Opinions on this porting?







Tony

 

Wow thats LARGE! The exhaust port is extreme, I have a set of housing like that but for a bridge-port you got large street ports. Just remember to add the bevel back on the ports. (very important)

 

I should have mentioned that is what it looked like when I took it apart.

I lost an inner water seal, an apex seal tip, and split a 2 piece apex seal into a 3 piece seal. Thinking that last part happend because of the lack of bevel on the back edge.

Tony

 

bleh! The exhaust port is quite rough. I'm not sure about it being so square if that makes any difference.

Definitely the lack of beveling can cause breakage of seals... Looks like quite a bit of overlap of ports as well (the intake ports on the front and rear housings are quite low). The intermediate hosing port looks like it was barely touched.

How close are the port edges to the oil control ring groove? From here it looks like it may be too far in..

 

Good eye...it's really close, if not too far in at least a centimeter up top on the rear plate.

 

Wow, that's a nice break!

I've never seen one quite like that. I've heard from builders that the beveling is necessary because the apex seal bows in slighlty when going over the port, so you want it not to bang against a sharp edge...

 

Weird exhaust port, you need the edge beveled on the exhaust as it closes the port, dont need it as much as it opens.

The secondary ports look a little bit too long, as already said to much over lap. by about 5mm. just a guess though

 

Seems to be a lot of wear on those irons, how many miles on them?

That exhaust port looks like poo.

 

Rich,

There is less than 12,000 miles on the housings, there were new at the last build. Irons have around 70,000 on them and are within specifications and the surfaces are flat. Do you mean in the discolored area at the bottoms?

Tony

 

REW motor?

That weird apex seal break is due to the bad exhaust port.
I've seen it before.

The exhaust port is pretty nasty.
I think a monkey with a die grinder can cut ports like that.

The intake ports look pretty mild.

Any chance you gonna tell us who did it?


-Ted

 

Hi Ted,

It is/was a 13-BREW. Ouch on your personal experience on the seal breakage. Who built that engine?

Not out to bash anyone. Just want to survive another year in keeping the car. The wife really wants me driving something else, even when it's recreational use only. Not winning that battle with the current situation.

Who knows, maybe the builder will contact me and offer to build another, better one, without the monkeys, and without tapping my wallet again.

Tony

 

What Apex seals are those?

 

It was a home-built engine, but the exhaust port wasn't chamfered correctly.



Familiar?


-Ted

 

Mazda seals and springs. Going with RA Super's. I know some will balk at that. I am so glad I didn't go 3mm ceramic (NPS I think was being pushed at the time) that the builder was suggesting. Assuming I would have gotten the same porting. Either the ceramic seal would not have cracked, or when it did, I might have had some damage.

Tony

 

Wow. Amazing. Guess I can nail the cause of my seal going from 2 to 3 piece as "known cause."

Thanks Ted.
Tony

 

it's okay for someone's first home-job, if they don't know better or are just experimenting, which doesn't seem to be the case if someone charged you for it. it's not very good at all for a professional.

 

This was not a first time port job.

 

I remember a while back I was very busy and needed a little help so I hired a kid to port and showed him how to chamfer etc.. He said he understood and I watched his finished product, he did a good job.
Later I found out he stopped chamfering. Anyhow it was only for a very short time and I will never let anyone touch anything I build, period.


Tony,
If I was you I would toss that motor. It looks to be "riden hard and put away wet".
I believe I know who built the motor, a west coast shop...

 

I've seen busted apex seals like that with a standard exhaust street port. Detonation is what killed that engine.

 

Chris,

Toss the housings, the irons, or the whole shebang? You know, and I know that you were the one I should have had build the engine back then. If only my tuning trip out there had come a couple weeks earlier. PM me if you have needed parts...I have the seals and the rings. Give me an estimate on $. Thanks.

Tony

 

99.99% of the time the car was being logged and there was no recorded detonation event. I am not naive enough to think that EVERY detonation event can be recorded, either.

The water seal was lost on the engine and I was flooding the car with coolant every time I shut it down. I stopped logging, and stop caring, the last hour of that engines life, but didn't mean to break anything else.

 

where did you learn to build motors? would love to do it yself but dont have the cash to make any mistakes

 

I've got to disagree.
Detonation tends to chip the tips of the triangle assist piece or the opposite side.
Unless you're doing something really stupid!
I mean, yes, the tips were broken, but detonation is not what caused the apex seals to split in half across the long side.


-Ted

 

I have personally seen apex seals SPLIT in half across the long side when detonation occured.
I heard it, the engine "grenaded". Big shot of nitrious. I pulled the motor apart. Same result.

 

Wow! That exhaust port is absolutely horrible. Even the shape is bad. Throw those rotor housings away. You can't salvage that at all no matter how much work you put into them.