neflyte3

Attended my first pylon race at hodges hobbies. Want to thank everyone there that helped me with all the problems. First got to the race with a predator 2. The CD checked the wing and the thickness and the wing was about 3/16 to thin. Is this common with the new pred 2's? Anyone had this problem. Well I added about 3/16 of packing/vynl tape to the wing to atleast be able to try to race. Did a test flight before the race started engine fired right up was hitting peak about 16.3k. Test flight went fine no problems did a few test laps and landed. I knew the plane was going to be pretty slow, fine first race I need the practice. Went out to the first heat tried to start the plane and nothing. So no first race changed glow plug and now the engine still wont start and wont turn over either. Took the engine apart and there is metal on top of the piston hell if i know where it came from. So i run into the hobby shop at the event (hodges hobbies) buy and new engine put it on go back new engine not broken in only turns about 14.8.k do 2 heats with that engine and the motor mount breaks. That was it I threw in the towel. Came back home and have been trying to breakin that engine at around 17.5- 17.0k with a cut down balanced prop mabey I can get a few more rpms out of it for the next race.

Also anyone know if you can order a new wing for the pred2 or will a viper wing work on it?

Druce

Yes you can order a new wing. I think they around $40.00. But I would think they would be all the same. Maybe nobody else at the other races last year checked wing thickness. Here in Canada we allow a 11.25% wing thickness so it wouldn't matter anyways. Did anyone else that had a predator fail to??


Maybe a piece of the bearing cage came lose in your motor and ended up on your piston. People here have been changing out their bearing for a good steel one right from the get go so this wouldn't happen. Not a performance thing just a motor saver

BUDMAN27

I am glad you got to be in your first race sorry you had so much trouble. Racing is a had biss. it takes no prisners. Just keep on pressing on and the good days are in frunt of you mate.

vicman

My Feedback: (10)

Try 70 bucks for a wing. I was not aware of any thickness issues myself.
Also a good call on the bearing cage. I wish I had known about that little issue before I sucked the cage off mine. Yes I was very suprised when I saw those wads of metal in my crankcase too.

goatboy

Did you check the glow plug to see if the element was missing? If you get too lean it can melt and leave deposits on the top of the piston and also score the side of the piston. I have seen this happen before. I have also been told.. but have not seen it happen, that the spring in the carb barrel can get sucked in to the motor. My guess is glow plug element, but check the bearings anyway, you never know.
Doug

daven

My Feedback: (1)

Are you sure that wing was 3/16" thin? Thats nearly a quarter inch, I am reall surprised to hear one that far out of whack. I would definately contact Lanier, or the distributor you bought it from. It is advertisted as AMA legal..

Its amazing how all the little details can make or break you on race day. I think you saw the ugly side of it, its not always that way. However, you normally learn from them, and they don't happen again.

neflyte3

I though mabey it was the glow plug element also but, after taking it out it was intact. I usually run the engine a few hundred rpms off peak.

With the wing guage they were using to check it with Just eye balling it it looked between 1/8" to 1/4" it was a big gap. I'm going to contact tower today where I got the kit and see if they will replace the wing.

I'm not the best builder, but have been looking at some kit q500's on matney's and supertrc sites I am guessing that those might be better than arf's quality wise. I also saw that supertrc has a new fuse only kit that accepts the viper wing anyone have any experience with those good or bad?

Also after examining my wing last night there is a nice prop strike in the wing. I heard a pretty loud pop when we were bunched up around turn #2 looks like the tape saved the wing from getting chewed off.

vicman

My Feedback: (10)

Goatboy,
It was definately the bearing cage.

If you can see the ball berings are all wadded up on one side and the cage is gone.

BUDMAN27

We use to have the same prob. with our Super Tigar .40 engine when we put a Nelson muffler on them. It got to the point that when I would buy a new engine I would automaticly take out the stock bearings and put Boca bearing in without ever starting the engine up.

neflyte3

Contacted lanier RC they said they would warranty the wing So shipping it out today.

BUDMAN27

Good

vicman

My Feedback: (10)

Yeah, I figure I will be ok with just replacing the bearing. The really good part is that I just took the motor off an put the Jett .40 on front since I am flying for fun at the moment.

DMyer

My Feedback: (2)

Looking at the picture of the galled up aluminum in the case and the retainer being missing... I would guess that this motors competitive days are over... that retainer went somewhere and I guarantee it wasn't someplace were it would do some good! Here is an old link to a real good thread with some excellent advice on the race setup, care and feeding of a TT40 Pro. Good luck.

So here is the text from Lee Von Der Hey.

