street porting and 6 ports
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Junior Member
Joined: Oct 2001
Posts: 20
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From: Vancouver
street porting and 6 ports
Hey everyone
I noticed in another posting that the 6 ports work differently between the 87, 88 models and the 88,89 models. One actuator turns different from the other and my understanding would be that the actual 6 port tube must be a different design between from each other. If say you took a 87 tube and tried to actuate it from a 90 actuator does it close when its suppose to open and vise versa. If any one could shed some light on this subject it would be very helpful.
The second question is how are these shops street porting a 6 port engine. I thought that was the idea behind the 6 port in the first place. Wouldn't the ideal engine be a 13B 4 port and street port it or even bridge ported. I have been tinkering with the idea of taking 85 GSL-SE 13B rotor housings, GSL-SE 12A front, middle and end housings to build a 4 port 13B. By using the FC oil pan it should bolt right into my FC.
Any ideas
Chris Y.
I noticed in another posting that the 6 ports work differently between the 87, 88 models and the 88,89 models. One actuator turns different from the other and my understanding would be that the actual 6 port tube must be a different design between from each other. If say you took a 87 tube and tried to actuate it from a 90 actuator does it close when its suppose to open and vise versa. If any one could shed some light on this subject it would be very helpful.
The second question is how are these shops street porting a 6 port engine. I thought that was the idea behind the 6 port in the first place. Wouldn't the ideal engine be a 13B 4 port and street port it or even bridge ported. I have been tinkering with the idea of taking 85 GSL-SE 13B rotor housings, GSL-SE 12A front, middle and end housings to build a 4 port 13B. By using the FC oil pan it should bolt right into my FC.
Any ideas
Chris Y.
Rotary Freak
Joined: Aug 2001
Posts: 2,267
Likes: 3
Porting 6-ports
First, the only difference between 86-88 and 89+ auxilliary ports are the means by which they are operated. 86-88s used exhaust backpressure, while later ones used the airpump and ACV to actuate them. The sleeves are the same.
Also, there's nothing wrong with porting 6-port engines. Anyone who claims they can't be ported, or that you won't get any benefits, needs to actually try it sometime (presuming they even know how to rebuild a rotary properly). That said, what you choose to build should be determined on what you are trying to accomplish. 6-port engines are great for converting to fixed closing timing (removing the auxiliary sleeves and reshaping the runner) and opening up the leading side (advancing the opening timing). This gives you an extreme duration and increases overlap, which is great on the high end. Exhaust ports would also require porting to deal with the extra flow from this setup. A four port engine is a good basis for more mild streetports that will provide more low-end torque and a broader powerband. Don't get me wrong, you can do some extreme porting on a 4-port engine too, but 6-port engines are readily available and easier to do in many respects. It all comes down to what your goals are, what your budget it, what your skills are, and what parts you have on hand.
--
Blake Qualley
Rotary Engine Illustrated
Also, there's nothing wrong with porting 6-port engines. Anyone who claims they can't be ported, or that you won't get any benefits, needs to actually try it sometime (presuming they even know how to rebuild a rotary properly). That said, what you choose to build should be determined on what you are trying to accomplish. 6-port engines are great for converting to fixed closing timing (removing the auxiliary sleeves and reshaping the runner) and opening up the leading side (advancing the opening timing). This gives you an extreme duration and increases overlap, which is great on the high end. Exhaust ports would also require porting to deal with the extra flow from this setup. A four port engine is a good basis for more mild streetports that will provide more low-end torque and a broader powerband. Don't get me wrong, you can do some extreme porting on a 4-port engine too, but 6-port engines are readily available and easier to do in many respects. It all comes down to what your goals are, what your budget it, what your skills are, and what parts you have on hand.
--
Blake Qualley
Rotary Engine Illustrated
It's Back!
Joined: Mar 2001
Posts: 1,049
Likes: 1
From: Cincinnati
Huh thats funny this post came up. I just posted on this very same.
All I know is Mazdatrix says not to do it, and I think they are the ultimate authority on rotary engines (or close) so I tend to agree with them, even thought I've never personally tried it.
