Y2KZX12R
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posted July 22, 2003 04:04 AM
Piston Ports...Doug M.
Doug, have you folks done any piston port development for your high rpm 4 stroke cycle applications? Were working on developing a special shaped port instead of the typical round holes or cone holes used by CART or IRL etc. The software indicates that the pressure footprint is barely larger than the port itself thus requireing alot of ports. Were trying a set of ) shaped ports with a tapered back cut using wire EDM. The port crosssectional area is only 20% bigger on the piston top but is 130% bigger on the ring side. Our thinking is that optimum port size and shape is different from a turbo application vs. N/A engine.
Any thoughts on this?
   
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Y2KZX12R
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posted July 22, 2003 04:12 AM
oh, what crank case pressures do these little bike motors generate at peak power? Without an evacuatiion system of course. Thanks.
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oldkawboy
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posted July 22, 2003 05:12 AM
Jim,
If I wasn't pushed for time, I'd answer these questions for you. LOL
Dan
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dougmeyer
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posted July 22, 2003 06:18 AM
Interesting. No we've only used conventional round ports, top and side. I'll see if I can release the pressure numbers to you. As is usually the case, now that you mention it, the port areas should vary and may be significant. One factor though, would be ring life as those engines need to last at least 500 mi at WFO.
Doug
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frEEk
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posted July 22, 2003 10:43 AM
quote:
Doug, have you folks done any piston port development for your high rpm 4 stroke cycle applications? Were working on developing a special shaped port instead of the typical round holes or cone holes used by CART or IRL etc. The software indicates that the pressure footprint is barely larger than the port itself thus requireing alot of ports. Were trying a set of ) shaped ports with a tapered back cut using wire EDM. The port crosssectional area is only 20% bigger on the piston top but is 130% bigger on the ring side. Our thinking is that optimum port size and shape is different from a turbo application vs. N/A engine.
Any thoughts on this?
blah?
ok, now that i'v read that 10 times anbd actually understand a full 25% of it... i seem to remember reading jsut the other day of someone producing an engine with a D shaped exhaust port. or are u talkin about something completely different? certainly the D shapped port makes sense, taking a cue from the serpent headers from micron.
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dougmeyer
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posted July 22, 2003 12:57 PM
Completely different
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K Bryant
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posted July 22, 2003 01:02 PM
I remember dealing with "D" ports back in the 70's with Denco and Dale Walker! Hey Doug, remember the "tongues" in the port/exhaust? Or am I dating myself too much...
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aliveagain
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posted July 22, 2003 01:18 PM
I believe they're talking about the ports that put pressure on the rings,hence the reference to n/a or turbo and crank pressure.
____________
I wondered why the baseball kept getting bigger. Then it hit me.
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Y2KZX12R
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posted July 22, 2003 01:51 PM
So what engines, that you guys build, currently use ported pistons?
(road race or drag) Are they ported in house? Can you post a pic of a current hole size and layout that is currently thought best? I can understand if you wont share that info.
The application on my end is a small block chevy circle track engine. But I like to see what other areas of racing are currently doing.
aliveagain.... exactly... tiny holes in the pistons. Just trying to seal up the engine better.
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frEEk
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ummm... yeah
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posted July 22, 2003 02:03 PM
ah, gotcha (i think)
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EastBayDave
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posted July 22, 2003 02:40 PM
should be known from the crate engines?
____________
Enjoy the ride!
02' ZRX1200
00' ZX12R sold
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aliveagain
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posted July 22, 2003 04:19 PM
total seal rings
____________
I wondered why the baseball kept getting bigger. Then it hit me.
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aliveagain
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posted July 22, 2003 04:24 PM
ok I'll bite,what are the tongues in the port/exhaust?
____________
I wondered why the baseball kept getting bigger. Then it hit me.
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Y2KZX12R
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posted July 22, 2003 05:17 PM
EBD, I'm not shure what your question was.
The tongues were used to raise the port floor and decrease the port volume.
Ford had a bad habbit of making crappy flowing heads with huge ports and wicked turbulance. (351c 4v comes to mind)
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Y2KZX12R
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posted August 02, 2003 04:15 AM
Any chance of some pics Doug?
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dougmeyer
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posted August 02, 2003 02:51 PM
Pics of what exactly. I have a great many.....
Doug
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Y2KZX12R
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posted August 02, 2003 06:40 PM
Well... like the pattern and dia. of the holes in the pistons od some of ther more advanced engines you guys are doing.
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Y2KZX12R
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posted August 05, 2003 04:43 AM
up
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dougmeyer
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posted August 05, 2003 06:09 AM
 Edited By: dougmeyer on 5 Aug 2003 07:10
Oh, I thought you were talking about old port stuff. No pics of any R&D stuff.
Read Hot Rod or Race Car Engineering magazine for the latest scoop.....
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Y2KZX12R
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posted August 05, 2003 07:05 PM
Hot Rod... lol
I was under the assumption that you guys developed your own pistons.
Thanks anyway.
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