20B N/A with RX8 rotors??

[Herblenny]

Well, I was just told that all my parts are cleaned and ready to be assembled..

But now I'm thinking.. Maybe I should go with 20B N/A??? Do anyone know if RX8 rotors could be used?? I think I've heard that you could use the RX8 rotors...

I'm now thinking about going old school and go 20B N/A Carb'd!

[Whizbang]

take to Logan with defined auto works in southern ohio. His FD is N/A and 20B and to the tune of 300hp

[Herblenny]

I've seen his work and talked to the guy who helped put it together...But his is EFI NA.. I believe. My guy is whom I trust and knows quite a bit about carb... he's just not sure about Renesis rotors as he hasn't taken one apart.. i'm thinking about bringing him one this weekend to take apart and compare the rotors.

I'm also waiting to hear back from Carlos Lopez. He and I talked about this before as my builder wanted to go NA/Carb 20B... now I'm thinking it might be easier and unique...

This is the picture Carlos sent me about a year ago.. I think this is the set up I'm now considering...

http://www.rotarycarclub.com/attachment.php?attachmentid=3368&stc=1&d=1227125627

[RotaryProphet]

My only concern with Renesis rotors is that they aren't designed to handle peripheral exhaust ports, so I have no idea how long the lighter/shorter apex seals will survive.

[Brent]

I bet Landers could prob. give you a pretty good idea whether or not they would work.

[Herblenny]

My only concern with Renesis rotors is that they aren't designed to handle peripheral exhaust ports, so I have no idea how long the lighter/shorter apex seals will survive.

ahh... I didn't think about that... Hmmm..

[need RX7]

Aren't you supposed to machine the rotors to use standard 13B/20B apex seals?
EDIT: Just searched evil forum and I guess it's not necessary, but I did see that the standard renesis seals warped too much on the peripheral exhaust ports so ceramics had to be used. I think if I were doing it, I'd use 13B seals. Also, the thread I saw was from 2004, so things may have changed.

I'm interested in seeing more input on this.

[To_Slow]

Well, I was just told that all my parts are cleaned and ready to be assembled..

But now I'm thinking.. Maybe I should go with 20B N/A??? Do anyone know if RX8 rotors could be used?? I think I've heard that you could use the RX8 rotors...

I'm now thinking about going old school and go 20B N/A Carb'd!

Yes you can use the rx8 rotors in an na 20b. The place i will only trust to do the rx8 rotors and has done them on numerous times. Is Roan At xtreme rotaries in Au. Trust me.. well worth the money.

Do not have shops around the state do your rotors and balance. Its a joke. Trust me, Been there done that. I'm not going mention names not that type of person.

Also the rx8 rotors will be machined to except the 13b style apex seals 2mm or 3mm.

Good luck with your project...

[Dzire]

http://i112.photobucket.com/albums/n176/dzire_2006/20B-MSPa.jpg

[RotaryProphet]

Is that a 20b with renesis housings? I never gave that any thought.

[warwickben]

how where do you get a dizzy for a carbed 20b i was told on the evil site cant be done heck id do that any day for my sa.

[Dzire]

yes it is
http://i112.photobucket.com/albums/n176/dzire_2006/20B-MSPb.jpg
http://i112.photobucket.com/albums/n176/dzire_2006/20B-MSPc.jpg

[Whizbang]

only issue i heard with that is the one exhaust port. and i think intake port is smaller than the others...

[RotaryProphet]

how where do you get a dizzy for a carbed 20b i was told on the evil site cant be done heck id do that any day for my sa.

http://www.rotaryshack.com/ignitions.html

[warwickben]

what would you guys use for carbs then ?

[charlies7]

I dont think its worth the trouble going with RX8 rotors. The performance gain over the 9.7 out of the S5 NA motors wont be noticeable IMO.

[RETed]

Is that a 20b with renesis housings? I never gave that any thought.

What a waste of time.


-Ted

[Herblenny]

I dont think its worth the trouble going with RX8 rotors. The performance gain over the 9.7 out of the S5 NA motors wont be noticeable IMO.

