I'm looking at purchasing a used .46 Thunder Tiger... How many gallons can go through it before it needs a rebuild?

Thanks

That depends on lots of factors. How it was broken in. How lean it
was run and what level of care did the previous owner gave it.

I have three TT46s. All of them run great. The one on my
Kaos has about 25 gallons through it and it runs as good
now as the day I bought it.

With new TT46s being as cheap as they are I really dont
think it would be cost effective to rebuild one.

Mike Hammer

Fewski,


In a thread several months ago, about the OS1.20AX, Dr. Nitro, who does engine running tests for a fuel manufacturer, listed the TT as one of the engines capable of lasting for over 100 gallons, despite having an OS-like ABC P+L...

I have my doubts about this information, after seeing some worn .46Pro engines, but I thought I would state this RCU information.

The "Search" feature seems to be impossible to use, so I cannot give you a link.

My oldest TT46Pro is now up to about 280 hours (I don't track by fuel consumption) and all it's needed during that time is a set of bearings. It's still got heaps of compression and runs within 300 rpms of a brand-new engine so I think it's got plenty of life left in it yet.

Treat them well and they sure last a *long* time.

Here it the [link=http://www.rcuniverse.com/forum/m_3402107/anchors_3410375/mpage_1/key_/anchor/tm.htm#3410375]link to Dr Nitro's post[/link].

Read post #23.

Ah, Ok. I use to have a rc truck and they only could run about 2-3 gallons max.

Sounds like the planes are nicer that way.

Thanks

Fewski,


If you break your ABC/ABN car engines [link=http://www.rcuniverse.com/forum/m_1850473/tm.htm]this way[/link], they will last a lot longer.

If you do an extra rich break-in, as the engine manufacturer and seller want you to do[>:][:'(], it will hold up for 2-3 gallons...
Parts cost more than engines...

Oh purleeeze Dar, will you stop trying to perpetuate this myth. That is absolutely, totally and completely wrong. In fact, the way you suggest doing it in your thread (500-800 below peak) is more likely to cause some damage than running it too rich. I've been there, done it and proved it on a real engine rather than just reading books and repeating what they say as can be seen in [link=http://www.rcuniverse.com/forum/m_2875125/mpage_1/key_/tm.htm]this[/link] thread.

The reason why many car-guys have problems with engines isn't because of manufacturer instructions. It's because of the relative isolation that is found in the car community vs the club atmosphere of the airplane community. Glow engines aren't something that comes naturally to many people, and making mistakes in mixture, choice of fuel, and use can greatly shorten the life of an engine. If you don't have someone there to show you the ropes, engines may not last long.

The much lower oil percentages used in buggy-fuel, combined with the extraordinary revs, are probably another couple of factors that lead to reduced engine-life as well.

Brian,


It is in your 'Blue Bird' rich break-in thread, I believe, that a couple of people wrote about their experience with car engines; saying that the 'traditional', very rich, manufacturer's recommended break-in yielded 3 gallon engines; and the much leaner, rich two-cycling break-in that I recommend produces 10-12 gallon engines...

I am just perpetuating what they had written.

I never had the opportunity to do a break-in on a car engine, or a helicopter engine (maybe you can hold it against me...).

(I tried to send you Christmas card but the Sceptre server rejected it...)

I have, or at least my son did it the way I suggested he do it. He ran it in at a full 4 stroke full throttle for a tank or so then started slowly leaning it out until it was almost peaked after a few more tanks. The fuel was true FAI so nothing like normal car fuels. After it was run in we did a slight mod to the cylinder head and now (still with the FAI fuel) it's at least as fast as other identical cars using 25% nitro. The main difference is he gets about 8:30 per tank while the others get about 6 minutes. So far he's only run about 5 litres through it but it's still as good as new.

For those into cars as well, it's a Mach .28 in a Hyper 7. Just for interest's sake, I analysed a sound track of his engine and on a very short straight it was turning 29,400.

How many recently manufactured - ie: past 5 years - R/C TT PRO46's of your own - ie: owned by and broken in from NIB by you - do you actually own and operate (fly) Downunder? "Real world" curiosity begs an answer. [:-]

---------------


Or buy a used one unless I really knew the seller well and knew that he/she was competent in handling engines.


Ed Cregger

Who the heck takes the photos used on the Tower site? Obviously someone in a professional photography studio.

I'm not sure I quite understand the relevance of your question unless you're inferring that TT PRO46's use more exotic materials than the normal run of the mill ABx's use.

"Real world" curiousity prompted me to do a hands on test of the oft repeated warning that rich running of a new ABx would ruin it completely in short order (nothing to do with "running in"). According to that warning I treated my test engine abominably for 45 minutes by running it so rich I could hold the cylinder head for several seconds before it became uncomfortable. Remember, the aim of the test was to see if it would be destroyed, not to try to run it in (I have to keep repeating that because no one seems to get the difference). At the end of the test, far from being destroyed, it showed barely any signs of being run and still had the original pinch. Repeat, still had the original pinch.

