Building Peripheral Port housings
OBEY YOUR MAZDA
Joined: Oct 2002
Posts: 3,060
Likes: 2
From: Denmark
Bumpity bump
As of last week the race car spun a bearing during testing, boring story I willnot go into details.
Anyways it was a bridged sixport in good condition, resurfaced and stuff, 120psi of compression, now im thinking its a shame to let such a nice motor to waste.
We will during the winter make this motor a P-Port using the baseline Scalliwag idea.
Maybe instead of using a holesaw I can have a friend make the holes with the Spark Erosion Machine that he uses at work.
MY question is: Would that be a better/more precise method of doing it.?
One more question: Does anyone have a picture of that annular discharge IDA Weber.?
As of last week the race car spun a bearing during testing, boring story I willnot go into details.
Anyways it was a bridged sixport in good condition, resurfaced and stuff, 120psi of compression, now im thinking its a shame to let such a nice motor to waste.
We will during the winter make this motor a P-Port using the baseline Scalliwag idea.
Maybe instead of using a holesaw I can have a friend make the holes with the Spark Erosion Machine that he uses at work.
MY question is: Would that be a better/more precise method of doing it.?
One more question: Does anyone have a picture of that annular discharge IDA Weber.?
Old [Sch|F]ool
Joined: May 2001
Posts: 12,880
Likes: 577
From: Cleveland, Ohio, USA
Turbo/non turbo shouldn't make a difference. The air is still moving at the same speed, the difference is in the density of the charge.
And with all of that port area, velocity will be horrible.
And with all of that port area, velocity will be horrible.
Senior Member
Joined: Jan 2004
Posts: 341
Likes: 0
From: Colorado
More weight, that is exactly what I am talking about. Velocity does suffer, I am sure about that but it shouldn't matter that much under boost or does it? When I had my semi pp running (1.25" pp with large street ported side plates + large exhaust ports) my BOV vented pressure just blimping the throttle up to 4.5k RPM with a T51R Kai. How about that for intake charge?
Originally Posted by Kim
Bumpity bump
As of last week the race car spun a bearing during testing, boring story I willnot go into details.
Anyways it was a bridged sixport in good condition, resurfaced and stuff, 120psi of compression, now im thinking its a shame to let such a nice motor to waste.
We will during the winter make this motor a P-Port using the baseline Scalliwag idea.
Maybe instead of using a holesaw I can have a friend make the holes with the Spark Erosion Machine that he uses at work.
MY question is: Would that be a better/more precise method of doing it.?
One more question: Does anyone have a picture of that annular discharge IDA Weber.?
As of last week the race car spun a bearing during testing, boring story I willnot go into details.
Anyways it was a bridged sixport in good condition, resurfaced and stuff, 120psi of compression, now im thinking its a shame to let such a nice motor to waste.
We will during the winter make this motor a P-Port using the baseline Scalliwag idea.
Maybe instead of using a holesaw I can have a friend make the holes with the Spark Erosion Machine that he uses at work.
MY question is: Would that be a better/more precise method of doing it.?
One more question: Does anyone have a picture of that annular discharge IDA Weber.?
Finishing can be done with a flycutter or a boring head on a milling machine.
Originally Posted by speedturn
On my PP road race motors, I used to get my side housings prepared by the same engine builder who puts in the PP in the rotor housings. Last year, I thought I can do that; anyone can pour some epoxy in the side housings to seal off those old intake ports. I chose the Devcon steel filled epoxy, since the side housings are made of iron. After the usual careful break in period, my PP engine ran strong, winning 2 races and one second place finish, and I was leading a 4th race when it suddenly lost compression on one rotor. During the autopsy, I found that the cause of failure was the steel filled Devcon broke out in large chunks out of one of the intake ports, which wiped out the side seals and that side of that rotor.
