Building Peripheral Port housings
 

This kind of goes with my resurfacing rotor housing project. Does anyone here have first hand experience or knowledge of the best way to bore the approximately 2" hole in the housing. I have a mill and a lathe and the positioning of the housing is not the question. The question is more the cutter tooling used.
Since tooling for mills is expensive I would like to know what has worked for others and avoid as much trial and error as possible.

I've never done bridge porting, but I do have some machining experience, I would suggest using a boring tool in ur mill with a carbide insert.

I'm no machinist but the aluminum cuts nicely with a drill bit! :) One day I took a fresh battery in my cordless and chucked a big ole 1/2" bit in there and drilled a starter port. The metal shaved away nice and clean. After I did that, I was told that if I'd have used ethylene glycol coolant as a cutting fluid it would have cut even nicer.

The metal insert was a bit tougher, but it's chrome-moly steel so it kinda should be :)

No pics, and if I had any they'd not be worth seeing, just a 1/2" hole vaguely where an intake port should go while I finally decide on a port configuration.

A 2" drill bit would not be as practical as you may think. A bi-metal holesaw may work but I have a feeling the hole may look as primitive as the tool.

A starter hole is a no brainer, he's talking bout a 2" hole. U need something that will cut a smooth, round, straight hole that size. Just like if u were making a carb adapter plate.

You might consider a flycutter in the mill. They are not very expensive at places like Kennemetal. You might have to start with a pilot hole and make multiple cuts, but it really shouldn't take long.

Just a thought...........

db

Fly cutters r for milling the surface, not boring a hole.

Actually a hole saw seems to work pretty well. The only bi-metal one I could find in my garage was just 7/8" but I was looking more for how the teeth cut the material more than the size since it is all relative.
Just in case any of you want to try this. I will not go into setting up the lathe jig so this is after the housing is mounted in position to bore.
Since the hole saw used a 1/4" pilot bit I used a bare bit and drilled a 1/4" hole the entire way through.
Most of you can figure out that if you get a hole saw on an uneven surface that it is going to try to "walk" on you and leave a pretty rough looking hole. Since the surface where the bit enters the housing is awkward this is how I kept it from walking.
I took the 1/4" drill bit out of the hole saw and put a smooth piece of 1/4" round stainless rod in its place.
This forced the saw to stay true to the pilot hole. If I would have left the drillbit in it would have had a tendency to side cut the hole. Since the side of the rod was smooth it could not cut change the shape of the original pilot hole.
I know that is a long explanation but it is real important that anyone who tries this method adhere to that step. Otherwise you might end up with a oval hole.

I am milling a set for Ken Sheepers. This port is based on what he currently uses which is very similar to factory peripheral ports as opposed to the Racing Beat that comes in at a different angle than what he is wanting. He has ran both types and prefers this from experience.
Just in case you have not looked at a housing in a while remember where I drilled this is a little below center of an existing hole. The second picture from the bottom would appear to be screwed up if you don't keep that in mind.
I will post a pic after I do an actual pport ready housing and if I run into any surprises. So far this is a pretty inexpensive way to tool up for a job ;)

http://webpages.charter.net/mikeroberts/port03.jpg

http://webpages.charter.net/mikeroberts/port06.jpg

http://webpages.charter.net/mikeroberts/port07.jpg

http://webpages.charter.net/mikeroberts/port09.jpg

http://webpages.charter.net/mikeroberts/port12.jpg

http://webpages.charter.net/mikeroberts/port13.jpg

hmm interesting, Im also thinking of building up a PP for myself, so just a few quick questions :)

when you have the 2" hole bored, are you going to use an insert of some kind and then seal the water galleries off?

and also the final port shape on the ionside of the housing? is this just going to be a round hole, as I am thinking of stopping just short of the insert and doing final port shaping using a die grinder or something to control the port timing a bit better.

any help, thanks.

