Tiger Shark Engine Rods
 

I bought a TS .52 ABC and the rod was worn out on the crankpin end in no time (at most one quart of fuel) by running it properly at slightly richer than full power so it could develop the heat required for a new ABC engine. OK...I got a new rod through the warranty. I ran the engine a bit more (at most one quart of fuel), the same way, and the same thing again...a wore out rod on the crankpin end. Then I was allowed to trade it in with some extra bucks direct to Kangke and got a NIB TS .56 Ring. I ran the TS .56 Ring very rich for 4 eight ounce tankfuls (10% nitro/20% lube) then gradually leaned it out with bench-running so the ring could seat. Altogether about 2 quarts of fuel. I noticed a bit of light clicking sounds when it was turned over but dismissed that as being normal (???) Then today I wanted to go for it on the bench with a mousse-can pipe and an APC 12.25 x 3.75 prop. It cranked easy and went up to ~13.4K pretty quick then slowly eased down to ~12.2K and that was all I could get out of it. I let it cool and tore it down wondering WTH was up. You guessed it...the ROD...wore-out on the crankpin end...AGAIN![:@]

Has anyone else experienced this problem with Tiger Shark engines? FWIW...I've NEVER had ANY engine do this to me...even after many gallons of fuel through it.

RE: Tiger Shark Engine Rods
 

Gene,

Are they bushed or billet high silicon aluminum?

Jim

RE: Tiger Shark Engine Rods
 

The TS rods are bushed but I have to wonder if it is brass or bronze. I'm not a metalurgist, but I think bronze is what you want here and NOT brass. The major wear is towards the piston on the crankpin end, and it seems like the rod/wristpin fit isn't real spiffy IMO either.

I've never even had this problem with ALL aluminum rods!

I will be calling James at Kangke this morning to see if this is a common problem they see.

RE: Tiger Shark Engine Rods
 

Per James, the problems I am experiencing are not a 'common' problem. I'm getting a new rod sent to me.

I was told I was running this RINGED engine improperly by running it rich from the get-go...gee...EVERY other engine manufacturer recommends running a ringed engine very rich initially. Rich to James was five or six clicks richer than full power...still two-cycling. I ran it rich to the point it was four-cycling. It's a finger-pointing match. The new rod will be ran at a setting just slightly richer than full power since the piston/ring/sleeve, and the rest of the engine, is essentially 'broke-in'. This will be interesting to see the results...yes...I WILL post them!

RE: Tiger Shark Engine Rods
 

Gene,

It seems to me that the only type of engine that would be harmed by a rich run is one with a tapered bore, which a ringed engine shouldn't have. There were a couple of old Super Tigre engines they called ABCD, for ABC with a Dykes ring. I don't recall if they were taper bores or not. As I recall, Dykes rings need to be run fast in short spurts so the ring will be forced out to the cylinder wall. If this is the case, Bill Robison, who does a lot of K&B Dykes ringed engines can advise you.

The hardest place to lube and the hotest is the upper connecting rod-wrist pin joint. This is where you need the lube during break-in. Seems like rich should be better to me.

I have broken in all my ringed Magnum & Saito 4-strokes just like you describe- slobbering rich to start with. They have all run extremely well.

What about adding some extra castor for the first gallon or so.

Gene-I just looked at the Tiger Shart instructions on their site and they do claim both non-ringed and ringed are ABC type construction so maybe they are taper bored. This means they may be different from normal ringed engines and need special break-in procedures.

RE: Tiger Shark Engine Rods
 

Gene:

If what Ed has discovered is indeed so; a tapered bore, even though it's ringed, is going to cause excessive loads on the rod bearings if it's run too coolly. Also, as he said, a Dykes ring needs high cylinder pressure to seat.

So, if your TS is both tapered bore and Dykes ringed, then the screaming break-in will be correct.

Bill.

RE: Tiger Shark Engine Rods
 

The sleeve is steel, not chrome plated brass. James says it is tapered, so I put some calipers on it to see for sure...the top (by the head) is .9185", the bottom is .920". I can't see where .0015" is going to 'trash' a rod on a ringed engine, particularily when there wasn't ANY apparent 'pinch' at TDC when the engine was brand new. The ring is a standard pinned ring, not a Dykes ring. With this being a ringed engine I can't see where a rich run, even to the point of 4 cycling, would hurt the engine in any way even with the very slightly tapered bore. If anything I'm thinking it would help the ring seat slightly faster. A ring should have a very slight amount of 'give' in its 'fit' to the sleeve...right?...it's called 'end gap'. The part that makes no sense is the fact that the engine started to show wear on the rod (making 'clicking' noises) when it was ran at full power vs. rich to the point of 4 cycling. After the first few very rich runs it made no unusual sounds when turned over slowly. The wear/play is CLEARLY visible with the naked eye. The bushing is almost wore through on the top end of the crankpin end and the case shows evidence of 'scuffing' from the rod.

