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Everything You'd want to know about Porting on a Rotary

A library of especially useful topics taken from Tech Talk.

Moderators: orx626, KillerRx4

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brown hornet
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Re: Everything You'd want to know about Porting on a Rotary

#241 Post by brown hornet » Tue May 07, 2013 9:03 pm

so i got soem pineapple racing "race extend port templates'

overlayed them on my own backyard extend port which was purely based on seal traces and what i thought was a good shaped port..

very surprised that there is next to no difference in the width and the top shape.. only the bottom section is extended lower which i didn't do...
obviously the pineapple port is widened exactly the same as what i decided on which i think was 2mm.

pic of overlay..
pineapple race extend comparison 2.jpg
pineapple race extend comparison 2.jpg (139.18 KiB) Viewed 7595 times


My RX7's - ..
The new one - not so stock anymore S3 - http://ausrotary.com/viewtopic.php?f=21&t=223532" onclick="window.open(this.href);return false;
The old one - DIY 13b 6 port turbo - http://ausrotary.com/viewtopic.php?f=21 ... &start=100" onclick="window.open(this.href);return false;

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drtool
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Re: Everything You'd want to know about Porting on a Rotary

#242 Post by drtool » Sat Nov 23, 2013 9:20 am

.


1971 RX2 coupe 12A TD
1971 RX2 coupe 13B BP
1995 20B Cosmo Type SX

Trader feedback here: http://ausrotary.com/viewtopic.php?f=14 ... 2#p2707662" onclick="window.open(this.href);return false;

BloodyKiwi
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Re: Everything You'd want to know about Porting on a Rotary

#243 Post by BloodyKiwi » Tue Mar 03, 2015 8:44 pm

Any info on 6 ports? I have one I want to tickle but not finding much info on these. :stupid:



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RX7_BEN
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Re: Everything You'd want to know about Porting on a Rotary

#244 Post by RX7_BEN » Tue Jun 27, 2017 9:13 pm

Hey guys, got some questions about exhaust porting for a turbo application

I'm building a 12a turbo motor at the moment using all n/a parts. The engine was initially built as a naturally aspirated extend port, so the exhaust port has been ported upwards as is commonplace for such engines. It's a typical round port with slightly squared bottom, but I'm thinking about making a few changes, mainly because I'd like the engine to come on boost a little quicker and figure while it's apart I may as well attack it.

If I understand correctly, exhaust ports for turbo engines these days are squared off and ported down (earlier port open time) in order to maximise port area whilst minimising overlap.

What I've been thinking is that I'd like to widen my existing ports a little, squaring them off and opening them earlier by porting downward. Is this going to be feasible with my already later closing ports?
I'm also limited by the rather small 12a n/a exhaust port baffles, so not a huge amount of material is going to be removed.

Pic of current ports
Image

As a side note, this is the inlet port I'm working with. The scribe mark indicates the shape I'm considering changing it to.
Image

I've been running the engine for a few years on 14psi with a T04z 1.0 split pulse rear and it doesn't make full boost until around 6000rpm.
Any thoughts on these proposed changes would be great!

Edit: Oh, here's a bit of an example of the modern age turbo type ports I'm talking about. This is on a 13b by Defined Autoworks, so won't be that large, but along those lines.
Image



qfiebay
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Re: Everything You'd want to know about Porting on a Rotary

#245 Post by qfiebay » Thu Jun 29, 2017 7:37 pm

Awesome read :bow:



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bumpstart
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Re: Everything You'd want to know about Porting on a Rotary

#246 Post by bumpstart » Fri Sep 08, 2017 8:29 pm

Image

Image

Image

Image

Image

Image

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here is one i fixed up over the original bridge .
i have pinned it. filled it with belzona. had a new inner groove machined
and given it a moderate monster J that is common ground on all plates , similar in dimensions to the old photo above

handmade viton water seals


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RX7_BEN
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Re: Everything You'd want to know about Porting on a Rotary

#247 Post by RX7_BEN » Fri Sep 08, 2017 8:34 pm

I like the new inner groove that's been machined.

This is what I ended up doing with my 12a housings if it's of any interest.

Image



pknoutrx2
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Re: Everything You'd want to know about Porting on a Rotary

#248 Post by pknoutrx2 » Fri Sep 22, 2017 10:35 pm

Hey Ben
Did you end up doing the intake as you marked out above?



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RX7_BEN
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Re: Everything You'd want to know about Porting on a Rotary

#249 Post by RX7_BEN » Wed Sep 27, 2017 10:31 pm

Nah I didn't, but I did modify the closing edge of the port a little to eliminate side seal issues. I can't find a picture at the moment.



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