Yes. The insert is actually just a tube. Since you drill through a water jacket it is at least the easiest way to accomplish this. All the pports I have seen always used an epoxy like Devcon with the exception of Jesus Padilla that uses some kind of silicone. Or at least that is what it looks and feels like.
And after I measured Ken's the tubing was 2" ID with a 2 1/4" OD. He has a huge dual 55mm throttle body fuel injection setup.
I understand why people use epoxy just to be sure they don't get any leaks but if this was mine and not Ken's here is what I would do.
I would start off with a thicker walled tube. I would prep my hole saw. If you feel the outer edge of a hole saw you will be able to feel that the teeth slightly bend outward because these are not made for precise work and it allows clearance to reduce binding. Basically I would spin the holesaw on the lathe and file the hole saw so it was true. I would bore the holes and get a precised measurement.
After I had the measurement I would put the tubes on the lathe and make them a little oversized and put a small taper at one end.
The tubes would then go into the deep freezer to shrink them as much as possible. I would put the tapered end of the tube in the bore then press fit them in.
It should work like a freeze plug. You have to make sure the the tubes are longer than neccesary since it needs to be ground to follow the curvature of the inner wall of the housing.
To bench test it I would make to block off plates. (see picture) One would be tapped for an air fitting to tap into it. Laying the housing flat with the fitting pointing up I would fill it with a flourescent liquid and hook the air compressor to it. Look and see if there are any obvious leaks and if not hit the lights and fire up the blacklight and see if there is any sign of even slight leakage.
If it passed that test I would grind it back and to a finished state and test it again.
Obviously if I did this pport setup it would be for a race motor anyway so if it had to come back out it would not be the end of the world and it could still be epoxied later.
I will conceed that is more trouble than it is worth but I just like to do things sometimes to see if it will work ;)
http://webpages.charter.net/mikeroberts/port16.jpg
http://webpages.charter.net/mikeroberts/BLOCKPLATE.jpg
This would be two plates sandwiching the housing using 3 bolts and using sheet rubber between the plates to seal.

If you were really anal retentive you'd bolt a complete "empty" engine together (just housings, no internals) with the tension bolts torqued to spec, then heat everything up to operating temp (flow hot/boiling water through it) so all the stresses are the same.

Kinda like boring cylinders with a deck plate.

Some head porters bolt deck plates on the cylinder heads and flow hot water through them before doing a valve job! Every little bit of accuracy counts :)

Dammit Peejay why you want to get me doing something like that?!?!?! ;) I think a hot liquid under about 180 lbs. of pressure will have to do.
Then again if I drilled and tapped the plate that is opposite of the air fitting I would put a small heating element and a temperature gauge as well as a pressure gauge to keep it from getting ridiculously hot.... dammit Peejay, see what you got started?!?!?! :)

At some point you have to shoot the engineers and make the damn product already! :)

That's why I said hell, I'll just pot the whole thing with Devcon and chew a port out of that. Not pretty, but pretty doesn't matter.

No don't shoot the engineer! At least not while I'm the one wearing the hat that day!
Yes, theory can only get you so far and you have to put up or shut up eventually. You just want to do as much practical research as possible and look for any problems that may be avoidable.
My wife went to WW Grainger and picked up my holesaw and I have to run by a shop and pick up a piece of aluminum pipe after work. So by New Years day hopefully I will be doing a pport.
Right now I don't have anything to use on the tailstock of my lathe to turn the pipe on so I am trying to figure out how I am going to make due on that.