My fuel is 10% castor, 10% synthetic, 10% nitro...more than adequate lubrication for any 2 cycle model engine other than old McCoy's, Fox's, Enya's, etc.

As said, time will tell as to the outcome of this situation. I'll post results when the new rod is used...and how it fares. Honestly, I hope everything turns out OK...otherwise I'm stuck with a POS engine!

RE: Tiger Shark Engine Rods
 

Gene:

With no taper to speak of, and a standard ring, you did right.

Bill.

RE: Tiger Shark Engine Rods
 

Sounds good to me. I would have broken it in the same way-very rich.

There is no darn way connecting rods should wear out, break-in method or not. The engines have to be designed and constructed for normal usage, which includes a lot of different break-in methods. In other words, it had better be nearly bullet proof if you want to survive in this competitive atmosphere. You can run an OS ringed engine rich. The same for a Magnum. You keep up or so away like MDS.

RE: Tiger Shark Engine Rods
 

I've got a TS56 which is an ABC with ring and so far I've had no problems (although there were *big* problems with the carb and I'm awaiting a replacement.

The instructions said to run it in with the mixture set just short of 4-stroking, which is what I did.

Like yours, mine had no pinch at the top end, although it's certainly not a "free spinning" engine like my others. It seems to have quite a bit of friction in the piston/ring/liner interface but this may disappear as more hours are logged on it.

I'll keep an eye on the rod though.

RE: Tiger Shark Engine Rods
 

I have the TS 52A and it's an ABC engine that is very tight until you break it in I have over 30 flights on mine and it just gets better. My instruction book says you are supposed to run it rich for 10 minutes at a time and start leaning it out after that. Sounds to me like you are over reving it I run an 11x6 prop on mine.

RE: Tiger Shark Engine Rods
 

Rich and ABC shouldn't be used in the same sentence when speaking of breaking in a model airplane engine. It is a known fact that an initial run of this nature can cause permanent damage to the engine's piston/sleeve fit.

EVERY ABC engine I have ever broke in was with fairly hot (almost full lean) initial runs and it just kept getting better and better. EVERY ringed engine I have ever broken in was done very rich, then gradually leaned out, and they just kept getting better and better. EVERY engine I have EVER owned NEVER had a problem with a rod...at any time in its life!...except for these Tiger Shark engines.

I will be following the Tiger Shark .56A Ring directions 'to the letter' when the new rod for it comes in. Honestly, I hope it works just fine...I don't need anymore fishing weights!:eek::)

RE: Tiger Shark Engine Rods
 

Gene
I've been following this thread with some interest because you never know what you might learn from someone else's problems (when they're solved anyway :) ). Like you, I'm baffled why your rods are wearing out. Your oil content is fine, your running in methods are fine but to me it seems that for some reason the rod isn't getting lubricated properly, how else can they wear out?? I presume they have an oil pickup hole and it's drilled through the bush? Admittedly it's unlikely you've had 2 or 3 faulty rods....

As for the possibility of a tapered bore and a ring, there wouldn't want to be any pinch because that would mean the ring was being compressed and closing up the end gap...

RE: Tiger Shark Engine Rods
 

A tapered bore on a ringed engine will wear the ring lands out on the piston in no time? Though this engine only has .0015" taper? I don't know if that is enough to matter so much? But a taper would also put extra load on the piston/rod when going towards the head.

Enjoy,

Jim

RE: Tiger Shark Engine Rods
 

I have several TS engines from 46 - 75 and have never had a problem with any. I am new to RC so I follow the directions exactly for everything. It says in the instructions not to four stoke the engine, possibly the factory knows more about them than we do.

RE: Tiger Shark Engine Rods
 

I can appreciate anyone following directions, especially someone who has little or no experience. I have been enjoying this hobby since the late 60's and have used MANY different engines. As stated, I have NEVER had this 'rod' problem with ANY other engine.

I have seen directions/instructions from some engine manufacturers that tell you to do things that engine EXPERTS say NOT to do, too. That is my arguement here. OK, these folks at the factory where the TS engine were made say to not four-stroke a new ringed engine. That is somewhat contrary to what experts like Clarence Lee, Ed Moorman, William Robinson, and the late George Aldrich advise to do with a new ringed engine. Sorry, but my money goes on what the four experts say ANY day before the factory guys. The factory guys want you to buy their engines (and repair parts)...the experts want you to be able to enjoy the hobby.

RE: Tiger Shark Engine Rods
 

Gene:

I greatly appreciate the extreme compliment you've paid by lumping me with those others, I don't feel I deserve it. All I can do is speak from experience, and sometimes speculate.

