ChinaRiders Forums

ChinaRiders Forums (http://www.chinariders.net/index.php)
-   Video and Pics (http://www.chinariders.net/forumdisplay.php?f=118)
-   -   CG250 Head - A Closer Look. (http://www.chinariders.net/showthread.php?t=19200)

Megadan 05-30-2017 02:30 PM

Personally, for my goals I don't believe a camshaft is necessary. I just want to get an honest 20-22hp out of one of these engines. No doubt it would help, but when you start changing cam profiles, you start to effect the powerband of the engine more, and I want to keep it happy in it's current operating range.

pistolclass 05-30-2017 09:32 PM

How about this ?
http://www.ebay.com/itm/MOTORCYCLE-Q...-/401311496266

Megadan 05-30-2017 10:13 PM

Don't tempt me lol

JerryHawk250 05-31-2017 08:36 AM

Quote:

Originally Posted by pistolclass (Post 257695)

I've been looking at them for a while. They are proud of those little turbos. I have bought full size turbos for less. So being here in south Louisiana there are lots of jet ski parts at the outboard repair shops. I'll find a good use one eventually to experiment with.

JeremyC 06-04-2017 02:07 AM

I'm eager to watch this play out! And yeah, that exhaust port is nasty.. makes me want to tear mine down just to do it myself. The intake port doesn't look too bad to me, until you hit the valve guide area. This could make an interesting winter project if you get the results we're all drooling over! :lmao:

Take lots of pics as you go! We're all going to want every detail.

Megadan 06-04-2017 02:20 AM

Quote:

Originally Posted by JeremyC (Post 258247)
I'm eager to watch this play out! And yeah, that exhaust port is nasty.. makes me want to tear mine down just to do it myself. The intake port doesn't look too bad to me, until you hit the valve guide area. This could make an interesting winter project if you get the results we're all drooling over! :lmao:

Take lots of pics as you go! We're all going to want every detail.

I will do the best I can to take pictures, but I tend to have a hard time stopping once I start working to snap a shot unless I deem it worthy lol.

While I was assembling my bike I went ahead and checked my stock ports, and they are more or less the same. I was wondering if maybe it was just this particular casting that was kind of crap, but it wasn't.

This most likely will be a winter project for me, but I want to try and get started sooner rather than later. My biggest problem is, I have other obligations through the year that require my attention more, so if I do get any work done it will either be in spurts, or all at once.

Ariel Red Hunter 06-04-2017 08:47 AM

Quote:

Originally Posted by JeremyC (Post 258247)
I'm eager to watch this play out! And yeah, that exhaust port is nasty.. makes me want to tear mine down just to do it myself. The intake port doesn't look too bad to me, until you hit the valve guide area. This could make an interesting winter project if you get the results we're all drooling over! :lmao:

Take lots of pics as you go! We're all going to want every detail.

Yes, I'm very interested in this as well. I have, in the past, recommended leaving the ports alone, because it is way too easy to screw the job up if you don't know what your doing. Not the case here. Megadan has a well thought out process in mind. I particularly like the ceramic coating idea. Should reduce oil temperature....ARH

humanbeing 06-04-2017 09:23 AM

Quote:

Originally Posted by Megadan (Post 257573)
...ceramic coating applied to the piston top...

:lmao: Coated piston (<$5) is the standard item in workhorse trike...
http://gd1.alicdn.com/imgextra/i1/18...1864097574.jpg

Megadan 06-04-2017 01:04 PM

^I wouldn't trust that coating to do much of anything that I am talking about. If you want to try it go ahead. I have my limits on things I would cheap out on.


Speaking of coatings. As much as I would love to do so, I am not going to dive that far into this. This exercise is literally just a matter of porting the head to see the results. I intentionally bought a second head for this so I can not only enjoy the bike while doing this on the side, but also have the factory head to switch back to if I discover I don't like the nature of the bike after doing said work.

The whole ceramic coating idea was part of a "if I were to go all out" discussion. I wanted to keep this as pure as possible and not introduce anything to skew the results of what just simple port work can do with a more "high performance" carb.

ben2go 06-04-2017 03:53 PM

I just looked at the head again. It has a hemispherical combustion camber, so your bike will have a hemi in it. :tup:

Megadan 06-04-2017 03:59 PM

Quote:

Originally Posted by ben2go (Post 258277)
I just looked at the head again. It has a hemispherical combustion camber, so your bike will have a hemi in it. :tup:

They should all be hemis. Not uncommon on old Japanese engine designs.

Ariel Red Hunter 06-04-2017 04:03 PM

Quote:

Originally Posted by Megadan (Post 258271)
^I wouldn't trust that coating to do much of anything that I am talking about. If you want to try it go ahead. I have my limits on things I would cheap out on.


Speaking of coatings. As much as I would love to do so, I am not going to dive that far into this. This exercise is literally just a matter of porting the head to see the results. I intentionally bought a second head for this so I can not only enjoy the bike while doing this on the side, but also have the factory head to switch back to if I discover I don't like the nature of the bike after doing said work.

The whole ceramic coating idea was part of a "if I were to go all out" discussion. I wanted to keep this as pure as possible and not introduce anything to skew the results of what just simple port work can do with a more "high performance" carb.

I don't know what high performance carb you have in mind, but in a round slide carb, Mikuni makes ANOTHER VM26, costs about 80 bucks, but has an enriching circuit instead of a butterfly choke with shaft hanging in the air stream...ARH

Megadan 06-04-2017 04:36 PM

Looking at a 32 or 34mm flat slide style carb with an enrichment circuit similar to what you just mentioned. I am open to, and welcome all ideas.

Ariel Red Hunter 06-04-2017 05:19 PM

Quote:

Originally Posted by Megadan (Post 258284)
Looking at a 32 or 34mm flat slide style carb with an enrichment circuit similar to what you just mentioned. I am open to, and welcome all ideas.

Wow. Bigger than 1 1/4 inch on a 250? Other than an Italian single cylinder road racer? My 22 hp AJS 250 CSR only had a 1 1/8 inch carb on it, for what ever that's worth...ARH

Megadan 06-04-2017 07:51 PM

As I said, just considering at this point. There are a lot of variables to consider,


All times are GMT -4. The time now is 02:04 AM.

Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.