HYPEREUTECTIC alloy piston technology is old news and is unrelated to crankcase design concepts. As suggested it is a viable alternative to Forged castings but there are minimal drawbacks associated with this alloy composition. What is realized is superior wear resistance, 15% less thermal expansion and increased thermal barrier properties. End result is excellent compromises/improvements for piston applications.

Crankcases manufactured of T-6061 bar stock have been subjected to T6 Heat Treatment, which is specific heat treatment process which may be applied to aluminum / silicon alloys, such as hypereutectic 390 alloys to increase the strength of the alloy by as much as 30%. In the case of T6 heat treatment, the process occurs in two phases. Not generally associated with “lost wax” or “sand casting”. I suppose cost is the primary consideration. Heat Treatment is a process in which metals are alternately heated and cooled according to a preset schedule of time and temperature to improve the characteristics of the metal.

The primary benefit I see for a machined crankcase is it strength, durability and in this case its one piece. There is no snout, backplate mount or end cap to be damaged. Lets face it a cast crankcase is structurally inferior to a T6 aluminum alloyed machined unit. Period, end of story… Drop the ZDZ case from lets say 50’ and then drop the Taurus case, undoubtedly the Taurus case will be undamaged, it maybe scratched but it will be structurally/physically sound. Of course this is my opinion…

As far as consistency of wall thickness, what’s more accurate CNC machining or investment castings???

Weight is a factor. When you compare the weight of a ZDZ-40 to that of a Taurus TS-42 guess what they’re nearly identical. So what did you gain with the oversized glow motor with ignition??? Certainly not improved performance, not unreal idle and smooth instantaneous transition, not long term durability, not user friendly accessible Carb’s, not nearly vibration free performance, nothing in the way of crash damage superiority.

For some the rear intake and rear exhaust makes sense. For others it’s a hindrance. To each his own… We can beat ourselves to death with this stuff. For a given application I would choose either engine depending on the specific needs of the model…

I have ordered a Taurus 3.2, per all the good talk about these engines.

Would you please tell me what props sizes and makes you have tried and what RPM figures you got for each? Your experience will be extremely valuable. I would like to buy a couple ahead of time and want to get a good place to start at.

Thanks for your time.

how come I can't find a used taurus anywhere? hmmmm!

If you missed it before, I'll say it again. The biggest benefit to a cast crankcase is a lower manufacturing cost if your volume of parts can pay for the dies.

The ZDZ-40 crankcase (front) sells for $27. Shocking, but true. Also a casting allows you some design freedom not allowed by machining. There are certain shapes and dimensions that cannot be machined because you simply cannot get a cutting tool in position to remove the metal. ZDZ, 3W, MacMinarelli, and Zenoah are cast. Michael, you aren't going to get rid of your 3W-150 SS and trade it in for a DA are you, just because the DA has a wrought alloy crankcase?

The Taurus crankcase could be made out of platinum plated ferro-impervium for all I care. The engine still won't run any better or longer than the inexpensive ZDZ. A crankcase is not a bank vault and does not need to survive atomic bomb blasts. It needs to keep the bearings in alignment and to keep the air out - that's all.

As for 6061-T6 aluminum alloy. They chose this alloy because it's relatively easy to machine, not because it's the highest strength aluminum alloy available (and it isn't even close). Gee, they were lowering their production costs, what a surprise.

just an added comment about 6061 -I used it to make parts for my modified Austin Healey --40 years ago -I made wheel hub adapters - brackets etc.. Now days, I regularly replace 6061 landing gear with 7075 T6 or 2024 T3.
6061 -commonly used for machining - will bend -will distort - over long intervals -that is - a box made from it - smacked on a corner will "rack" or shift into a new shape.
It is good stuff - but it's bending resistance is not all that high- I did not invent the stuff - I just use it.
If you want real stiffness-go to the aircraft grades - but for the case on the hand done engines - I would use it-but I expect it to do only what it can -
Castings will typically fracture if really smacked - but they also will bend - depends on the metal guy who decides what he really wants to pour -or inject and or forge -etc.,
Either material is plenty good enough for our use-but one is not "demonstrably better" than the other in all characteristics.
Production costs are the single biggest reason for choices here.
I know I dove my 80 ZDZinto the ground vertically from about 500 ft -clear up to the firewall!
The casting did not bend or break-
Perhaps a fluke--
the bearings again got flat spots - I would not expect then to survive -based on years of fixing others crashed engines of may types.

