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  #1  
Old December 11th, 2015, 08:22 PM
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Pablo Cocito
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Gas flowed head?

I just got a performance cylinder head from Turner and I expected to find the ports "ported"... Is this how it's supposed to be or I got a normal head?
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  #2  
Old December 11th, 2015, 08:26 PM
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Gene
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I just put one on also, no real noticeable difference that I could tell, granted I didn't do a really good side by side either..
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  #3  
Old December 11th, 2015, 08:31 PM
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Pablo Cocito
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But could you tell visually that it was ported?
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  #4  
Old December 11th, 2015, 09:11 PM
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Gene
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No. I'm not sure what is ported. Frida said all they had was 1 gasflowed and I twisted her arm to buy it in hasty desperation. I did ask at some point, Frida sent their info page which isn't too specific. Turner Engineering supplies performance cylinder heads for Land Rover Engines

I'm sure she'd fill you in, they're great to deal with.

Did you just purchase yours?
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  #5  
Old December 12th, 2015, 12:36 AM
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Luis Constantin
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Can't tell by the picture on the phone if it's ported. But it could sure use a polish.
Next time my heads are off, they're going in for extrude honing. That's the new (well kinda new) performance technology. It's been around for a few years now.
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  #6  
Old December 18th, 2015, 09:03 AM
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Pablo Cocito
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To follow up on my post I will paste the answer I received from the guy that knows:

Dear Pablo
Thank you for your e mail , I have checked your file and the head supplied
is gasflowed.

The work has been carried out directly behind the valves and consists of
shaping work to enhance the flow in and out of the cylinder head. The
exhaust port is enlarged and blended into the port behind the valve, the
inlet port is worked on to remove sharp corners and features that cause
unwanted turbulence in the inlet tract. Typically gasflowing heads of this
type by this method will increase performance between 10 15%. We only
remove enough metal to enhance flow without risk to the long term
reliability of the component. These cylinder heads are aimed fairly and
squarely at road users to improve driveability and overall performance.

Our method of gasflowing does not include polishing of the ports other than
the areas directly behind the valves due to the fact that research has shown
that typical flow losses due to friction with the port wall is in the region
of 3 4% and that polishing may reduce the losses by approximately 1% only.
For example if the losses are 4% then after polishing it will be 3% only.
In the case of a road engine where carbon deposits quickly replace whatever
surface finish is on the port with a layer of carbon this quickly negates
any small benefit. This is a well known fact in the tuning industry.
Polishing work in this area adds cost but in practice brings very little to
the party by way of value/performance.

Our method allows us to provide cylinder heads at reasonable cost/value. The
majority of the cost in your case of the product that you have bought is the
cylinder head assembly.

Having ported cylinder heads for the past 25 years or so without complaints
about lack of performance including engines which are raced we see no need
to alter our policy or waste time carrying out work which has proved to be
of little benefit.

I trust the above explains.

Regards
Richard Turner
Turner Engineering
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  #7  
Old December 18th, 2015, 10:20 AM
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makes sense. simply widening the ports makes little sense considering that velocity decreases as the square of diameter, and the pressure drop is the fourth power of the radius. This is a system you must optimize, you don't just make it bigger to make it better.

And of course, the obvious point: The intake and exhaust ports are exactly the same diameter as the gasket as well as the inlet and exhaust manifolds.

And the more depressing reality: This isn't a racing engine
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