Custom Porting Templates - RX7Club.com - Mazda RX7 Forum

2nd Gen General Discussion The place for non-technical discussion about 2nd Gen RX-7s or if there's no better place for your topic
Sponsored by:

Custom Porting Templates

Reply

 
 
 
Old 09-14-18, 02:22 PM
  #1  
Full Member
Thread Starter
iTrader: (7)
 
jjandros's Avatar
 
Join Date: Dec 2012
Location: Virginia
Posts: 221
Thanks: 0
Thanked 4 Times in 4 Posts
VA Custom Porting Templates

***DO NOT post pictures or measurements of manufacturers templates***
Everything needs to be done from scratch as to not impede on anyone's Intellectual Property.
I am attempting to use a port template of my own design not copy someones.
Thank you for understanding.

Motor: S5 13bt
Trying to go about designing my own set of templates as someone has already ported my irons and they look pretty bad even after I cleaned up and deepened the bowl a bit. I will post up pictures in the next few days but for now I'll describe what they look like.

No porting on primary intake ports or Exhaust housings. Medium street port with an extremely shallow bowl. The inside edge of the secondary ports look to be matched to the runner thereby taking a bit of material away from the side towards the secondary oil control ring path. The motor rarely smoked and only did so under hard throttle (likely due to the Racing Beat oil pressure regulator not being shimmed properly).

Usually I would just buy a set of porting templates but since I don't think the previous "builder" utilized a template and after having ported a few motors I think I'd like to build one myself.

I have a few diagrams showing the stock port timing but would like to get more precise so I can see how I want to design it. If you have access to good diagrams, pictures of scribed oil ring, side seals, and corner seal paths it would be extremely helpful. Measurements that you've gathered or utilized in your experience would also be helpful. I will be using plexiglass on top of and open motor to see how the ports will work before deciding if I will use my design.

I will post a few of the pictures, diagrams, and measurements I have gathered so far for reference.
CAD references by shainiac can be found in this thread:
https://www.rx7club.com/rotary-car-p...ng-cad-952065/

What I've already decided:
A large street port with a mid sized exhaust port
Bowl will be deep and smooth but not polished
Primary and secondary intake port opening timing will be kept stock but widened
Primary and secondary intake port closing timing will be lengthened
Intake runners will be port matched

In your experience:
How far up and down you you extend the primary, secondary, and exhaust ports?
How far do most like to extend the exhaust ports to the sides?
How far outwards do you like to take your primary and secondary ports?
When porting towards the oil control ring line to smooth out the intake runner how close do you like to get to the secondary oil control ring path?
Do you prefer to have a rounded cutoff or straight line cutoff at the end of the intake ports?
jjandros is offline  
Reply With Quote
Old 09-14-18, 02:36 PM
  #2  
Full Member
Thread Starter
iTrader: (7)
 
jjandros's Avatar
 
Join Date: Dec 2012
Location: Virginia
Posts: 221
Thanks: 0
Thanked 4 Times in 4 Posts
VA



jjandros is offline  
Reply With Quote
Old 09-14-18, 04:35 PM
  #3  
Full Member
Thread Starter
iTrader: (7)
 
jjandros's Avatar
 
Join Date: Dec 2012
Location: Virginia
Posts: 221
Thanks: 0
Thanked 4 Times in 4 Posts
VA

Here's a picture of how the port looked after being cleaned up with a wire wheel.
It looks someone began attempting a street port on the two end irons and then quit half way through.
I've been running these irons without much issue and it looks like the port was brought inwards towards the oil control ring.
Therefore I thinking of following the inner line up when I extend this "port job" but I'm afraid the porting has already entered the secondary oil control ring path.
Anyone have experience porting on the inside edge and where or where not to go?

Here's the beginning of the housing port.
All I've done so far is match the exhaust insert to housing.
I'm thinking of cleaning it up, beveling the bottom edge a little and calling it done.