Diablo wrote:

>>It needs to keep the bearings in alignment and to keep the air out - that's all.

I'd have to say that seems like a vast oversimplification of the role the design of the crankcase and crank play in the reliability, smoothness and yes, power the engine produces.

I see that you agree that ZDZ crankcase manufacturing processes were chosen to cut cost for mass production; exactly what I have suggested from the beginning....and I will restate my assertions that Taurus is not bound by this restriction. Any time an engine, or whatever other type of product, starts being primarily driven by manufacturing cost considerations, either the design, or implementation is going to suffer.

>>The engine still won't run any better or longer than the inexpensive ZDZ.

I'm confused by this statement? It just doesn't seem to make any sense to me. Whether it is Taurus vs. ZDZ, or Mercedes vs. Volkswagen, how the product is designed and built, and what materials are used, certainly will make a difference on how long it lasts and how well it runs. All engines are not created equal.

Bill

Hey if ya got the bucks get the most expensive. But when it crashes you are going to be out a lot more $$$ Also most of these engines will never wear out, but will die in a bad crash. Thats my 2 cents Captin John

Hi Captin John,

>>Also most of these engines will never wear out, but will die in a bad crash.

Thanks for throwing a bucket of cold water on all this!

Bill

Hope you don't mind. I'm new here. And I just finished reading I think 70 posts.
I have to tell you the smilies I saw didn't equal the laughing I've done while reading.
a couple of guys are talking about performance and precision machining. one even likens his new engine to a swiss watch.
And the you have one guy who likes overgrown glowplug designed gassers. reminds me of the history channel and the extinction of dinosaurs. man how archaic.
And then there is one dude that really is sharp with the swiss watch being broken. Probably can't tell time anyway.
A couple of you really sound as though you have put a lot of time and effort into what makes a "good" engine. And you should be applauded for it. As for the snipers and cavemen Oh well no matter what anyone has to say about anything there always will be someone that knows more. And be careful what you wish for you might get it to regret. I just might come back for a good laugh again sometime.

Hi Dick,

>>Manufacturing costs are paramount in any manufactured product!
Steady boy!
ALL engines are bound by costs!

Jeez Dick, you take my comments and extrapolate to the extreme. Of course this is the case, but what my point was that all manufacturers are not bound by the SAME cost constraints and therefore the products will be of different quality....such as the Mercedes vs. VW comparison.

>>Sometimes the high bucks stuff is the best - sometimes not.

We absolutely agree. Wow.

Dick, you really should try a Taurus out instead of blindly saying it can't be better because it dosen't have rotary valve induction. The data seems to point to another conclusion. If you want to state that you don't want one because it doesn't have rear induction or rear exhaust, there's no argument, but all the rest of your arguments are moot unless you try the Taurus out, or at least look at one, before concluding it isn't better.

We can obviously beat this subject to death(oh, that's right, we already have. Sorry to be so boring guys) and neither one of us is going to change our tune....but I sure would like your opinion on the Taurus after running one, because I sincerely think you would be objective in your testing....and then become a vocal advocate for Taurus...even if you don't run one yourself because of the rear end stuff.

Bill

Well -perhaps -some day --I will see one -
right now -I have only 24 hrs in each day and all my time for engine stuff is full.
FWIW- we are doing comparison tests on various exhaust setups on rotary valve and reed valve engines - (has nothing to do with piston port stuff tho ) just trying to do what is required at the moment to help a friend.
I will not be putting the results here - So far the info we have would drive some people crazy.
You would probably love these tests.

Boy! I sure enjoyed stalspins comments that this has made him laugh!
I wish he would have taken a moment tho to share his background and info on engines.
It is either vast or half of that.

