Paul

 I've been thinking about building a 3 rotor P-port, and some of the
 sealing
 techniques used around the
 intake tube. I know you have suggested epoxys in the past but what
 about using
 lead or tin?
 fairly easy to melt and will easily handle the heat. My thought was
 to clamp a
 steel plate to one side of the rotor housing
 fill the water jacket up with lead or tin then mill the hole in the
 rotor
 housing for the P-port. Has anyone suggested that yet?
 I think body shops have been doing that for years to fix panels on
cars.

 Tony

 It is worth a try. I think it will cool when you pour it into
 the water jackets and not bond. However heating the rotor housing
 to 1100 F in an oven and then poring the liquid brazing
 stuff might work. You will have to clean out the water jacket
 with a die grinder to get rid of the oxide and coolant deposits.

 We don't mess with any of that in the welded p-port version.

 Paul Lamar

  We finally have a reliable system that works and easily repaired
after
 a couple of years of trial and error AKA R&D :)

 We don't really use epoxy anymore. We tig weld a SS tube to
 the steel rotor liner. Pin hole leaks are sealed with liquid
 silicone rubber.

 http://www.rotaryeng.net/Welded-steel-p-port.html

 We also have a youtube video or two on the subject.
 See the attached pdf for a list.

 There is no reason for the tin or lead to bond to the aluminum
 so you would probably wind up with leaks.

 Paul Lamar


There are alloys used to sweat dissimilar metals together, along with
fluxes to clear oxides from the surfaces. Temps range between 350 to
1200f depending on metal types to be joined. --
http://www.muggyweld.com/index2.html


I am going to try this method when I do my P ports, both with the
stainless tube, and aluminum tube. A benefit may be eliminating any
silicone sealants required.

 Although I can tig the stainless tube to the housing myself, I am not
certain it will be successful after the hard chrome gets melted and
 mixed with the stainless on the liner, as I am not sure what the
outcome
has been with this phase of the project.

Ed Carver


Mark Steitle has been flying for awhile with welded p-ports.

We have 4,400 hits around the world  for almost a year
and no nay sayers yet :)

http://www.youtube.com/watch?v=NKJ00JsnS8A

Hard to guess how many have been built.

We only resort to the silicone if you find a leak
after the engine is assembled. It is rather
easy to check for leakage if you do this.

I have probably close to several hundred hours fooling
around trying to bond in p-ports. One engine developed leaks
after it ran and I had to drive half way to Denver to pick it up,
take it home, disassemble it and start over.

It can be done if you do everything exactly right and use just the
right procedures and materials. Aluminum is hard to bond to
as it develops an oxide coating that epoxy does not stick to
rather quickly when exposed to air. We discovered this
back in the 1960's when we tried to build bonded aluminum
monocoque race car chassis's at Chaparral.

Here is an eye opening little test.

Take four small strips of aluminum. Bond two to together with
epoxy. Treat the next two with an aluminum prep kit and
bond them together. Now try to bend them both after cure.

Paul Lamar


Paul
Thats certainly one way of doing it, The nice thing about using the
HTS-2000 rod is there is no welding
you would be drilling a hole in essentialy a solid block of aluminum
straight thru to the rotor housing
that's it no grinding cleanup nothing, if done correctly no leaks
either. You should realy watch the videos on their website it's
pretty impressive stuff.

http://www.aluminumrepair.com/index.asp

Tony

As I said above it won't bond to the aluminum in the rotor
housing unless you get rid of the oxide first and then by heating
the rotor housing to 1100 F. If you don't do that as the mixture
cools it will shrink moving away from the inner and outer walls
in the rotor housing water jacket.
Furthermore you could destroy the existing heat treat on the
rotor housing. Try the tig welding trick. You will like it as
it only takes 5 minutes. It does not distort the aluminum housing.

The video has nothing to do with what you are suggesting.
Notice they are heating what they are bonding parts to.
Notice also that they are filing the old part to remove
the aluminum oxide coating. You will have to go into
the water jacket and grind out the entire interior
surface with a burr inserted into a die grinder.

Also good luck finding a low cost oven large
enough to heat the entire rotor housing to at least 500 F
and maybe 1100 F.

However you are welcome to try it if you wish.
Makes sure you build up the p-port engine and run it
full power as we have. Pressurize the cooling system to
50 psi to be certain there are no leaks.

If it fails make sure you let us know :) I always let
people know when something I try does not work.
We learn more from what does not work than we do from what
does work.


Paul Lamar

That makes me wonder what alloy the housings are made of...6XXX?

Todd

Low heat expansion high silicon content. I don't have the number
but it could be a Japanese alloy.

Paul Lamar

Paul, The alloy is likely to be A356 or 357.
In japan 356 is much more common.
Bill Jepson