I'm starting to think that now.. I was only considering 8 rotors as I have a spare renesis at home.. I guess I need to see of I could get hold of some S5 NA rotors cheap:)

What a waste of time.
-Ted

I kind of have to agree with you... But I think they are using aftermarket 3 rotor shaft and renesis stacks up nicely vs. going peripheral porting the housings. In some ways it makes sense... I guess you could go 4 rotor like this using Renesis engine..

[Herblenny]

http://www.rotaryshack.com/ignitions.html

Thanks for this link.. Damn, That thing isn't cheap!

I think Carlos Lopez also makes them. Not sure how much he charges though..

[charlies7]

I'm starting to think that now.. I was only considering 8 rotors as I have a spare renesis at home.. I guess I need to see of I could get hold of some S5 NA rotors cheap:)


I saw a set on ebay for like 80 bucks..I almost jumped on it. But I figure I should buy a block first. LMAO:beatdeadhorse5:

[warwickben]

would you have to make your own intake mani or does some one make a 20b mani for a carb?

[Herblenny]

would you have to make your own intake mani or does some one make a 20b mani for a carb?

Carlos Lopez makes one... as you could see from the previous picture I've posted...

I was told by my builder that he could build one also... I'm on full throttle for this so hopefully it will be built by DGRR :)

[dregg100]

i guess i missed it, but whats it going in? the duece?

[classicauto]

IIMO as stated its a bit of a waste of time.

The main problem is that even with a higher static compression, you still ahve to seal the rotor in the housing to make that compression. So all the machining, and the side seal differences of the RX-8 rotors will result in a loss of dynamic compression when compared to a S5 rotor designed to operate in this style engine.

And the dynamic compression the rotors make when they're running is ultimately what makes the power.

[Herblenny]

I understand classicauto! I've decided not to use the RX8 rotors.. I'm going to find some S5 rotors and start the build 'real' soon..

[warwickben]

Better post pics and info as you go. Wounder if u can use jeff20b dildls trick with that dizzy. If I don't know what iam talking about on 1st gens u use 3 coils and 3 ignitors. On a 20b you would use 4 coils and 4 ignitors.

[Herblenny]

Better post pics and info as you go. Wounder if u can use jeff20b dildls trick with that dizzy. If I don't know what iam talking about on 1st gens u use 3 coils and 3 ignitors. On a 20b you would use 4 coils and 4 ignitors.

Can you post some more info on that?? As I'm kind of clueless :)

[warwickben]

check my thread out for info
http://rotarycarclub.com/showthread.php?t=3618
basically trailing is stock 1 coil to control it threw the dizzy.
then each leading plug has its own coil. the spark plug wire goes from the coil right to the plug.

on my na 12a 1980 sa, i cant stall the car out now. what i mean is if i drop the clutch in first at a dead stop the car will buck once and pull forward. my car idles slightly under 1000 rpm. you get a much stronger spark on the leading plugs since each has its own coil.they only problem i can see with this setup is cause the leading now is a wasted spark setup. ie both plugs fire at the same time.i dont know enough about 20b's to know if that would cause a problem with the 3 rotor setup. if jeff20b shows up he can explain it alot better.


http://photos-h.ak.facebook.com/photos-ak-sf2p/v295/35/95/1094692814/n1094692814_30100239_6476.jpg
http://photos-814.ll.facebook.com/photos-ll-sf2p/v295/35/95/1094692814/n1094692814_30100584_498.jpg
http://photos-814.ll.facebook.com/photos-ll-sf2p/v295/35/95/1094692814/n1094692814_30100585_1337.jpg

[Christopher W.]

Gmonsen, from the other forum, is using the RX8 rotors in his 20B N/A. They thought he was having a problem with the rotors and side seals but it turned out it was something else. Logan at Defined Autoworks is building my 20B N/A and he says that there is no real advantage....to much possible downside for to little upside.

[Herblenny]

warwickben, So you're saying leading and trailing fires at the same time?? Hmm..

