Yes!!! I check this thread every day and it never fails to deliver...

 

fapfapfap...

 

this build is amazing, pure genius, good work + keep it coming!

 

Mooi project!
Dan zijn er nu twee 4-rotorprojecten in Nederland!
Man, jij bent goed bezig!
Wat voor ontsteking ga je gebruiken?
Stel je zelf de mapping in?

Or in good english..ish:
What ignitionsystem are you going to use?
You are mapping yourself (the engine i mean)?

Very interesting read, keep up the good work!

Grtz Dennis

 

What crank HP @ what RPM you're guestimating?
Willing to throw out there what volumetric efficiency to expect @ peak power?
I know you know the answeres.

p.s., considering the intake/exit overlap, you agree 11:1+ compression ratio would be very sweet?

 

I'm using a standalone ecu to control ignition and injection. I'm keeping the make and model of the ecu for myself for the moment, because it has never been used on a rotary engine before. I will be doing the mapping myself. Me and a few friends have our own chassis dyno so the car will be extensivly mapped and tuned.



Well at the moment the engine is built to make good VE at mid-range rpm's, so it should be a pretty strong engine with a decent amount of torque, but I expect VE to drop pretty quick at higher rpm's. So I don't think it will have 600+ peak hp, probably a good bit less, but I don't mind. I'd rather have a nice torquecurve so I can actually use the power, Remember I'm using a stock TII transmission and this car will be driven mostly on the street. I don't see the point of having an 11:1 compression ratio, There doesn't seem to be any gain with going any higher than 10:1, I'm using 9,4:1 rotors

 

I think you'll be pleasantly surprised about the power a N/A 4 rotor will make. I wouldn't be surprised if 600 were easily attainable on your setup.

Awesome updates as always.

 

in theory almost any ECU can run a 4 rotor, the only thing you'd give up is the timing split, which is fine.

the only thing that seems to be uniquely important to the rotary is that it NEEDS an accurate ignition timing. it seems like you can run tons of timing, or really lean fuel mixtures and its fine, but you get some crossfire, or if the plugs fire at weird times = dead engine with no explanation. it doesn't quite work out, but you can look at the broken dowel pin threads and narrow it down to ecu manufacturers!

 

x2

 

Why the secret?
Hmmm, so when your engine or some very delicate part(s) goes "kaputt", you just make another one?
I would use a proven system, just to be sure but hé, we're not making a LeMans 2012 car here, right?
Man, can't wait to hear and see it running, no matter how many bhp it produces, not important imho!

New pics yet?
Exhaust? Intake?

Grtz Dennis.

 

been lurking since the first post. never had anything to say except what everyone else has been saying. great stuff.

 

I hope this engine makes 500hp for 200K miles worth of fun, superb work!

 

Ah yes, I knew that , but I'm confident that this will work fine. I'll be running zero split, with 4 dual tower ignition coils. So negative split shouldn't be possible. But apart from that the unit should be really accurate.


This is a proven system, I'm not an idiot. I've already used a similar unit on my racing motorbike for a few years and don't want to use anything else anymore. I'm familiar with setting it up and tuning it and never ever had any problem with it whatsoever. It also came as a set complete with all required sensors, ignition coils and a lsu 4.9 wideband sensor / controller, so it's a combination that's proven to work well together.


Anyway, some progress pictures:


Fitting the radiator here



Added the cooling fans, I used push fans and placed them before the rad



Engine bay shot

 

Looking awesome!

 

Looks great

I still really wish you had gone electric water pumps though.

You planning on running dual oil coolers or something more "custom" ?

 

An GP Sport-spoilerkit on that thing, and we're done! Or maybe a RE-Ameninya (spelling?)...

It looks awsome John, I wish that we lived closer eachother so we could "invent" over an beer

 

yes elc water pump would have been cool as!

i am all so curious about the oil cooling john!

 

John, your ignition might not work very well as planned. It's not a good idea to have a dual post coil going to both plugs in a rotor housing. Your idea may be the easy way to accomplish ignition on a 4 rotor, but you might want to consider alternatives.

It's been years since I read about it but something about less spark energy is available to the leading spark plug due to the ionization is greater around it or it's less shrouded etc, and there is less ionization around the trailing plug, so more spark energy lights up the trailing plug which does nothing for power. Basically you'll have lots of misfires which is typical of p-ports at low RPM (brap), but it will be much worse and significantly down on power.

Again it's been years since I read about the coil per housing problems and I haven't thought about interesting ignition projects in at least that long. Hopefully someone else with some ignition experience will add a couple more cents of knowledge here.

Hmm, maybe ask peejay, j9fd3s and maybe Karack. I'd also ask RETed but he's on the other forum now.

 

Few things. Looks great but unless those rubber bushings screw off some how, or the passenger frame bracket unbolts, how do you plan on ever getting the radiator out?

Also, I hope you're using more/better fans than those. Those are not only tiny compared to what's available (I'm assuming you're going to shroud whatever you use) but pushers are no where near as effective as pullers and it looks like you've got all sorts of room for a good set of pullers. I'm using a pair of Derale fans from Summit that pull 2200CFM EACH. Now that's moving some air. And my bay is WAY more cramped than yours so it should be a no brainer.

 

In that case you can use an 8-cylinder set-up, right?
Isn't it better to use no trailing at all then (with the zero split)?

Why aren't you using a 5-channel set-up? (1 leading in wastespark mode + 4 trailing channels).

Grtz Dennis.

