Modular Timing P-Port design idea
11-16-2009, 12:50 PM
#1
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Thread Starter
Join Date: Sep 2007
Location: Indianapolis
Posts: 60
Hi everyone, I have a bit of a hairbrained idea I thought I'd throw around and see what everyone thinks.
I threw together a rough drawing of what I have in my head and attached it to this post. It is very rough, mind you.
The main idea is to have a sleeve inside a sleeve. The main sleeve will be pressed in and tack welded to the housing.
The second sleeve with have the same OD as the ID of the determinant sleeve, but could one of many IDs, depending on the application.
My goal was to have a port profile for a somewhat "streetable" motor, but for track days or fun at the drag strip, I could swap in a different profile.
This would also allow one to test different styles or sizes of ports.
In my rough drawing, I had the original bore in the rotor housing at ~2.248 and the OD of the main sleeve at 2.250.
The ID of the main sleeve and the OD of the inner would be approx 2.00 and perfectly round.
I had planned on buying a 1.5" ID tubing for the inner sleeve, so I'd have room to play with for non-round shaped ports.
You can also see the 2.5" O-rings I drew in to seal the sleeves/manifold. I figured this would make positive and inexpensive way of sealing everything up.
Finally, the entire system would be plumbed into a 2" tubing manifold and 54mm ITBs. And I realize I would need different fuel and possibly timing maps for each set up.
Feel free to input any and all suggestions.
*Note, the images of the sleeves are Untrimmed. I made the inner longer than the other in the drawing so the differences are more noticeable.
-Alex
I threw together a rough drawing of what I have in my head and attached it to this post. It is very rough, mind you.
The main idea is to have a sleeve inside a sleeve. The main sleeve will be pressed in and tack welded to the housing.
The second sleeve with have the same OD as the ID of the determinant sleeve, but could one of many IDs, depending on the application.
My goal was to have a port profile for a somewhat "streetable" motor, but for track days or fun at the drag strip, I could swap in a different profile.
This would also allow one to test different styles or sizes of ports.
In my rough drawing, I had the original bore in the rotor housing at ~2.248 and the OD of the main sleeve at 2.250.
The ID of the main sleeve and the OD of the inner would be approx 2.00 and perfectly round.
I had planned on buying a 1.5" ID tubing for the inner sleeve, so I'd have room to play with for non-round shaped ports.
You can also see the 2.5" O-rings I drew in to seal the sleeves/manifold. I figured this would make positive and inexpensive way of sealing everything up.
Finally, the entire system would be plumbed into a 2" tubing manifold and 54mm ITBs. And I realize I would need different fuel and possibly timing maps for each set up.
Feel free to input any and all suggestions.
*Note, the images of the sleeves are Untrimmed. I made the inner longer than the other in the drawing so the differences are more noticeable.
-Alex
11-17-2009, 09:31 PM
#5
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Join Date: Sep 2007
Location: Indianapolis
Posts: 60
A restrictor plate would do very little to actually effect port timing. The opening against the apex seal determines when the chamber to starts and stops filling with air.
If the size of the port is different away from the apex seal, it will affect flow and velocity, but not timing.
I want to have the sleeve as close as possible to the combustion chamber so that it actually has an effect on port timing.
If the size of the port is different away from the apex seal, it will affect flow and velocity, but not timing.
I want to have the sleeve as close as possible to the combustion chamber so that it actually has an effect on port timing.
11-19-2009, 10:29 AM
#6
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Join Date: Jan 2009
Posts: 26
Despite this modular sleeves would be interesting, I´m rather curious if it will work. You can´t affect overlap sufficiently to notice difference in streetability etc. Early opening is benefical in all engine speeds. Closing timing of intake ports mainly affects powerband and even more important is intake runner length... So I would rather go for variable intake length, much more effective for your intended aplication IMO
12-24-2009, 03:54 PM
#7
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Join Date: Sep 2007
Location: Indianapolis
Posts: 60
Here is my idea. I'm trying to draw in all of the correct materials, so here's a list:
ID of hole in housing: 2.125"
OD of permanent sleeve: ~2.127" This will 2.500OD/2.000ID tubing turned town to 2.127/2.005 just to clean up any imperfections from extrusion.
ID of permanent sleeve: 2.005
Modular Sleeves: OD ~2.003 to allow for thermal expansion. These will be turned out of 2.250 OD/1.250 ID tubing. The reason for such a thick wall thickness is so I can have enough material to machine in the port profile I want.
The runners are 1.5" 16ga alum. For my smaller "street setup, I'm leaning towards the 1.5" and the 42mm twin TB setup from a CBR 600RR and a pretty long runner length.
For the more adventurous setup, I will probably use 2" tubing and the 54mm TBs off of the earlier RC51 Honda V-twins.
Here's a couple pictures of the progress I have so far.
These are drawn how they will be initially machined. The sleeves will then be profiled and ground down to contour to the rotor housings.
Any and all comments welcome.
ID of hole in housing: 2.125"
OD of permanent sleeve: ~2.127" This will 2.500OD/2.000ID tubing turned town to 2.127/2.005 just to clean up any imperfections from extrusion.
ID of permanent sleeve: 2.005
Modular Sleeves: OD ~2.003 to allow for thermal expansion. These will be turned out of 2.250 OD/1.250 ID tubing. The reason for such a thick wall thickness is so I can have enough material to machine in the port profile I want.
The runners are 1.5" 16ga alum. For my smaller "street setup, I'm leaning towards the 1.5" and the 42mm twin TB setup from a CBR 600RR and a pretty long runner length.
