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Chung Yang vs. Zenoah - interesting read

23K views 13 replies 9 participants last post by  Phill 
#1 ·
Chung Yang versus Zenoah Controversy

We see much controversy on the various RC and Scooter Forums about which is best, the Chung Yang or the Komatsu Zenoah Engines. It is much like the ongoing controversies about many products like Ford/Chevrolet, Colt/Winchester, Fram Baldwin, Sony/Panasonic. We all have our favorites, and it is fun to argue which is best, but in many cases, there is a lot of mis information passed around. Here are a few facts for everyone to think about when passing judgement or making decisions to purchase.

Where are Chung Yang and Zenoah Engines Made?
Zenoah is a Japanese Company, but their engines are not neccessarily made in Japan. They are made in more than one country in Asia, most likely, not Japan. Just like Japanese Cars, and components. Many cars made in USA, and components all over the world. With the Japanese names, everyone thinks they are made in Japan….not so.
Chung Yang is a Taiwanese company. The Chung Yang RC and Scooter engines, at this time are all made under one roof in Taiwan.

Who copied who?
Did Chung Yang copy Zenoah on certain engines? Not necessarily. The engines in the 22.5cc to 30cc category have been manufactured in many countries for light industrial and lawn and garden uses all over the world. They also have been, and currently are being manufactured my many different companies. Lets just say the the broadest application may be “weed wackers”, not R. C. Cars, Boats, Planes etc. They are all clones and no one has been able to remember who made the first engines of this widely used design. They are kind of like “Small Block Chevrolets”. Used and made by many companies for many years.

Number One Seller Chung Yang or Zenoah?
Who sells more engines, Chung Yang or Zenoah? Reliable sources say that Chung Yang sells more engines “Worldwide” than Komatsu Zenoah in the single cylinder 22 to 30cc category. Chung Yang also has more variations and part numbers of these engines than any other company in this market. In this sense, Chung Yang is Number One.

About Quality
Regarding quality comparison. The manufacturing standards of Chung Yang are equal to or in some cases better than Komatsu Zenoah, according to engineering comparisons of manufacturing procedures. One example is the finishing process used on most of the cylinders. This is the process of preparing the cylinders before the chrome plating process, and finishing the chrome plating. The end result is the Chung Yang cylinders have a better finish bore and are more accurately round to promote good ring seal, life and sealing of the rings. While Zenoah uses the bore, hone, plate, final hone process to finish the cylinders, CY uses the bore, Plate, ID grind for much more consistent cylinder wall finish, and measurable cylinder size and roundness. This procedure leaves a cylinder wall finish that is more compatible to the piston rings. We have compared many CY Cylinders to Zenoah cylinders in the past few years, and will most always find the CY cylinders to have closer tolerances of roundness and taper than brand Z.

Manufacturing Processes
We see discussion on chrome plating problems on engines, but we are not getting the full story. Chrome plating of cylinders is a very old procedure for a finish bore on a 2 stroke internal combustion engine. In some applications like Motorcycles & Snowmobiles, it was discontinued back in the 1970′s. It was originally used, as it was the most economical manufacturing process to finish the bore in a cylinder. It remains in the small Chung Yang and Zenoah engines, as it is the most economical way to finish the smaller cylinders.

About Cylinder Chrome Plating Problems
The problem with chrome plated cylinders is that they do not lend them self well to modification of the ports after plating. When you grind the ports in the cylinder to try and improve the performance, you can create a problem. In the exhaust port for example one may raise or widen the exhaust port to move the powerband higher in RPM. In a chrome plated cylinder as it comes from an engine factory, the chrome in the ports extends out of the cylinder bores and into the port a little way. Porting of the cylinders, breaks this wrapping around of the chrome, and leaves a sharp blunt edge, which gives a place for the ring to grab the chrome and start it to peal from the cylinder. If it does not peel at first, it grabs small chrome particles that get spread on the cylinder walls. These small chrome particles are very abrasive, and much harder than steel or aluminum. Eventually, they will destroy the cylinder, rings and piston. This is much more likely to happen in a modified engine. If an engine builder is not experienced on the cause of these problems, they may be improperly porting the cylinders, causing premature engine failure. The engine manufacturer is not the one to blame in this case.

