Modular Timing P-Port design idea
11-20-09, 11:24 PM
#26
I like the Teflon idea. I priced 2" OD/1.5" ID tubing and its about $40 a foot. Wouldnt need much.
With Teflon though, how do you make some sort of sealing surface, ie flange?
You cant weld it or fuse it, right?
I was actually thinking the Teflon would just be a cylindrical sleeve.
The permanent outer metal sleeve would have the flange and the replaceable Teflon sleeve would be captured between the taper right at the housing surface and the intake manifold flange.
The intake manifold side ID at the flange would be the same as the largest Teflon sleeve ID; you could machine a velocity stack into the ID on the reduced ID Teflon sleeve for a smooth transition to the intake manifold.
You would need a pin through the the permanent sleeve into the replaceable teflon one so it did not rotate, or some other means of "clocking" it.
With Teflon though, how do you make some sort of sealing surface, ie flange?
You cant weld it or fuse it, right?
I was actually thinking the Teflon would just be a cylindrical sleeve.
The permanent outer metal sleeve would have the flange and the replaceable Teflon sleeve would be captured between the taper right at the housing surface and the intake manifold flange.
The intake manifold side ID at the flange would be the same as the largest Teflon sleeve ID; you could machine a velocity stack into the ID on the reduced ID Teflon sleeve for a smooth transition to the intake manifold.
You would need a pin through the the permanent sleeve into the replaceable teflon one so it did not rotate, or some other means of "clocking" it.
11-21-09, 12:40 PM
#27
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Actually the way that I'm talking about is exactly how Racing Beat builds their p-ports. They take and bore a hold through and thread it. Their insert is also threaded. The insert doesn't go all the way into the housing. It stops at a flat just before the end. The bore that extends into the engine is the same one as the I.D. of the sleeve itself. They just use epoxy to fill in and seal it all off but none of it is welded. Expansion also isn't an issue. The idea may not be practical for someone with limited resources but it is definitely possible and works quite well.
paul had a really good idea, it makes the threaded insert under simplified. we're also using honda throttle bodies, they come in the right sizes, and they are easy to find
our schedule is to have it up and running summer of 10...
11-21-09, 08:51 PM
#28
Im going to look around and see if I can scrounge up a 2 1/4" tap and find some junk housings and go to town.
To do the threaded method, I would have to have a "backstop" or some smaller ID portion that is flat and close to the combustion chamber.
I am really curious if that void between the threaded insert and the combustion would keep the port timing as the largest diameter?
To do the threaded method, I would have to have a "backstop" or some smaller ID portion that is flat and close to the combustion chamber.
I am really curious if that void between the threaded insert and the combustion would keep the port timing as the largest diameter?
12-24-09, 04:16 PM
#29
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.
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