:D :D :D

Annular dis-charge

:D :D :D

Now how do I know you would be the 1st to make a smart remark!
BTW. I've given up trying to edit responses. It's like everytime I try I get kicked off or website not re-sponding or some other s..t!:)

You brightened up my boring work day :D

ANNULAR DIS-CHARGE, how old am I again :p:

Gonna go ring my Weber distributor :)

Seriously though, it sounds interesting. I herd of a few boys using the 55mm side draft unit for similar high HP results.

I said "We've already established" as in earlier posts in this forum by more than one source have confirmed that Ken has hade over 300hp at just a smidge over 50mm. I have never made any claim to making or even improving the design of the original "record setting" housings.
Since you said there was ALOT more that could be done to them I asked a fairly straight forward question; who is putting out more horsepower than Ken and Jesus?
Since as you say "The norm for ID's are at minimum 48 to 50 mm with IDA carbs. WIth EFI the high HP people are in the 53 to 55mm ID's".
I just want to know who these people are because the fastest one I know is Ken.

Hey Scal!
Remember there're a lot of people that been doing this long before and have gotten the same results that is HP wise I meant. Let's put it this way some of those people I'm taking about don't really like to disclose any info about their setup especialy when they can run the 1/4 mile at 8.40's with a PP motor on nitrous!:)
There're are also some road racers who are even more secretive about their setups that I know of.
Some of these people have already jump on the renissis bandwagon!

I know people can be secretive. But I thought there may be some even larger and faster pports out there you knew about on NA. The reason I don't think making the inlet tube any bigger is that unless you do some build up and grinding at the inlet the intake timing is huge already at just over 50mm. Since the port goes into the radius it is even longer. At some point (which has to be pretty soon) the overlap just gets too big to even get it to start.
You are also right about people doing this long before also. I've had a few Puerto Rican rotary guys tell me since I started this thread that this design (like Ken got from Jesus) has been used in Puerto Rico for years and no one seems to remember who the first people that did it. It appears it has been around longer than the Racing Beat design. At least in Ken's case using the exact same setup one with the RB and the other with the ones he had me copy he gets more horsepower from the Puerto Rican pport.
Have you heard anyone else refer to these as Puerto Rican pport? Paul Yaw's are the same way.
I would love to see how these would work with side exhaust ports :D

Are you working wiht Boosted12A on this project? If so, I'm the guy who found the VW adapter for the project. :)
I love you proposed set up. I'll have to think it through a bit, but it sounds like what I want to do to the Midget with this core motor I just got.
BTW - I've always wanted to use an SU on a rotory!

I have an annular discharge 51 IDA. I dont think im going to use it though. Crisspeed: do you think there is more hp to be made with the berg 58 or the modded 51? And as far as the puerto rican pp style. Do you just mean the 90 degree circular port? Because if so, the old man that i have been building motors with has been doing them since the 70's. He did a lot of tested in the automotive engineering program that was sponsered by mazda at western washing university back in the day and tried numerous different port designs. He built hundreds of the pp's for racers throug out the 80's for himself and many other road racers.

CJG

yes, like the ones pictured early on in the thread. Supposedly the guys in PR's have been doing them there forever too. Trying to get a date on forever is not easy though.
They almost always use carbs and conventional distributor ignitions though :(
I think the SU ideas for a street semi-pport are really good. Maybe someone can get some pics of some mockups and we can throw around ideas.
I may have to knock around in the garage a bit and throw something out to get comments/ideas on.

Nah, its just a boggo 12A from an 85 GSL. The car was a deathtrap, so i scrapped it and wanted to use the engine in another car (after a small amount of fiddling around anyway!)

But it's going to look sweet with those 5 carbs :D

The Berg is the way to go for more power.
For drag racing the Berg 58 is the way to go. A buddy improved his 1/4 mile time from consistent 11.1's to 10.6's!
I know of some people who are also testing the 62 mm carb.
For road or circuit use depending on the actual racing conditions needed the moded 51 is the better way to go. It mostly depends on the power/torque band needed for the particular track. You might be faster with the bigger carb but it's not going to be quicker if you're going to be running out of the power band like a course with a lot of low speed turns. Testing is the only way to determine what's best for every track/course.

Thanks a lot for the info. I am defenitely more of a road racer, SIR is where i will be racing most. Do the 58's usually make good pwr on the big PP's from around 6-7k on up? or are they even more peekier? Also i had one other question. I was just curious as to what size of chokes most of the guys are running? I was thinking of initially ordering the 58 with a set of 46mm chokes, F11 tubes and then big mane jets and small air's and starting there. Does this sound about right?

