Morning ,
A Few days ago in one of Jeff`s threads ,he mentioned my “ legendary” hahaha over ported housings.
Last night I took so time to go dig out the housing, and some others to compare it to.
Pic :Outside: Look at the size of the port! The branch/header used had to be 2.25” to match up to the OD of the port. The sleeve was also removed. Trigger happy with the porting tool by any chance?

Pic : Inside 1 :The “stock” looking housing is in fact a street ported exhaust, with quite a bit of duration there!Perfect for a nice large 50Deg+ closing Street port.The F#%#% port has wayyyyy to much duration.

Pic: Inside close : I tried to take the pic at a 90deg angle,to give the actual size of the port. Huge isn’t it?

Pic :3 Generations of 12A.Here is a nice comparison shot. Housing on the left is from a +-82. Housing in the middle is from +-1978.Housing on the right is from +-1973,Twin Dizzy.

Pic : Stock VS Ported. The older members here will remember the Smiley port. Does it just take you back???Was how it was done back in the 70`s!The housing on the left is from a later year than the one on the right. They differ by 2 years If I recall properly.

The first few shots is evidence that there was a learning curve in my life as Rotary engine builder/porter.
The engine`s port duration was simply to much to be started with a starter. It could be started by run starting the car. That would result in 1 rotor coming online : Rrrrrrrrrr.put.put.put.rrrrrrr.put.rrrrr and then a few secs later the other one. Haha,what fun that was. Idle was never a long,pulsing BRAP-BRAP like a normal bridge.Rather a very-very fast brapbrapbrap-cough-splutter- shake-shake-brapbrapbrap.

As I remember it came on song at about 7000rpm.It would buck and splutter, cough and carry on at anything below 5000 when driving. I think it idled at min off about 2100+ rpm. Anything below and it would die.
So there you have it! Some info on my STUPID engine.

Karis

 

Nice heart there!

 

And a new smilee is created.

 

wtf!..lol

 

haha,nice one!

where is Jeff Today?Is he sleeping in?

Karis

 

Considering it was like 5:30 AM his time when you posted that, I'd say it was likely that he was still sleeping.......
Those dern time differences can sure cause confusion.

Nice pics. I bet ya won't port one quite that far again.

 

Holy heart shaped port!

Now that I know a little more than I used to, I know to ask about your side seals. Were they nice and tight? Side seals make or break the idle on large ported engines.

 

I didnt think yoiu slept at all Jeff?With your amount of projects going, LOL

They were in good condition,as per mazda specs.Smiley port does make the older engine builders on the Rx club smile!

Nope,i will definately not go this far again!Must have been a brain glitch in the first place.

Karis

 

Ok, I have been trying to understand this smiley port. Is it the 3 holes? I just dont see a grin...

 

I'm glad US spec rotor housings didn't have the three holes. I wouldn't call joining them a smiley port, unless your upper lip kinda hangs a little too low. It looks more like a valentines day kind of thing.

I smile when a port I made performs well. That's the closest I get to a smiley port.

 

what a werid port..
were you thinking about ya gf when you did the last port.
got lost in what you were doing..

lots like it would **** things up when the rotor past the first part of the heart make it run real shitty.

 

I agree. The top should have been straight across. Kinda like this guy.

 

Ok,maybe a drunk smiley?haha

Remember guys this was waaaaayyyyy back in the 70`s.Our fist Rx2`s and R100`s had 3 small holes for the exhaust port to keep the noise down.It soon turned into the "smiley" or heart port it you like.The modified port flowed fine,even for a PP back then!

Karis

 

That's cool.

Hey a few years ago an Aussie built a PP 10A and joined the three holes into a triangular port. He didn't widen it at all as far as I know.

He posted an audio clip of it firing up. I might still have it somewhere.

 

I found it. How do I post something that's 237KB?

 

jeff
upload it to putfile.com or youtube.com
you may have to create an account

i see lol i didnt really peice the two together but i can see the 3 points"edge's" of the old circle ports.

seems to be lower port timming than the pre82 housings wonder how that sounded

 

wow thats pretty funny.

 

I guess I'll have to send it to PercentSevenC.

 

and just when i had seen it all, you gotta love this place sometimes

 

Yip,the good old RSA sometimes have weird ways of making the old Rotaries run

 

Yeah, Jeff, email it to me (percentsevenc@gmail.com) and I'll post it. I'm interested in hearing it, too.

 

Here's one link that dantheman can keep up for a while.

http://people.tamu.edu/~basile/10App_idle.mp3

%7c, you have mail.

 

I've actually heard this sound clip before. The link I found it at is here:

http://mrec.rotary.net.nz/media/sounds/10app_idle.mp3

If that one goes away, I've also uploaded it myself for redundancy's sake:

http://media.putfile.com/10A-Peripheral-Port-Idling

 

I originally downloaded it on 5-12-04. I don't remember any of the details now, other than it had a Weber and the three exhaust ports were joined into a triangle.

 

sweet..
and the 10a was a single rotor? im not to sure.