I called and asked my PP housing builder, Nick at Rotary Reliability in Santa Anna, CA. Nick has been making his own PP motors over 20 years now; 20 years ago he set a Bonneville Land Speed Record with his own PP motor. Nick said, don't use the steel filled Devcon, use the Aluminum filled Devcon. I am a Mechanical Engineer, and I have been contemplating why aluminum over steel, and the only reason that I can think of is that maybe the aluminum filled Devcon conducts heat better than steel filled Devcon, so it is able to conduct heat out of itself and into the water cooled iron housing better. All I can say for sure is that Nick knows his stuff; my old 12A PP motor that he prepared the housings for lasted over 26 hours, and was still running well when I sold it to another road racer. On my current 13B motor, my Aluminum filled Devcon ports now have about 4 race hours on them (not counting break-in hours,) and I have won two more races with it this summer, beating out the 3 liter Porsches. Hopefully it will last many, many more race hours.
The Devcon to use is marked:
Aluminum Liquid F-2
10720
The Devcon is very expensive. Another tip Nick taught me is that you can use another, cheaper brand of epoxy to fill up to 3/4" from the face of the intake port, and then use the expensive Devcon to fill that last 3/4" that sees the heat of the rotors.
Do not pour the Devcon flush with the face of the side housing. Leave the Devcon at least .040" lower than the face of the side housing. Also remember that the Devcon may expand slightly while curing, so always pour it lower than the face of the side housing.
I called and asked my PP housing builder, Nick at Rotary Reliability in Santa Anna, CA. Nick has been making his own PP motors over 20 years now; 20 years ago he set a Bonneville Land Speed Record with his own PP motor. Nick said, don't use the steel filled Devcon, use the Aluminum filled Devcon. I am a Mechanical Engineer, and I have been contemplating why aluminum over steel, and the only reason that I can think of is that maybe the aluminum filled Devcon conducts heat better than steel filled Devcon, so it is able to conduct heat out of itself and into the water cooled iron housing better. All I can say for sure is that Nick knows his stuff; my old 12A PP motor that he prepared the housings for lasted over 26 hours, and was still running well when I sold it to another road racer. On my current 13B motor, my Aluminum filled Devcon ports now have about 4 race hours on them (not counting break-in hours,) and I have won two more races with it this summer, beating out the 3 liter Porsches. Hopefully it will last many, many more race hours.
The Devcon to use is marked:
Aluminum Liquid F-2
10720
The Devcon is very expensive. Another tip Nick taught me is that you can use another, cheaper brand of epoxy to fill up to 3/4" from the face of the intake port, and then use the expensive Devcon to fill that last 3/4" that sees the heat of the rotors.
Do not pour the Devcon flush with the face of the side housing. Leave the Devcon at least .040" lower than the face of the side housing. Also remember that the Devcon may expand slightly while curing, so always pour it lower than the face of the side housing.
My guess would be differential thermal expansion.
The DevCon AL probably has a higher thermal expansion coefficient (than the iron/port) essentially locking the epoxy plug in the port.
Most epoxies actually shrink (a few %) during cure - I assume the Devcon is no different. The epoxy will probably expand out, in the unrestrained port direction, during engine use as the temp rises.
Cheers
Senior Member
Joined: Nov 2003
Posts: 295
Likes: 6
From: Mich. USA
if you want to make a big precise hole in aluminum there is an easy way if you have the tools.
1- center drill (no flexing in the tool that will determine the placement of the port)
2- use your hole saw, a smaller one though, like 1/8" under what the final hole should be.
3.1- I make my own boring tools, It's easy as hell, take a 1" or greater steel round
3.2- turn one end down so it fits in the chuck or collet of your machinery
3.3- cross drill a 3/8" hole in the other end of the 1" round
3.4- cross drill and tap another hole in the round that intersects the 3/8" hole
3.5- take a broken 3/8" tap and walk to your bench grinder (it's a hard metal and makes good cutters.
3.6- grind away until the thing is shorter than your hole dia (plenty of clearance)
3.7- now grind a cutting edge into whats left of the tap (I know kind of unclear)
It should look similar to a cutter for a lathe
3.8- stick your cutter into the 3/8" hole you drilled earlier and secure it with a set screw in
the hole you tapped earlier.
3.9- chuck this boring bit into your machine and make a hole a few thou under desired
so the final pass just cleans it up and makes a nice surface.