Besides, do you know how to break "Expert" down? "X" is an unknown quantity, and "Spert" (spurt) is a drip under pressure.

Haw.

Bill.

RE: Tiger Shark Engine Rods
 

Gene:

Sorry. Back to your problem.

Unless TS got a batch of bad bearing material, the only thing that comes to mind is a bad crankpin. Have you checked it carefully? No axial grooves, or out of round? Either could cause repeated rod bearing failures.

Also, even with no improper machining to the surface itself, the pin could be misaligned with the main bearing surface; the pin out of parallel.

After three rods failing in a row I'd ask for a new crankshaft to go with the next new rod.

Bill.

RE: Tiger Shark Engine Rods
 

Perhaps a dumb question or two but I've noticed on many of the
bushed type connecting rods there's a hole drilled thru the connecting
rod and the bushing for lubrication. Does the TS rod have this? And
do the holes line up? (I ask this because I found one on a new engine
that did not and replaced it before running.)
Hope you solve your prob Gene.

Jerry

RE: Tiger Shark Engine Rods
 

OK, let me see if I got this right. It says very specifically in the instructions not to four stroke the engine, you decided the instructions are wrong and ignored them, and Kangke still warranties the engine? Now that’s a company who believes in customer support!!!!
With all due respect to Clarence Lee, Ed Moorman, William Robinson, and the late George Aldrich, whom I agree are some of the best, nobody can know everything about every engine. It make no difference if the engine is ringed or not, if it has cylendar taper it needs heat at the top to straighten out the bore. Steel sleeves have less taper than others because of the rate of expansion per BTU absorbed. Even the Lycoming O-320 E2A in my Piper has taper. If you follow the instructions and the part fails, it's on the factory, If you blatantly ignore them you’re on your own. I too have been flying RC since the late 60’s and control line before that. Radios, engines and the alloys they are made of, servos, glues, and even the materials the planes are made of are changing every day. As an example I just purchased a new Multiplex radio for my 35% extra, it took two hours just to get a servo to move, every one must be programmed individually.
Like you Gene, I have habits that are hard to break, they have worked for me for years, but as Bob Dillon said “the times they are a changin”

RE: Tiger Shark Engine Rods
 

I looked over the crankpin VERY carefully...it looked just fine...smooth as silk. Misalignment...hmmm...you got me guessin'. I have seen one TS .52 ABC trash two rods and the TS .56 Ring trash one rod...two different engines...the same problem...makes me wonder???

Yes, the rods do have lube holes. I got the new rod today and looked it over quite well before installation. The holes were opened up ~.005"-.010" in diameter (I VERY carefully drilled them out with a 1/16" bit) and put a chamfer on the outside of the holes to be SURE they get lube this time around. The engine is nice and smooth with wonderful compression.

I've got an APC 11x7 on it, as the directions said to use on a .56, and tomorrow it will get a run at two or three clicks off of full power, as the instructions stated. If it 'goes South' this time around I'm done with it. Hopefully it works just fine though.

RE: Tiger Shark Engine Rods
 

Gene, try using 5% or even 0% nitro in your fuel.

I'm wondering if the TS56 doesn't have a compression ratio that's better suited to very low nitro. I know that when I ran mine on 10% it once threw the prop by backfiring and if they are a low-nitro engine then it could be detonation that's causing the rods to fail.

I stick to about 5% these days and the engine is much more nicely behaved in terms of starting and running -- except that it won't transition for SHIrT due to a massively over-rich mid-range so I'm waiting for a new carby (it didn't transition on 10% fuel either).

RE: Tiger Shark Engine Rods
 

Three different rods in the same engine? Sounds to me like the cylinder bore wasn't machined perpendicular to the crankshaft bore. Wearing out the big end of a connecting rod that easily (Let alone three!) is usually the fault of too many RPM or bad engine geometry. With an 11x7 prop I don't think you have an RPM problem. If the operator was making mistakes like too lean a mixture or overheating the engine the small end of the connecting rod would go away first.

RE: Tiger Shark Engine Rods
 

ChuckN

The cylinder bore being out of angularity would have exactly the same effect on the con rod bearing as having the crank pin out of parallel with the crank shaft center line, and it would also force the rod either forward, causing excess wear on the forward side of the rod, or if off in the other direction the rod would be forced against the back plate showing excessive wear there as well as wearing the back side of the rod. I'm sure Gene would have mentioned either point of wear, if they existed.

Bill.

RE: Tiger Shark Engine Rods
 

I have a couple of engines and several friends have some engines made in China that seem to have clunky rods. I have suspected for some time now that the bushing material is a bit too soft?

I also have a "thing" about their bearings, but that's another story...[:'(]