Well guys,since this is the "last page "it will be interesting to see who gets the last word....hmmmm,let's see,my money is on.....

Well, we all agree on one thing, a cast crankcase is cheaper to produce. So they cost less, when its time replace a damaged unit this is a plus. That said there inferior structurally… Chances of having to replace one are far greater than with a Taurus machined case. And yes, there are benefits associated with "design" freedom. It has been proven time and time again that there are decided advantages in varying crankcase/block designs over the years, there is no doubt here…

I would not consider replacing the three 3W-150SS lightweight engines I have in lieu of a cast verses machined crankcase. However I feel the machined cases are far superior… I have a DA-150 and DA100, in this instance the case was not the deciding factor…

We don’t really know thus far what the life expectancy is barring an accident on either engine, makes sense from and engineering and metallurgy view that a precision machined, hand fitted engine of superior design and components will last longer than the latter. Performance should also be better, just makes sense. Mercedes last much longer the VW’s….

T6-6061 aluminum alloy is used because it is more than adequate for the job, availability, cost and tooling characteristics. Without doubt there are many superior alloy compositions available. T6 is substantially better than the cast alloy used in manufacturing ZDZ cases; additionally it’s heat-treated.

Used Taurus Engines are not available because they have only been available to the public for three years. They’re not mass-produced and or mass advertised. Each engine is built to order hand fitted, assembled and test run, individually. Those that own them are keeping them…

If we run out of pages on this thread we can start another thread, lets see what we will call it??? Taurus, or the rest???
Cheaper works? Rear intake really sucks? Side intake, why? Rear exhaust , yeah. Or how about What I own has to be the best because I say so...

I am having fun with this thread, thats what it's all about.. Right?
There's nothing like a motor-head/ego-strokeing... This has got to be male bonding at it's best....

Ya'll have fun now, Tell next time...

Michael

It has been fun - but remember - a cast crankcase is MORE expensive to produce - you have to design and tool for it - BIG $$$$$

Bar stock is good -but how is it better than a cast alloy of which you dont know the composition?
That's a puzzler.
You obviously like your little engine
It would be awful to have paid good money - then not like it.

Dick makes a good point("your little engine").Michael & Bill are talking about the Taurus 2.6...that's ONE engine out of a whole line up.Yeah,the 2.7 has some impressive numbers & I'm sure it's a great engine...but what about the others? If all of these engines are state of the art ,superior design, yada,yada,yada,one would think that word would have gotten around by now(3 years) & some of the big names would using one of the big Taurus twins as oposed to DA ,3W & BME.Seems to me that there is only a very small number of people using the small Taurus engines.The ZDZ's have been out about 3 years(?) & these things are hottest selling engines on the market.Try getting an 80 single now.

If the Taurus was really built without regard to cost and with only performance as the goal, then it certainly would not be using a cylinder and piston from a concrete saw. They would have designed their own cylinder, and it wouldn't be piston ported. You really expect anyone to believe that Makita happened to develop the best cylinder for an airplane engine propped to 6500-7000 rpm when they were manufacturing concrete saw engines? Could it be that Taurus just selected an inexpensive and durable cylinder/piston from an industrial engine because it would keep the cost of their engine low? Kind of like Brison and Fox?

I hope I don't get the last word here....so the BS flows like wine.


Stalspin wouldn't be Mr. Taurus (L'il Bull) ....would he? The prose looks familiar.

No tellin - people who post goofy stuff - then don't reveal themselves - well - they are either using their mom's computor -without her knowledge - or part of the "one handed typing club" if you know what I mean--

Go back to post #83. Must be I did not get enough water on. HA!!!!!!!!!!!! Captin John

First, I think Michael is speaking from direct experience with the 2.6, 3.2 and 3.7, but he'll have to give you the facts on that. Yes, my only direct experience is with the 2.6.