Further running more like Dar's method (although in fact a little over 1000 revs lower than peak) showed localised over heating of the piston. I very much doubt this would have affected the end result performance-wise of the engine (although by now it had lost all its pinch) and if it happened in an engine then normally no one would know about it because who else would strip an engine down after being run in to have a look?

However, now that I've seen for myself that an ABx can (not necessarily will) have some damage from being run too hot when new, I've modified my own running-in process to try to avoid any possible damage. I'm simply passing on a "real world" observation of a test that I did as carefully as possible. The choice of what any individual does is entirely up to them.

But to answer your main question, I've never owned or run any TT engine of any description. However, the ABx engines I've run in have included an Irvine 40RLS, OS 46VF, Stalker PRO61RE, Rossi 45 and of course a Bluebird NS 51. To be fair, the only one I've run in after my findings has been the 46VF, the others were run in fairly rich but in a full 2 stroke. I now begin with a 4 stroke and slowly lean out to gradually build up heat.

Thanks. I thought not. [sm=72_72.gif]

Ok fellows, I cannot help myself from jumping into this discussion. It baffles me why this engine break-in procedure keeps coming up with a new idea of re-inventing the wheel. The basis for any engineering discussion starts out from the review of engine experts, and goes from there to form some logical conclusions. Let's start out by reviewing what is in Dave Gierke's publications "Radio Control AIRPLANE ENGINE GUIDE", "2-Stroke GLOW ENGINES FOR R/C AIRCRAFT volume 1",and critique what he has to say about model engines besides what Dar has on the RCU site. Can someone explain to me why there is so much effort being exerted to see how fast a new engine can be sent into the air out of its' box? Is it the cost of fuel, or the time it takes to follow someone elses rules? I have spent a good portion of my life working on full size aircraft following manufactures instructions completely in order to make it a safe machine to be transported in. Why is it so difficult to follow manufactures instructions after purchasing a model engine? It really comes down to deciding whether you want to do it your way, and if promoting your way in print and someone ruins their engine, are you going to buy then a new engine? I sure would not get into a pond of crocodiles in suggesting someone follow my new method of breaking in an engine if I had to replace it.

I suggest that the Gierke books be read and digested while comparing what Dar says, and then argue the engineering facts about these small 2 and 4 stoke model engines. If anyone wants to page through these books with me, my e-mail address is: [email protected]

OK all-- bought a ttpro 46 about 3 - 4 years ago ran on 10% nitro for maybe 2 tanks in the bench I did add some extra castor to the mix it was 18% syn/castor mix added 2oz of castor to the gallon, Ran rich for about a half tank sort of 4 strk, then leaned it out and ran up and down on throttle shut down cooled and repeated til it held rpm at a lean setting always checked and plenty of oil coming
out the exhaust, At this point it got a davis dieselhead and has run and still running happily, this is one of my best running engines
my tt61 was never run as glow diesel from day one, and fine ditto for my Os46AX
I do not know what happen to the post on that guys ASP 91 that fried the piston tore the bushing out of the rod scored the crankpin
that most be the leanest run in history. I have one converted to diesel and it recieved the same glow run as my tt pro 46 and yes its alive and well martin

Well said Aerorich........LOL..... Read engine direction, ask for directions, pick up shoes, put the toliet seat down, ......it's a guy thing........who needs it, LOL

-----------------


How about the possibility that engines spending their entire working life in a desert-like environment may not last as long as those same engines operated in a pasture-like environment?

Happy New Year, Dar, and everyone.


Ed Cregger

Thank you very much, Ed!

I too wish you and everyone here, a happy new year.


What you say is a possibility.

However, Israel, in most parts, is not exactly a desert.
We planted it full of green...

--------------


Thank you, Dar. I wasn't aware that Israel has lots of vegetation.

My three year stay at Luke AFB in Arizona made me painfully aware of the effect of sand and grit on mechanical items. I was thinking that Israel might be similar to the area of Arizona that I was familiar with.


Ed Cregger

Ed,


Some parts of Israel, the more sparsely populated parts of the Negev, the Judea and the Arava regions, do have a New Mexico/Arizona-like climate.

The Mediterranean coastal area, the Sharon, the northern valleys and the Galillee are quite green.
Israel transported water to these areas and planted millions of pine trees.

Israel is the only country in the whole world, where the number of trees has grown between 1900 and today.
It is still growing, despite the acts of some people, who try to set this land alight...

Where we fly, the climate is a bit more Florida-like... pretty humid.

Thanks for the reply Checklst. I really find the RCU threads pertaining to engineering changes in engine designs as Ed Moorman brought out in his column in the RC Report December issue, and elsewhere, concerning the SK .90 engine being designed for low rpm's with high torque to be the most beneficial. Discussing engine break-in, and oil types to use is just hammering a subject matter that is already well established. As Ed mentioned, under propping the .90 engine can make the engine have problems at the higher rpm's. I have found my new SK .50's have a very tight pinch going through TDC, and thus used my heat gun to warm the cylinder before trying to make the first startup. While the engines became easier to hand prop after a few tanks of fuel(10% nitro & 25% all castor), they still have a tight pinch going through TDC. These engines seem to have very little break-in info in the box.

Rich S.