I just got my irons back from porting and I noticed there were some differences in the ports in the front and rear irons. The port shapes seem to be identical however inside they are not. The rear iron has a rather large dip towards the e -shaft and there is a noticable gouge where it seems you can see a seperation in the material. The dark area is the dip and the line is the "gouge" or seperation. And no it's not dirt.





It doesn't seem as bad in pictures but should I be concerned?

 

I would smooth it out, but i'm kindda ****
You will hate the fact, that you know it ain't perfect.

 

It won't hurt anything. Sometimes a casting is flawed. Fixing it could cause other issues since it would probably then be slightly behind the port opening. I'd leave it alone. There is nothing to be had from touching it. It's actually a common issue.

 

That's my thing, it already dips down below the port opening. It feels like this

 

compared to R.E.Amemiya portings that does looked flawed...

just to be a "guy who doesnt know jack-shi", i would smooth her out and flatten the edge with a dremel.. but hey... this is from a guy "who doesn't know jack"



..good luck though

 

It looks like what is left from the original port. When stock, there is a short area of the port that is machined. It's straight and perpendicular to the face of the iron. Goes down about .1" Then it is just rough casting after that. The person who ported your motor just left a witness of the intersection after smoothing and blending. I'm no expert but I think they look pretty good.

 

Yes that side housing just had a bad intake core shift during casting.

There is nothing to be done but get another housing with better core shift or live with it. You cannot port the area to the optimal shape as it will compromise the oil seal track.

Whoever ported the housings probably did the best they could with the housings provided.

Not as much flow down there at the bottom of the port anyways as compared to the upper part which looks fine in pics.

 

Ok well I sent the pics to the place that did it too and they are reviewing the situation and I think your probably right blut t2, that's what they said too. I think everything will be ok as the place is pretty much an authority in the rotary community, I'll reveal that after I hear back from them.

 

BLUE TII hit the nail on the head perfectly. Its core shift in the casting and its a tiny flaw that wont yield any noticable loss in power at all. Blending it will get into the oil seal track, it's just not worth dicking with and the person porting did the correct thing. You wont gain anything (at least not measured via dyno or calibrated ***) even if it were a perfect casting and that bump wasent there.

~Mike...........

 

That's good to hear, anueryism avoided lol

 

I answered this in the third gen Section for the original poster there. You will see casting flaws as much as 1mm from the factory. If you guys knew what stuff mazda let by on there remans or original engines and people were still making 400hp+ back in the day, you wouldnt let something like this bother you. As it has already been posted, it wont solve anything by smoothing it out.

 

Open up the opening edge a hair bit more. Do not focus on doing more to the closing edge as it doesn't yield much gain. Match the bottom of the port outlet w/ the nitrided plating to remove the pressure drop point.

B