Does anyone have dyno numbers or know where to point me to for a comparison between the two different types of ignition??

Knowing that I can turn my regular distributor into a fully electronic programmable electronic ignition (okay, it'll still have the rotor which must distribute the spark) I was wondering what the crankfire has over the distributor ignition besides 0 moving parts that can wear out.

for the distributor the path for the spark still needs to go from the coil>rotor>cap>sparkplug wire>sparkplug....

the crankfire is coil>sparkplug wire>sparkplug

what effect does the rotor and cap have on ignition if everything is the same (advance curve and coil rating)????

Here is some guy spouting "info".

http://www.rhinoracing.com/yaw/ignition.htm

Mike

A crank trigger is the only way to go if you have the option. I doesn't have the problems that a dizzy has, worn out parts, limited accuracy, etc. A crank trigger can more accurately measure crankshaft position, will not wear out. I doubt you will see a measurable difference in a crank trigger and a good quality dizzy (Mallory, MSD, etc). What you will find though is the ability of the supporting systems to make more power. Typically crank triggered systems are some sort of computer controlled unit. This allows individual cylinder timing and fuel optimization, that is where you will find more HP and torque.

Crank triggered coil on plug ignition is about a close to optimal as us mere mortals can get. Be nice when Megasquirt figures out how to do timing without using the dizzy.

Crank trigger is dead accurate due to the lack of torsional twist in the crank as opposed to a cam activating heavy valve spring pressure (amongst other things)

The crankfire system is just more precise . The distributor shaft Rides in bushings and is driven by a gear thats driven by another gear . All of witch are prone to wear.
The proof is obvious when timing a crankfire engine, versus a std, distributor . The timing mark is rock steady with the CF system . The distrbutor fired system visably jumps around.

Dave

Speaking strictly theoretically, if you have the distributor provide both the timing signal and distribute the spark (the box figuring the advance), then you're still subject to spark scatter from slop in the distributor drive. Much less of a problem on a Type IV, since the dizzy is driven off the crank rather than the cam. I've seen some positive statements quoted for one of those multi-coil setups driven off the dizzy (which is only used for the timing signal, not even distributing the spark). Generally, they'll say things like "still runs smooth with a huge plug gap", or something like that. So far, I haven't seen any quantitative tests that show the advantages of running that huge plug gap. (NOTE: this was on other engines, not a Type IV, not even an aircooled engine).

Besides the obvious wear problem, I think the main advantage of a distributorless system is that, by reducing spark scatter, you can run the timing a lot closer to the detonation limit w/o going over it. Many distributors (esp. cam driven ones) can show 6-8 degrees of spark scatter even when new. It's even worse if you're running points. However, in practice, that spark scatter doesn't seem to prevent Jake, et al, from reliably getting 70-80hp/liter out of a Type IV. I suspect that if unless you're running right on the limit, you'll never see the difference between a fresh distributor and a distributorless system. Of course, you don't see much difference between a fresh set of points and a breakerless system, either, unless you're revving the piss out of the engine.

I like the idea on a theoretical level, but I strongly doubt there are any practical benefits other than eliminating wear as a factor. On a 120hp/liter S2000 or a 180hp/liter bike engine, maybe. On a 60hp/liter Type IV, no.

I have used crankfire on the dyno against a 009 as well as a Mallory system...

setting the crankfire up advance wise was a challenge. Out of the box it did WORSE than the Mallory. After it was set up it made 11HP and 18 lb/ft of torque more. They both spanked the 009s ass so bad that it wasn't even funny...

I'm thinking about offering my system again, since I talked electromotive into making the coil packs for it again. The buggest trich was the trigger mount. I have plans for them and have made them work many times...

Megasquirt can already run a Distributorless ignition system.

It marries the Ford EDIS ignition with the Megasquirt ECU with only a couple of modifications. The EDIS system uses a 35 tooth wheel with 1 tooth missing and a variable reluctance sensor to track crank shaft position. The EDIS module controls dwell and provides the coil drivers. Timing is programable along with fueling. The coil provides spark to 2 cylinders at a time. On compression it provides spark for combustion and the opposite cylinder recieves a wasted spark.

