Drop-in 279cc engine for the RX3?

detours · 04-20-2016, 07:57 PM

Following some links, I found a 279cc Zongshen engine called the CBS300. It looks a little different than our NC250, but I wonder if it would be a drop in replacement? The oil filler might be under the exhaust, but maybe ...

Here's an image on Facebook that shows the same HP and torque as our 250cc models.

https://www.facebook.com/zongshenmot...type=3&theater

And a chart on this mychinamoto forum page with pretty much the same numbers.

I wonder why the numbers match our NC250 so closely. Maybe it's just that efficient? Normally a bigger bore improves power, but it all depends on engine design.

AdventureDad · 04-20-2016, 08:04 PM

Its probably for a much different application. I agree it doesn't make sense. It would be a pointless conversion for an RX3. Probably like Ford (or whomever) using different versions of 4/6/8 cyl engines.

BlackBike · 04-20-2016, 08:57 PM

Detours...Weird as I was driving today I was pondering exactly what you posted..what if?

kohburn · 04-20-2016, 09:26 PM

drop it into the TT

Eco Mouse · 04-21-2016, 01:19 AM

Far less work to just install the already existing big bore kit, and see what happens.

I keep changing my mind from BBK to the Turbo as my first major mechanical upgrade.

detours · 04-21-2016, 02:40 AM

I'll have to look for that big bore kit. I've got a spare engine in the garage from my swap and a big bore kit might be the perfect thing to do with it.

Anyone have a link?

kohburn · 04-21-2016, 07:11 AM

Quote:

Originally Posted by Eco Mouse

Far less work to just install the already existing big bore kit, and see what happens.

I keep changing my mind from BBK to the Turbo as my first major mechanical upgrade.

you can tell from the torque profile that the cam is very different.

what big bore kit?

SpudRider · 04-21-2016, 08:21 AM

I think I would rather wait for the RX4 with the 450cc engine, which Zongshen plans to introduce next year.

http://www.chinariders.net/showpost....postcount=4969

Haggis · 04-21-2016, 10:38 AM

The GasGas Cami motor makes 20.6.kW or 28 HP and the bike only weighs 117 kg.
It uses a carb instead of injection.

kohburn · 04-21-2016, 02:28 PM

Quote:

Originally Posted by Haggis

The GasGas Cami motor makes 20.6.kW or 28 HP and the bike only weighs 117 kg.
It uses a carb instead of injection.

the AKT version of the rx3 uses a carb instead of injection also.

if you look at the 250/300 charts though the displacement has less of an effect than the cam - the 250 is cammed for lower end torque - at 4500 rpm it has almost 50% more toque than the 300. the 250 has a much more flat torque curve and the 300 has a much more peaky torque curve.

BlackBike · 04-21-2016, 02:31 PM

Quote:

Originally Posted by detours

I'll have to look for that big bore kit. I've got a spare engine in the garage from my swap and a big bore kit might be the perfect thing to do with it.

Anyone have a link?

CSaddict · 04-21-2016, 02:49 PM

http://www.aliexpress.com/store/prod...746771916.html

rtking · 04-21-2016, 03:07 PM

Quote:

Originally Posted by CSaddict

http://www.aliexpress.com/store/prod...746771916.html

I don't think this big bore kit is meant for use with the ZS177 engine, unfortunately. Our bore is 77 mm, so to get to 300cc, you'd need to go with a 84mm overbore and a custom piston.

BlackBike · 04-21-2016, 04:02 PM

Quote:

Originally Posted by rtking

I don't think this big bore kit is meant for use with the ZS177 engine, unfortunately. Our bore is 77 mm, so to get to 300cc, you'd need to go with a 84mm overbore and a custom piston.

ouch, also not to mention, how would it run with the fuel injection software on the delphi? may make it run like s#$&. i dont know , just saying. would be a neat project.

bet it would make a cheap hawk or bashan scream with a carb set up. (water cooler added of course)

Eco Mouse · 04-21-2016, 04:35 PM

Would it really matter what the new bore is vs. the old? When they are giving you a new sleeve, and piston to match? Obviously, if the bolt holes and water passages don't line up, that's an issue.

Would this make it more of a stroker? Maybe what's missing is a longer connecting rod?