 

I can't recall if John is going big fire 180 degree or a true 90 degree rotor phasing. But either way, wasted spark on Leading is what I'd prefer. Trailing doesn't add power, at least on an NA, so you don't need it.

Just a note about trailing and boost: If you don't have working trailing ignition, the trailing hole can fill in with carbon, then act like a glow plug igniting your incoming mixture under boost. This is less of a problem (or not a problem at all) if NA. So John doesn't really need trailing ignition. And his engine would run better with wasted spark leading.

 

yeah i ran my 20B initially with 3 FD leading coils and an E6K and it was weak! if i was going to do it again, i would use 6 coils... its something like waste spark is ok, because one plug is in pressure and one plug is not, but when you run a dual post coil on one housing BOTH plugs are in pressure, so you need more power.

for cooling, i've found the PP to be really easy. i used an S4 water pump and housing, stock thermostat, new stock radiator, and a lower water hose with a spring form in it, and temps are rock solid @85c. i don't do a lot of street driving, but it does ok with no fan. i think the brap brap = it runs cold at idle.

so i would recommend some sort of anti collapsing device in the lower radiator hose, a section of pipe would do it, and then i'd think it would be fine?

i'm not mentioning oil temps, but i used a GSL-SE cooler, and mounted it horizontally. it has a cereal box duct from the undertray to the cooler, and it seems to work amazingly well. so i think part of my rock solid coolant temps is having low oil temps too.

and in case this sounds too good to be true, the PP also gets great gas mileage!

 

Jeff,

I don't know if I'd go as far as saying trailing ignition doesn't add power, even on N/A. It may not add significant power, but it is worth something. Here is a clip from the Mazda paper on the R26B 4-rotor engine with the far trailing plug, and its effects on power output and BSFC:



I can't find anything on the standard leading plug's effects, but if the far leading plug is responsible for up to ~3% increase of torque, the standard leading surely adds at least that due to more optimal position.

 

Yes, if I've got the option to run trailing ignition, I certainly will because it seems to help starting as it acts like a spark plug non-fouler, for those cold mornings.

But if trailing would be a monster to tackle, such as the way I did ignition on my early MegaSquirted 20B with a 6-1 CAS, or even the 4 rotor 12A doing it the old school way with a dizzy, I'll just run wasted spark leading only because you'll still have three or four coils and ignitors in the engine bay that need homes, and because they're NA, I couldn't justify adding three or four additional coils and ignitors for what like 3% more torque or 2 HP or some tiny unmeasurable amount more fuel mileage.

 

Woah, lot's of feedback! I'll try to answer and explain a few things


I don't really see the point of an electric waterpump, sure it isn't driven by the crank so it saves a tiny bit of power but I would have to run a larger alternator and there would be more strain on it. It's also less reliable, and I don't think any of them will actually pump more water than the S4 one I'm using, maybe at lower engine rpm's. I personally would only use one if I ran into fitment issues of some sort.

I will be using 2 FC oil coolers, I think they're more than up for the job and I already had them.


Ah yes, beer would be nice No spoilerkit on this FC though, I don't like the look of most of them, and I hate doing bodywork so I'm keeping the outside and interior stock-ish.


Haha, of course it's possible to remove the radiator
The bottom 2 rubber mounts are held in place with 2 nuts, undo those nuts and you can slide the 2 mounts inwards. After that slide the radiator a bit towards the engine and tadahh, radiator removed in less than a minute.



About the fans, I left the top part of the radiator uncovered of the fans on purpose, you'll see when I'm done with all the ducting. The top part of the radiator won't be covered by a shroud and it will have a seperate air duct flowing air towards it, this is to get more air through it when moving at speed or being on the dyno (and having a large fan in front of the car). I tested a lot of different fan's and although I don't have any cfm numbers these seem to be working very well. The oil coolers will be located right in front of them with ducting between the oil coolers and the fans so they will push air through the radiator but pull air through the oil coolers. Another reason why I wanted the fans in front of the radiator is that I'm planning to use a vented hood, so pulling fan's would be subjected to rain, debris ect. Although there are waterproof ones I didn't like the idea of that. If I get water temperature problems I will probably add a few pulling fan's but I think these will do.


Having 4 dual tower coils firing every 90 degrees IS an 8-cylinder set-up. I don't think a 5-channel setup can work, you would have to have a quad-tower coil, I don't even think they exist, and even if they do spark output would be pooor. Now having an 6-channel setup would work. You use 4 channels to sequentially ignite the trailing plugs and 2 wasted spark coils to fire the leading ones, so you basically have an FC ignition setup, but just 2 of everything. This has been done before, and I having wasted spark on the leading plugs has a tiny benefit too, Problem with 6-channel ecu's is that most of them are expensive and don't even have all the functions I want.



@Jeff20b

Great info, I have read about not being able to use a single twin power coil on one rotor housing before, but I know that others have used a similar setup than the one I'm attempting now with succes so I think it also depends on the exact setup. When shopping for an ecu I initially wanted to go with 2 DIS-coils (one for the 4 leading plugs and one for the 4 trailing plugs) which would eliminate the problem but it is a bit complex, so I asked the ecu manufacturer if they knew a good coil setup and they recommended the use of a certain twin power coil that's supposed to give a really strong spark. So I ditched the complicated DIS-coils idea and am going to try this first. Maybe it's a good idea to try out a few different coil setups on the dyno, should be interesting. Trying using only leading ignition with 2 coils should just be a matter of plugging the sparkplug wires differently and setting up the ecu. I think doing 8 coil on plug's is also possible but I'll have to check that.