TOPIC:

last week I had some time to prepare a Z1 head for bigger pistons.
The stock 64mm combustion chambers are to little for the new 70mm pistons and were opened to a 69mm diameter.
Compression ratio will be 10:1 with a 1000ccm head gasket.
Intake and exhaust channels were ported to fit bigger carbs and exhaust system.
Maybe the following pics are interesting for someone ...

Post edited by: no name, at: 2006/05/12 17:44

next ...

sorry can upload one pic every time

another one

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Nice work there. Thoses chambers shine better than some engine cases I have seen.

looks nice.

Hey No Name - The head looks good, but I have a question on the final finish of the combustion chambers. Why did you bring it up a such a high polish? I have never really seen that done to that degree before. Isn't it better to have a rough finish in the combustion chamber to promote a better swirl?

Anyone want to chime in on this high polish finish? I still have mine apart and don't mind putting some extra time into optimising the head work if it will be beneficial.

Cheers-Colin Firth

'77 Kz 650 Custom - (Miss July on 2006 Kzr Calendar-Last year’s project Wiseco 700) Newest rebuild includes Wiseco 810 kit, Kz750 cams, Kz750 intake valves, 750 GPz springs, Ported head, WG Mikuni 28's, Velocity Stacks, Dyna Ignition and coils, MAC pipe, 14 tooth front sprocket. Returning to original '77 Moon Dust Silver. Goal is to have a stock-looking, ultra-sleeper bike that will tighten up any loose dental fillings off the light and surprise other, bigger bikes.

reborn650 wrote:

Hey No Name - The head looks good, but I have a question on the final finish of the combustion chambers. Why did you bring it up a such a high polish? I have never really seen that done to that degree before. Isn't it better to have a rough finish in the combustion chamber to promote a better swirl?

Anyone want to chime in on this high polish finish? I still have mine apart and don't mind putting some extra time into optimising the head work if it will be beneficial.you want to keep intake ports a little rough to suport turbulence and keep fuel from ending up on bottem of port.combustion chamber is kept smooth to avoid hot spots,but dont remove too much from chamber or you will drop compression same with porting you dont want to just start hogging on ports or youll end up with a motor that wont run below 7500 rpms you just want a smooth transition in and out,smaller ports are generally more responsive for a street motor in lower rpms where most bikes spend the majority of their time.im experimenting with thermal coatings on the project im currently screwing with.piston coat on piston domes and chambers and valve faces to keep heat in chamber.coating on intake ports to insulate the fuel/air from heat and coated exhuast ports to keep extra heat out of motor.we shall see how it works.now if i just had a digital camera id post some pictures of it(hey solomrus!)i need to finish the kitchen so i can get back to work on my toys!

Cheers-Colin Firth

'77 Kz 650 Custom - (Miss July on 2006 Kzr Calendar-Last year’s project Wiseco 700) Newest rebuild includes Wiseco 810 kit, Kz750 cams, Kz750 intake valves, 750 GPz springs, Ported head, WG Mikuni 28's, Velocity Stacks, Dyna Ignition and coils, MAC pipe, 14 tooth front sprocket. Returning to original '77 Moon Dust Silver. Goal is to have a stock-looking, ultra-sleeper bike that will tighten up any loose dental fillings off the light and surprise other, bigger bikes.

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@reborn650

please read my first post.

I made heads like this sometimes before and they still run fine.
The chambers were prepared for 70mm pistons with a dome and much more compression than the stock parts.



The capacity of every chamber is the same now and the polish reduces carbon building.

Post edited by: no name, at: 2006/05/14 15:49

Post edited by: no name, at: 2006/05/14 16:00

I hogged out my intake ports so much that only 1mm of material is left on the intake ports opening. If you dont make them bigger how the heck is a bigger carb going to help? I hogged out the exaust ports so big an elephant can fall right in, and no way do the gaskets fit anymore so i made my own. Ha! And it smooooth. An hour ago i rode a wheelie through second and just said this is too easy and backed off the throttle. Porting a head is physical. Its hard work and takes time. I dont believe in being conservative, but sensible. It makes sense to me to enlarge the openings and smooth the heck out of them. You can tell how the fuel will flow by feel with your finger. Simple. So open wide, rock on.