mglavin

My Feedback: (31)

Taurus Engines are not chainsaw engines converted to aero use...
There are several chainsaw retrofit/conversions out there, BME 44's and 50's, Sach's, Husky's and many other's over the years actually are/were built from chainsaw short-blocks and converted to aero use...

Taurus Engines are built with a propitiatory lower-end, CNC machined from aluminum, clearenced and custom hand fit on an individual basis. A forged, double cheek, single throw, fully supported, fully counter-balanced crankshaft is supported with precision pre-loaded bearings at either end of the shaft. These are not to be compared to cantilever designs which are prevalent in most other engines. Carbs, ignition systems, piston assemblies, rods, bearings, high temp oil seals and all other components are selected to match the need and expectation's of Taurus Engines...

Mahle, a major international industrial and automotive engine parts and power module manufactuerer provides the cylinder jug assemblies to Taurus and many other engine manufacture's. Specifically Makita/Sachs/Huskavarna/Dolmar and many others. Many well known automotive engines, even high performance racing engine components are also provided by this industry giant.

The simple fact that the cylinder's utilized by other engine manufacturer's fro chainsaw's and other industrial applications does not relegate these engines to have been bore of chain saw's... There are considerable differences.

Antique

My Feedback: (4)

Hey Taurus lovers....

Why would a manufacturer PRE LOAD a ball bearing?? Pre loading is for tapered roller bearings...They want drag ?? Our race engines turn more rpm with nice loose bearings..
Does Taurus manufacture the whole crank and rod assembly ?? Or is it a modified Sachs or Husky assembly ?? Balanced by Taurus?? What percentage ??
Is the carb a Walbro WT76A as also used by Sachs on a 3.2 chainsaw ?? Modified ?? Different size holes ??
Is the cylinder made by Mahle to Taurus specs FOR Taurus or is it the same cylinder, machined on the outside diameter, used by the Sachs or Husky chainsaw ?? Does Taurus do any porting ??How about the piston ?? Made for Taurus ?? Modified by Taurus ??
Does C&H make a special ignition just for Taurus ??
What class "precision" ball bearing?? Is there a "non precision" ball bearing ??
Hey Serge .."Tear your arm?"
Give me a break..It's a 3.2, maybe 30 lbs trust at the most....If you want to feel thrust you should hang on to a 289cc Herbrandson 34 hp race engine..
Agreed,the case and hub are very well machined..
I have not seen the inside of a Taurus to verify any of this for myself...
Cantilevers are bad ?? Ever look at a Dubb Jett, world champion race engine ?? A new DA 50 ?CANTILEVER ..Cantilevers got a bad name from A&M..The concept itself is good, the hub is supported by a ball bearing directly behind the hub, not farther away as in most 2 bearing(one front, one rear) designs..Only way a non cantilever can be as rigid as a cantilever is to have TWO bearings on the front and one on the rear...3W, DA, Preciision Eagle, etc....
I can't think of any manufacturer currently using a chainsaw crankcase, other than the Lee Sachs engines sold by B&B..
Although the magnesium alloy chainsaw cases are lighter than machined aluminum cases, just not as pretty...
Anyone who could make an engine that looks like the Taurus would have no trouble making a manifold to rotate the carb...A few minutes on a CNC mill with less than a buck's worth of G10...

If the cylinder has ZN44 cast into the base (44 mm bore) it was originally made for, and still used by, the Sachs/Makita chainsaw....

AJF--2

My Feedback: (119)

Ralph, I certainly do not argue with you. You certainly know what you are talking about and most of it is way over my head. Here is what I do know. I have had a ton of engines over the years, and of them all I love the Taurus the most for many reasons. I also love 3W, BME, Zenoah, ZDZ etc.. but my favorite is Taurus. I do not understand much of the tech stuff , but 2 years ago I was running a G62 on a 96" Staudacher turning a 22/8 7200 RPM. Last week my Taurus 42 turned a 22/8 (same Zinger Pro) 6900RPM. But what I love most of all is being able to call Bill O and talk to the man that turns the bolts on my engine--knowing I can trust him and I am sure he knows what he is talking about. I met Bill at Joe Nall last year. He is far more concerned with my being happy with his engines than he is growing into a big company. That impresses me. You can't buy that from Horizion (I tried) of any other company. With your knowledge and experience, this may not mean much to you, but to us fuel and fly fellas I take great comfort in that. EXAMPLES--1 when my ignition went out on my 3.2, there was no mailing the engine and waiting. thru email Bill figured out the proplem and I was flying in 4 business days. When I got the new ignition, there was a note to mail him the bad one "first chance you get". EXAMPLE 2-- I bought my TS42 from Bill Pryor and it came with an extra prop shaft. I needed it changed and could not do it myself. I mailed the engine to Bill who changed it , checked it and sent it back to me. He only wanted some money to cover shipping-What I included with the engine was what it cost me to ship it to him. When he mailed it back he sent it thru a different carrier and it was more. "Don't worry about it" he says-and remember I did not buy the engine new from him. Simply put- I love dealing with companies like that-- I am also sure that the fact that Taurus lovers go on and on and if you are not one, it grates on your nerves a bit. It did mine too, until I bought one.

