Poweraxel

the blue wire diliema:
Since i dont run the crane rev-limiters or any other crane ignition options that are included with the box and i dont run the multi-spark features... i really dont think it matters if the blue wire is hooked up... the crane box(s) simply await a signal from the haltech (or an ignitor) rather simple

so in my opinion the blue wire doesnt matter.. only unless you use there rev-limiters,multi-strike features or any other RPM output. these features are more used with piston motors than our "odd" firing rotary motors

what do you guys think?

turbostreetfighter

that is waht i think too!!

silverrotor

iTrader: (1)

I'm not using their rev limiters but like I said before, the wasted spark, on the Leading Coil Pack translates to 8 cylinder mode. Therefore, no Blue Wire needed, right?

RICE RACING

I use the multi strike as it makes the engine run much better @ idle and low throttle operation at low engine speeds.

It is even more critical on a rotary as the combustion chamber is so long and the continued striking of the ignition after the main spark (triggered by either ECU of Ignitor) clean up emissions and allow you to run a leaner a/f ratio I have found too.

If you are not using multi striking then this is not a problem, If you are using muti striking and it is not switching off untill 6000 rpm due to the blue wire not being hooked up to a ignition switched positive 12v (normally switches off @ 3000rpm) source on a rotary then you could get sparks happening into the next cycle on the wasted rotor.......from what I have been able to find out the multi striking happens for 30deg crank angle after the initial spark, when I get home I will see if this means that the above situation can actually happen with a leading firing angle of between 15 to 5 deg advance.

RICE RACING

No, wasted spark systems generate 4 sparks every two engine rpm, this means exactly the same firing number as a 4cyl 4 stroke, same as when you hook up a Autometer tach, you switch it to 4 cyl mode and it reads the right rpm.

THIS MEANS YOU MUST HOOK UP THE BLUE WIRE to positive 12v to make it in 4cyl mode. To read the correct rpm.

If you leave the blue wire off the unit will wait for double the frequency of sparks to register the "righ" rpm to switch off the multi striking, If its only generating 4 sparks but the unit is looking for 8 (as in a 8cyl engine) then this means you must do double the rpm for the unit to switch this feature off. So instead of switching of at 3k it will switch of at 6k if it is wired up wrong.

turbostreetfighter

so back to the original question...can this blow your engine worst case scenario? i have used them both ways and did not hurt anything or notice a difference even.

MWW

RICE RACING

Tonight mate Tonight

I was waiting to get back a reply on how many crank angle degrees the multi strike went for. So the answer will be revealed in a few hours.

RICE RACING

OK everyone here is the answer !

Looking at TDC of the front rotor, we have exactly 30 degrees of crank rotation untill the leading spark plug hole is exposed in the wasted rotor.

So what we need to know exactly from Crane is the range of multiple spark from 0 to 3000 rpm, i read somwhere that just before the unit switches to single strike it fires for up to 30 deg (crank rotation) after the initial spark.

Now if the blue wire is left off, we need to know how many degrees the Crane unit fires for at 1500rpm or 2000rpm etc to see the effect.

Say for example if the Crane fires for 45 deg of crank rotation @ 2000rpm, this would mean when set up on a 2 rotor wasted spark set up with the blue wire left un connected (hence looking for double the pulses, therefore unit thinks it is running at half actual speed) that you would be causing a premature spark in the wasted rotor (compression phase) If the leading ignition timing is set to fire any less than 15deg advance.

45 deg (crane multi strike rate/duration) - 15 deg (timing intial strike) = 30 deg buffer which is the exact time untill the leading plug hole is exposed to the new charge in the wasted rotor. It can very easily happen from the above senario........ We just need to establish what the exact Crane specs are for multi strike duration over it operating range from 0 to 3000rpm (then apply this to either senario 0-3k correct operation or 0 to 6k no blue wire connected). Either way the buffer we have to not get into trouble is the initial leading timing figure + the 30 deg buffer, before the compression phase on the wasted rotor is "exposed" to the leading plug chamber.

I think you could very easily get into trouble in the higher revs when the timing is pulled back especially under boost, this will not leave you with much of a buffer if the unit is still multi striking above 5k rpm.

