What does "fully port matched and polished" mean?

G

gera229

New Member
What does "fully port matched and polished" mean?
I've seen engines that are worth a little bit more with this description like on the motovelo engine kit.
 
Drewd said:
With regards to "Happy Time" engines, it means you are trying to polish a turd.
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That is a wholly uninformative remark, please just answer the question or dont. I would like to know as well, how can this be done at home and is it worth it?

With regards to what it is, in automotive terms at lease polishing means forcing an abrasive putty through the intake manifold (or whatever you are trying to polish) to smooth out the surface of the metal inside to maximize airflow and prevent micro-currents of air that restrict overall flow.
 
Razorthirty said:
That is a wholly uninformative remark, please just answer the question or dont. I would like to know as well, how can this be done at home and is it worth it?

With regards to what it is, in automotive terms at lease polishing means forcing an abrasive putty through the intake manifold (or whatever you are trying to polish) to smooth out the surface of the metal inside to maximize airflow and prevent micro-currents of air that restrict overall flow.
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Actually it's quit the contrary a slightly rough surface flows the air better. Read this sticky and all will be thoroughly answered here. http://motorbicycling.com/f52/basics-port-polish-port-matching-16646.html

foureasy said:
per wikipedia, under cylinder head porting and myths


The reason that polished ports are not advantageous from a flow standpoint is that at the interface between the metal wall and the air, the air speed is ZERO (see boundary layer and laminar flow). This is due to the wetting action of the air and indeed all fluids. The first layer of molecules adheres to the wall and does not move significantly. The rest of the flow field must shear past which develops a velocity profile (or gradient) across the duct. In order for surface roughness to impact flow appreciably, the high spots must be high enough to protrude into the faster moving air toward the center. Only a very rough surface does this.
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LOL

Yah, it was a crude remark made... NOT directly informative to the OP, but absolutely true!

LOL

...the golf ball is perhaps the best comparison...

...and GASKET and port matching are a very valuable thing to do to keep the engine from digesting itself. they really DO need cleaning up.

There's entire threads on this subject that should be read in the mods section.

I would NOT attempt to start a new engine without taking apart the basic components. Alf has presented a great write-up on this subject.

Good luck
rc
 
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