My dad is an old tool maker and he tought me this, we have a half dozzen different sizes layin around the shop.
The end result should be way more precise than the hole saw method and should hold the sleeve a lot better. I can't imagine the surface is smooth with a hole saw, the more rough the less surface area and less holding force.
Making the tool might take an hour but it will make a perfect big damn hole.
If you want pics of a tool like this I can email one, just pm me
john
1- center drill (no flexing in the tool that will determine the placement of the port)
2- use your hole saw, a smaller one though, like 1/8" under what the final hole should be.
3.1- I make my own boring tools, It's easy as hell, take a 1" or greater steel round
3.2- turn one end down so it fits in the chuck or collet of your machinery
3.3- cross drill a 3/8" hole in the other end of the 1" round
3.4- cross drill and tap another hole in the round that intersects the 3/8" hole
3.5- take a broken 3/8" tap and walk to your bench grinder (it's a hard metal and makes good cutters.
3.6- grind away until the thing is shorter than your hole dia (plenty of clearance)
3.7- now grind a cutting edge into whats left of the tap (I know kind of unclear)
It should look similar to a cutter for a lathe
3.8- stick your cutter into the 3/8" hole you drilled earlier and secure it with a set screw in
the hole you tapped earlier.
3.9- chuck this boring bit into your machine and make a hole a few thou under desired
so the final pass just cleans it up and makes a nice surface.
My dad is an old tool maker and he tought me this, we have a half dozzen different sizes layin around the shop.
The end result should be way more precise than the hole saw method and should hold the sleeve a lot better. I can't imagine the surface is smooth with a hole saw, the more rough the less surface area and less holding force.
Making the tool might take an hour but it will make a perfect big damn hole.
If you want pics of a tool like this I can email one, just pm me
john
Senior Member
Joined: Nov 2003
Posts: 295
Likes: 6
From: Mich. USA
pretty sexy site!
http://images.google.com/imgres?imgu...ial_s%26sa%3DN
http://images.google.com/imgres?imgu...ial_s%26sa%3DN
Originally Posted by RXBeetle
if you want to make a big precise hole in aluminum there is an easy way if you have the tools.
1- center drill (no flexing in the tool that will determine the placement of the port)
2- use your hole saw, a smaller one though, like 1/8" under what the final hole should be.
3.1- I make my own boring tools, It's easy as hell, take a 1" or greater steel round
3.2- turn one end down so it fits in the chuck or collet of your machinery
3.3- cross drill a 3/8" hole in the other end of the 1" round
3.4- cross drill and tap another hole in the round that intersects the 3/8" hole
3.5- take a broken 3/8" tap and walk to your bench grinder (it's a hard metal and makes good cutters.
3.6- grind away until the thing is shorter than your hole dia (plenty of clearance)
3.7- now grind a cutting edge into whats left of the tap (I know kind of unclear)
It should look similar to a cutter for a lathe
3.8- stick your cutter into the 3/8" hole you drilled earlier and secure it with a set screw in
the hole you tapped earlier.
3.9- chuck this boring bit into your machine and make a hole a few thou under desired
so the final pass just cleans it up and makes a nice surface.
My dad is an old tool maker and he tought me this, we have a half dozzen different sizes layin around the shop.
The end result should be way more precise than the hole saw method and should hold the sleeve a lot better. I can't imagine the surface is smooth with a hole saw, the more rough the less surface area and less holding force.
Making the tool might take an hour but it will make a perfect big damn hole.
If you want pics of a tool like this I can email one, just pm me
john
1- center drill (no flexing in the tool that will determine the placement of the port)
2- use your hole saw, a smaller one though, like 1/8" under what the final hole should be.
3.1- I make my own boring tools, It's easy as hell, take a 1" or greater steel round
3.2- turn one end down so it fits in the chuck or collet of your machinery
3.3- cross drill a 3/8" hole in the other end of the 1" round
3.4- cross drill and tap another hole in the round that intersects the 3/8" hole
3.5- take a broken 3/8" tap and walk to your bench grinder (it's a hard metal and makes good cutters.
