rudder turns

Hi Guy,I can't disagree with you more,The reason I disagree with you is that I have 12 TTpro46 engines,And never had a problems with any of them. They are not made from cheap parts. I have had 2 OS 46 fx engines and have had problems with the nickle coming off the sleeve,[:@]same as some other members in my club having the same problem with there AX engines. I mostly use 10x7or8 and 11x6 APC,with 15% fuel. Thanks Ed

JohnBuckner

My Feedback: (1)

Now we are making progress and we can assume the tack readings were accurately done but that assumption above is also a big red flag-What did the engine tach when you lightened the prop load and did it run any better ??? Good grief its a three buck prop, thats a little cheaper than a new sleeve and piston.

John

handyman

My Feedback: (2)

lbs for lbs..penny for penny.they make a great eng..............they run and run and run.............

Gray Beard

My Feedback: (-1)

I liked them well enough to use them but I have never bothered to rebuild a hundred dollar engine. As I recall when the FX first hit the market the chrome was falling off the cylinder on a lot of the engines. I saw it happen to several engines. Once OS started getting in a bunch of engines for service the problem went away quickly and the problem engines were replaced with new ones. It didn't take OS long to fix the problem. I did rebuild my OS engines as needed but it was more of a cost thing, the engines were high dollar and I couldn't replace them for a few bucks. I use the SK .91 for my two stroke engine, it's the smallest one I use these days. When I have a problem with one I just buy another one. I have only had a problem with one of them and that was crash damage, my bad!! The engine is $100.00 with a muffler so not worth spending more money on a complete rebuild. If I just had a bearing problem then a couple of bucks spent at rcbearings.com would be worth it. I have just never had to just replace the bearings on one.

hithere34

Well I've decided to go down the rebuild path.  I now have the engine completely dismantled.  The exterior and cage of the rear bearing is very rusty but 'seems' to roll OK.  The front bearing has fewer signs of rust and rolls a little smoother.  I intend to replace them anyway but out of curiosity from my description do they sound knackered?

Not sure what to look for with the piston/liner...it seems a reasonably tight fit.  I've taken a couple of photos, not sure how helpful they'll be.

Now to order replacement parts.  Can anyone suggest a supplier with reasonable prices?  I don't mind buying from another country, just have to wait a little longer for delivery and in this game if there's one thing I've learned it's patience.

hithere34

If you can't view the pics try right clicking and selecting 'view image'

hithere34

From March 8, 2012

hithere34

From March 8, 2012

JollyPopper

My Feedback: (6)

I don't have those parts in my hands so I can't tell for sure, but they certainly appear in the pictures to have been severely overheated. Even the liner appears to have been really hot. Look at the pictures of the bearings that JAKA posted in an earlier post and compare them with yours. Even the inner races look cooked. Castor oil will coat the bearings after sitting but it has a different appearance than yours. Castor looks like hardened honey while yours looks like charcoal. Coupled with the fact that your post #25 says that you can turn the crank past TDC with little effort, (should be a definite pinch at the top even with the head off) I believe your engine has had at least one lean run when it got severely hot and took the pinch out of the liner. That would cause the problem you have. I'll bet even money that replacing the piston/liner assembly and bearings will give you the increased RPM that you're looking for.

pimmnz

As above, I can see some deep scores in that liner too. One lean run...Bearings will be easy to replace, take them to any good bearing retailer and they will have them, give these ones a clean and the standard part numbers will be seen. The piston and liner will have to come from a model retailer. You will need to remove the piston pin from the piston, there will either be a small ring retainer or a couple of teflon pads at the end of the pin, extraction will mean tapping the pin out either from the opposite side of the ring, or simply through one of the holes if pads are fitted. It might be a bit reluctant if there is a lot of oil coke/staining on the pin, but a bit of persuasion will see it free.
Evan, WB #12.

bkdavy

My Feedback: (1)

Go to http://www.tiger.com.tw/product/9141.html and download the pdf version of the manual. It has the exploded view of the engine and the carb, part numbers, and everything else you'll need.

Given the performance issue, replacing the front and rear bearings, piston, and liner, the engine should run like new.

I'm confident you probably don't have a problem with the carb or o-rings since you stated earlier that the engine transitioned well. Normally air leaks around o-rings or clogged high or low speed needles evidence themselves with transition problems.

I seem to recall in past searches for parts that TTPro parts were harder to get here in the states, but I'm betting you can find them much easier down under.

Good luck and let us know how it turns out.

Brad

speedracerntrixie

My Feedback: (29)

Just replace the engine. TT engines have an issue with pre-mature wear. They always have as they use cheaper materials and processes. I used to use the .36 heli engine as at the time it was more power then the OS 32 but they wore out in about 3 gallons of fuel. I used to always have a spare piston and liner. Seems like yours is at the same point. Depending on what airplane it is on, you could bolt on a 10X6 and just fly it. It's still going to be reliable, just won't make the power it used to.

mighty9

My Feedback: (10)

Dont listen to anyone telling you they wear out quicker than other brands.They must not know how to take care of them. Also dont listen to the people that say replace it .There is no greater satisfaction then running an engine you have built with your own hands.Anyone can buy a new one, When i sold my tt engines they had at least 20 gallons through them some with tuned pipe use.

jaka

Hi!
Agree fully!!

We live in a world of "buy and trow away" today (for god knows how long)...why not fight back a little! I take pride in fixing things!

If you can turn the crankshaft over with the head removed without feeling the piston grip at top dead center, then the engine is pretty worn. Perhaps not worn out but bad piston to cylinder fit and those very bad bearings will certainly reduce rpm.

As said before get good bearings! C4 or C3 fit bearings, not standard bearings as those are to tight! Swiss company WIB makes some of the best bearings for our engines.
Luckily for us TT now offers all their .40 SE PRO (perhaps .46 too) engines with a plastic retainer equipped rear bearing.

Gray Beard

My Feedback: (-1)

I have never seen one wear any faster then any other brand of engines. This one looks like it was run very lean more then once. No brand of engine will put up with lean running. I started buying my bearings here state side from rcbearings.com with good results. Before that I was buying them from BOCA Bearings and started having problems with there products. Last time I rebuilt one I was able to get the piston and liner off the rack of my LHS engine parts rack. This is a very good hobby shop right in Las Vegas and has a lot of items that are hard to find. I'm blessed with a good hobby shop plus a few that aren't so good. They even come in handy once in a while. In OZ I would ask Brian Winch at [email protected] If that address doesn't work I do have his full address.

speedracerntrixie

My Feedback: (29)

Thats a bold statement to say about someone you don't know. I have been around t long enough to know how to take care of an engine. Why do you think the TT is so much less money then an OS? Do you think there is that much profit margin in an engine? It's the fact that the manufacturing costs are less. The difference between Japanese and Chinese labor costs are going to account for some but the main factor is the process costs. In this case it is the materials and heat treating process that TT uses. It's just plain inferior to OS. Yes it looks like this particular engine has been abused but the main issue with TT ABC/ABN engines is that the upper end of the sleeve looses it's shape quickly. If you were to look at it's piston closely you would most likely see a non consistant sheen around the crown. This means the liner is a poor match for the piston. Poor heat treating process.

hsukaria

All the discussions in this thread have been good and informative. I would like to add however, the fact that the TT 46 Pro is ABN, not ABC. You could get yourself a lower cost ABC engine that would last longer than the ABN. Or you could even get a ringed engine and then you would only have to replace the pistion ring instead of piston/liner pair and save money in the long run. Lots of options out there. Nothing against TT, I have a 4-stroke TT and it has been a great engine.

rudder turns

Hi Guys,I just looked at tower Hobbies,and they have allot of parts for the TT pro46 engine I replaced the rear bearing in one of my TT engines and I was warned NOT to try to expand the crank case with a torch,or heat gun.It can permanently distort the case, instead Boca bearings recamends to put the case in the oven,at 350 degrees,and put the bearing on the crankshaft, and put in a plastic bag in the freezer to contract the bearing,After the case is hot a good hard bang on the counter and the bearing came out easily,[X(]Quickly putting the crankshaft and bearing back in. Just make sure that your wife is out, Thanks Ed

Gray Beard

My Feedback: (-1)

Rudder, that is very true, you can warp a case if the heat isn't done evenly. There are several ways to do it though. Most people use the oven. Freezing the bearings isn't needed very often but you know, sometimes it is worth doing.
I use a tall pot full of water and just drop the case in and bring to a boil. The water evaporates almost instantly. I have never seen a case warp with just a covering heat gun being used but that doesn't mean it can't happen. I have one friend that uses the pot like I do but he uses vegetable oil instead of water. It's an old VW mechanics trick, the oil can be brought to a higher temp then just water. Just too many ways to do the same thing.

mighty9

My Feedback: (10)

My statement was no bolder than yours and wasnt directed towards you. Os are good engines but they dont always last longer than other engines.

hithere34

Dare I say it, here is anotherelement that perhaps supports the replace rather than rebuild course of action. While you guys have been catching up on your zzzzzs I have been busily beavering away taking the engine apart. Now I've never done this before so I googled how to do it and the very first hit I got was a very goodvideo done by someone who seemed very experienced. He used a torch to heat the body to facilitate the removal of the bearings...so I did too . Have I warped the case? Who knows and I guess I won't know till I try to put the new bearings (which I've ordered) back in.

So what I'm trying to say is that after spending twelve bucks on the bearings, another sixty or seventy (by the time it gets to Australia) on the piston and liner, another fifteen on a conrod and who knows what on a wrist pin kit the value proposition is starting to look very shaky. There is the potential to do things the wrong way through ignorance and end up with an engine that still doesn't perform like a new one.

I thoroughly agree with the repair rather than replace philosophy but not when it costs you extra to do that with the inherent risk that you'll do something wrong.

BTW thanks to everyone who has so far contributed to this discussion. You're a fine and knowlegable bunch of individuals and I've thoroughly enjoyed reading your posts (yes evne the OS vs TT ones)

GREG DOE

Jaka. Let me relate my experience with the new plastic bearing retainers. We race a lot of AMA
424 Quickie 500, and Club 40 with the TT Pro 40. Everyone knew that the first generation
bearings didn't stand up, and needed to be replaced before running the engine. I was pleased
when I bought an engine a year ago that had plastic retainers. Unfortunately the rear bearing
in that engine failed on me last fall. The retainer crumbled into small chunks, which were hard
enough to score the piston. My recommendation is to replace the newest bearings if you race.

A lot of the help you get on forums like this one are OPINIONS. Some opinions are good, some
not so good. You and everyone else has to decide what is good info, and what is bad. For example
one person suggested you "make sure you idle needle valve isn't backed out far". That will affect
the idle, but will not affect the top end, assuming you readjust the high end needle. I know this
because we back the idle needle out as far as we can, and use Lock Tite on it. Or we cut off the
end of the needle flush with the inside of the carburetor barrel. It's worth a few hundred RPM.

Finally my OPINION of the TT Pro engines is that they are an amazingly well built engine at an
excellent price, with lots of horse power. I'll continue rebuild mine as needed.

bkdavy

My Feedback: (1)

You probably don't need to replace the connecting rod or wrist pin if they look clean, no cracks or dings. Piston liner, piston, and bearings should be all it takes. The wrist pin doesn't rotate very far during operation. And since the engine was running with the existing crank and connecting rod, they're probably fine. You're just trying to correct a low compression situation and possibly bad bearings.

I use a torch to heat the case to get the bearings out. Just keep the torch further away from the case, keep the flame low, keep moving it around, and don't try to heat it rapidly. Or us the oven. I've never warped a case. Should you be careful? Sure. Just don't lose a lot of sleep over it.

And in the future, you might want to consider the rebuild costs when purchasing a second hand engine with unknown history. Its a risk you take.

But they're also fun to work on!

Brad

Square Nozzle

My Feedback: (1)

The fact that one of the head bolts was rounded out tells me that someone had taken that engine apart before. I would check to see that the cylinder liner is in properly and the exhaust port in the liner lines up properly with the crankcase port..

jaka

Hi!
Thank's Greg!
Im I pylon racer too and I replace all my bearings with WIB C4 bearings in my engines. I year ago I bought a .40 TT Pro SE and saw that the rear bearing looked like a WIB bearing with plastic retainers so I thought it was ok (I have followed the bad TT bearing discussions that has been going on on the Q-500 forum). I have only run this engine for about 10 flights so far in a "Viper" and up till now everything has worked ok, but might look at the bearing again. Over here in Sweden we run 10x6 props in our Q-500 series so we don't put as much load on the rear bearing as you do running 9x6 APC props!