT .46 Pro problem.
 

I put my bearings in close to the same way. On the TT I found that the rear bearing would go in with the block heated to 300° but the front wouldnt go in until the block was about 315°. I put the crank in a bowl of ice while the block heated up and put the front bearing in first and put the rear bearing in second. The front cooled enough to stay seated. I reassembled with ARO.

The conrod was still a real pain to get in and out again... I used a ziptie on the top of the rod and tried to lift it evenly but the last little bit it got stuck. I rotated the crank a little bit and it popped out. I did the same thing going back in. I hope the rod bushing didnt get marred up.. It didnt look like it, and the piston didnt suffer any damage that I saw. It was just so tight. Everything is smooth and compression is still nice - hoping to run it later today. I'm excited to see how it runs on the new Jett muffler.

RE: TT .46 Pro problem.
 

I had a chance to run this engine today. I had the main tank hooked up directly to the engine. I put a check valve on the pressure line to the tank to provide a more constant pressure in the tank. Because the engine is inverted and I don't have an electric starter, The engine was a pain to start but I was able to get it to run for awhile. I found the check valve to cause a slight surge at WOT (engine would speed up when pressure came through). Perhaps there is another checkvalve that could be used that'll provide a more consistent pressure instead of the open/close/open/close cycle I noticed today. Given I didnt get much better (consistent) than 13,800rpm on 10% nitro/stock muffler I connected the hopper tank and conveniently the glow driver went dead. I grabbed a D-Cell glow driver and got the engine running but the sun went down and the main tank ran empty. Once the engine started, it seemed to run much better on the hopper tank though the fuel level was so low I couldn't get an accurate Peak RPM on it. Since its supposed to stay pretty decent over the next few days, I'm going to try another tank of fuel and swap the stock muffler for the Jett muffler and re-check RPM's. I wanted to get a baseline on the new prop, inverted engine, and new bearings on the stock muffler.

Do most people with inverted engines have to use an electric starter? This engine ran like a top right-side up with the fuel tank directly behind the engine. Hand flipping got it running in two flips. Upside down was another story.

Having to run the hopper tank is something I didnt want to have to do if I didn't need to, but it seems as though I will have to with this engine.

RE: TT .46 Pro problem.
 

An electric starter makes engine starting a lot easier when trying to start a inverted engine

RE: TT .46 Pro problem.
 

Yeah.. I figured. I couldn't flip it fast enough for it to pick up the fuel after priming. Any fuel that went into the carb while priming just dripped out the throat. Do they make a rechargeable starter or do I have to go buy a field box with a battery and do it that way? (I can't really afford the latter so I'm hoping there is a decent one to be had that'll run on a 7.2v pack).. I suppose I'd then have to use a spinner and lose my nylon locknut, too eh? (I use locknuts now since I lost a prop off the K&B .65 last fall)

RE: TT .46 Pro problem.
 

To make my elec. starter "self contained" (get rid of the 12V. battery and long cord ) I use 2 R/C car battery packs wired in series and they are strapped right to the starter.
I use 3000 MAH NiMh 6 cell (7.2V ) packs that give me a bit over 16V. fully charged...makes my Sullivan starter really zing!:D
Been using the same 2 packs for about 5 years...bought them as a "two fer" sale @ Tower for something like 30 bucks.

About the prop nut...you could use a small Alum. spinner nut...?

RE: TT .46 Pro problem.
 

Okay. I recently acquired a Hobbico Field Box/Kit. Its got a power panel and 12v Lead Calcium 7Ah battery, Electric Fuel pump, Glow plug clip, and Hobbico Torqmaster 90 electric starter. This box and all that came with it are in NIB condition. My buddy had this in his garage for 3yrs after getting it in a trade from another guy that had it for 3 years. I charged the battery for 12hrs (12V at 650mA) and tried all the attachments out. All works however the glow plug clip requires the "heat adjustment" to be at full to glow the plug well, and the Starter doesnt have enough power to turn my TT .46 Pro over. I figured the battery might be junk, but hardwired the starter to the 12v battery directly. Same result. I tried the two 7.2v packs (not same maH rating, but fully charged NiMH) and got the same result as the 12v battery. I figured the 14.4v configuration would get it zinging for sure but no go.. What gives?

RE: TT .46 Pro problem.
 

I had some brand new NiMh 7.2V car packs that would not provide enough current to run an electric starter. The starter pulls quite a lot of current, and the batteries had too high of an internal resistance to be up to the task.

I gave them to a friend of mine to use on something else. Now I have a 4S (14.8V) LiPo on my Sullivan starter, and it really works!

RE: TT .46 Pro problem.
 

Or just invert the airplane in a good airplane stand....nothing to it!!!! Capt,n

RE: TT .46 Pro problem.
 

Problem is, the engine isnt on/in an airplane. Its on an airboat. Its not finished, but this is the general idea of what my setup is:
http://i153.photobucket.com/albums/s...IMG_0135-1.jpg
I'm running the engine on the bench in the fashion it'll be ran on the boat. Get all of the bugs worked out before running the boat. This starter is supposed to start up to .90ci engines...

RE: TT .46 Pro problem.
 

Gotta be either the batteries aren't delivering enough current...or something is not quite right with that starter?

Try hooking the starter to your (full size ) car battery as a test. Check the wires and connectors...I've seen the crimped on connectors have quite a bit of resistance...maybe they are loose or dirty? Run the starter for a little while to loosen it up...might be a little tarnish on the commutator.

My 3000 mah NiMh can (aparently ) deliver adequite current...they are just your basic "Epic" 6 cell packs. I put Deans "Ultra" connectors on the batteries and starter connections, because the std. Tamiya connectors are kinda cheap...can't handle the current loads as well as the Deans.

The wires on my packs are 13 Ga.

Right off the charger, while still warm, my 2 packs measure around 16.6 to 16.8V. and it will spin a .46 over with very little effort.

RE: TT .46 Pro problem.
 

Well, The Hobbico panel uses banana plugs on all of the panel connections, however the battery is connected by crimped spade terminals. The batteries are 3900mah and 1500mah respectively both with deans and the series wiring harness is 16ga wire and deans connectors. I have my boat batteries in the basement for winter and I actually did try it on one of those. It spins the same RPM, though the torque is better on the marine battery. On the marine battery it would turn it over good once it got past the first compression stroke. I got the same result on the small 7Ah battery directly connected. I think the wires going from the battery to the power panel aren't big enough so I'll solder in some heavier gauge wire and solder the terminals. I'll try the starter through the panel again after and if it works then I'd blame the small wiring. (the stuff in there now looks like 18 or 20ga.)

Is there a better more conductive connector option than these banana connectors?