Dave

There are a number of variations on the EDIS system, too. The trick on the T4 is making and mounting the trigger wheel. The best thing I've heard of so far is replacing the spacer between the cooling fan and the fan hub with the wheel, and mounting the trigger in there somewhere. If you did this, the EDIS setup is by far the cheapest and easiest way to go. Jake, if you sold the trigger wheels and pickup as a separate kit, you'd sell at least one of them (to me). The Electromotive stuff is expensive, but used coil packs, a used EDIS box, and one of the DIY controllers (MegaJolt Jr Lite, for example) could be put together for no more than an optical Mallory. And it would never wear out.

Hi Mike! Wow, what a coincidence. Guess what I just did? I just came in from driving my 914 for the first time with crank-fired ignition! I can see it in the papers now "Monkey sucessfully fabricates hall-effect crank possition sensor for 914"

Seriously. Remember a few years ago when I was trying to fab a crank possition sensor with magnets mounted in the rim of the fan pulley? Well the failure of that project has been bugging me for years so tonight I went out to the garage and dug out all the pieces and tried again. It wasn't the physical design that was the problem it was the wiring. This time I shielded the signal leads all the way to the ECU and bridged them to +12v with 1k ohm resistors so that when pulled to ground they would make a nice crisp square wave. It worked! Engine fired right up, I set the timing baseline with the laptop and went for a drive. It was sweet.

If you recall I was previously running a Crane optical sensor in the dizzy. With the optical trigger there was much less spark scatter than with points, but there was still a noticeable amount. I think it's probably because even with a tight dizzy there is gear lash between the dizzy shaft and the crank, not to mention dizzy shaft wobble. I bet at idle speed that dizzy shaft is rattling back and forth across that gear lash. Running off the crank-trigger there is much less spark scatter as viewed with the timing light. The engine definitely idles more smoothly. I don't expect that there is really any more power - maybe a little, or like has been said - the potential now to extract a hair more, but nothing earth-shattering. It definitely seems smoother though, and I like that. It's still firing through the distributor for now (for spark distribution only - not timing or crank possition). I've got the coils for waste-spark but need another compatible ignition amplifier. As soon as I round one up I'll try to go distributorless and see what happens.

-Ben M. (now with new improved crank-fire action)

great job airsix!!!

how hard was this upgrade? tell me more!!

I'd never really thought about distributorless ignition on the 914, but I'm intrigued now...

Ya'll like my dizzy???

SDS with crankfire....Yeah Baby!!!

I'm running an aftermarket digital ECU. That's what made the project doable. To use crank-triggering for your ignition you need a digital controller to control the advance curve. If you are not planning on replacing the stock injection it's really more trouble than it's worth. However, if you are converting to Megasquirt(+ignition) or other digital ECU that can control the ignition, I'd go for it.

-Ben M.

Cool. I sent a picture just like that to Jon Watts about 3 years ago. Right before my crank-fire project fell on it's face. That was right before I gave up and put the dizzy back in. Ever since then there's been an expanable freeze-plug in the top right-hand drawer of my tool chest just waiting to plug the hole currently occupied by my distributor. It's been waiting in that drawer since 2001 and I think I'm finally going to get to use it.

-Ben M.

ps - Drove the 914 to work. I always love driving it to work after a big modification like this. It's kind of ceremonial. Not the same as "test drives".

ahh... I wasn't planning on going back to FI anytime soon... I may do Megasquirt later and do this then...

Ben,

How many sensors for the crank position?

For the above distributor setup I mentioned, 4 sensors are used for crankshaft position.

I guess I should just go with the EDIS crankfire I have, I know it's able to support over 700hp and 9,000rpm with stock components on the Ford Mustangs (I think they do normally swap out the coil for an aftermarket unit)

Anyone have pictures of the crankfire wheel and pickup mounted on a /4 ?

