interesting information on head porting.

[bleh]

http://mototuneusa.com/think_fast.htm

i know the website design is pretty hard to follow and sketchy but it is obvious he is not into web design.

his theories contradict what the vast majority of tuners will tell you but he is right!! i learned a good amount reading it.

cliffnotes:

-a head that flows the best will not always give you the most power

-having smaller intake ports increases velocity helping to fill the chambers more efficiently giving more power

-a rough surface on intake ports creates turbulence in the air going over it keeping the fuel off, helping atomization.

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Hallo bleh,

 

kennst du schon interesting information on head porting. (Anzeige)? Dort ist vieles zu finden.

 

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[LateNightCable]

That's interesting. It reminds me of a little tid bit that I read about some old man in a primitive part of the world who came up with a way to increase combustion efficiency. By chiseling grooves into the heads to create turbulance.

I'll see if I can find something about that on the web.

[reggid]

i suppose that if i had pin hole size ports that would help .

I think the point of the article is that you have to have the correct size for the engine. It is possible that one manufacturer has oversized the ports and another has undersized them so thers no rule that says oversizing or undersizing them is better, it would depend on how the engine comes from the factory.

From what i can see thers no ground breaking info but rather just observation.

[reggid]

http://mototuneusa.com/think_fast.htm

cliffnotes:

-a head that flows the best will not always give you the most power

but an engine that flows the best will!

It makes sense to me that you have to consisder the engine as an entire system to see how things behave with each other, rather than by simply looking at individual parts to get the best results.

[bleh]

its a big deal since most people usually assume that when they port and polish any head it will give more power. the size and shape of the ports should be dictated by the desired amount of air/fuel to be put in each cylinder. this amount of the mixture changes with displacement, rpm, and also with the rest of the flow of the engine. so to compliment what you had said: to best flowing head will not always be the best flowing in the best flowing motor.

upon further thought, the same can be said about the exhaust ports: if the exhaust is at the optimum velocity leaving the cylinder it will create a vacuum while the valve is shut helping to pull the exhaust out of the cylinder.

to move onto my application: i was considering doing a bunch of head work. mainly cams, valve springs and retainers and gear for fine tuning, but i was thinking of doing a diy port and polish since it really is not that hard to evenly grind away material. upon reading the article and knowing my goals(more upper rpm torque, a.k.a. M4D VT3CH y0!), i decided to leave my head with stock ports, just a nice cleansing and thicker, composite intake manifold gasket. so we will see what my girly gets me for christmas.