Author Topic: re clock pre cup and re shape combustion chamber?  (Read 2577 times)

January 30, 2010, 08:57:35 am

Rabbit on Roids

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re clock pre cup and re shape combustion chamber?
« on: January 30, 2010, 08:57:35 am »
so, what if we clocked our prechambers a little bit? and what if we re-shaped the combustion chamber so it was kinda circular? so it was more swirl-inducing... and then have the pre cups clocked to say 1, or 1:30 so the fuel wouldnt just come straight out of them, but come out and swirl around the combustion chamber?

is this just a big FAT pipe dream? or is it just too early for my brain to be thinking properly?

Reply #1January 30, 2010, 11:15:11 am

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Re: re clock pre cup and re shape combustion chamber?
« Reply #1 on: January 30, 2010, 11:15:11 am »
Puff puff pass. Don't hold the mic  ;D.

Got thought though.
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Reply #2January 30, 2010, 11:27:26 am

Rabbit on Roids

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Re: re clock pre cup and re shape combustion chamber?
« Reply #2 on: January 30, 2010, 11:27:26 am »
yea, kinda figured they already would have been clocked differently from the factory if there were any gains to be seen from doing it. but what the hell, it was worth the thought.

idk, my mind wanders aimlessly all day, random thoughts just come and go as they please, and this one got stuck in my thoughts enough for me to remember it, so i thought i would atleast ask, rather than have the idea thats gonna make the 1.6 capable of 500 horse power, but never present it to the general public.

i guess is what im trying to say is its better to have the idea and prove that it doesnt work, than to never have the idea, and have it be just what you needed.

Reply #3January 30, 2010, 12:25:44 pm

janb

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Re: re clock pre cup and re shape combustion chamber?
« Reply #3 on: January 30, 2010, 12:25:44 pm »
I will bet there is potential improvement to be made, as this design has to be over 40yrs old.  I will guess the piston tops would need modified to enhance swirl.  There are surely some thermodynamic engineers who are dreaming of 'VW-IDI' performance mods, somewhere in the world.  I'm not sure if the limitations of our valve placement sill dictate simple 'up and down' and no dynamic swirl, but probably will hinder the quest.

Keep you mind going, 'dream-time' is not wasted, (especially on VW-D's 8) , as is TV time.
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Reply #4January 31, 2010, 12:39:48 am

NintendoKD

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Re: re clock pre cup and re shape combustion chamber?
« Reply #4 on: January 31, 2010, 12:39:48 am »
forward thinking, rabbitonroids, you and I think alike.  I would like to know more about this, and how it will affect compression.  link?
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Reply #5January 31, 2010, 03:32:39 am

gldgti

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Re: re clock pre cup and re shape combustion chamber?
« Reply #5 on: January 31, 2010, 03:32:39 am »
I will bet there is potential improvement to be made, as this design has to be over 40yrs old.  I will guess the piston tops would need modified to enhance swirl.  There are surely some thermodynamic engineers who are dreaming of 'VW-IDI' performance mods, somewhere in the world.  I'm not sure if the limitations of our valve placement sill dictate simple 'up and down' and no dynamic swirl, but probably will hinder the quest.

Keep you mind going, 'dream-time' is not wasted, (especially on VW-D's 8) , as is TV time.

i'm all for ideas and such, but i'm absolutely certain that recardo, the designers of the IDI swirl chamber, knew plenty enough to make this setup just about as good as it can be (whilst having VW mass produce it, anyway). sure some gains might be had making some small changes that were'nt included for us because its more expensive/difficult to machine on the production line/net gain not worth it - but we would need to ask recardo or VW about that i reckon.

recardo still the world leaders in thermodynamic design i think...
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Reply #6January 31, 2010, 06:42:47 am

theman53

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Re: re clock pre cup and re shape combustion chamber?
« Reply #6 on: January 31, 2010, 06:42:47 am »
If you look for AKI-76 (think that is his name) he cut some pockets in his pistons on his build to do what you are thinking about. He is wanting to rev 7,000 plus and had to lower the crown of the piston for his block/rod/crank combo, if I remember right. It kind of looked like a small twig with 2 berries probably 1 or 2 mm deeper than the original design. The "twig" looked like it went more to the center of the pistons too.
    I guess my point is the guy seems to be a genius when working on that kind of thing and would probably be the one who has already tried it. If anyone has.

Reply #7January 31, 2010, 07:42:04 am

Rabbit on Roids

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Re: re clock pre cup and re shape combustion chamber?
« Reply #7 on: January 31, 2010, 07:42:04 am »
forward thinking, rabbitonroids, you and I think alike.  I would like to know more about this, and how it will affect compression.  link?

link? it came straight outta my brain... original idea for all i know. and if anything, it will lower compression more since the pistons would probably need to be milled.

have you ever thought of putting some other pre cup in the AAZ head? or do they not fit?