[Herblenny]

Gmonsen, from the other forum, is using the RX8 rotors in his 20B N/A. They thought he was having a problem with the rotors and side seals but it turned out it was something else. Logan at Defined Autoworks is building my 20B N/A and he says that there is no real advantage....to much possible downside for to little upside.

yeah... that's kind of what I read from Carlos Lopez.

I'm definitely going to go at this point with S5 high comp rotors.

Now I'm going back and forth about going with EFI or carb. If I could get a carb set up pretty cheap, I might just do carb.. If EFI, I know I could go NA now and go FI later and use the EFI.. Hmm.. decisions..

[djmtsu]

How much do you want to spend Phil?

http://www.tweakit.net/shop/product_info.php?cPath=326_27_176&products_id=118&osCsid=fd2f6de1becc88ae3ef02f2a1cab4045

Sweetness.

[need RX7]

http://www.tweakit.net/shop/product_info.php?cPath=326_27_176&products_id=118&osCsid=fd2f6de1becc88ae3ef02f2a1cab4045


I fapped.

[Herblenny]

http://www.tweakit.net/shop/images/20b_throttles_fitted.gif

It looks nice!!

[Herblenny]

wait.. I just found out thats the same set up as the picture I post earlier (from Carlos Lopez).
http://www.rotarycarclub.com/attachment.php?attachmentid=3368&stc=1&d=1227125627

[dregg100]

basically trailing is stock 1 coil to control it threw the dizzy.
then each leading plug has its own coil. the spark plug wire goes from the coil right to the plug.

i think you have this backwards. leadings fire at the same time and can be off of one coil and the trailings fire individualy.

[warwickben]

look at the schematic(sp?)i posted on the last page trailing has one coil and works with the dizzy, leading has 2 coils one for each plug and fires at the same time. alos after to do this you can switch the way you hook up the dizzy with the trailing. ie plug wire from coil to dizzy you put in the leading spot and the plug wires get plugged in to the leading spots.

[RotaryProphet]

How much do you want to spend Phil?

http://www.tweakit.net/shop/product_info.php?cPath=326_27_176&products_id=118&osCsid=fd2f6de1becc88ae3ef02f2a1cab4045

Sweetness.

I actually ran those throttle bodies (obviously the two rotor, not the three rotor version) on my stock internal 12a motor (with a big honking Master Power 70mm turbo on it, and a Megasquirt controlling EFI) and made 238 RWHP @ 13.5 PSI of boost. They're -fantastic- throttle bodies, and I have the dyno sheets to prove it.

The same exact setup but with my bridgeport 12a yielded 398 horsepower at the flywheel on my engine dyno @ 7psi of boost at 11,250 RPM. So they can definitely breath. (Side note, the engine was practically un-driveable on the road... so.. yeah. What do you expect?)

[dregg100]

look at the schematic(sp?)i posted on the last page trailing has one coil and works with the dizzy, leading has 2 coils one for each plug and fires at the same time. alos after to do this you can switch the way you hook up the dizzy with the trailing. ie plug wire from coil to dizzy you put in the leading spot and the plug wires get plugged in to the leading spots.

sorry, i meant the schematic was wrong.

[warwickben]

nah the schematic is right. trust me lol.

[warwickben]

Herblenny have you thought of this if you go carbed.

http://www.camdensuperchargers.com/images/fastrides/dlemon001.jpg
http://www.camdensuperchargers.com/images/fastrides/dlemon002.jpg
http://www.camdensuperchargers.com/images/fastrides/dlemon005.jpg

[Herblenny]

WOW!

Actually, I'm going to be building 2 x 20bs. One NA (carb or EFI) and one FI low compression... This is my only chance right now to build both engines.. Once I have the S5 rotors, building will begin this winter... This time, 100%!

[warwickben]

how hard would you saw it is to build your own 20b. like buy a core 13b and the parts needed to make a 20b. what i mean is finding the parts.would it be more money then buying a 20b and rebuilding. cause my sa is going to be off the road for a few years and i know i want to replace my 12a with at least a 13b but like every rotary owner i really want a 20b. id really like to keep it carbed.