For the more adventurous setup, I will probably use 2" tubing and the 54mm TBs off of the earlier RC51 Honda V-twins.
Here's a couple pictures of the progress I have so far.
These are drawn how they will be initially machined. The sleeves will then be profiled and ground down to contour to the rotor housings.
Any and all comments welcome.
12-25-2009, 05:02 PM
#8
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Join Date: May 2002
Location: California
Posts: 22,465
i like! couple of comments.
i think it would work better if it sealed with the apex seal, but if it didn't it would still work fine, especially on the closing side. but even without the sealing, velocity goes up, which is good. add some length tuning and its going to have a square power band!
our sleeve actually looks pretty similar (paul is aiming for ease of fabrication/simplicity of instal with the 787B port timing/shape) the big difference is that we are planning to just bolt a honda throttle body up to the sleeve, the non vtek is 60mm which is just about ideal for a 13B. for us it's easy to get.
the only other thing i can offer is that i got to drive a stock port 12a and my PP 12a nearly back to back, and the PP has more power under 4000 than the stock port has total. low RPM power is not the problem with the PP (although moving the powerband from 8000-9000 to 5000-7000 might be awesome on the street). and the PP will happily idle at the same rpm as the stocker too.
i'm still tuning, so drivability is unknown. so far it doesnt like part throttle. it likes 50% or more....
its also muffler kryptonite, the amount of exhaust energy is amazing
i think it would work better if it sealed with the apex seal, but if it didn't it would still work fine, especially on the closing side. but even without the sealing, velocity goes up, which is good. add some length tuning and its going to have a square power band!
our sleeve actually looks pretty similar (paul is aiming for ease of fabrication/simplicity of instal with the 787B port timing/shape) the big difference is that we are planning to just bolt a honda throttle body up to the sleeve, the non vtek is 60mm which is just about ideal for a 13B. for us it's easy to get.
the only other thing i can offer is that i got to drive a stock port 12a and my PP 12a nearly back to back, and the PP has more power under 4000 than the stock port has total. low RPM power is not the problem with the PP (although moving the powerband from 8000-9000 to 5000-7000 might be awesome on the street). and the PP will happily idle at the same rpm as the stocker too.
i'm still tuning, so drivability is unknown. so far it doesnt like part throttle. it likes 50% or more....
its also muffler kryptonite, the amount of exhaust energy is amazing
12-25-2009, 07:14 PM
#9
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Thread Starter
Join Date: Sep 2007
Location: Indianapolis
Posts: 60
Im curious how this think will react differently to exhaust. I plan on having just one exhaust setup. I know this is a compromise, but I dont have the money or the patients to swap exhaust every time I take it to the track. Ill draw up the exhaust when I have time.
In a nut shell:
2"OD primaries with approx 18" to the collector.
2.5" collector
2.5"-4" BurnsStainless megaphone to a 4" perf tube resonator (nothing to burn out lol)- unsure on total length of the resi, though.
4"-3" burn transition.
3" Borla XR-1 oval in before the dif.
3" RacingBeat rotor muffler because its stainless and purdy.
-This setup should be pretty loud and flow enough for the big ports. I could always build it without the XR1 just to see if its tolerable for tracking and add XR1 if not.
-For the street, SuperTrapp makes a nifty little baffle cap that clamps onto the tail pipe. It's tunable so you can add/remove baffles to suit your sound requirements. This could be removed in a couple minutes once at the track.
If I get time, Ill scramble a mockup of this in SolidWorks sometime soon.
-Alex
In a nut shell:
2"OD primaries with approx 18" to the collector.
2.5" collector
2.5"-4" BurnsStainless megaphone to a 4" perf tube resonator (nothing to burn out lol)- unsure on total length of the resi, though.
4"-3" burn transition.
3" Borla XR-1 oval in before the dif.
3" RacingBeat rotor muffler because its stainless and purdy.
-This setup should be pretty loud and flow enough for the big ports. I could always build it without the XR1 just to see if its tolerable for tracking and add XR1 if not.
-For the street, SuperTrapp makes a nifty little baffle cap that clamps onto the tail pipe. It's tunable so you can add/remove baffles to suit your sound requirements. This could be removed in a couple minutes once at the track.
If I get time, Ill scramble a mockup of this in SolidWorks sometime soon.
-Alex
12-29-2009, 03:42 PM
#10
Senior Member
Join Date: May 2002
Location: California
Posts: 22,465
in theory smaller intake should tolerate more muffers better.
i mocked up the engine just to spin the rotor and see how long the ports are open together. its a LOOOOOONG time.
suggestions on the exhaust;
you wanna make the design flexible, i didn't get mine right the first time, i want #2 to be able to become #3 easily.
1/4" thick flanges are not strong enough, i'm thinking about making mine slip fit actually.
you may also want to think about making the headers with a section that lets you change length too.
i don't know what your intended use for the thing is, but too quiet just wont be a problem... however restriction is, especially at idle.
i mocked up the engine just to spin the rotor and see how long the ports are open together. its a LOOOOOONG time.
suggestions on the exhaust;
you wanna make the design flexible, i didn't get mine right the first time, i want #2 to be able to become #3 easily.
1/4" thick flanges are not strong enough, i'm thinking about making mine slip fit actually.
you may also want to think about making the headers with a section that lets you change length too.
i don't know what your intended use for the thing is, but too quiet just wont be a problem... however restriction is, especially at idle.