CJG

You know... speaking of side exhaust ports, I just had a funny idea. The limitation on port size on the intake is enforced because of exhaust gas dilution, no? IE, you can't go too far downwards because it will overlap more and more with the exhaust and past a point won't start. Well... if you were running a side-port exhaust with its dwell, you could open the intake port earlier than is possible for a standard exhaust engine, no?

Of course, then you have to get more exhaust port area (maybe)...


Oh, as another thought about Scalli's choke idea; what about a bigass square port, like out to the limits of what the seals will ride in. Then just have a series of chokes with less port timing to experiment with on an engine dyno and use it as a research engine. Seems to me that you could cover pretty close to the full range of possible port configs.


Finally, again I know that ports bigger than a certain size won't run at a low enough RPM to start the engine, but if you had some of the original side ports just to get it running and up to 3k RPM? Obviously this would turn out something pretty peaky, but... *shrug*

Just throwin' out thoughts.

Of the 3 PPs that i have dynoed this year i am using 43mm chokes with the 44mm id PP hole (297hp) and 42mm chokes with 42mm id PP hole (272 and 276 hp) E-tubes always F-7 with mains 240-250 and air jets 140-160. On our dragracing motor we use 48mm chokes with id PP hole 49mm (rectangular shape)

Okay, here's a question. My family has just acquired a full out Bridgeport mill thanks to a ridiculous deal on a used one. Of yet I don't know a hell of a lot about machining things; what would be a "proper" tool to bore holes for a pport?

I mean, I could put a 2" holesaw in it, but that seems kinda silly now.

Any other tool I can think of is going to be cutting more metal (bigger chips, etc.) Even though it may not be conventional I don't see a more efficient cutter even without expense in mind.
Since the cutting path is so thin it will cut faster than anything else making that big a hole.
Be sure to get the carbide tipped bi-metal holesaw blade.
Congrats on the Bridgeport! I will I could find a deal on one I could not walk away from.

hehe

I'm so faffin cheap, I'm just getting a couple of cheap holebores and using a hand drill.

If it breaks, I'll repair it using yet more unconventional methods :D

I feel sorry for your drill and your wrists. There is a huge amount of imbalance on the load as your are going through.
Even drilling through a door with a big holesaw is an asskicker when one side grabs and that ain't nothing compared to when your go through the hardchrome on a housing.
Good luck, use a lot of oil and be careful.

Hmmm. Okay, that's an answer I wasn't expecting to hear, but something of a welcome one. :D

Carbide tipped would probably work better; in my second practice housing on our drill press, the normal bi-metal one I was using seemed to... ah... stop cutting so well by the time it got to the iron bit.

Still going to have to get "real" tools for the Bridgeport, as I've other projects in mind (sequential shifter!) but... the peripheral port one was one of the most important.

I've had a few thoughts about this again, and If I'm going to be doing this cheaply, I need to use common stuff that I've got lying around.

I'm thinking about simply dumping the housing in a vat of car-oil, supporting it in some sort of vice, then drilling into it whilst it's still bathed in oil.

But that would use LOADS of oil, and I'd get the stuff flying everywhere. So I think I'll just get a mate to pour oil over it from a jug (or a bucket with a tap in the bottom)

i've also just remembered that my Dad's got a HUGE drill in his shed, so that should make the drilling a tad easier - that thing is almost two foot long!!

But I might have to make a support panel to ensure it won't move, a vice will either move or warp the housings now I think of it. Two bits of tubing and a bit of metal sheeting should suffice.

Don't mind me - I'm just thinking as I'm typing. :D

But I have to admit, the hardest part will be the fuelling. Since I want to run a semi-PP and I only want the PPs to open at high RPMs. I'm thinking about having the carbs for the PPS operated from vacuum, does anyone know if the diaphragm from the NIKKI carb would work like this?

best bet would be a small hole saw and then use an adjts boring head thats what i did

It finally dawned on me on why I probably thought about the holesaw idea to begin with. One of my early fabrication jobs introduced me to a magnetic based drill.
I found out why they used a holesaw type drill bit for larger holes the hard way.
If you ever see really large steel poles like the ones used for lights around big freeway interchanges that was what this shop built.
They have to drill various holes in the poles for the cabling system that lowers the big ring of lights.
With the poles on their side Scalli had a short run of drilling the holes. The magnetic base stuck to the pole and you drilled a hole.
Well I could not find the right annular bit one time and I snuck to the drill press area and snagged a regular bit.
I used the one drill we had with a regular chuck and fired that bad boy up.
Everything was great until right when it went to go through (as usual) and it grabbed. It grabbed so hard that the magnet let go. I was straddling the pole and it whacked the hell out of me but at least the bit was away at the time.
My boss caught on the the ruckus and came to check and bitched me out and explained that was the reason we did not use regular bits. Of course by that time I had already figured that out.
Since the annular bit grabs less mass it takes less power and less risk of kickback. As I found out it could still happen with an annular if enough force is applied. :eek:

Here are what those bits are like, basically a holesaw with an attitude. http://www.durabore.com/annular-cutters-durabore.htm

now i could do with one of those 1 1/2" bores ;)

Those are horribly expensive. Even on Ebay the bigger ones will bust the bank compared to a holesaw.
For example the 1.5" you want lists for $130.
If you look at the holes I made with $15 holesaws I cannot see spending the big money now that this process has been proven to work.
They make a carbide grit holesaw that is supposed to be even better.

haha - i know they cost shitloads, but i still wouldn't mind having one for my project

I don't know when I'll actually get started on it, but I'll be making my own P-Port sometime soon. I just picked up a good engine today, got a GREAT deal on it. It was a new engine from Mazda a couple years ago, now it has 20k on it. The machining of the housings is not a problem at all for me, but the port timing and angle of the port is. Time to start researching to find what timings/angle will give me the power where I want it.

I have a 51 IDA and three MFR PPorts for sale!

My dad and I will be making the PPort housings ourselves, we have the right machines and tools to do it with. But how much do you want for the 51 IDA, cause that's the carb I want.

And how much are you asking for those housings?

Are they 13b or 12a based?

$550 for the carb and $500 each for the 13b pp
housings. These are in the parts for sale section.
Sorry for the post here also, just thought someone
in this thread might be more interested. Price is firm
find me a better price for the same items and I'll
buy them.

Dammit - I need 12a PP housings :(

Has anyone here done or seen a 10a PP?

I think there is at least one in OZ. look in some of there forums and i think you should be able to find it. i think i saw a pic of one in a r100. Looked so cool.

CJG

Look at the ports on my p-port engine, I need advise to make them larger without tinkering too much with the intake and exhaust timing and without f'ing up anything. They are from my model rotary engine made by OS.

Complete motor teardown here: https://www.rx7club.com/showthread.p...hreadid=280086

That little motor is cool! Without effecting the port timing the only way you can go is sides. If you do anything you may want to make it look a little more like a square than a circle.
But as far as I know you are in fairly unexplored waters to you don't want to do anything too radical. You may want to check with some of the RC model hobbyist and see if they have any information.
I would square off both the intake and exhaust side if it was me but I have fugged up a lot of shiite in my 43 years so you may want to keep that in mind :eek:

Oh, I figured I'd talk about this in here because it's sort of applicable.

Picked up an SAE paper the other day; by Mazda, from '90. It's modeling power output of peripheral port motors, followed by coming up with an "optimum" port timing. What's interesting is that the port timings they come up with are completely different than any other published ones I've yet seen. The "baseline" port shape is about the same as the published values for the MFR ports on Paul Yaw's site, but the "optimized" port is... well, I'll just come up with a little chart.

Baseline Optimized
Exhaust Open 73 BBDC 73 BBDC
Exhaust Closed 65 ATDC 55 ATDC
Exhaust Area 9.2cm^2 12.5cm^2
Intake Open 100 BTDC 80 BTDC
Intake Closed 75 ABDC 80 ABDC
Intake Area 20cm^2 25cm^2

Note that there's both less port timing and more area... and all the port timing changes made for less overlap. The ports are a lot more rectangular, extending out towards the edges of the rotor housings farther than the more square baseline ones.

Oh yeah, also note that the port they publish for the "baseline" one opens the intake 14 degrees earlier than the MFR one Yaw has the data for, but is otherwise identical. This might be explained by the fact that all the MFR housings I've seen for sale are supposed to be for earlier motors, so perhaps there's even development work done between the later MFR housings and the ones we're familiar with.

They don't actually publish very detailed dyno results. The "optimized" timing beats the "baseline" port by a good 2-5% volumetric efficiency from 7500 RPM on up, and trails by 1-2% below. The one dyno plot they have is of a 3-rotor motor, and seems to indicate a gain of 30hp at 8500 and 50hp at 9000, while only losing 10hp at 7k or below. Absolute power numbers... aren't on the graph, regrettably. And even the comparison numbers are estimates, as the graph is of a type used to merely show a trend.

