I have been thinking about my next project to begin working, hopefully this fall. I had orgianlly thought about a 20b NA FD, but after looking throuigh many of my RX7 Magazines and brochures I have came across the R-Magic P-Ported housings and LIM. Below is a pic of the housings and LIM

What is the life expectamcy of a P-Ported engine?

I know the size and loaction of the P-ports greatly effect the overlap of the engine cycle along with the life of the engine and idle/resposiveness. I have just contacted R-Magic to find out the specs of the P-Ports on the housings.

I am also trying to think about the streetability of the engine ( only reason is for maybe the occasional drive on the street and drive to the track and back). Also If I am not mistaken the secondary throttle plates, which feed the p-ports, open at a slightly slower rate than the primaries. My other thought is to devise away to incorporate similar to how the 5th/6th ports open on the FC's and RX8's, to open the P-ports in a simialr manner, but around the the same time/rpm the secondary injectors kick in (3500-4000 rpm), Like I said before the ONLY reason I am thinking of adding the sleeves is to make it somehwat streetable.

Here are the main parts I have been think about using:

R-magic P-ported housings and LIM
FD Irons
S4 or S5 N/A rotors (or maybe just the 9.0:1)
550 or 720cc primaries and 720 or 950 secondaries
FD UIM/TB
And maybe a Haltech to run everything (anything better?)

Does anyone know of anyone that has used the R-Magic housings and LIM? I have only been thinking about this since late last night, so I am sure alot will change, but what do you guys think so far?

 

Well, peripheral porting IS the most extreme and most UNstreetable type. However, if the only times (other than racing) you are using the car is to drive it to and from the race, you can probably get away with it. At least I'd put up with it

Life expectancy, as always with higher performance race engines, is short. Depends how hard/often you use it, but probably one season or less.

How much power are you aiming for? What type of racing is it?
You are correct you definitely need a good EMS, a Haltech E11 is one of the best out there right now, and many companies offer competitive systems such as Microtech, Autronic, Motec, Wolf, etc.

It would definitely be a cool project, if you can cough up the $$$$ something like this would require to do right.

 

Oh, and I just re-read your post.
Are you thinking of using both side ports AND peripheral ports? (you said use valves to open up the p-ports at higher rpms only)
That is how Scoot made a couple engines before - there's that famous dyno video of the few japanese guys sitting in the hatch of a red FD spitting out 710 rwhp. I'm sure you've seen it.
Only a handfull of people have successfully done engines like this.

 

Yeah that is how the R-Magic rotor housings and LIMs are set up, its just the inner two side ports that would be used, the outer two would be blocked off. By anychance do you know or remeber where you read about the scoot cars? So that red FD is using the side and peripheral ports? Hmmm interesting!

BTW this peripheral port thing is pretty new to me, I saw it and thought what the hell! So I still need to do more research on it.

What makes the engine not last as long when it is periphreral ported?

 

I'm not sure to find good info about those Scoot engines. There are guys in PR doing that too, probably a couple in Aus. JudgeIto (rotary guru) has experimented with it as well. Just search "Scoot" on the forum and you'll find info, as well as info about their 4-rotor NA FD.

Here's a pic of theirs I happen to have on my harddrive. I don't know much about those engines though so I can't help you out much.

The most comman cause of failure with peripheral ported engines is coolant leakage. Any other rotary specific failure (ie: apex seals, overheating, etc) will kill one just as easily though as well.

As you probably already know, with a peripheral ported engine, the powerband is in very high RPMs.
Good power usually starts around 5,000 rpm and pull hard till redline (11-12k). When you run these speeds you need the necessary (and expensive) modifications to allow this.
This puts excessive wear on components, and that is another huge reason why they don't last as long as other porting techniques.

 

here's that scoot port job

 

Like I said before I am sort of new to the whole p-port, so if I gather correctly, the causes of failure is the coolant leakage through the P-ports, and just added abuse from the engine revving about 4krpm higher...

My question is how do you know the redline of an engine?

 

stock plus what is safe with what mods youve done

 

Well now it is my goal to make it streetable, I have been looking through all my RX7 mags from Japan again and I came across a company that makes Peripheral ports for race, standard, and street. So I am going to contatc them and find out more info on it, as well as maybe try to contact Scoot, becuase I belive they use the same setup.

