18cc head stock?

[Dodgeboydan]

Just finished the tear down of my gx200 clone. I decided to see what the stock chamber volume was. After checking my results twice, I confirmed that it measures 18 cc. I thought maybe I had a gx160 clone, but I checked the bore and stroke, and it's deffinately a gx200. This engine appears to be bone stock. Am I right in thinking the head should be larger? I'm stumped. Anyone ever seen this?:shrug:

 

[Newoldstock]

A picture posted will answere all your questions.

 

[cheezy1]

No..they came with 18cc and mostly 22cc. Depends on the brand of clone. Mystery solved:hammer:

 

[Newoldstock]

No..they came with 18cc and mostly 22cc. Depends on the brand of clone. Mystery solved:hammer:

I have never seen a 18cc Chinese clone head.
Only 22 and 14.

I have not seen everythig however.....

Too date I have only ever seen dish pistons in clones ( 160 and 200 ).
An 18cc head would seem to sugest someone in China has decided to build a modernized version of the 160.

OR

This may sugest someone has specialy ordered something.....

In any event a picture and some casting numbers will quickly solve this question....

 

[Dodgeboydan]

Wow this took some research. Turns out the head is a 14cc, once I measured it with a professional kit. This makes a lot of sense when my motor is a gx160 clone. I got the wrong stroke specs offline, so it had me thinking I had a 200 when it's actually a 160:doah::doah::doah: now that I feel stupid......

 

[cheezy1]

:doah:...:laugh:

 

[Newoldstock]

Wow this took some research. Turns out the head is a 14cc, once I measured it with a professional kit. This makes a lot of sense when my motor is a gx160 clone. I got the wrong stroke specs offline, so it had me thinking I had a 200 when it's actually a 160:doah::doah::doah: now that I feel stupid......

No one is perfect.
I was waiting for that picture to come up and the casting number.

Last couple of years some things have changed some clones are even coming with larger valves now.

The toolking tht use to manke the heads wears out.
Every now and then I get suprised by a new casting number with a slight but significant enough change that its noticeabal.

AN 18cc head however, just not going to happen untill the Chinese modernize the GX160 and adopt the FT tier three piston.

 

[Dodgeboydan]

There are only two numbers I can find on the head one is inside between the rocker studs and its 7711 and the other is on the outside bottom of the rocker valley which is hx02. I tried searching, but I can't seem to find anything that matches those numbers. What's your guys opinion on building a 160 instead of a 200? Also, if I were to find a 200, would the 14cc head make a good upgrade, or will it not flow as well as an 18cc. I will be porting whichever head I use

 

[rmm727]

a gx160 block is easy to identify. Look for 1 large cooling fin before the head. A gx200 has 2

A gx160 is no different to build than a 200. Parts interchange except the cranks (unless you want the compression ring to stick out past the deck). gx160 carbs have a smaller venturi. I have a 160 on my Golden Pinto. NR racing 252 marine cam, 18lb valve springs, .080" shaved 22cc head, and Dover cheater stock carb. Runs well, but there is no replacement for displacement.

 

[Newoldstock]

There are only two numbers I can find on the head one is inside between the rocker studs and its 7711 and the other is on the outside bottom of the rocker valley which is hx02. I tried searching, but I can't seem to find anything that matches those numbers. What's your guys opinion on building a 160 instead of a 200? Also, if I were to find a 200, would the 14cc head make a good upgrade, or will it not flow as well as an 18cc. I will be porting whichever head I use

The head will fit the 200 block no issues.

I won't sugest any modifications or upgrades or offer you any more advice however untill you lay out a detailed plan of what you want the engine to do and type of bike its going in.

Ther's realy no point without a plan.

 

[Dodgeboydan]

This motor will be going into my bonanza drag bike. The plan is to make it as quick as possible while maintaining reliability. The plan thus far(before I found out I had a gx160) was to use a stock bore and stroke Gx200 clone block, stock clone crank, ARC billet flywheel, ARC billet rod, a gas ported flat top Honda piston, 14cc head ported heavily but not so far as to kill velocity, a 1" header, a .625 stock style methanol carb, Isky Black Mamba cam, Isky lifters, chromoly pushrods, champion shaft rockers, 26lb springs, lightweight retainers, stainless stock size valves.