EJB:

As far as the "name" pilots using them, that typically takes an effort by the factory to support(sponsor) a "name" pilot.....and guess what, that takes marketing dollars. Typically this takes place at a high-level, meaning a 150cc motor. I seem to recollect some talk about DA giving away their 150's when they came out to the top pilots at the TOC. That's how they got established. It wasn't cheap. The hype from promoting these motors trickles down to the smaller motors in the lineup. How many "name" pilots do you see flying ZDZ40's, BME 50's, or 3W-50's. Whether right or wrong, Taurus has chosen not spent money on this marketing approach....and they might not have the right large motor to do it. I admittedly have no direct knowledge of their larger motors.

ZDZ has sold more engines, no doubt and for good reason. Is it because they're the best? That's open for debate(that's pretty obvious, huh?). Let's first talk about marketing and advertising dollars? ZDZ runs ads and actively promotes their products through many vehicles. Taurus does not. They depend on word of mouth and so far it's worked well enough to keep their products backlogged typically at a 3 week wait. That's probably not a big number, but it's significant. Why? Let's consider mass-market vs. low production, basically hand-made products. These types of products are not designed to serve the mass market and probably never will. They're not built for everyone, they're built for the discriminating few that can see beyond the marketing hype and buy the best product despite the lack of market visibility. There are many examples of this approach in just about all product categories. Taurus has not spent money on marketing through the normal vehicles because if they did, they couldn't keep their production standards at the same level and serve a mass-market.

The ZDZ and Taurus are two totally different types of products and they both serve the R/C market in different ways. Some people(more) will buy ZDZ's and some will buy Taurus'(fewer), and it has nothing to do with which motor is best, it has strictly to do with marketing. The number of units sold definitely does not necessarily have anything to do with it being the best product on the market. Have you guys every heard of Microsoft?

Diablo:

And now let's try to address Diablo's arguments. First, I for one never said the Taurus was built without regard for cost. In fact I admitted cost has to be a factor in just about any engine produced. What I said was that Taurus has different cost constraints than ZDZ. Diablo likes to call the Taurus a concrete saw motor because it happens to use a cylinder and piston from a company(Mahle) that's known for making tons of high-quality cylinders and pistons(among other things) for a wide variety of applications, including chainsaws. Would the Taurus be better with a custom built cylinder and piston? Yes, it probably would, and it would also cost another $100. But even Taurus has to make cost/performance decisions, and if they took that route they would be making their potential market even smaller, probably too small to stay in business.

So I ask you, who cares where the cylinder and piston came from? Isn't the way the engine performs what you should be caring about? Diablo, you seem to be totally discounting the facts about the performance of the Taurus and are only focused on where the cylinder came from. Isn't what you should care about is the quality of manufacture, smoothness, ease of starting, warranty(3 year), and of course power output. My opinion, based on facts that are available to all of us, is that in all of these categories, the Taurus 2.6 and 3.2 are superior to the ZDZ, BME, 3W, and Brison and all the other small engines currently available. Yes, I'm only talking about the 2.6 and 3.2. I do not have facts on Taurus's bigger motors, but the one thing I do know is they'll have the same quality. The only category the Taurus doesn't win in is price. For me, it is well worth the extra $100 over the ZDZ for the incredible craftsmanship and superior performance of the Taurus engines. ....then of course there's Dick Hanson, and he's right, if you demand your motors have rotary valves, and rear exhausts then the Taurus is not the engine for you.

captnjohn:

You're going to need a fire truck to put this puppy out...but that's ok, it's too much fun to let it die quietly.

Bill

Hi Bill,
Nope, I don't buy the marketing argument.I think word of mouth & all the info(& BS) on the net supersedes the hype & advertisments.When the RCShowcase ads first came out I was not impressed...paid no attention...yeah,they looked like overgrown glow engines.But it didn't take long for the word to get out on RCO & other forums as to how great these engines are.
Yeah,like I said before the 2.6 has some impressive numbers.But the Taurus 3.2..superior?...I don't think so.Two examples on rcfaq with a Menz 20x10 @ 7200 & a Menz 21x10 @ 6900.That ain't nothin' to yell about.My Brison 3.2 will turn the 21x10 @ 7200. The Taurus might be smoother but I don't care,I'll take the power.If the big Taurus twins were equal or superior to the others,guys would be using them...we would know..hype or not.