If I get some money together I might try and street port my spare 12A. I dont' see how you could safely port a 6port engine unless you do exhaust only.
All I know is Mazdatrix says not to do it, and I think they are the ultimate authority on rotary engines (or close) so I tend to agree with them, even thought I've never personally tried it.
If I get some money together I might try and street port my spare 12A. I dont' see how you could safely port a 6port engine unless you do exhaust only.
Senior Member
Joined: Feb 2001
Posts: 611
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From: louisville, KY
Re: Porting 6-ports
Originally posted by Blake
First, the only difference between 86-88 and 89+ auxilliary ports are the means by which they are operated. 86-88s used exhaust backpressure, while later ones used the airpump and ACV to actuate them. The sleeves are the same.
Also, there's nothing wrong with porting 6-port engines. Anyone who claims they can't be ported, or that you won't get any benefits, needs to actually try it sometime (presuming they even know how to rebuild a rotary properly). That said, what you choose to build should be determined on what you are trying to accomplish. 6-port engines are great for converting to fixed closing timing (removing the auxiliary sleeves and reshaping the runner) and opening up the leading side (advancing the opening timing). This gives you an extreme duration and increases overlap, which is great on the high end. Exhaust ports would also require porting to deal with the extra flow from this setup. A four port engine is a good basis for more mild streetports that will provide more low-end torque and a broader powerband. Don't get me wrong, you can do some extreme porting on a 4-port engine too, but 6-port engines are readily available and easier to do in many respects. It all comes down to what your goals are, what your budget it, what your skills are, and what parts you have on hand.
--
Blake Qualley
Rotary Engine Illustrated
First, the only difference between 86-88 and 89+ auxilliary ports are the means by which they are operated. 86-88s used exhaust backpressure, while later ones used the airpump and ACV to actuate them. The sleeves are the same.
Also, there's nothing wrong with porting 6-port engines. Anyone who claims they can't be ported, or that you won't get any benefits, needs to actually try it sometime (presuming they even know how to rebuild a rotary properly). That said, what you choose to build should be determined on what you are trying to accomplish. 6-port engines are great for converting to fixed closing timing (removing the auxiliary sleeves and reshaping the runner) and opening up the leading side (advancing the opening timing). This gives you an extreme duration and increases overlap, which is great on the high end. Exhaust ports would also require porting to deal with the extra flow from this setup. A four port engine is a good basis for more mild streetports that will provide more low-end torque and a broader powerband. Don't get me wrong, you can do some extreme porting on a 4-port engine too, but 6-port engines are readily available and easier to do in many respects. It all comes down to what your goals are, what your budget it, what your skills are, and what parts you have on hand.
--
Blake Qualley
Rotary Engine Illustrated
I've heard two sides as far as combining the normal and aux port (removing the separator).. What's your opinion on this? And how far back should it be removed? All the way to the manifold? INTO the manifold? My goal is ~200 at the wheels, and I don't give a damn about streetability.-Tesla
Rotary Freak
Joined: Aug 2001
Posts: 2,267
Likes: 3
Porting 6-ports
Originally posted by Suparslinc
Huh thats funny this post came up. I just posted on this very same.
All I know is Mazdatrix says not to do it, and I think they are the ultimate authority on rotary engines (or close) so I tend to agree with them, even thought I've never personally tried it.
If I get some money together I might try and street port my spare 12A. I dont' see how you could safely port a 6port engine unless you do exhaust only.
Huh thats funny this post came up. I just posted on this very same.
All I know is Mazdatrix says not to do it, and I think they are the ultimate authority on rotary engines (or close) so I tend to agree with them, even thought I've never personally tried it.
If I get some money together I might try and street port my spare 12A. I dont' see how you could safely port a 6port engine unless you do exhaust only.
--
Blake Qualley
Rotary Engine Illustrated
Junior Member
Joined: Sep 2001
Posts: 25
Likes: 0
From: Charlotte/Raleigh NC
some shops will tell you not to enlarge the ports on a 6 port engine, but it is very possible and gives good results. however most of the work is done to the 2 ports of the center housing. the 5th and 6th ports are usually not enlarged much.
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