Antique

My Feedback: (4)

No argu ment from me...The reason for the long post relates to the advertising of the engine, specifically the part about the crank and the cylinder..Let's call a spade a spade...A chainsaw cylinder is just that, originally made for a chainsaw...Unless the internal porting is changed it's still a chainsaw cylinder...Same with the crank..The description of the crank would describe almost any chainsaw out there, Stihl, Sachs, Homelite, Husky, etc....
Unless the crank is made just for the engine and/or balanced differently, it's still a chainsaw crank...
A few crank facts....A&M was making 2.0, 3.2, and 4.2 engines, using their own copy of the Sachs chainsaw case..The copy was exact, an A&M front half would bolt up to a Sachs rear half..A&M originally used the Sachs crank..It was probably more cost effective to make their own, so they copied (exactly)the dimensions of the Sachs. Unfortunately they got the balance factor wrong and used pressed in roller bearings on both ends of the rod..Loose and shaky, especially the 5.8 .The smallest engines were OK, but as the size increased the longevity went away..A&M Cranks were softer than the Sachs cranks, so they bent easier in a crash..Then came the cantilever..Same metallurgy, soft and loose...The cantilever crank on the 4.2 MK2 was not a bad design, but in practice the soft hardware store washer that took up the thrust when the prop was tightened would deform and lock the crank in the case..
Fixed a few of those with a hardened steel washer and proper clearance....Cantilever cranks got a bad name.
The other cranks are pressed together, one half with a taper on the end for the flywheel, the other end straight with a left hand thread for the clutch...Most RC engines use the tapered end for the prop hub, and cut off the other end flush with the case and use a seal, or flush with the bearing and make the rear case solid with no seal...Maybe a little less friction..Some cranks are two piece and some are three..The two piece cranks are forged and ground with the front shaft, the web, and the crank pin being one piece, pushed onto the rear half with the taper for the flywheel. Very strong and rigid, only one pressed joint..
Many others are three pieces, front and rear pressed onto the crank pin..Not quite as rigid...Most 3.2 engines use the tapered end for the hub..Unfortunately the tapered end is ground smaller than the ID of the bearing, making it less rigid..The other end is the same diameter all the way to the end with the left hand thread..Stronger, but no taper..Best way to use this crank is to have the end ground to a taper, and a 3/8 diameter for a nut..This way the strongest end of the crank is used..Works great, Been there..
A well designed cantilever crank is very rigid. The front bearing is directly behind the hub, no excess length to bend...
The other style crank can be as rigid as the cantilever if there are two bearings on the front and one on the rear. Zenoah twin, G23, and Precision Eagle are two that use this style..
A two or three piece crank with only one bearing in front can't be as rigid as one with two..The crank will wiggle slightly in the center, on the press fit, because a single front bearing with a hub 1 or 2 inches away can't control the flex in the shaft..
Don't know if Taurus engines have one or two bearings on the front, or if they make and balance their own crank...
These statements are from 15 years of personal observation, take 'em any way you want....

serge1

My Feedback: (1)

You're right AJF... Bob always reply to my email the same day if not in the next hour. Try to get that from other companies....Sorry but I am completely sold to taurus.

Bob Pastorello

My Feedback: (198)

we KNOW you meant "Bill".... I just happen to respond to stuff cause I don't have a life, owned some Taurus motors, and like to help if I can....

Bill DOES always provide very responsive communications, whether by phone or email.

serge1

My Feedback: (1)

Ah ah ah..Sory Bob. Yes I mean Bill...However you're so helpfull
also...You helped me to make my journey in the gasser world a
lot more easyer..

Thanks again.

Serge