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MrDangerUS

PolyQuad head design, +100HP potential

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Four-valve heads are certainly "cool", but comparing to modified 2-valve config, they exhibit a certain flaw - low speed torque is never impressive.

The key to making low speed torque is two-fold:
a) how much charge is trapped at valve closure and
b) how effectively the charge is burned."
Replacing 4V head charge "tumble" with the "swirl" motion presents itself as a key element of the successful (re)design.

To read more about PolyQuad head design, read this article:
Polyquad Article - MotorTech Magazine

If anyone wants a PQ head modified (be it for any multi-valve head), then Ultra Pro Machining in the USA http://www.ultrapromachining.net/About.html (704-392-9955), who does so many cup car heads, or Austec Racing in the UK http://www.austec.co.uk/Cylinder-head-Modifications.asp

(01293 531080), are up to speed on this.

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Upgrade today to remove Google ads and support TLF.

The problem with Austec Racing is they don't take Non- TVRs very seriously... or at least they never used to. 

Reputations are a hard thing to shake.  I used to live 2 minutes away from them

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I was there a couple of weeks back. Seems very Pork orientated now.


88 Esprit NA, 89 Esprit Turbo SE, Evora, Evora S, Evora IPS, Evora S IPS, Evora S IPS SR, Evora 400, Elise S1, Elise S1 111s, Evora GT410 Sport

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When I opened the link I saw the name David Vizard so got my full attention. His work over the past 40 years or so is the stuff of legends.

 

Bit long to read at the moment but will do so when I have some more time.


DanR

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Austec is not that important/relevant in the overall scheme of things.

 

Read the article. PolyQuad concept is amazing!

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When I opened the link I saw the name David Vizard so got my full attention. His work over the past 40 years or so is the stuff of legends.

 

Bit long to read at the moment but will do so when I have some more time.

Yes, David is a world renowned expert on engine design and development for automotive and marine applications. As the critically acclaimed author of over four thousand technical articles and 32 technical books, he has earned a global following of his ground-breaking work, with specialist areas in Mini, Ford and Chevrolet. He has a Patent for PolyQuad head design.

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Here is an updated article:   http://www.motortecmagazine.net/the-future-of-4-valve-engines/

Nex time your head is out, if you decide to "PolyQuad" it, it can be done by David Martin of Austec Racing  in UK.

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Mr. Vizard's credentials are impeccable and I've read through much discussion in forums in regard to his Polyquad theory. The concept is persuasively described in the articles, however not a single example of the outcome realized has yet been presented by anyone, including well established tuners. It has also been noted by some of the professionals who contribute that some of the desired swirl has been accomplished by nothing more exotic than offset grinding the 2 intake cam lobes per cylinder several degrees apart. That said, I do not presume to know enough to dare challenge the like of DV in these matters, just wish someone would get a 907/912 done in Polyquad fashion and share documented results! 

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Great stuff as usual Dave. I would add that DV's emphasis is on shoring up the lower range efficiency of a 4 valver so should therefore imply minimal concerns for either peripherals or core components it would seem.

Cheers

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