I have thought of some new ideas for the streetablity of the car, first is to incorportae how the FC secondary throttle plates open at a darstically slower rate, if floor ro mclosed position. Second to make it even more street able place a second set of throttle plate in the LIM or UIM ( or even in the ports themslevs)that can be controled manually (or some how wire up a boost controller to run it) to open the runner from closed to full open. 1/4 will be for street use and full open can be used for track events.

What is the bolt pattern differnce of the FD and FC exhaust ports?

I am always up for a challenge, and I like the impossible. If it doesn't work then no big deal, if it does it will be one kick as ride!

 

You keep talking about streetability and peripheral porting in terms of the same engine !?!?!

 

Yeah I have decided to really make it streetable, I have been doing alot of sreaching and a 1k idle is easily obtainable, alot of people run a little higher of an idle because it sounds better and or the engine is not tuned well enough.

Also in terms of power, from about 4-5k on up, it will make about 50 more hp than a bridgeport at the same rpm and the number slowly drops as the rpms increase.

I really think you can have/make a Peripheral ported engine streetable, if I can get my idea of opening up the ports higher in the rpm range, when they would be needed or usable, it should not have a problem running on the streets....

 

Let me explain myself and reasoning a little better. Right now I have a S4 TII that I just got on the road about 3 weeks ago, after an extensive overhaul of just about everything. I orgianlly wanted a S5 NA but I could not find any close enough to me or anything that was worth the while to be shipped, which then this S4 TII popped up in the local newspaper. I am not a fan of turbos, ecspecially with rotaries, main reason: Why would the sole manufacturer of the Rotary not use it in there racing cars??? Because it is not as reliable as NA.

I had then thought about the RX8, the performance figures are decent, about what I would be looking for, but the car design could use some work, besides $30k is alittle out of my league right now. So then I came across making an NA FD. Plus I can actually work on the think the is the main reason for wanting to start another project, I am so board right now. So inshort I am want a NA FD with power figures better than an RX8 and close to stock Twin turbo setup...

Ok While at work toady I have thought it over a bit more.

If I am thinking correctly an 800-1k idle should be obtainable, heres why:

The peripheral ports will be controlled by both load and rpm, a voltage of some sort.
800-1k rpm Primarys used, Peripheral ports closed
Idle to 3k Slowly open throttle plates for P-port to closed to 1/4
3k-4k open throtle plates for P-ports from 1/4 to 1/2
4k-5k open throttle plates from 1/2-full

The load sensed will control at what rate the ports will open, much like how a wastegate acts but backwards, instead of closing it will open.

 

Heh.

It's a cool idea to try. The Mazda KLDE and KLZE engines (2.5L V6, found in Ford Probe GT's (93-97) and Mazda MX-6's and 626 LS's) have an intake manifold that uses computer controlled vacuum solenoids to open a set of plates to open a second channel of intake air into the motor. The first one opens at a low RPM (can't remember teh number ATM) and the second plates only open at 4,200 RPM, with more than 70% throttle.

If you could rig up a system like that...the guys at VRTuners.com made a control panel that let you adjust how far open/closed the plates would be...dunno if they'd be able to mod it to make it work up to 9k RPM though. (KL engines only rev to like 7.5k stock, and 8k modded, except in extreme cases where they go higher).

It makes a very nice torque curve, pulls like hell at the upper RPM's. My last car was a Probe GT, (KLDE engine) and it pulled harder than my current car, a V6 mustang...

The TII i drove in though...was faster in 2nd gear than the mustang or probe in first...

 

It's been done before. Be forewarned, a P-port motor will cost AT LEAST $3500. Probably more if its built right. Intake and exhaust manifolds will need to be custom fabricated. It'll be a high-rpm, high maintenance motor. Programable EFI will be a must (i.e Haltech). In short, it'll be expensive. BUT, very cool.

 

What the exact setup I am looking at doing? If so I would like to talk to the person/people that had done it. If you are talking just about P-Port then you HAVE to REREAD the post, because it is not only P-ported but it uses the stock primary ports as well.

piratius, thanks for the tip I will have to look into that do they have a specific name for it?

 

Not to be a dick, but if you can't afford a 30k car it seems like this undertaking may be a little out of you budget.


