fizzwater2

My Feedback: (61)

I was cruising Tower Hobbies the other day, looking for something to use a "welcome back" coupon code on, and happened to notice that they're advertising the TTpro .40 as an "ABN" engine now.

Were they originally ABC, before Tower started being the distributor / owner / whatever they are? I don't remember for sure, but I thought the old engine box said ABC on it.

vicman

My Feedback: (10)

All my boxes say ABC. Both the old blue and the new red ones for engine 9140. Hmmmm.

HighPlains

My Feedback: (1)

Another reason to just fly Jett's in 426

The bearings don't blow

The muffler is not a piece of crap falling apart

The carb does not fall apart

he chromes the sleeves.

And it's made here.

GSJames

What are the relative merits of chrome vs nickel? I suspect that nickel is CHEAPER for the manufacturer but that it has reduced wear and probably a higher friction coefficient. Since the sleeve is brass with only a plating of the other metal, I imagine that the coefficient of thermal expansion would not be affected. Bob, what's your take???

Bill Vargas

My Feedback: (5)

Here' an idea,,, get Dub to make a 424 engine,,, so it won't do the following,,,

The bearings don't blow

The muffler is not a piece of crap falling apart

The carb does not fall apart

he chromes the sleeves.

And it's made here, And maybe another TRUE American will have a job



BV

vicman

My Feedback: (10)

$80 is hard to beat even when you add a $18 bearing.

fizzwater2

My Feedback: (61)

Except they're 99 bucks now..

BarryReade

My Feedback: (1)

You also have to remember that Tower or their parent corp bought out Thunder Tiger.  The are going to mess with it till they ruin it.  I think Bill has the correct idea of getting Dub Jett to make a 424 engine.  He probably has been avoiding having a large production run as he seems to like to custom build all of his motors.

HighPlains

My Feedback: (1)

So how many TT40's does the average 424 racer own? Two or three?

BarryReade

My Feedback: (1)

I would say more but, maybe I am not average.  I have 8 that I know of and some are torn apart and have been cannibalized to keep others going.  I haven't been flying 424 but have three racers on the boards, so to speak, and plan on moving up from C40 next year.

djlyon

The last 2 TT40 pros I bought was probably more than 2 years ago. I bought them well before Tower took over. They are both ABNs. They do not say ABC on the box and the instructions point out that they use ABN construction.

Denis

vicman

My Feedback: (10)

I have 6 or eight ranging from NIB to junkyard dogs.

My NIB ones are two years old and say ABC on the box. Dennis do yours have the same part number?

djlyon

Hi Vicman
This is all very interesting. Yes the part # are all the same as are the part# for the piston cylinder assemblies. On my older engines the box's , which I still have, say ABC but the instructions for each engine which I still have say the material used is ABN!!! So I think going back to at least 2005 these engines have been using ABN cylinders not ABC as stated on the box. This is like OS was doing, calling them ABC when they were really ABN. I would never even have looked at this except for Fizz bring it up

Denis

fizzwater2

My Feedback: (61)

I have one left NIB that I found in a hobby store in Arizona once when I was there - the store was having some sort of special sale, don't know if it was going out of business or what - but they only wanted 65 bucks for it, so I couldn't pass it up.

I used to have 4 - counting this one that's never been run. Now I have three, plus a spare muffler & carb.. the rear bearing let go on my best one, trashed the piston, sleeve, and the head isn't too great, either. The case and crank MIGHT be useful, but it was cheaper to buy the 65 dollar whole engine.

I'll have to admit, I never looked at the instructions that came with them. Maybe they've been ABN forever, and tower is finally calling them correctly..

daven

My Feedback: (1)

Dubb could make a 424 motor, but it would be $200 plus...

fizzwater2

My Feedback: (61)

but, the bearings wouldn't fall apart, the muffler wouldn't fall apart, the liner wouldn't peel, etc, etc, etc...

daven

My Feedback: (1)

I guess I thought the cost of the TT was one of the big attractions?

Otherwise, just run the 426 motor on the long course with a low pitched prop to keep the speed down (10x6 maybe).... Or a simple thing like a detuned muffler for 424.

Still going to be close to $250 at the end of the day, and if you want a carb vs. Venturi, another $35, etc..

Lewis S.