Well I got home and I looked at the hole saw. Like a kid in a candy store I made a beeline for the garage! I popped another housing up on the lathe and ran the 1/4" pilot and ran the 2 1/4" hole saw. It worked great.
I can also tell looking at it without a tube epoxied in why they epoxy them. There is no place for the water to circulate past the tube.
I probably won't try to press fit it after all.
So like I mentioned earlier the only hurdle now is figuring out how to support the tailstock end of the tube on the lathe so I can turn it down to fit in the hole now.
http://webpages.charter.net/mikeroberts/port17.jpg
http://webpages.charter.net/mikeroberts/port18.jpg
http://webpages.charter.net/mikeroberts/port21.jpg
http://webpages.charter.net/mikeroberts/port23.jpg
http://webpages.charter.net/mikeroberts/port25.jpg
http://webpages.charter.net/mikeroberts/port27.jpg
http://webpages.charter.net/mikeroberts/port29.jpg
http://webpages.charter.net/mikeroberts/port32.jpg
http://webpages.charter.net/mikeroberts/port36.jpg

that is a surprisingly clean cut the hole saw made...
though i have no experience with machining or cutting hard metals i remember trying to use a hole saw to install a new dead bolt onto my door...

let just say... shit! the cut wasn't the cleanest possible... thank good ness the dead bolt covers my sloppy hole.

Hey, let's not be talking about "sloppy holes"! ;) I used a Starrett holesaw and it is pretty nice. Before I made the cut I reversed the lathe and lightly ran a flat file against the side of the teeth. This trued the saw somewhat.
The main thing to remember is that I did not use a drillbit in the holesaw. The flutes on the side of the bit you have acted like a rotary file and distorted the 1/4" hole because there is a shitload of uneven side pressure. When you look at the picture be sure to take a good look at the smooth 1/4" shaft in the holesaw.
I am convince now that any time I ever use a holesaw for a door or anything else I will predrill the pilot hole and used the smooth shaft. It really is the shit.
If I did not have a lathe this would have been a lot harder.
Accurately positioning and keeping the housing still is the most critical part. The second part is how much "play" you have in what you use to drill with.
That is where the lathe really comes in.

Any machinist will read this thread and laugh to the point of tears. I am no machinist and my lathe is not much to brag about. But from a "tinkerer's" standpoint I am feeling pretty good about it. Especially since no machinist offered to give any advice and I just had to wing it. ;)

I showed this thread to my dad - he owns a machine shop. He laughed a little at your lathe, guessed at the brand and cost, then told me he would have used an end mill (I think that's the name) instead, but the cost is about $80 for a 2" one. Then he made this suggestion for turning that pipe on your lathe (The first sentance is word-for-word, the rest I summarized):

Your best bet would be to turn a plug for the end and put a live center in your morse taper. Or you could cut the tube into the short lengths that you need, then make a plug to fit inside the tube so you can tighten down the jaws without crushing it; then you wont need the tailstock for support.

Make sense?

Wow! Good thread... mainly due to the action photos!

Tell your dad thanks for the advice and to quit laughing at my cheapass lathe! ;) It's the best "new" lathe/mill combo that a poor white boy can buy!
Making the plugs is a great idea. I was looking through my J&L Industrial catalog and found a "bullhead" live center that has a big tapered end that is made for pipe. They cost around $100 so I think I will try your dad's idea.

What? The long winded explanations aren't the highlight?:confused:

What 3 in one machine do you have Scalliwag?

Question: Wouldn't you want the the "outer hole" to be the OD of the PP Tube and the housing hole to be the same diameter as the ID of the PP Tube; so that a lip is created to seat the PP Tube on. Of course this would require the housing end of the tube to be contoured to match the housing contour.

That is a great idea that would require a little more work. I woill have to look to be sure but I think you would not have to cut the tube to follow the contour though.
You may be able to bore the OD of the tube until you are an 1/8" or so from cutting through the inner wall. You would then change out the OD bit for just under and ID bit and bore through. From the pictures it is hard to tell but there is enough solid aluminum to do this without the water passage exposed.
This way you could leave a 90 degree cut on the tube and push it in the bore.
If the cuts are true enough by the time you hone it you would hardly (if at all) be able to see a seam.
I might give this a shot. It will require more tooling.
If it involved making the tube seat on a contured surface that would be pretty difficult to obtain a nice seal.