Last edited by jjandros; 09-14-18 at 04:38 PM.
jjandros is offline  
Reply With Quote
Old 09-14-18, 07:00 PM
  #4  
malignant narcissist
iTrader: (2)
 
diabolical1's Avatar
 
Join Date: Feb 2002
Location: FL
Posts: 9,056
Thanks: 0
Thanked 15 Times in 14 Posts
I actually made a few different templates way back when I was honing my porting skills (and had dreams of being mentioned among those I greatly respect when it comes to porting rotaries).I don't have measurements handy because at the time I didn't take any. However, I know they work because I have used them each at least once. This sounds like something you're trying to do ASAP, so I'm not sure if you would have the time to wait for me to get a hold of my templates and some stock housings to take measurements for you. It will probably take me at least two weeks to get to where I have my templates and housings.

What I will say about my experiences with making templates (I started doing them around 2004 or so and made my last one maybe sometime in 2009-ish I think), the ones that are any good eventually got to look a lot like the ones available for purchase. I don't say that to discourage you at all, I think you should go for it - and the plexiglass is a great idea. That's what I used for all but one of mine. I said it simply because there's a reason for it, and it took me while to figure that out. There's a zone, if you will, and once you start to stray outside it - depending on what your goals are - predictably strange and bad things start to happen (performance and/or reliability start to suffer, you perform a water injection mod, etc.).

As far as your thread is concerned, it may be worth trying get some key people to provide input. I've been away for a while, but from what I've seen Jeff20B, Peejay, J9fd3s and BlueTII are still around. It's worth a few PMs in the event that they don't naturally get involved. Jeff20B is a whiz when it comes to the measurements and actual specs, I don't say that to take anything away from the others I mentioned, but I have always admired that aspect of his inputs. Also, it's worth your while to get a degree wheel - I downloaded one for free and mounted it to cardboard.

Anyway, I will leave the speech at that, and move on to whatever parts of your actual questions I am able to answer. Since you specified a S5 engine, I will limit my answers to MY experiences with them.

Originally Posted by jjandros View Post
In your experience:
How far up and down you you extend the primary, secondary, and exhaust ports?
I don't have concrete answers for this one, so I'll skip it except to say this: with the intake ports, I eventually started taking a page out of our Australian brethren's book. I now put decent squared bevel on the lower edge of the port, just off the port floor.
Give THIS a look. There are quite a few around.
How far do most like to extend the exhaust ports to the sides?
As a general rule, I don't anymore. The most I did when I used to was maybe blending a 2-3 mm into them. When I learned about the apex seal "bowing", I stopped touching the sides.

How far outwards do you like to take your primary and secondary ports?
If you mean the "opening" side, then I think the magic number was 11 mm. Again, I remember Jeff20B had posted a number and when I checked it against a housing and rotor I had laying around, it was spot on. I actually ended up tossing one of my templates that I had not yet used because of it. Please look it up though to confirm. I'm not confident that my memory is correct.

When porting towards the oil control ring line to smooth out the intake runner how close do you like to get to the secondary oil control ring path?
Again, this is a line I don't mess with. Did it once and did it incorrectly, then swore never again.

Do you prefer to have a rounded cutoff or straight line cutoff at the end of the intake ports?
If you're talking about the top of the aperture, then I generally leave them straight.

EDIT:
For your particular situation - which is fixing someone else's questionable work. I'm not going to try to persuade you away from your plan even though I might question a few decisions. However, I noticed you mentioned not wanting to touch the opening side, but I would humbly advise that you reconsider simply because when it comes time to blend the old into the new, it might help.