I've seen Dave Hunts wheel, not too sure how or where he mounted the sensor.

My homemade wheel...it has two trigger magnets and one sync.

Backside

front mounted

So, something like that, but with a 36-1 toothed wheel would work well for EDIS. On the MS lists, they've mentioned that the trigger wheels on Fords are rings, and not hard to remove from junkyard pulleys. I vaguely remember they're 7" in diameter, but I could be off completely on that. If so, making a simple plate to mount that to the hub should be easy. Then it's just a case of making a mount for the VR sensor itself (also junkyard available cheap, along with the rest of the EDIS setup).

Hmm. The PO put an 009 on my car (carbs), and I've been considering an optical Mallory, but this could be a lot more fun.

The Ford trigger wheel comes off of a pulley for the serpentine belt. Easy to remove

Mount it to an enlarged version of the spacer washer between the hub and the fan.

The VR sensor will mount to the inside of the cooling shroud below the area of the oil cooler. It needs to be something like 100 degrees before TDC #1 so that area works really well. It's similar to Mark's mount.

Mind you I still haven't run it.

Dave

Here's a picture of the sensor mounted on the cooling shroud

Here's the trigger wheel

thanks Dave....mind if I copy???? hahahahaha

I do wish the 36-1 wheel was lighter, I guess something could be done about that

Quantitaive? What will you accept?

The fact that now I don't foul out plugs every 100 miles?
That the engine will idle smoothly till hell freezes over?

I don't run a crankfire setup. but MSD/dizzy....with a large plug gap. I'd tell you that the motor runs much smoother at low rpms, but that would be subjective.

I doubt there is any HP gain up top. The big gap is for down low. The high voltage spark is to ensure that the big gap is jumped at high rpms.

From what I read, those coilpacks don't generate any more voltage than your basic standard coil.

Coilpacks probably don't generate all that much more than a stock coil, however they generate it straight to the plug. Anything with a dizzy has to jump from the rotor to the cap first, and THEN it jumps the plug gap. Last time I looked, air had a moderately large resistance.

Also - a coilpack gets twice as long to charge as a single coil does at any given RPM. (Assuming wasted-spark setup)

Mike - the 36-1 disk aint that heavy, and you could always make it skinnier. I would get a lightened flywheel and make a very light hub to mount the disk on if you are that worried about it.

Also (Mike) here are the subaru group names I promised you:
Subaru-tech (all subarus)
LegacyB4 (the twin turbo engine).

Remember our discussion from lunch on Tuesday regarding your new business name

Dave, if you are gonna use that on the engine kit I'm building for you I mus have that trigger wheel for balancing. It must be indexed in the position that it will be installed..

Jake

It's in the box. It's indexed via the dowel on the fan hub. I know it has to be part of the balance and once it's in it has to stay.

Yes, I'm gonna include it in the build as the spacing washer on the fan hub. I'll have the VR sensor on the cooling shroud but I'm gonna start the engine with a Mallory, get a fuel map that isn't dangerous, then tune the fuel map with the O2 sensor. When I'm happy with what I've created, I'll get some chassis dyno time to even out the the fuel map and tidy up the ignition. Programmable ignition is the last thing I would like to add. I think I'll have enough challenges building it and getting the fuel right. It's best to change as few things as possible at any one time.

I love gadgets and I like to fiddle but, right now I don't believe programmable ignition adds a lot until knock sensing or ion sensing can be incorporated. The Megasquirt people will include the ability to use the Ford wheel and VR sensor in future versions. If, in the future they incorporate sensors, which they will, to run the ignition closed loop I'll be all over it. As it stands now I'm gonna watch and wait.

At times I'm a little crazy but I'm not nuts, so I'll take it one thing at a time.

Dave

tat2dphreak, forgot to say thanks for the compliment. Stop bowing. I'm just a monkey loose with tools. Once in a while things fall together.

Mark, NICE setup. That's the RIGHT way to do it IMHO. Same goes for you Dave. Thumbs up guys. This is the stuff I love.

