new cy 4 bolt 270 info!

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tmrperformance

tmrperformance

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F-270 Four Bolt
New Chung Yang F-270 4 Bolt Base Engine Specs


now i know many are going to reply about plating issues and all the common cy issues many have faced in the passed, however i have been working with the US rep for some time now to get things straight so that we can use these engines with out the reliability factor being in the toilet.
the new design is very promising i will provide a link to where u can view pictures of the very impressive 4 bolt 230 as well. no 270 pictures are available as of yet, but the internals do look the same. there are many positive changes on this new cy, among them is better plating which appears to be excellent! the new cy case will accept a zen top end with the simple change from the torx bolts supplied to a set of allen head bolts.
the dome has a flat squish area, the intake side transfers are higher than the opposing transfers, the int and e. ports are 180 degrees of each other, the piston ring locating pin has been centered on the intake side of the piston, the exhaust port has been moved up, the piston skirt has been modified with a larger cut out in the skirts, along with many other high performance geared improvements! the engine is a true 26.9cc, it has a 35mm bore and 28mm stroke, a combo that always makes great power! enjoy the info, soon more to come!


and the link!

http://www.emjayltd.com/reference-2/chung-yang-f-230-disassembly/


27cc, 35mmx28mm Bore & Stroke

Made to compete with the Komatsu/ Zenoahs in that size category.

F 270 New Version Engine:
1) 4-Bolts Crankcase
2) 4-Bolts Cylinder
3) New Piston
4) Powerful Clutch Spring
5) Lighter Clutch Shoes
6) Big Muffler
7) Star shape bolts

F – 270 Specification
Model (2 Cycle Gasoline Engine) F-270
Cooling Type Air Cooled
Displacement cc 27cc
Bore mm 35 x 28mm Stroke
Max. Power PS / rpm Unknown
Max. Torque kg-m Unknown
Min. Fuel Consumption g/PS . H 500 Two Bolt 23 550
Fuel Recommend Pre-mixed (25 Gasoline : 1 Engine Oil)
Oil Recommend FC grade 2 Cycle engine oil
Ignition Type TDI
Carburetor WT-668
Spark Plug Std. NGK: CMR7H
Starter Recoil
In rpm Unknown
Clutch
Stall rpm 10,500 Two Bolt 23 8000
Length mm 158 Two Bolt 23 168
Overall Size Width mm 240 Two Bolt 23 150
Height 199 Two Bolt 23 197
Weight kg. 2.24 Two Bolt 23 2.56
 
Nice...about time CY made a 4 bolt.

Will be interesting to see the price compared to a ZEN 4 bolt.

I would imagine the case and cylinders will be available at the same time.....or some of us would hope anyway.
 
Rossco said:
Nice...about time CY made a 4 bolt.

Will be interesting to see the price compared to a ZEN 4 bolt.

I would imagine the case and cylinders will be available at the same time.....or some of us would hope anyway.
Click to expand...

so far it looks like engines may be the only thing up for grabs. this will take place in about another 60-90 days.
 
Very interesting write up. Take it it will take some time before stock on parts will catch up with complete engine production.
Nice info, thanks.

Question:
Why do hobby motors not have two rings like with other 2 stroke motors?
 
Bigger the Better said:
Very interesting write up. Take it it will take some time before stock on parts will catch up with complete engine production.
Nice info, thanks.

Question:
Why do hobby motors not have two rings like with other 2 stroke motors?
Click to expand...

2 rings= added friction and drag which= less rpm's
 
Makes sense to me. I just notice it on a lot of the chain saws and stuff at work when they tear them down. The darn rings are huge too. I guess they are not out for RPM's more then sheer power at low RPM's though.
 
Rossco said:
I've a question also.........does any maufacturer make chrome moly rings???

They would be awesome coz you would never have to rering.
Click to expand...

id actually prefer a ductile iron ring, and like stated u want the ring to wear to the cylinder. something has to wear for there to be good enough ring seal to run efficient.

on alot of my engines (even though some will argue) i run a hone through them and it helps with break in of the ring.
 
pipeous said:
Why torx bolts? why not stay with the norm? I hate when companies do their own thing different than others so you have to be brand sensitive.
Click to expand...

i always switch to stainless steel allen heads on all my builds, so i personally don't have a preference as to what any company chooses to use. but i understand where ur coming from...i also use grade 12.9 hardware
 
Last edited:
i have recently done some f270 testing and so far with the out of box tune, it has made 3.38hp and 1.98 ft lbs of tq! this was on the third pull right out of the box, with stock air filter, can muffler and stock tune! i expect some more gain after the ring fully seats and the engine wears in a bit... updates coming soon!
 
major update!!!!!

this cy f270 is supposed to be a 35mm bore and 28mm stroke, well after taking this apart to have a look around i have discovered a few things you all should know!

it is not a 26.9 but is a 27.2cc!!! its 34mm bore and 30mm stroke!
 
levi133 said:
hey y arent u comming to race i thought u were building a acohol car whats up
Click to expand...

been busy building engines for quite some time now and time is hard to come by.. my car is still in pieces as well. i have all i need to build it but the engine...the engine was actually sold to a customer, he offered me the right $$ so i sold it off.. ill be building a new one in the future, i just don't know when.. right now im swamped and need to get done as much as i can, when im caught up ill get back to work on my rig
 
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