Most of the stuff I need machined I have to get a machine shop to do it. This will only get you so far.
This is the one I have from Harbor Freight:
http://www.harborfreight.com/cpi/pho...6199/46199.gif

If I ever figure out how to use a real lathe I may buy a real one ;)
I also found what I need to use to put the tube on the lathe for less than $20 It is a bullnose live center
http://www.harborfreight.com/cpi/pho...0099/40090.gif

I've been eying that one!!! My Machinists neighbor laughs, but I don't have 20K to invest in real tools~

Every now and then Harbor Freight puts them on sale for $549.00. If they are not on sale you can usually talk the store manager into putting it on sale for you. At least the guy in the Fort Worth store will.
Once I actually make some money from some of my shannanagins I will buy better equipment. But I will buy used and have someone that knows equipment check it out for any health problems.
For me, the limitations of this machine is pretty much equivalent to my personal limitations since I only know enough to be dangerous.
Right now I would not know what to do with a "real" lathe if I had one :)
But when I setup my machines for milling and finishing rotor housings I had 5 machinists at two machine shops consulting me and making the parts and setting everything up. I think the surface grinder that machined the plates I needed was $65,000 new is what they told me.
Some things have to be left to people that know what they are doing. But there are plenty of remedial tasks that these little machines can do and save a shitload of money.

hey i just want to say i like the pics. ok well hole saws work good but if u really want a hole the u can bore to let say .0005 id go wit an adj. boring head u can pick them up for rather cheap from Enco 220-1532 R8 SHANK & 12PC 3/4 3" BORING HEAD PACKAGE W/ 131 $99.95 that tool can bore up to a 3 3/4 in hole they work really well and the carbide bits will cut great i have my own bridge port and i use that boring head alot works just as good as a $400 bridge port setup

hope that helps u a little bit. I have a question how did u figure out where to put the port?

I took measurements off of Ken Scheepers current housings. Those are supposedly done off measurements from the factory Mazda pports.
But since Ken did not get his hands on those I could not confirm it. His best run was 10.87 last season in All Motor class. http://www.nhraimport.com/2002/drivers/k_scheepers.html
The first half of the race season was spent working out the big "bugs" on the new car and the last half was working out little ones. I am not sure how much he will be able to knock off on his time next season but all signs are pointing that it will be faster.

I just made a tube and put it in the housing and now I am going downstairs to take some pics and post them.

That is a great price but my lathe takes a #3 morse taper. The mill head takes an R8 but from henceforth I will refer to this as "cheesy-ass mill" and one of the reasons is because there is not enough room between the head and the table to even get a housing in position to cut :mad:
But as you will see in the pictures that as along as you use cheesy-mill's lathe with a hole saw it seems to work pretty well.
I know this is starting to look like a redneck joke, but humor me until you see the results! ;)
I would never let a little thing like common sense get in the way of trying something that should not work and I am not about to start now! Every now and then even a fool gets lucky :)

You can buy them with a #3 taper could you email me the specs on the hole ryantmoses@yahoo.com

Well here is the unepoxied results. It fits pretty tight and seems to be pretty tight all the way around the tube. I had to use a redneck press (a mallet and block of wood) ;) to put it in.If nothing else I am sure it looks better than most people would have expected.

http://webpages.charter.net/mikeroberts/port37.jpg
http://webpages.charter.net/mikeroberts/port39.jpg
http://webpages.charter.net/mikeroberts/port41.jpg
http://webpages.charter.net/mikeroberts/port43.jpg

I think that looks very good. You are a pioneer!

hey that is looking very good there, and now with pics it doesnt seem so hard after all, I think I will be trying my hand at making my own PP housings now :)

although another thing I have heard, is to have threads cut on the inside of the hole and the outside of the insert, so the insert actually screws into the housing, and then epoxied, making a very good seal, but this may require more specialised tooling.

have you got any idea what the specs are for the inlet timing for opening and closing of the ports? its just to me the port duration of the inlets is very big compared to the exhausts in the current form anyway, dont know if you plan to open out exhaust ports?