[Herblenny]

You are going to have hard time finding 20B specific parts.. ie, one iron and the eshaft.

You could go 3 rotor or 4 rotor by going with aftermarket single piece eshaft and stack 12A or 13Bs. But you would have to go peripheral intake or go renesis irons and housings like the pictured earlier.

Personally, I would go oem 20B for turbo and stackable 3 rotor for NA... reason being, single e shaft doesn't handle high HP as it could twist easier... Think of it as a long wire vs. short.. It takes less force to twist long wire vs shorter one..

I just got off the phone with my builder and we are now shooting for Feb. 09 to get at least one engine built!

[dregg100]

nah the schematic is right. trust me lol.

im not trying to start an argument, but you are wrong my friend. the leadings are the ones that fire at the same time. take an FD for example, the leading plugs have one coil. two plug wires coming off of one coil and two harness wires going to it(12v+ and signal). then there are two trailing coils. each coil has one wire coming off for a spark plug and two harness wires going to it (again 12v+ and signal) now tell me how it is that the leadings fire independently based on that?

normally i would keep my mouth shut, but running a setup like you have mentioned kills power and on a boosted setup risks blowing the engine(i think you are still na) hell it may blow up an na, i honestly dont know. im just speaking from every car i have built, not a schematic someone drew up.

[warwickben]

dregg100 pm sent.

[RotaryProphet]

im not trying to start an argument, but you are wrong my friend. the leadings are the ones that fire at the same time. take an FD for example, the leading plugs have one coil. two plug wires coming off of one coil and two harness wires going to it(12v+ and signal). then there are two trailing coils. each coil has one wire coming off for a spark plug and two harness wires going to it (again 12v+ and signal) now tell me how it is that the leadings fire independently based on that?

normally i would keep my mouth shut, but running a setup like you have mentioned kills power and on a boosted setup risks blowing the engine(i think you are still na) hell it may blow up an na, i honestly dont know. im just speaking from every car i have built, not a schematic someone drew up.

Actually, if you look at his schematic (I just did, to figure out what this was all about), he has the sensor that fires the leading plugs split to two coils, so as to fire both the leading at the same time, then the trailing fires as per stock through the distributor. I ran my ~400hp turbo bridgeport 12a this way (although through a pair of MSD boxes) for months. Your hung up on the fact that there's two leading coils and one trailing, which makes you think the leading is firing at different times, but what you're ignoring is that the trailing is still firing through the distributor, and both leading coils are wired to the same signal, and so they both fire at the same time. It's a spark power issue, not a spark timing issue, all the coils still fire based on the distributor's sensor.

[warwickben]

Thanks. I was going to run a singal msd box then found out the down sides of it with a rotary. The great thing about this is it only cost me 45 for the ignitors and 30 for the 3rd coil.

Jeff20b is work on a setup like this for 20b's and the 4 rotor he is building.

[dregg100]

Actually, if you look at his schematic (I just did, to figure out what this was all about), he has the sensor that fires the leading plugs split to two coils, so as to fire both the leading at the same time, then the trailing fires as per stock through the distributor. I ran my ~400hp turbo bridgeport 12a this way (although through a pair of MSD boxes) for months. Your hung up on the fact that there's two leading coils and one trailing, which makes you think the leading is firing at different times, but what you're ignoring is that the trailing is still firing through the distributor, and both leading coils are wired to the same signal, and so they both fire at the same time. It's a spark power issue, not a spark timing issue, all the coils still fire based on the distributor's sensor.

i forgot about the dizzy!!

[rotaryextreme]

I LOVE RCC because it is so much more civilized then other rotray forum's. This was a very nice way that things were discused in difference. Other forums you get flamed and labeled...ugh.