04-20-2016, 07:57 PM	#1
detours Join Date: Sep 2014 Location: Arvada, CO Posts: 1,004	Drop-in 279cc engine for the RX3? Following some links, I found a 279cc Zongshen engine called the CBS300. It looks a little different than our NC250, but I wonder if it would be a drop in replacement? The oil filler might be under the exhaust, but maybe ... Here's an image on Facebook that shows the same HP and torque as our 250cc models. https://www.facebook.com/zongshenmot...type=3&theater And a chart on this mychinamoto forum page with pretty much the same numbers. I wonder why the numbers match our NC250 so closely. Maybe it's just that efficient? Normally a bigger bore improves power, but it all depends on engine design. __________________ Red 5 standing by! 2015 CSC red RX3 with 19" front wheel, Shinko 804/805, skid plate, tall seat, 13T/45T sprockets, progressive shock, Winyoochanok windshield, GENSSI LED headlight, SW-Motech tankbag, Shorai Lithium battery 2014 Ural Patrol
	1

04-20-2016, 08:57 PM	#3
BlackBike Join Date: Feb 2016 Location: George West, Texas Posts: 4,097	Detours...Weird as I was driving today I was pondering exactly what you posted..what if? __________________ ***************************************** 2015 Bashan"Blaze" BS250GY-31 (DB-07K-250) GONE 2017 Suzuki V Strom 650 XT "We are all born ignorant, but one must work hard to remain stupid." ~Benjamin Franklin~
	0

04-20-2016, 09:26 PM	#4
kohburn Join Date: Dec 2015 Location: Coastal NC Posts: 537	drop it into the TT __________________ -whatever you do, just be awesome. - 2008 Kawasaki Versys - 2016 CSC TT250
	0

04-21-2016, 02:40 AM	#6
detours Join Date: Sep 2014 Location: Arvada, CO Posts: 1,004	I'll have to look for that big bore kit. I've got a spare engine in the garage from my swap and a big bore kit might be the perfect thing to do with it. Anyone have a link? __________________ Red 5 standing by! 2015 CSC red RX3 with 19" front wheel, Shinko 804/805, skid plate, tall seat, 13T/45T sprockets, progressive shock, Winyoochanok windshield, GENSSI LED headlight, SW-Motech tankbag, Shorai Lithium battery 2014 Ural Patrol
	0

04-21-2016, 08:21 AM	#8
SpudRider Join Date: Jul 2008 Location: Idaho Posts: 25,054	I think I would rather wait for the RX4 with the 450cc engine, which Zongshen plans to introduce next year. http://www.chinariders.net/showpost....postcount=4969 __________________ Spud "Never argue with an idiot. He will drag you down to his level, and beat you with experience." Mark Twain 2015 Zongshen ZS250GY-3 (RX3) 2006 Zongshen ZS200GY-2 (Sierra 200) 2005 Honda XR650L 2004 Honda CRF250X 1998 Kawasaki KDX220 Mods made to my Zongshen ZS200GY-2: http://www.chinariders.net/showthread.php?t=6894
	4

04-20-2016, 08:04 PM	#2
AdventureDad Join Date: Apr 2016 Location: South Mississippi Posts: 253	Its probably for a much different application. I agree it doesn't make sense. It would be a pointless conversion for an RX3. Probably like Ford (or whomever) using different versions of 4/6/8 cyl engines.
	0

04-21-2016, 01:19 AM	#5
Eco Mouse Join Date: Jun 2015 Location: Las Vegas Posts: 158	Far less work to just install the already existing big bore kit, and see what happens. I keep changing my mind from BBK to the Turbo as my first major mechanical upgrade.
	0

04-21-2016, 10:38 AM	#9
Haggis Join Date: Mar 2016 Location: Scotland Posts: 21	The GasGas Cami motor makes 20.6.kW or 28 HP and the bike only weighs 117 kg. It uses a carb instead of injection.
	0

04-21-2016, 02:49 PM	#12
CSaddict Join Date: Dec 2015 Posts: 200	http://www.aliexpress.com/store/prod...746771916.html __________________ 2016 CSC RX3 Ginger Edition Check out my blog here: https://www.facebook.com/My-CSC-Zong...0302595973417/
	0

04-21-2016, 04:35 PM	#15
Eco Mouse Join Date: Jun 2015 Location: Las Vegas Posts: 158	Would it really matter what the new bore is vs. the old? When they are giving you a new sleeve, and piston to match? Obviously, if the bolt holes and water passages don't line up, that's an issue. Would this make it more of a stroker? Maybe what's missing is a longer connecting rod?
	0