I saw where the RB PP's are threaded. It looked to be more trouble than it would be worth. Since they bring the tube through at a different angle there is less suface area of the housing that the tube is in contact with.
As tight as they were to press in I don't think they will be moving even without the epoxy. I had also left a should on the outside that acts as a stop so the tube only goes in so far.
These housings are also going to be thermally sprayed (see my thread on resufacing housings) so "masking" the bis ass hole will be interesting.
The ones that Ken runs now has two one inch beads welded on the outside.
As far as specs on the timing I don't know. I just duplicated the hole he is running now. It looks pretty big to me too. But Ken has been running pretty good times with the port already so he wants to stick to it.

Haha! I'm not a pioneer unless you are referring to age :). I just like getting things done as practical (i.e.- cheap) as possible without sacrificing quality.

what are u goin to do the exhaust port use a race port template from mazdatrixs? looks good same with your respray of the houshing. do u have any idea how much the respary is goin to run us?

I honestly did not pay any attention to Ken's exhaust port so I don't remember what it looked like :doh:
Ken will be doing any of that though.
Right now I am estimating $300 per housing as long as I am having to send them out to be sprayed. If a housing ever has an apex seal break or something scar the housing once it have been sprayed I will be able to re-spray for about $125 though. That is where it really starts looking attractive.
But before we count them chix we need to actually test it ;)

sounds good keep the pics coming

props to you my friend. :) looks good :

how much you gonna charge me if I send ya some housings to PP them?


like.... Four of them. :bigthumb:

I would do them in an unfinished state as here with the tube extending into the housing and unepoxied for $125 each. After I finish the epoxy work and grinding I could determine how much I would do a finished housing.
You could determine the length you wanted the tube to protrude the housing. PM me if you are interested.

for the exhaust port, can't you just drill out the sleeve and port out the inside of the housing to the size of the existing hole?

That would not be good at all. You do not want to bring the exhaust port very much higher than it is because of the timing. You can bring it down lower though.
It is best to have someone who is very familiar with porting rotaries helping you out or have a tried and true housing to copy off of.

http://webpages.charter.net/mikeroberts/port39.jpg

so after this, where would u use/put the epoxy? (water seals area only??)

and how would u cut this off nicely?

-mike

You mark the tube where it needs to be cut and pull it back out. Cut the end of the tube off fairly close to the line.
With the tube still out of the hole use a rotary file or brush to clean the inside of the water passage that the tube passes through.
Put the tube back in the hole and be sure it is aligned correctly. Then put the epoxy in the side passages being sure to force the epoxy into all the crevices as you put it in. You don't have to fill it to the top. The ones I looked at were pretty close to the top but did not require any work to "flush" the surface when the epoxy cured.
Once the epoxy cures is where hopefully you have had some experience porting with rotary files. If not then to be safe you may want to use a less abrasive cutter because not you have to to file the tube flush to the wall.
Try using your rotary tools on a cut off piece of tubing to get the "feel" of how fast it cuts. You need to realize that as quick as aluminum cuts you can be in trouble quick.
You can get cutters that make less aggresive cuts and have more control.
The trick to this is a lot like welding. Get your workpiece and yourself in as comfotable position as possible and have good lighting.
With that in mind just go slow and be patient.... and post pictures! After all they are worth a thousand words ;)

i havn't started my project yet, trying to put everything togther, but i'll be sure to take many many pictures..

-mike

In addition I'd probably retain the tube with a small tig weld on the outside of the housing.

Scalliwag, How do you get the Timing correct? from the guys i've spoken to about my Engine timing and port size makes a huge diffrence?

Also how do you make the Tube flush without damaging the housings Coating?