But, good luck any way. :-)

 

I sorry did post in the wrong thread? I am not making a singleturbo 20B. All engine parts and assembly is going to run about $4k depending on whoI have build it. Really all I need is a Standalone ($1200) , s5 counterwieghts and rotors ($200-300), R-magic kit ($2300) and custom exhaust(which the exhaust will cost no more than what the piping and flanges are going to run est $150).

Lets see $4000+$1200+150= $5150 est (not including cost to open second throttle plates)

 

It took me about ten minutes to stop laughing when I read this crap A full custom exhaust costing ONLY $150?! Let's see, here's a realistic estimate:

1. Motor: $4000
2. EFI: $1000
3. Tuning: $500
4. Exhaust: $600
5. Custom Fuel System: $400
6. Miscellaneous: $500
7. Racing Flywheel and Clutch $1000
_____________________________________
$8100

This is a bare bones estimate (no custom intake manifolds which you'll probably need, beefed-up oil system no high ratio ring & pinion etc...). Not to mention, it dosen't include your funky side port/P-port idea (actually, that is a good idea; Mazda used it on the orignal Mazda Cosmo in the sixties). For the record, a turnkey P-port runs about $8000 at Mazdatrix:
http://www.mazdatrix.com/r-20.htm

 

The exhaust will not be that expensive, I have friends/family that are will to help out as much as possible (ie no charge for welding/bending/cutting) of exhuast, so I just need to purchase the parts for the header (should have made that more clear the $150 would be just for the header, my bad).

Also depending on the FD I buy I will be selling alot of the stock parts since I will not need them. I will be using the stock TB, LIM, UIM. I did not include tunning, fuel system, and drivetrain because either way if I did this setup or stock i would be upgrading, besides other than the block itself the rest of the drivetrain well remain stock.

I still have alot of planning to do from now until Oct, I forst need to figure out HOW to open the p-ports, so until I figure that out money is no concern, that will be taken care of at a later date...

 

Uh, using the stock intake manifold is pretty much impossible with a peripheral port. Have a second look at the picture on the Mazdatrix website. Stock block? Not if you want your engine to last. The rotors will need to be balanced, clearenced and snap-ringed. You'll want to use high compression rotors... s5 N/A or rennesis. You'll want to port the exhaust.You'll also want to.....I could go on.

I'm not ragging on your idea. I think it's an AWESOME idea (I'm considering doing it myself . You just need to realize that building it will take a lot of time and money. Certainly a lot more time (and possible even more money) then building a fast turbo FD. There'e a fellow named Evan Gardner who has an P-ported FD who races SCCA in Cali.

 

$4000 for the engine you describe? LOL!!

 

Like I said, this ia a bare-bones estimate!

 

I understand where you are coming from, with the whole money situation. I was at work on my break when I was typing the orginal cost so I know I was off and I was missing stuff.

Also if you look at the picture of the R-magic housings and LIM, you will see that the LIM is made to use P-ports and the primary side ports, and I remebr reading some where the exhaust is already ported. I have a book that has about the same setup I am looking for minus the use of second throttle plates to control the p-ports opening. The front, center, and rear housings will be used and the eccentric shaft. I was thinking of using S5 rotors and counterweights, but now I am entertaining using the Renisis (which the engine cost will go up about $800). I already thought about sending the whole rottaing mass (even flywheel and pressure plate) to Racingbeat to get balanced the the rotors clearnaced.

I talked to them yesterday and told of my idea and they were pretty surprised, but thought if I could get the second throttle plate thing to work it would be very do able and maybe start a new trend Anyways I was asking them about apex seals, and they recommended since i was going to use it for low rpm use to stay with the steel, but keep the rpms lower <9k. But since I may use the Renisis rotors I am not sure if it is better to machine the rotors to fit the older style or leave them the way they are.

 

The Renesis 2mm seals are all new, and of better quality than our RX-7 2mm seals.

How about doing this intake porting, but on a Renesis engine (so you have side exhaust ports). I'm pretty sure that's never been done.

 

Thoughts?
You have no clue what youre talking about.

I'd highly suggest you read the Mazdatrix narrative...
http://www.mazdatrix.com/r1-5.htm


-Ted