The capper to this is that the time of the paper (and some of the talk about variable length intake tracts on a 4-rotor later on) seem to indicate that this was either being developed for the R26B LeMans motor or for a follow-on effort... either way, it makes me *REALLY* curious.

Thought some of you might be interested.

Wow that is interesting stuff! Once I get caught up with all this new shop stuff I got going I want to setup a degree wheel and layout a housing to that spec and see what it looks like.
I may talk David Sanchez into letting me do a couple of his extra housings to that spec as well.

Well, they have some lineart pictures... I'm half pondering scanning the article and turning it into a PDF for people to look at. The SAE number is 900032 and it's in the transcripts (the big, yearly, bound best-of books) so it should be possible to find in a library.

I'm seriously *SERIOUSLY* thinking about carving those ports into a spare (in questionable shape) 12A we have. Could use the ITA car I share with my dad as a testbed... uh... and maybe they wouldn't notice the Weber-fed peripheral ported motor. :D Well, okay, more seriously, in the class I autocross in it would be perfectly legal to run a pp motor.

Might be trickier to machine... the hole is 46mm diameter at the surface where it mates to the intake manifold, and much larger on the port-side. Or, in terms of area, 17 square cm widening out to 25 square cm.

Oh yeah, the model says that 30 square cm ports will get even *MORE* flow across the 7-9k RPM band, but only by around 1% over the 25. And I have to wonder if there's room to *fit* 30 cm of port area without going the whole width of the housing.

Oh, hm. I just thought of something that could make building this a bit more of a headache. Exhaust.

I'm under the impression that in most PP cars, the exhaust sleeves are taken out for. Problem is, because the port timing on the "optimized" motor isn't that different than stock, obviously most of the added area is going to come from expanding to the sides. So, this both means that the normal sleeves won't work and that there needs to be a sleeve in there to prevent a sudden expansion in the runner which would kill gas velocity and cause turbulence.

Well, this led me to start thinking, of course. The stock-style flanges aren't really all that complicated... seems to me that it would be possible to bend a piece of steel tubing into the right shape and weld a flange on the end. There might have to be some extra aluminum coming out of the hole to get it to go in, but I think it should work.

If you were real good with blacksmithing skills (hey aren't we all?!?!?! ;) ) you could shape a malling form so you could take a red hot short piece of pipe and whack it down onto the form. The form would need to be shaped the way you wanted the inside of the sleeve to look.
You would hammer form the piece to shape on the form. You could use a very short cut of pipe that matches the collar and weld it on from the inside. Then rotary down the weld.
The backside of the collars at the flanges have to be pretty square to sit right in the reccess.

Sure that is a lot of work but it could be done. The hardest part would be making the form.

The form doesn't seem that hard, really... but it would really probably be simpler to do it the even-more old fashioned way, with a hammer and anvil.

Doubt it would be perfect by any means, but it would be doable with equipment I have. And welding... well, I know some guys. ;)

It'd be something just about unique too.

What I figure on using a form is that it would be easier to match the shape for each pair.
Plus if you ever got it right you could knock the out quicker and probably sell some sets of "high-flow exhaust sleeves" Hey you gotta admit that sounds pretty cool!

Well, that's a very good point... both consistency and doing it as a business venture. ;)

I figure though, y'gotta start somewhere... the business thing gives me ideas though.

See, the reason I got this paper in the first place is because of a long-term project I'm working on. I'm trying to figure out a mathematical model for rotary engine performance based on the normal geometry and ports. This has, obviously, been done before... just not in form that's easy to use (so far). The trick bit is a thought I had to have it go and come up with a theoreticially "optimum" port configuration. Say, you want the most power possible from 5-9k RPM... you tell it that and it comes up with a configuration with the most area under the power curve. Or you want part-throttle running to still be good, or to get emissions under such and such level... all the stuff is *out* there.

LIS, long-term project.

Wow that is a monumental task you have there. Especially when all the other variables have to be factored in; length and diameters of runners and exhausts and the length from the exhaust port the tubes come together.
If you factor in boost and compression ratios of the different rotors that could be used this becomes enormous.
That would be very baddass to pull off. I sure hope you do :D A fully staffed research facility and a lotto powerball win (or dead rich relative) would sure speed things up.
Building the motors and manifolds and getting an engine dyno and documenting every detail makes me numb just thinking about it :eek:

Well, boost I was basicially going to avoid screwing with. Although, I did see an interesting paper presented this year about modeling transient performance of a turbocharger... I don't see any reason why it wouldn't be possible to go back and tack more features on after it's working. :D

I'm thinking that intake and exhaust manifold tuning are comparatively simple and well understood. Or, to put it another way, I think that it *might* be possible to do them afterwards without messing up the data. I hope.