I will try again to get the info from crane

NZConvertible

That's not how I understand it.
The trailing plug fires once per rotor phase, which is once per engine revolution. Since there are two rotors, the trailing coil pack is fired twice per revolution, which is the same as a 4-cyl.
Because of the waste spark system, the leading plug fires twice per rotor phase, which is twice per engine revolution. Again, two rotors, so the leading coil is fired four times per revolution, the same as a 8-cyl.
So if you connect a tach to the trailing coil, it must be set to 4-cyl mode, and if you connect it to the leading coil, it must be set to 8-cyl mode.
I'm not sure about that blue wire though...

maxcooper

Jason,

Ignition events per main shaft revolution by engine type:

2-rotor, leading = 2
2-rotor, trailing1 = 1
2-rotor, trailing2 = 1

4 cyl, single coil = 2
6 cyl, single coil = 3
8 cyl, single coil = 4

With the Crane on the leading coil, you need to tell the Crane it is a 4-cyl if you want it to know the true engine RPM.

-Max

RICE RACING

Jason, yes please do not confuse every one

Leading coil ignitor puts out 2 signals per one main shaft revolution at evenly spaced intervals, I think you are getting confused with the amount of sparks coming out of the coil ? this is not the issue as we are looking at signals that trigger the coil not the number of outputs on the coil.

Again a trailing ignitor on a a wasted spark system will produce over 2 crank rpm (one complete piston 4 stroke cycle) 4 evenly spaced signals, which is the same as a 4 cyl 4 stroke engine engine.

Remember the Leading coil only sees one input from the ignitor from either the front rotor or the rear rotor in a repeated manner F,R,F,R,F,R,F,R and so on, but it sends an output to both front and rear rotor for each input from the ignitor. One of these is WASTED and does not count in measuring rpm.

Which means as maxcooper points out that for the unit to correctly measure RPM from leading ignitor input to the coil it must be set as a 4cyl engine, plain and simple Now back to the original question, can someone help me get the multi strike specs (duration) from Crane over the operating range up to the switch off point (3k rpm)

silverrotor

iTrader: (1)

Jason, that Is how I understood It when I hooked up the Crane Cams Ignition Box.

It was right up 'til reading this thread I'm still left confused on whether I should have the Blue Wire hooked up or to leave It alone as It Is now.

RICE RACING

Easy, you dont have to believe me ! Just get a timing light (hooked to the leading plug lead), have friend in the car and rev it to 2.9K with the blue wire hooked, you will see multiple "eratic" ignition firing points through the light on the pully, go over 3.1K and they will stop and show one consistent "strike" through the timing light.

Now turn of the engine, disconect the blue wire and you will notice it multi strike to 6k rpm........... easy test


I know I did it on mine to check for correct rpm setting (i.e. which way to hook up blue wire)

silverrotor

iTrader: (1)

Okay, you twisted my arm. I could be quite the sceptisist.

Does having a non Turbo have anything to do with the relevance of the Blue Wire hooked up or not?

NZConvertible

Bugger, I got it wrong...
I’d previously downloaded the ignition animation mpeg from Rotary Engine Illustrated and had another look at it today to double-check what I’d posted. I was more than a little pissed to see I was wrong. I logged on tonight fully expecting the above replies. So, just to prove I'm not completely stupid...
The trailing coil pack is two separate coil/ignitor combos, and each is fired once per revolution. I'm not sure if the tacho wire on the trailing coil pack receives a signal from both ignitors or just one. If it's both, it sends out two signals per rev, just like a 4-cyl. Otherwise it'll just be one signals per rev.
The leading coil is one double-post coil that’s fired every time one of the rotors needs spark. Each rotor needs one spark per revolution, and there are two rotors, so the coil is fired twice per revolution, again just like a 4-cyl.
Sorry if I confused anybody, especially silverrotor, who went to the trouble of PMing me only to be given a load of BS! If anyone’s still having trouble understanding how the rotary ignition system works (particularly the waste spark), I highly recommend you download that video and study it. It’s usually much easier to understand stuff like this if you can see it happening right in front of you.

RICE RACING

Jason

Now we are all Crane experts I know Crane were F*ck all help when I told them I wanted the unit to run on 2 rotor with wasted spark. they just said it was not designed for it

homo's

I wonder how many companies miss out on business from people with "different engines" just because they do not take the time to do some research to see if their products are suitable....... I would say quite a few fit in that boat

silverrotor

iTrader: (1)

Finally. Some resolvement. Great to know I could hook up that wire. Good deal guys. FINI!