What do you think about this porting?
#2
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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)
Last edited by Latin270; 09-20-06 at 02:52 PM.
#3
7 Rx-7s since 1980
Thread Starter
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
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
#4
Rotary Enthusiast
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..
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..
Last edited by atihun; 09-20-06 at 04:10 PM.
#5
7 Rx-7s since 1980
Thread Starter
Originally Posted by atihun
bleh!
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..
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..
#6
Rotary Enthusiast
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...
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...
#7
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
The secondary ports look a little bit too long, as already said to much over lap. by about 5mm. just a guess though
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#9
7 Rx-7s since 1980
Thread Starter
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
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
#10
Lives on the Forum
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
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
#11
7 Rx-7s since 1980
Thread Starter
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
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
#13
Lives on the Forum
Originally Posted by Asleep
It is/was a 13-BREW. Ouch on your personal experience on the seal breakage. Who built that engine?
Familiar?
-Ted
#14
7 Rx-7s since 1980
Thread Starter
Originally Posted by crispeed
What Apex seals are those?
Tony
#15
7 Rx-7s since 1980
Thread Starter
Originally Posted by RETed
It was a home-built engine, but the exhaust port wasn't chamfered correctly.
Familiar?
-Ted
Familiar?
-Ted
Thanks Ted.
Tony
#18
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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...
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...
#19
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Originally Posted by Asleep
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
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
#20
7 Rx-7s since 1980
Thread Starter
Originally Posted by Mr rx-7 tt
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...
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...
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
#21
7 Rx-7s since 1980
Thread Starter
Originally Posted by Mr rx-7 tt
I've seen busted apex seals like that with a standard exhaust street port. Detonation is what killed that engine.
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.
#23
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Originally Posted by Mr rx-7 tt
I've seen busted apex seals like that with a standard exhaust street port. Detonation is what killed that engine.
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
#24
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Originally Posted by RETed
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
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 heard it, the engine "grenaded". Big shot of nitrious. I pulled the motor apart. Same result.
Last edited by Mr rx-7 tt; 09-23-06 at 01:39 AM.