3.6- grind away until the thing is shorter than your hole dia (plenty of clearance)
3.7- now grind a cutting edge into whats left of the tap (I know kind of unclear)
It should look similar to a cutter for a lathe
3.8- stick your cutter into the 3/8" hole you drilled earlier and secure it with a set screw in
the hole you tapped earlier.
3.9- chuck this boring bit into your machine and make a hole a few thou under desired
so the final pass just cleans it up and makes a nice surface.
My dad is an old tool maker and he tought me this, we have a half dozzen different sizes layin around the shop.
The end result should be way more precise than the hole saw method and should hold the sleeve a lot better. I can't imagine the surface is smooth with a hole saw, the more rough the less surface area and less holding force.
Making the tool might take an hour but it will make a perfect big damn hole.
If you want pics of a tool like this I can email one, just pm me
john
1. Centre drill the hole true and use a dowel (not bit) in the holesaw.
2. You probably want to drill undersize and then finish with some other cutting tool.
3. Before using a hole saw, I turned it on a lathe to true it up and reduce friction (5 minutes?). This was not really required because I drilled quite a bit undersize. The resulting bored hole was quite smooth but required a cutting fluid due to friction with the hole saw.
4. Be careful when transitioning from the aluminum housing to the inner chromed steel liner - don't rush it.
A few other recommendations:
Some sort of mechanical method of locking the intake insert in place is probably not a bad idea (I believe racing beat threads theirs'). I ended up cutting a matched conical hole and sleeve insert (smaller towards the inner housing) doing an interference press fit with epoxy on the sleeve. They aren't likely to be going anywhere soon...
Cheers
Senior Member
Joined: Mar 2001
Posts: 482
Likes: 0
From: St. Pete, FL
Originally Posted by peejay
Turbo/non turbo shouldn't make a difference. The air is still moving at the same speed, the difference is in the density of the charge.
And with all of that port area, velocity will be horrible.
And with all of that port area, velocity will be horrible.
I can lay my hands on a engine from the late70s early 80s.. that is a 13B with a Street ported primary, FULL bridge Secondaries.. adn PP housings. It has a custom intake with 6 individual runners leading to a 6 barrel Throttle body. The throttle body is progressive.. primaries open, then secondaries.. then ...umm.. Terciaries? (SP) which are the PP runners.
The individual runners are CLOSED at idle.. only the primaries are cracked. Idles smoothly. Then it makes good torque.. then secondaries open as you apply throttle and it starts ripping.. THen if you need it.. and are over 5 or 6K the PP runners open.. and all hell breaks loose.
You must DRIVE the engine.. not just stomp it. The catch on the whole thing. You stomp it and I am sure it will bog if down low.
It had a 16K redline.... the guy who made it was a machinist, and race car designer.. and actually the design he and another have created is a winning chassis out there.
The point.. you can control the intake runner velocity IF you take the time to create the sealed runners and throttle body to accomplish that.
I imagine there are too many on here who want to turbocharge it with a large plenum.. but that.. will have horrible port velocity.. as we all know.
Undercover
Joined: Aug 2001
Posts: 1,983
Likes: 0
From: Ohio
Im trying to load up some cool picks for you guys, but i keep getting an upload error message of: the jpg dadad that i selected only partialy uploaded, then it wont actually upload it??? any help here guys? its been doing this same problem to me a bunch lately.
CJG
CJG
Full Member
Joined: Jul 2003
Posts: 56
Likes: 1
From: troy, oh
I am gathering parts to start my own homebuilt p-port so I stop in to check this thread occasionally. Good to see it still going. Since it sounds like there are a few of you who have built or are building these, I was wondering if anyone has found a good source for the aluminum tube/pipe. All the places that I have checked don't stock it and want to sell me 25' of the stuff. Any leads would be helpful.