My Feedback: (229)

Hi Guys,
Saw the posting; want to clear something up... I did all of the original evaluation of the TT-40 Pro engines for Nepro when the K&B 40 was going away back in 2003. They were ABN then and ABN now. They were never ABC. The big difference was they were double nickel plated VS and single layer OS used at that time. The Thunder Tiger liner never showed signs of peeling and as far as wear and life span, nickel will hold up just as well as chrome with the fuel that we run and at rpm's in 424. Overall this has been the best engine to ever become available for the sport flyer who wanted to race. For a mass produced engine, they are very consistent, hold up well and are readily available. Do they have some short comings, sure, what engine doesn't, but they are easy work arounds. Heck when they had the K&B 4011 for Nepro 424, you had to buy 6 to get one good one, or pay Clarence Lee, Fran Mitchell or myself to build you one. Even at that it took hours to carefully break it in, and one lean run to kill it.

Lewis

fizzwater2

My Feedback: (61)

I honestly think the TTpro 40 is a great deal for the money, even at 99 bucks. Yes, I have more than one, but I typically have more than one airplane set up at a time, too. I do NOT spend a lot of time testing, comparing, or running engines. I just don't see that much difference between them. The ONLY trouble I ever had was that steel caged bearing letting go at the wrong time.

You don't even need 18 dollar bearings.. I have used stainless rear bearings from RC-bearings, something like 6 or 7 bucks, and they've run just fine. Wish I would have changed that one BEFORE it let go, that's about my only recommendation for the TTPro. Take a look at that rear bearing, and if it's the steel cage type, change it sooner rather than later.

And yes, the price of the engine is one of the things that helps attract new folks that have not yet been bitten by the race bug. That, and the fact that it has a throttle, if they decide NOT to race, they always have a really nice sport engine that can be used somewhere. I know around here (Kansas City) that there are several folks getting their feet wet in 424 that would NOT have started had the engine of choice been a 200-250 dollar item.

But - once they get their feet wet and find out how much fun you can have racing, several have gone on to own Jetts & Nelsons. Still, our best turnouts here are the 424 races.

oskartek

Chrome is very hard which gives it very good wear characteristics. This hardness also results in a very low coefficient of drag. This keep the heat build up down as the parts rub against each other.

In the plating process it develops micro-cracks. These cracks offer a means to relive thermal stress (both in the plating tank and in service). This result in good bond performance over the life of the plating. In our application it allows for lubrication to collect. This collected lubrication can weep out of these micro-cracks and offer some “last chance lubrication” should the equipment be subjected to lubrication failure (lean runs).


The disadvantages of chrome are mostly in the manufacturing process.

These disadvantages are:
Hexavalent chromo sulfuric acid is very toxic. This means that there are a lot of costs associated with it to meet environmental concerns.

It is what is known as a very inefficient process. This means that the chromic solution is susceptible to contamination.

It does not plate evenly. This means that to control dimensions it must be machined (ground). This lack of precise plating thickness control means that part features that don’t need to be plated must be masked to maintain their dimension.

Unlike chrome electorless-nickel plating is a fantastic plating process.

A major benefit to elctorless nickel is that it has a very low environmental impact compared to chrome.

Electroless nickel plating is what is known as a very efficient process. This is to say contaminates (within reason) do not affect the bond strength.

Electorless nickel it is very easy to control plating thickness. This means that there is no need for a second machining operation to reach the desired bore size. It is vary easy to plate to size accurate to less than 0.002mm (.0001 inches) thick. It also means that the whole cylinder can be plated removing the need and cost of masking.

The dis-advantage with Electroless nickel plating are:

It is very soft compared to chrome plating when it if first plated. It has a high coefficient of drag this results in its tendency to gall. This galling will produce heat that can cause the plating to fail debond (peel).


Happy flying, Oscar

jaka

Hi!
I think all Chinese /Taivanese .40 engines use ABN technology today. The only engines with chrome plated cylinder today are MVVS and Rossi. And the MVVS .40 is no longer available!

By the way! Have you tested the Kyosho GX.40 ??? Same as the ASP.40 but with a little larger silencer exhaust opening.
I have used this engine now for two years in Q-500 pylon here in Sweden and I'm impressed with how it works.
It turns a 10x6 (yes, we are only allowed to use 10x6 props in Q-500) RAM at around 14000rpm on 80/20 fuel. Same as the TT.40 SE.
I have three Kyosho GX.40 and they all turn the same rpm.
I was out today (9 degree celsius and cloudy, deck hight about 100-150m) and got 14100 rpm on the tach using a Nova Rossi 4A plug, The 0,20mm head shim removed and using 10x6 RAM prop. Rear ball bearing replaced with a WIB C4, 28x15x7mm bearing (same size as in every other .40 engine) and silencer modified with three metalscrews to hold up.