End User caused Engine Failure
There are other factors involved in what causes the failures of the chrome cylinders mentioned above. Oil type, mixture, fuel octane, air filter function and maintenance, and engine rebuilding, just to name a few. Mistakes are often made with either with choice of oil, or mixture ratio, whether intentional or not. An often overlooked factor is “ring life” Piston rings do not last forever. Single ring pistons have a 40% shorter ring life than 2 ring applications, but single rings are chosen for performance reasons. How often should you replace the rings? Probably in 8 hours or less of operation. Calendar time has no bearing on when engines should be rebuilt. You should determine how much fuel has been burned by keeping a log, or track the hours of operation. You can replace the piston and rings to keep the engine fresh and performing at its top level, or run them until the engine and cylinder fails, and blame the engine. The more RPM’s, the higher the compression an engine has, the shorter the ring life. To simplify it, modified engines require more frequent maintenance.

Here's a link from were i got the info from. All i've done, copy & paste: http://www.emjayltd.com/importexport/chung-yang-products/chung-yang-vs-zenoah/
 
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#3 ·
Now you tell me after I sold my CY and bought a zenoah. :(

You'd expect to see that CY is number one as they have the contract to supply engine's for HPI

as for the chroming issue, I don't on planning porting and polishing my "chev small block" so that wont really be an issue. :D

Thank's for the good reading material :D
 
#6 ·
and then again ZENOAH is supplying FG i believe.....
 
#4 ·
Nothing wrong with a Zen Ricksta. I've got 2 CY, 26cc stock & a 30.5 OBR Reed Ported. I'm looking at buying a new motor. OBR 7.5hp Full Mod Zenoah 4 Bolt 27.2cc +3mm Long Rod but still waiting to see what numbers OBR push out with there Reed Crankcase, Zen Top End, +3mm Long Rod.
 
#5 ·
im heaps happy with my cY's, first one had about 30-40 litres through it untill the crank bearings failed, engine had craploads of power till that and then i bought a F270 and have put a RCMK crank in it running a lightened flywheel and asoon as that thing spools breaks loose its just sitting on the spot wheelspinning and thats with 19/55 gearing in a baja
 
#8 ·
Informative read yes indeed.

Did anyone click on the link to see where it came from?

If so then click the about us button and viola:

http://www.emjayltd.com/

The opening line says it all-

We are the official “Master Importer” for Chung Yang RC Products from Taiwan to the USA.

Damn, i thought is was a good read until i saw that.:eek:

In saying that though, HPI must of done their homework when deciding what engine to supply with there cars.

When maintained correctly CY engines last well.
 
#9 ·
Absolutley top point, just reading the info (which was very informative) is very one sided and considering where it came from its no surprise.

Yes CY have improved their standards quite a bit latley but it will never equal that of a Zen.

The only homework HPI would have done before choosing an engine is what can they most profit from! What is the best price they can get out of the manufacturer.

ive had cy's and plenty of zens, i know the zen is by far more forgiving if it sucks in a bit of crap, my last G290 sucked in some dirt, i did 10+tanks on it before it finally died. my last cy sucked in some dirt (less than the zen in my opinion) and it didnt last 2 tanks after that. This is however before they improved the plating so might be different now.

i wouldnt put too much importance on the above info though as its just a sales pitch from a CY importer to try and sell more of their own product.
 
#10 ·
Well this is how i see it, ive had a modified Zen and modified CY's, only 1 zen but 2 cy's. 1st cy died, put the zen in, that died even quicker and went back to cy, new engine is the f270 with a rcmk crank and hell all i can see is that it absolutely screams, before and after the crank so i dunno, maybe ill keep the zen thatll come with my leopard, see how that goes n go from there...
 
#11 ·
well thats just it Mr Baja, everyone's experience is different in some way and thats to be expected. if you have a good run with CY why change? I know i wouldnt.

I do know however about a year ago CY had an issue with their plating and was causing a few top ends to die quickly. I lost allot of respect/confidence with cy at this time and switched to zen and stuck with it, now that CY seems to have addressed this problem dont be surprised if a CY ends up somewhere in my hobby collection.

i just dont agree with importers of CY's posting what they claim to be factual info when they clearly have a biased opinion, i think thats wrong.
 
#13 ·
the fulie is a CY, just with fulie stickers on it. have a look on the side of the cylinder and it will say chung yang (SP?)
 
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