So You Wanna Race ?
Racing the Thunder Tiger .40 Pro
Our 1998 racing season is here and there has been a few rule changes which allows several engines to be used in our club Q-500 races. One of these engines is the “Thunder Tiger .40 Pro ABC.� Because of the way the engines rules are written you can make some very slight changes to the engines that improve consistency, durability, and performance. Let’s start at the bottom and work our way up. The rear bearing in the Thunder Tiger should be replaced with a bearing that has a good quality ball retainer. The Super Tiger G.S. .40 rear bearing is a perfect replacement for the Thunder Tiger rear bearing. There has been quite a few rear bearing failures with the Thunder Tiger rear bearing ball retainers (the ball retainers come apart). This is the reason for replacing the rear bearing. The front bearing in the Thunder Tiger is fine (there has been no problems experienced with these). To replace the Thunder Tiger rear bearing you will need the following tools: a 2.5mm allen wrench, a propane torch, and a puller for the front collet (a battery terminal puller works fine). First remove the backplate, head, piston & sleeve assembly, and carburetor. At this point you should have a main case with the crank, front and rear bearings with the thrust washer and collet still assembled. Do not use a screwdriver to try to remove the thrust washer and collet !!! Using a battery terminal (from most automotive parts stores) pull the front washer off the crank. It will pop off easier if you warm it up a little. Once you have the thrust washer and collet removed you should be able to push the crankshaft through the back of the case. Now you should have a case with two bearings in it. Set the case on the edge of your bench, light up the propane torch and carefully heat the area where the rear bearing is seated. Do not overheat the case !!! You should be able to pick the case up with a glove or a rag and lightly tap it on your wood bench two or three times until the rear bearing falls out. Once you have the rear bearing out, slide the new replacement bearing on the crank with the flat side of the bearing ball retainer forward. Then reheat the case where the rear bearing seats. Reassemble the crank and make sure the front and rear bearings are seated all the way in the case. Reinstall the collet and thrust washer by adding the propeller and spinner nut. The propeller and spinner nut should be very tight. At this point, when the case cools off, you should be able to hold the case in one hand and pull the crank in and out by holding on the propeller so you can feel if there is some end play. It is absolutely necessary to have end play, without end play you will have a binding in the front end which will cause premature bearing wear and poor performance. If you feel or hear a slight clicking when you pull in and out on the crank you have end play. If not, start over. It might take a few times until it’s right. The crank should also rotate freely in the case without any drag. If not, this means that the bearings are not aligned properly. You must keep disassembling and assembling until it’s right. This is a very big part of what makes the engine fast and dependable.
Our next step with the Thunder Tiger .40 Pro is a little critical so pay very close attention to the following. The piston and rod assembly can only be installed one way. If you look inside the piston you will see that there is more material on one side than on the other where the wrist pin is located. The side with more material has to be positioned towards the front of the engine. The connecting rod is also offset slightly. Look at the bottom of the rod and you will see that there is a difference. The part that has more material on one side has to be positioned towards the front of the engine. Now that you know which way everything goes, it’s time to disassemble the piston, rod, wrist pin, and circlip for a slight modification. With a pair of small needle nose pliers, remove the circlip that holds the wrist pin in. Wash the piston, rod, and wrist pin in acetone. After there parts dry, assemble the piston, rod, and wrist pin. With the wrist pin not installed all the way, put a drop of “Red Loctite� in the non-circlip side of the piston and a drop of “Red Loctite� on the wrist pin that is sticking out of the piston on the opposite side (about 3/16�). Push together and let them dry for about fifteen minutes. With a small brush and some acetone, clean out the groove where the circlip goes. Do not reinstall the old circlip, use a circlip from a “Nelson .40� engine. The Nelson circlip fits much better and is a lot springier. Make sure it’s properly seated in the piston or you will be greeted with disaster when you run you engine. The reason for the “Red Loctite� is that the wrist pin has a little play in it which eventually wears out the piston by egg shaping the mounting bosses.
The next step is the last step required fir assembling the Thunder Tiger .40 Pro. The head shim that comes with this engine, which is usually stuck in the head, should be removed and replaced with a thinner one. Very carefully remove the old aluminum shim with a razor blade or knife. Replace this shim with a K&B 6.5 (.40) .010 shim. This should make your total deck height very close to .010�, which is about optimum for racing. Do not over tighten the head bolts, just slightly snug is fine. Now that the engine is assembled, you need to very carefully break it in. The following steps are highly recommended for successful break-in. First you need a break-in propeller. Use a 9-6 cut down to a 7-6 propeller and make sure it’s balanced. Bolt the engine to your bench or test stand making sure everything is solid. With the throttle wide open and using the break-in propeller you should be running at 13,000 to 14,000 R.P.M.’s (very rich). You will need to run about a half gallon of fuel (15%) at this rpm range to lubricate and loosen the engine up. Run another half gallon of fuel through the engine periodically turning the needle valve in until it reaches about 17,000 R.P.M.’s (the engine should still be running rich). Do not lean the engine out with the break-in propeller !!! Next, remove the break-in propeller and install an A.P.C. 9-6 propeller. Back out the needle valve half a turn and run a tank of fuel through the engine with the R.P.M.’s about 500 R.P.M. down from R.P.M. peak. You can run a couple more tanks of fuel through the engine to help break it in. At this point the engine should be peaking around 16,500 to 17,000 R.P.M.’s. Now you are ready to race the Thunder Tiger .40 Pro. Bolt it on your favorite Q-500 racer, set the engine 500 R.P.M.’s down from its peak R.P.M. and turn it loose.
Note: Not all engines set the same, there are quite a few variable such as tank brand, tank location, weather conditions, fuel, etc., etc. Just be sure that your needle setting is conservative. No engine like to be lean! The following is a list of what you need and where to get it to complete all the steps mentioned in this article.