Figuring on setting it up with the piston .005 out of the hole, .065 milled off the head, an Autolite surface gap sparkplug, reworking the port to smooth the transion into the bowl, try to rebuild the port on the bottom side with epoxy and grinding to achive a nice short turn radius, open the seat throats up to around 86% of the valve diameter. I will also open the cross section of the port to help support more mass flow while not going to far and killing velocity.

I'm looking to achieve a volumetric efficiency of at least 90%. I feel that alcohol is a good choice because of its high latent heat of vaporization. This is the best combination I can come up with that I believe will achieve my goal of a powerful, reliable combination:thumbsup:

 

[Newoldstock]

This motor will be going into my bonanza drag bike. The plan is to make it as quick as possible while maintaining reliability. The plan thus far(before I found out I had a gx160) was to use a stock bore and stroke Gx200 clone block, stock clone crank, ARC billet flywheel, ARC billet rod, a gas ported flat top Honda piston, 14cc head ported heavily but not so far as to kill velocity, a 1" header, a .625 stock style methanol carb, Isky Black Mamba cam, Isky lifters, chromoly pushrods, champion shaft rockers, 26lb springs, lightweight retainers, stainless stock size valves.

Figuring on setting it up with the piston .005 out of the hole, .065 milled off the head, an Autolite surface gap sparkplug, reworking the port to smooth the transion into the bowl, try to rebuild the port on the bottom side with epoxy and grinding to achive a nice short turn radius, open the seat throats up to around 86% of the valve diameter. I will also open the cross section of the port to help support more mass flow while not going to far and killing velocity.

I'm looking to achieve a volumetric efficiency of at least 90%. I feel that alcohol is a good choice because of its high latent heat of vaporization. This is the best combination I can come up with that I believe will achieve my goal of a powerful, reliable combination:thumbsup:

So have you done any of this kind of thing before?
I need to ask because its all very technical sounding terms but withourt a flow bench and a dyno as well as some instrumentation its not easy at all to get all that to do what you say.

Maybe if you water things down a little.
Generaly speaking most people who use the PZ22 carb are real happy with it and the little clones have not rouble pulling on it with the stock valves.

Everything else sounds good.
Just concerned about the porting and the methanol.
If done right no trouble, but Methanol in its own right is a pain in the arse.

I think if you stick with gas, a low level clean up job in the ports ( stock valves my personal feeling is there is not much to be gained with excessive portig there ), good valve job and put that all together it should be well mannered and quite peppy.

The Z4M piston your looking at is good although I have never tried it gas ported before ( Gasoline and deposits might hamper that in the long run )

The 14cc head has limitations.
It does have some shrouding issues for the valves.

What about a flywheel?
The standard ARC one is a little heavier than others.
Might be worth pricing a lighter one.
I still use the GXV flywheel because they are cheap and I havfe a few of them...
I find the light weight does help excelleration.

 

[Dodgeboydan]

I was also thinking of going lighter on the flywheel. I had also seen a few mentions of the gxv flywheel, but I was a little hesitant because I didn't know their limitations. Are they safer than a stock clone flywheel? Lucky for me, a good friend of mine runs a blown alcohol pro mod in ADRL Pro Extreme, and not only has he taught me a lot about running methanol, but he also has unrestricted access to a flow bench and a velocity probe. He said he thinks we can adapt a clone head to it. I have built quite a few automotive engines, and have always considered engines to be my strong point. Being new to clones, I'm trying to learn their strengths and weaknesses, but I also figure many of the tricks used to gain power are universal, no matter what the engine is

 

[Newoldstock]

Well I think you need to build a few engines to be honest, or have a lot of parts to put on and take off to experiment with.

Your choice though.

Just my opinion though, there are a few fellows here with a lot more engines under their belts and making alot more Hp than my little motors ( mine are not drag motors ).
Keep reading and asking.