Senior Member
Joined: Nov 2003
Posts: 295
Likes: 6
From: Mich. USA
There are alot of places online that sell short lengths
http://www.onlinemetals.com/merchant...owunits=inches
www.mcmaster.com as well
http://www.onlinemetals.com/merchant...owunits=inches
www.mcmaster.com as well
Undercover
Joined: Aug 2001
Posts: 1,983
Likes: 0
From: Ohio
Finally able to get some pics up. thought id share some of my eye candy with you guys. just wasnt sure that you guys new mazda actually did sell both d port and rectaungular ported housings. the rectangular windowed ones made more peeky power in a narrower power band. These were most often used for qualifying and referred to as qualifier housings. the d ports were slightly more conservative and used for the rest of the race where some endurance was needed. enjoy.
CJG
CJG
Undercover
Joined: Aug 2001
Posts: 1,983
Likes: 0
From: Ohio
Because its cost prohibitive for most. I picked up 3 sets a couple years ago and sold one set off last year. You can call up mazda motorsports and order them out. but its going to run you about 13-1500 a housing. But its the easiest way to bolt together a naturally aspirated 1.1 liter that makes 290-320hp.
CJG
CJG
Full Member
Joined: Nov 2003
Posts: 192
Likes: 8
From: .
Heres a 13B MFR housing with the D shape inlet port.
The other 2 pics are the housings that I do.
By the way, Devcon is crap. I've seen it fall out of other peoples engines after less than a year. I made my own filler using industrial grade Araldite(not sure if you can buy it in the USA) and aluminuim powder for the housings or steel grit for filling the original ports.
The other 2 pics are the housings that I do.
By the way, Devcon is crap. I've seen it fall out of other peoples engines after less than a year. I made my own filler using industrial grade Araldite(not sure if you can buy it in the USA) and aluminuim powder for the housings or steel grit for filling the original ports.
Senior Member
Joined: May 2005
Posts: 283
Likes: 0
From: MA
So if we build our own housings, on top of that, for the price of a carb, you can pick up a megasquirt kit and throw some injector stacks on there. Slide throttle body it and your good to go, fuel economy AND horsepower
OBEY YOUR MAZDA
Joined: Oct 2002
Posts: 3,060
Likes: 2
From: Denmark
OC94Rx7 and I made one rotorhousing today, its actually not that hard afterall.
We had a little fitment issue in the mill but we solved it.
Pics so far. http://www.wankelkim.net/rx7/P-port/
Will need to make another housing and the aluminum inserts
We had a little fitment issue in the mill but we solved it.
Pics so far. http://www.wankelkim.net/rx7/P-port/
Will need to make another housing and the aluminum inserts
Originally Posted by PDF
Heres a 13B MFR housing with the D shape inlet port.
The other 2 pics are the housings that I do.
By the way, Devcon is crap. I've seen it fall out of other peoples engines after less than a year. I made my own filler using industrial grade Araldite(not sure if you can buy it in the USA) and aluminuim powder for the housings or steel grit for filling the original ports.
The other 2 pics are the housings that I do.
By the way, Devcon is crap. I've seen it fall out of other peoples engines after less than a year. I made my own filler using industrial grade Araldite(not sure if you can buy it in the USA) and aluminuim powder for the housings or steel grit for filling the original ports.
A couple of questions:
What is the hole above the spark plug?
What is the ID/OD of your insert?
Did you press fit the insert all the way through?
Cheers
Undercover
Joined: Aug 2001
Posts: 1,983
Likes: 0
From: Ohio
Originally Posted by trydis7
Nice work.
A couple of questions:
What is the hole above the spark plug?
What is the ID/OD of your insert?
Did you press fit the insert all the way through?
Cheers
A couple of questions:
What is the hole above the spark plug?
What is the ID/OD of your insert?
Did you press fit the insert all the way through?
Cheers
CJG
Full Member
Joined: Nov 2003
Posts: 192
Likes: 8
From: .
Originally Posted by trydis7
Nice work.
A couple of questions:
What is the hole above the spark plug?
What is the ID/OD of your insert?
Did you press fit the insert all the way through?
Cheers
A couple of questions:
What is the hole above the spark plug?
What is the ID/OD of your insert?
Did you press fit the insert all the way through?
Cheers
43mm ID 60mm OD. The sleeve doesn't go right through, it's pressed against a shoulder.