Hi EJB,

FYI, marketing is real. It runs this country. Good marketing can kill a good product any day of the week. It's sad, but true.

>>yeah,they looked like overgrown glow engines.

They are. Tell me what in their design isn't like a small glow engine...and don't say the ignition.

>>But it didn't take long for the word to get out on RCO & other forums as to how great these engines are.

Did it every occur to you that that is what you're seeing happening right now before your very eyes with the Taurus. Most people only have 20-20 hindsight, while few have the vision to see changes while they are happening.

>>Two examples on rcfaq with a Menz 20x10 @ 7200 & a Menz 21x10 @ 6900.That ain't nothin' to yell about.My Brison 3.2 will turn the 21x10 @ 7200.

By your own admission you are quoting a very small sampling of data on rcfaq.com, and the reliability of the sources is not even known. I will take the liberty here of posting numbers from Michael Glavin that he has posted before. These numbers are the result of being tested by the same person, on the same day, with the same props, and with multiple examples of each motor:

Menz S 21/10:
Taurus 2.6 6900, Taurus 3.2 7400, Brison 3.2 6900
Menz S 22/10:
Taurus 2.6 6300, Taurus 3.2 7000, Brison 6300
Mejzlik 22/8:
Taurus 2.6 7200 Taurus 3.2 7900, Brison 3.2 7200
Mejzlik 22/10:
Taurus 2.6 unknown, Taurus 3.2 7200, Brison 6800
Mejzlik 20/10
Taurus 2.6 8200

I have seen some better numbers on the Brison. The one you quoted is right up there with the best I've heard, but even that doesn't match up to Michael's Taurus 3.2's.

I don't think you own a ZDZ, do you, and I assume you've never owned a Taurus, or probably ever seen one. I again ask you, what makes you so certain it isn't a superior motor, when you have no hands-on experience with it. I have personal experience with the ZDZ40, Brison 2.4 and 3.2, Taurus 2.6, BME 44(plus Zenoah, Quadra(40's - 100) and some other less exotic brands) in the small engine ranks and DA and 3W in 150cc engines. I'm not blindly singing the praises of the Taurus, I'm doing it relative to my experiences with these other motors. If you want to equate the small Taurus' to the quality of another motor, I would put it at a least the same quality as the DA150.

>>If the big Taurus twins were equal or superior to the others,guys would be using them...we would know..hype or not.

Maybe, maybe not, but I have no idea what the reality is there, because as I have said, I have no experience with them and therefore won't speculate.

Bill

Earlier there was alot said about how these engines would hold up in a crash and we were subjected to alot of hype about alloys and casting, etc. But the Taurus engine mount is't given to you for nothing. When I spoke with the Taurus rep he was glowing about how the mount is designed to give in a crash so the major components of the engine survive. Now call me stupid if you will but don't you think the engine EMBEDDED in the firewall will sustain more damage than the engine that's designed to breakaway. I don't think I got the last word on this thread but the the Taurus engine was designed to survive. Pete

The problem boils down to this. There simply is not enough data out there to demonstrate statistically that the Taurus is superior to a Brison in power. I have tached a Brison 3.2 that gives identical performance to Michael Glavin's best numbers for the Taurus 3.2 with a Mejzlik 22x10 prop. Until Taurus engines get into the hands of more modelers, there is no way to prove that it is better (on average). So far, only a very few of their engines are out there. EJB and I have seen, tested, tached and flown quite a few of the ZDZ motors. The 40 single, 80 twin and 80 single as well as the Brison 3.2 and 2.4, 3W-100 and 3W-80. We've been voting with our wallets for the ZDZ.

I do hope more of you guys buy the Taurus. That way, I'll get to see how they really measure up without having to invest my money. Personally, I'd much rather have the ZDZ-80 single than a Taurus 2.6.......and they cost about the same!