The trick is crunching the numbers without doing literally *EVERY* possible combination by using fairly simple tricks to get it to see trends. Say you have 20 variables to define where the ports are. You have upper and lower limits to where they can physicially be on the engine without eating seals, leaking oil, or other various stupid things; those limits are programmed in beforehand. So for each of those 20 variables, you try 20 different settings, making 400 setups. That seems like a lot, but computers are here for a reason. ;) You compare the area under the curve on all of them and pick the best few. Most of them are going to be useless, but likely there will be a chunk of data that looks interesting. So you take that chunk and repeat the process, narrowing down each time... and keep doing it until the gains each time are too small, or the power blinks off and you lose all the data. :p:

There will end up being a *lot* of engines made and run on dynos to verify things, by necessity. Probably a dozen or 3, which is a daunting prospect to a college student. I'm... not sure *exactly* how to deal with that part of things. Research grant, maybe... or I could take out a loan, cut a deal with Mazda to get a shitload of unported housings (and a slightly smaller shitload of internals) rent time on a CNC mill, do nothing but build and dyno engines for a year or two, publish some of the results, sell the ones that turn out really good to racers, get hired by Mazda on the condition that they pay for the rest of the expenses that I'd incurred (probably cheaper than if they did it themselves) and successfully pave the way for rotaries not only coming to prominence in racing but in the consumer market as well! :cool:

Okay, maybe that slipped from "good, if fanatical, idea" to "flat out delusions of grandeur". :D

Where can you autocross with a home-built PP?

SCCA only recognizes MFR p-port housings. Does NASA have an autocross series now?

- Pete (Interested...)

I'm in Midwestern Council, which is a *LOT* more loosely organized... but evidently a lot less bureaucratic. As people have said, it only exists for the purpose of going out and racing... anyway.

Autocross rules are at http://my.execpc.com/~mcscc/mcgcrv6.pdf but I'll summarize. The first part of the class is, like anything else, based on what car you have. The second bit is modification... from stock, prepared, modified, to race. What's neat is how the modifications are listed though... there's a list of types of modifications, and each has a points value attached to it... stuff like running specialty compound tires is 3 points, changing spring rates is 2, cams are 2, etc etc etc. For a total of 0-2 points you're in stock, 3-7 is prepared, 8-17 is modified, and over 17 is race. So you get to do *WHATEVER* you want to the car. If you're thoughtful (or nutty enough to do it without much suspension work) you could run a turbo 1st gen in prepared... or spend those points on suspension like most do.

Well, the car I share with my dad is prepared... pretty close to the limits of ITA. Adding up the points honestly, I'm autocrossing in the race class... so really, there's no class that they can stick me in that's *MORE* modified. Heck, a lot of the other people out there are running hotter cars... the guy who won the last time I went out last year was running a turbo VW Rabbit with coilovers... and knew what he was doing behind the wheel *FAR* better than I did. :p:

Oh yeah, this is "high speed" autocross; open-tracking as a lot of people prefer to call it.

Actually, what's really neat is that they pretty much will let you race anything you bring down even in wheel to wheel... one guy who I've seen out a few times has a Porsche 914 with a lot of modifications including a 911 motor (of some vintage or other; sucker's keeping pace with the GT-1 cars) and... someone who had a Ford Mk. 4 that was constructed out of spares.

... anyway. I'm done rambling.

Neeeeat.

Sure beats being bumped into (E Mod? D Prepared? I forget) just for having a street ported engine. Even though the rest of the car is bone stock. Reminds me of why I never bothered autocrossing. :)

RALLYcrossing, on the other hand... :) You can do pretty much what you want, since the car is not the limiting factor.

Another thing to consider to make your problem worse is variable intake runners, like on the 787B to give a broader peak power range. I've thought of doing something like this but more specifcially just for tuning intake runners, so that I could devise a system like on the 787B of variable intake runners to yeild a peak hp range over a larger area. Of course this would depend specifically on the port that someone had, exc.exc.

- Steiner

Theoretically his model should account for a variable intake runner by default. Whatever data he generates on a motor with different length runners could be used to find the optimum length at particular RPM ranges.
Let's say he finds the peak horsepower/torque for a 6" runner and then the same for a 12" with the same diameter tubes. Even if your test runners are fixed it could still create the model for a variable.

The 787b is an awesome piece of machinery BTW :D