Ben

[warwickben]

iam so used to getting flamed on the other site. i had a huge problem when i put that ignition setup in my car. the coils arced out ect ect ect. turned out i used a 1981 dizzy wiring drawing for the dizzy to ignitors. turned out all i had to do was swap red and green. 15 post calling me dumb ect read the manual search ect. iam one of the few people on that site with this setup with a 80 dizzy lol yeah no help.

any ways i hope the build on your na motors is coming along good ect.

[dregg100]

updates?

[RX8Ualiv]

has anyone looked at the rotary in the mazda furai prototype? it has a
renesis based R20b, which means that it has multiside ports, a more
powerful coil setup, high compression renesis rotors, and is N/A.
it produces 450 whp on E100 ethanol, but will run on good premium fuel
like shell v-power 93 octane. Racing Beat developed the motor under
cooperation with Mazda Motorsports, and i would like to get more
technical specs. i do know that the e-shaft and rotor assembly is
lightened and computer balanced and has what we could call a
stage 2 street/race port job, and a sprocket drive setup
with a better high flow oil pump and aluminum rotor housings
to replace the ones that are cast iron, which is lighter and
dissipates heat more efficiently, ceramic apex seals, and only consumes
half of the oil of the earlier 20b.
if anyone knows anything more please add to this thread, as i would
like to find out the exact specs as i intend do install this with a T56
6-speed and a l99-00 vette differential with a custom track bar, custom rear
trailing arms and custom a-arms.

[RETed]

You're asking about an engine in a prototype vehicle...?
Uh, good luck.


-Ted

[gmonsen]

As Herblenny knows, I have an FD powered by a 20b NA using high compression Rx8 rotors, monster street port, custom headers, ignition, with rotating assembly balanced to 10,000 rpm. It was making around 360-365 WHP in early runs. I haven't played with it at all over the winter, but will be tuning it this spring. I don't think it can do better than maybe 375 even at 9,500-10,000, if it can even get enough air there. (But it sounds great at those rpm's...)

The power is just fine, as this setup was developed for linear power, instant response, big low down torque, reliability, and great sound.

Gordon

[malekith]

I actually ran those throttle bodies (obviously the two rotor, not the three rotor version) on my stock internal 12a motor (with a big honking Master Power 70mm turbo on it, and a Megasquirt controlling EFI) and made 238 RWHP @ 13.5 PSI of boost. They're -fantastic- throttle bodies, and I have the dyno sheets to prove it.

The same exact setup but with my bridgeport 12a yielded 398 horsepower at the flywheel on my engine dyno @ 7psi of boost at 11,250 RPM. So they can definitely breath. (Side note, the engine was practically un-driveable on the road... so.. yeah. What do you expect?)

Curious as to the liftime of the turboed stock internal 12a... how many miles have you driven it for and are you willing to provide details for the build?

[GtoRx7]

I've seen his work and talked to the guy who helped put it together...But his is EFI NA.. I believe. My guy is whom I trust and knows quite a bit about carb... he's just not sure about Renesis rotors as he hasn't taken one apart.. i'm thinking about bringing him one this weekend to take apart and compare the rotors.

I'm also waiting to hear back from Carlos Lopez. He and I talked about this before as my builder wanted to go NA/Carb 20B... now I'm thinking it might be easier and unique...

This is the picture Carlos sent me about a year ago.. I think this is the set up I'm now considering...

http://www.rotarycarclub.com/attachment.php?attachmentid=3368&stc=1&d=1227125627

Hey Herblenny, I know you posted this a while ago and dont want to be late to the party but there is a little issue with this post. Did Carlos Lopez send you that picture and actually tell you he built that intake system? Because that is the intake system I built and had countless hours and money making. I sold it to a guy in new zealand and he put it on his 1st gen (your picture). I ordered the tweak-it throttle bodies, and had to do alot of revisions making them adapt, cutting them apart, custom balance bar with a custom adapter plate, custom intake manifold flange, custom fuel rail and holders etc etc. It basically used two old race 13b manifolds modified tremendously to fit the 20b. Carlos gave me the idea to use those two 13b race manifolds, and that was it.