Last edited by diabolical1; 09-14-18 at 07:11 PM.
diabolical1 is offline  
Reply With Quote
Old 09-14-18, 11:52 PM
  #5  
Lives on the Forum
iTrader: (9)
 
BLUE TII's Avatar
 
Join Date: Mar 2001
Location: CA
Posts: 6,794
Thanked 98 Times in 87 Posts
What are you trying to accomplish with the porting and what turbo and at what boost are you running the turbo?
BLUE TII is offline  
Reply With Quote
Old 09-15-18, 02:25 AM
  #6  
Full Member
Thread Starter
iTrader: (7)
 
jjandros's Avatar
 
Join Date: Dec 2012
Location: Virginia
Posts: 221
Thanks: 0
Thanked 4 Times in 4 Posts
VA

Originally Posted by diabolical1 View Post
I actually made a few different templates way back when I was honing my porting skills (and had dreams of being mentioned among those I greatly respect when it comes to porting rotaries).I don't have measurements handy because at the time I didn't take any. However, I know they work because I have used them each at least once. This sounds like something you're trying to do ASAP, so I'm not sure if you would have the time to wait for me to get a hold of my templates and some stock housings to take measurements for you. It will probably take me at least two weeks to get to where I have my templates and housings.
This is going to take me some time to really feel like I get it right so if in two weeks you're able to get a hold of them I'd appreciate any and all information I can consume.

Originally Posted by diabolical1 View Post
What I will say about my experiences with making templates (I started doing them around 2004 or so and made my last one maybe sometime in 2009-ish I think), the ones that are any good eventually got to look a lot like the ones available for purchase. I don't say that to discourage you at all, I think you should go for it - ...
Well if I was discouraged easily I probably would be wouldn't post on forums or work on FCs at all for that matter so no problem there. All I ever ask is that for questions that require knowledge or experience, that people attempt to refrain from opinions with no backup. Opinions with backup are just constructive criticism or input. On a side note, these irons seem to be in pretty good shape and are well within spec, the only issue is the questionable "port job" at this point. I have two extra sets of irons that I can break out if need be but would rather see if I can salvage these and make them work like I want. Since it's my decision to experiment with it, if it ends up not working then I'll have to suck it up and replace them with another set. But, the goal is to keep these not only usable, but to also design a template that will provide consistency for future builds.

Originally Posted by diabolical1 View Post
As far as your thread is concerned, it may be worth trying get some key people to provide input. I've been away for a while, but from what I've seen Jeff20B, Peejay, J9fd3s and BlueTII are still around.
Thank you for the advise, I will give them a night or two to jump in on their own before I begin to ask them directly for assistance.


Originally Posted by diabolical1 View Post
I now put decent squared bevel on the lower edge of the port, just off the port floor.

The most I did when I used to was maybe blending a 2-3 mm into them. When I learned about the apex seal "bowing", I stopped touching the sides.

If you mean the "opening" side, then I think the magic number was 11 mm. Again, I remember Jeff20B had posted a number and when I checked it against a housing and rotor I had laying around, it was spot on. I actually ended up tossing one of my templates that I had not yet used because of it. Please look it up though to confirm. I'm not confident that my memory is correct.

Again, this is a line I don't mess with. Did it once and did it incorrectly, then swore never again.

If you're talking about the top of the aperture, then I generally leave them straight.
Great info, thank you. As a reference. When I say the bottom of the port I'm talking about the smaller end of the "tear drop", outside is the edge closest to the water jacket. Just so we're on the same page.

Originally Posted by diabolical1 View Post
For your particular situation - which is fixing someone else's questionable work. I'm not going to try to persuade you away from your plan even though I might question a few decisions. However, I noticed you mentioned not wanting to touch the opening side, but I would humbly advise that you reconsider simply because when it comes time to blend the old into the new, it might help.
Honestly, questioning my decisions is fine I'm looking for experienced advise from people that have found things to be tried and true first hand, not the whole grapevine scenario. So, if you have advice with solid reasoning, please throw it up with a quick explanation. I'm not hurt by advise and hopefully others won't be hurt with what advise I decide to take and which I don't.
jjandros is offline  
Reply With Quote
Old 09-15-18, 04:24 AM
  #7  
Full Member
Thread Starter
iTrader: (7)
 
jjandros's Avatar
 
Join Date: Dec 2012
Location: Virginia
Posts: 221
Thanks: 0
Thanked 4 Times in 4 Posts
VA

Originally Posted by BLUE TII View Post
What are you trying to accomplish with the porting and what turbo and at what boost are you running the turbo?
Setup I am currently running/upgrading to:

S5 13BT short block
60-1 P-trim T04B built by BNR
HKS cast exhaust manifold
HKS wastegate
Knockoff Greddy intercooler Piping
Corksport Intercooler
Tial Q series 50mm BOV with -8psi spring
Either the full S5 intake manifold and Greddy compression tube I have
Or S5 LIM and S6 UIM, throttle body, and TPS with a Greddy elbow compression tube (This is the only thing I don't have)
Modified Apexi Power intake
Stock Mazda thermostat and water pump
Racing Beat high pressure oil regulator
Oil catch can
Koyo N-flow Radiator
Ford Taurus 2-speed fan
Mk4 Supra Fuel Pump
Aeromotive FPR
FFE Fuel Rails
1000cc Injectors (primary and secondary)
Stock ignition coils (at least right now)
3" Racing Beat Downpipe
3" Racing Beat Pre-Silencer
Apexi N1 cat-back (modified to be 3" all the way)
Haltech Sprint RE ECU with terminated harness
Racing Beat Flywheel
A/C delete
Retain P/S by lowering the bracket
OMP delete (removed by previous owner and will be eventually reinstalled when a trade comes up)

If I feel like blowing the tires off I want to be able to do so. Although I'm not shooting for ridiculous power goals, I'd like to see 280-300 to the wheels for street driving and 350 with increased boost. 350 is probably a bit of a stretch, but if I get close I can tweak things from there if I want more. I would rather go slightly under my goal and build it up than go overboard and end up either selling parts off or not enjoying the drive.

I want a streetable car with plenty of responsive and a relatively wide, higher up power band. I want as much "brap" sound at idle as I can get without performing a full bridgeport. I'd like to keep the car streetable and enjoyable, so I'd like to keep lower end power loss reasonable. I tend to use the FC as my pleasure car. As such, it sees roughly 150 miles a week and will be seeing a few SCCA events a year. As such, I'm more worried about "the seat of the pants" feel and joy of driving the car then I am about a true power goal. Hopefully that makes sense to someone.
jjandros is offline  
Reply With Quote
Old 09-15-18, 07:28 PM
  #8  
Lives on the Forum
iTrader: (9)
 
BLUE TII's Avatar
 
Join Date: Mar 2001
Location: CA
Posts: 6,794
Thanked 98 Times in 87 Posts
OK, your set-up is the same set-up that I had on my TII except I adapted a 60mm wastegate onto the BNR Stage 4 because it always had such high boost creep no matter what I did with internal wastegates (S5 based hybrid, S4 based should not have that problem because they have turbulent flow before the wastegate to help it exit.
.

My first port job was an engine from Pineapple Racing.

Fixed the Pineapple ports so they didn't kill side seals (the old school rotary porting templates are flawed they should look like the ports you have in your current engine) and did what you are talking about- big bowls on the 2ndary ports and later closing with a traditional street port exhaust. It was a dog down low, but power came on super hard at 3,000rpm. Hard to drive.

Next engine I ported was very different (fresh irons= clean sheet). I ported with a very light touch using a dremel tool and kept the port runners stock and the bowls shallow (like a clean-up port) being careful not to port down to clean metal if there was a deep spot in the casting. I did as close to stock closing timing as I could on intake with a proper scissor closing (ported about 3mm up) and ported as much opening timing as possible (made the plexiglass template with seal tracks). Exhaust was 5mm or so early opening with rounded bottom edge (more gradual opening) and straightened out the top of the port with bevel added back into edges (a "D" port).

This engine was a beast down low, much easier to drive and made the same peak power as before because the 60-1 in the HiFi compressor housing could only flow to 385rwhp.


Old too big exhaust ports (NA late closing streetport sytle) versus smaller stock closing exhaust ports on Left






In the end it made 340rwhp at 10psi and 380rwhp at 14psi and I was able to push the turbo 18psi on race gas, but it only made 385rwhp- but more power under the curve.