Mike, my setup is similar to Mark's. Three magnets and two sensors. Two of the magnets mark TDC and 180-from-TDC. These magets are mounted with a specific pole facing the sensors. One of the sensors reads these two magents only. The third magnet is invisible to this first sensor. The magnets are actually possitioned to pass the sensor about 40 degrees ahead of TDC and 180-of-TDC. The ECU is programmed with this baseline so that it knows when it gets a signal it will be another 40 degrees of rotation before the piston is at the top. That gives it time to prepare a spark to occur at the programmed advance angle before the piston gets to the top. The third magnet is mounted with the oposite pole facing the sensors as the other magnets. One hall sensor only sees the North side of a magnet and the other sensor only sees the South side of a magnet. So one sensor only sees the two opposing magnets, and the second sensor only sees the third magnet. This third magnet leads the TDC magnet by a few degrees. It's just a marker so the ECU can tell which of the opposing magnets is TDC and which is 180 opposed. Now the ECU knows which end of the crank is which so it can fire the right coil at the right time. You probably knew all this - sorry if I bored you. I'm interested in the missing-tooth systems. I am sure they have better resolution especially when rpms are changing very rapidly.

-Ben M.

Hey Ben,

thanks for the info, yes, I knew that already, but I am sure others that are reading this will be educated

The Haltech I have (it belongs to Brad) uses the same basic method for the timming as your system does. It is an older system and it can only be used with the distributor...it couldn't have been that bad, the original mapping on my Haltech is for a twin-turbocharged 911

Oh, I didn't mean I dislike the three-magnet system. It works really well. So what are you working on these days for your own 914's powerplant? Are you going to run that Haltech in your 914 for a while? On a stock motor or something wild?

-Ben M.

I'm giving the Haltech back to Brad...at the time he gave it to me, Megasquirt did not have anything for ignition that complemented the adjustibility of the MS itself.

For fuel, I am using the MS without a doubt, now for ignition I have the choice of using MS'n'spark which uses 4 magnets mounted on the crank for position. The MS'n'Spark keeps the distributor for spark allocation similar to your system.

Another option now available is the MS'n'EDIS which is what Dave has started to install on his new 2.0 that he and his son are going to build.

After seeing Daves install, it's seems the choice now is a no-brainer. I've been without an engine for so long, I had nothing to use for mocking anything up. Now I have an 1.8 to use to get dimensions off of and to test fit the parts. I already have all of the EDIS components, I was not sure if the 36-1 would be able to mount behind the fan, I guess I never saw Daves installation or I just had a brain freeze and forgot about it.

motor? 1.8 temporary to use as a test mule for the turbo...at first I had ditched the turbo idea since I felt I couldn't afford to do it correctly (I still can't, LOL)

since the turbo is already paid for (early subaru FV48 like yours), I figured what the heck?!?!?!? Now the biggest stumbling block is deciding which exhaust system to use and to send off to Jet-Hot.

My two choices are:
used header (european)...this means mounting the turbo way in the back behind the axle or running a really long pipe off of the header to the turbo and mount the turbo up in the engine compartment

or, use late 1.8/2.0 "log" exhaust, I'd use a "Y" pipe to join the two and mount the turbo in the engine compartment.

For the intercooler, I have an early Volvo unit, I'm sure it'll work for now, but a nice modern aluminum unit would be much better.

I am pretty sure both Ed's run thier turbos inside of the engine compartment....as always, there will be comprimises to each method. I am not looking for a high output, high rpm track machine.....bottom end and mid range torque is going to be more important right now. It might be a half-ass way of doing it, but I figure I can always upgrade the turbo at a later date when funds match the need

Hmmm....turbo again

YOU CAN"T TURBO A 914! But what the fuck do I know.

A future turbo is one reason I got this system. All I have to do is buy a 2-bar MPS (for up to 15psi) and I'm good to go with boost retard.




All the Volvo intercoolers I've seen are huge. Where do you plan to put it?
I've been thinking about a air/water intercooler to keep the heat out of the bay.
Still in the thinking stage.