Super Tiger G.S. .40 Rear Bearing - from your local hobby shop.

Nelson Circlip - Performance Specialties
P.O. Box 3146
Gardnerville, NV 89410
(702) 265-7523

6.5 K&B Head Shims .010� - K&B Manufacturing, Inc.
2100 College Drive
Lake Havasu City, AZ 86403
(520) 453-3030

Loctite #271 Red - Most automotive parts stores

Battery Terminal Puller - Most automotive parts stores

P.S. Always clean and oil you engines after flying !!!


Lee Von Der Hey

djlyon

Generally after a retainer failure like you have there the piston , cylinder and head are done. I have had 3 TT40s do this. I sent one back to Thunder Tiger, not under warrentee, and they replaced the piston, cylinder, head and bearing and charged me 29 bucks. Not bad. The other two had less damage and I polished the shot peaning out of the head and top of the piston and put them back to work. They are still turning 17K+.

Denis

vicman

My Feedback: (10)

The cylinder and piston are fine, luckily. All the debris was confined to the crankcase. The only area I have some concern about is the end of the rod. There was a pc kinda stuck to it and limiting the rotation. Once I pulled it all out everything turned freely. Basically I need to get a new bearing and maybe a head shim.

Nice article.

DHG

My Feedback: (7)

Denis,

Were these recent purchases? Somebody told me TT had found a better source for their bearings and the problem was mostly solved now. I have two of them, purchased in 2006, no problems yet.

It worries me that our #1 newbie racing engine would blow up and/or need parts replacement right off the bat. Sort of detracts from what we're trying to accomplish ... know whadda mean?

Duane

djlyon

They were all pre 2006. 2 maybe 2004. 2 had bearings from Taiwan and one had a bearing from Japan but there were no no-name bearings. Non had any rust or corrosion. The retainers just came apart. Two came apart after lots and lots of races. The newist one came apart after breakin and perhaps 5 runs on the course.

Denis

BUDMAN27

Dmyer that realy is a well writen art. on racing engines.

vicman

My Feedback: (10)

Mine was bought at the end of 05. Did break in with a 9x6 and ran maybe 20 tanks with anything from 9x9 to 8.75x9. The incident occured with a 9x7 like we are sposed to use for racing.

Electric Delta

My Feedback: (13)

My TT .40 also suffered a failed rear bearing retainer at the last Q500 race in Americus in February. The retainer bits left a nasty scratch on the piston. The engine was still running, but wouldn't turn over 15,650 or so. Compression still felt good. I put in a new piston and sleeve. Looks like the newer pistons are machined from barstock, the older one looks like a casting. It still all fit together nicely. Well, in the second heat at the March 24th race, my mystery #1 Q500 went down in a spectacular mid-air crash, taking out my #1 engine along with it; it broke the crankcase where the muffler attaches. The re-built TT was on my Predator II, as yet un-run. I had no other choice (besides dropping out of the race -> not an option after driving 500 miles) but to run it and race it. In spite of all the new parts, it STILL wouldn't turn over 15,700, and I had to tough out the rest of races with it. Ugh. At least I had no further "incidents". Another learning experience for me... come better prepared! Dummy me had a nice new-in-the-box TT .40 that I left at home; oh well, there wouldn't have been time to swap engines in between races anyway.

BUDMAN27

Oh I don,t know about that. I have seen some of the big boys swap out engines inbetween heats befor. It can be done.

Electric Delta

My Feedback: (13)

Well, we only had 8 people flying in B-class total, with the A-class guys judging the pylons for us and otherwise helping out. With 4 pilots racing at a time, you were either flying, re-fueling, or calling for a fellow pilot, so you didn't really get much of a break in the action to work on anything.

BUDMAN27

Oh I see what you mean

SmokinJoe

I trashed a TT46PRO last year when it chewed the bearing cage.

Now the first thing I do before running the engine is change the rear bearing out for one of Dave Shadell's $18 bearings and no more worries.

Druce

I think these motors are being pushed to hard. I don't think there intended to do the RPM that these motors are putting out. Ever think of using a little more pitch and a little less RPM. Might save a motor or two. After all it's not just rpm,s a little more pitch helps too..
Just a thought..