So, my advice is keep the ports small and low volume for high intake velocity. Even stock ports can flow more than the turbo anyways. Port for overlap, but stock closing for the low end power since the little turbo limits top end power anyways.

Here is the thread from when I first did this smaller is better port engine-
https://www.rx7club.com/2nd-generati...-build-857528/
BLUE TII is offline  
Reply With Quote
The Following User Says Thank You to BLUE TII For This Useful Post:
KNONFS (09-17-18)
Old 09-16-18, 12:45 AM
  #9  
malignant narcissist
iTrader: (2)
 
diabolical1's Avatar
 
Join Date: Feb 2002
Location: FL
Posts: 9,056
Thanks: 0
Thanked 15 Times in 14 Posts
Originally Posted by jjandros View Post
This is going to take me some time to really feel like I get it right so if in two weeks you're able to get a hold of them I'd appreciate any and all information I can consume.
Well, I will get the measurements to you because I said I would. However, I don't want you to think of it as "consumable information" so much as you should probably look at it as pieces of a puzzle or steps in a process. Remember I said earlier that I pretty much ended up with templates that were available for purchase. That is because my thinking/maturity transitioned from trying to make the biggest port I could make to making the best port I could make. So I just want you to keep that in mind whenever I get you the numbers you wanted. My templates will all work, but there are some I would not use. Does that make sense? And I will say which is what whenever I post them.

Well if I was discouraged easily I probably would be wouldn't post on forums or work on FCs at all for that matter so no problem there.
Excellent point. I was just trying to make sure that I didn't come off as being overbearing. Sometimes when I look at old posts I made when talking about porting, I think I was be being overbearing, so I no longer want to do that. Maybe I'm overcompensating now, but whatever.

Honestly, questioning my decisions is fine I'm looking for experienced advise from people that have found things to be tried and true first hand, not the whole grapevine scenario. So, if you have advice with solid reasoning, please throw it up with a quick explanation. I'm not hurt by advise and hopefully others won't be hurt with what advise I decide to take and which I don't.
Well, my only real question about your plan was that you expressed a desire not to touch the opening edges of the intake port. That's like the one part of the port that doesn't much care about your application, it's simply going to give you more usable power. That's where the overlap is coming from. I mean, overlap can come from the exhaust as well, but in your application I would probably say don't mess with the exhaust closing much (a little shaping is okay), if at all. So, to me, it sort of defeats the purpose of porting the intake in the first place if you're not going to open it earlier.

That being said, how positive are you that the person who did it did not already port the opening edge some already? Did you measure it against the stock ones you said you had?

Overall, I would second the advice BlueTII gave for the intakes. Go with earlier open and don't stray too far from the stock closing. For the exhausts, you're using a turbo, so they can open earlier, then add a gentle arc to the closing edge. I like the D-ports as well, but I do them inverted, and the curved part is a little more subtle.
diabolical1 is offline  
Reply With Quote
Old 09-19-18, 03:22 AM
  #10  
Full Member
Thread Starter
iTrader: (7)
 
jjandros's Avatar
 
Join Date: Dec 2012
Location: Virginia
Posts: 221
Thanks: 0
Thanked 4 Times in 4 Posts
Started mocking up the oil and coolant lines as well as got some of my painting finished painting tonight. I'll be focusing on templates this week. I still need to figure out how many inches my down pipe will need to be extended as well but it's coming together nicely


Last edited by jjandros; 09-19-18 at 03:27 AM.
jjandros is offline  
Reply With Quote
 
 
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
metalliman
1st Generation Specific (1979-1985)
0
01-13-03 07:32 PM
Fennix_sr
1st Generation Specific (1979-1985)
7
12-01-02 05:20 PM
Rpeck
2nd Generation Specific (1986-1992)
12
05-19-02 05:28 AM
Grizzly
2nd Generation Specific (1986-1992)
1
03-25-02 01:18 PM
hIGGI
1st Generation Specific (1979-1985)
16
03-24-02 02:50 AM


Thread Tools
Search this Thread
Quick Reply: Custom Porting Templates


Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: