My MicroSquirt Install Options

[Bartlett 914]

FINALLY made some more progress on this install. I got the toothed wheel back from Mike Mueller, who did the mods for me. It fits just fine and I installed it on my latest 2056 during the cam break in. So it spins just fine, as expected.

I did a lot of searching in the back room of my local NAPA, opening every VR sensor box they had to find one that was small and light. This is the one that I found and I assembled a quick test bracket. The VR sensor will mount on the existing case stud so there will be no holes or other modifications made to any parts.

Installing this system will require the motor to be removed and the fan housing to be unbolted. Even though removing the motor isn't ideal for a 'bolt-on' system, I think that eliminating the need for permanent modifications is a worthwhile goal.

Anyway, here's the pics. I have a couple videos as well that I'll post shortly. (IMG:style_emoticons/default/cool.gif)

This looks like you are moving the fan out by the thickness of the gear wheel. How is this going to work?

[jhadler]

This looks like you are moving the fan out by the thickness of the gear wheel. How is this going to work?

My guess is that the toothed wheel is replacing the steel spacer that goes behind the fan... Thus preserving the required spacing...

-Josh2

[McMark]

Yup, the timing gear is the exactly the same thickness as the stock washer. There is a picture, earlier in the thread, that shows the stock washer on top of the gear (Post #69). 100% non-modify installation. True bolt-on.

[Bartlett 914]

Yup, the timing gear is the exactly the same thickness as the stock washer. There is a picture, earlier in the thread, that shows the stock washer on top of the gear (Post #69). 100% non-modify installation. True bolt-on.

That would work. It is just that in that picture, the plate looks thicker. I assume is is reduced in thickness on the back side. Is this correct?

[toon1]

Can you use the micro squirt without the ignition feature? I would be interested in using only the stock D-jet parameters initially: TPS, MAP. I have a friend interested in this.
Thanks and great job so far (IMG:style_emoticons/default/smile.gif)

you can! although, you don't need Micro to do it unless you are worried about space. Micro is $400.00.

If you are just planning to run fuel only, you would be better off running MSI with the V3 board. You can upgrade to MS&SE later to run spark.

[McMark]

MicroSquirt can do fuel only, but you'll still need the crank sensor, so why not do ignition. MicroSquirt will not trigger off coil fire like MegaSquirt will.

That would work. It is just that in that picture, the plate looks thicker. I assume is is reduced in thickness on the back side. Is this correct?

Yup. In the picture in post #69 you can see the area that was milled.

[smdubovsky]

MicroSquirt can do fuel only, but you'll still need the crank sensor, so why not do ignition.

To make conversion easier. Its ALOT easier to get fuel only working at first, then convert the ign over once you have a good handle on it. I plan on doing fuel only on my -6 as a start. Im gathering all the plumbing parts to start soon.

MicroSquirt will not trigger off coil fire like MegaSquirt will.

Eh? You mean it wont trigger off the hig-voltage points directly driving the coil right? I have a MSD running off the SC dizzy magnetic trigger wheel. I should be able to use the mag-pickup or the MSD tach output to feed rpm to the US right? I was planning on doing another 60-2 trigger wheel on the flywheel eventually (like a 3.6 and the same as my haltech 911 conversion) but was going to feed the US w/ the tach signal at first (batch fire.) Don't want to have to mess w/ making the trigger wheel just yet.

[Dr Evil]

I'll do the Mega Squirt, then. The guy wants it to be a basic upgrade to the D-jet that will fit in the stock D-jet stuff. If I could have used the Micro it would save me some assembly time, but cost me money as he is going to pay me to assemble it as well.

Thanks for the info (IMG:style_emoticons/default/smile.gif)

[Krieger]

Nice work Mark! Keep us posted.

[McMark]

I originally tried to run the MicroSquirt fuel only with crank position sensed by when the coil fired (trigger on coil negative), but it would not work because of EM feedback. The coil is a really really dirty place to get a signal from.

[Brian_Boss]

I'm sure Mark considerd this but why couldn't you use the FI trigger points in a stock D-jet distributor for Microsquirt?

[toon1]

I'm sure Mark considerd this but why couldn't you use the FI trigger points in a stock D-jet distributor for Microsquirt?

The D-jet trigger points won't work( the reason why escapes me). It's easiest to get the signal from the -side of the coil.

[smdubovsky]

D-jet points trigger the coil directly? (excuse my 914 ignorance, but I remember people messing w/ them at the cookouts.) If so, there is high voltage on that line when they open = no good for a trigger. You COULD use the points as a trigger if you're NOT driving a coil directly from them, like if you're using a MSD or CDI ignition.

[Dave_Darling]

The D-jet points only hook up to the ECU, not to the coil. Each one triggers once per full cam revolution (two crank revolutions), not four times. It would probably work OK as an RPM indication, but not so good indicating crank or cam position.

Plus the D-jet distributors are old and sloppy. Controlling the spark directly is much much more precise.

--DD

[McMark]

Jeff Keyzer and I installed the MicroSquirt on a motor that I have bolted to my test-fire stand and installed the crank fire components to test it out.

Great news! It ran! Well, a little bit anyway. Now that we know it will run, I need to install exhaust manifolds for the O2 sensor, clean up some wiring, check the fuel pressure, and a few other things. Then we'll do some real tuning.

Things are moving along. Hopefully, next month I will have this all finalized. It's taken long enough. (IMG:style_emoticons/default/cool.gif)

[mightyohm]

Mark's VR sensor solution is top notch. Great, steady RPM signal - much better than anything I have ever seen off of an ignition coil.

[McMark]

Yeah, I was really surprised by how clearly the MS read 175 rpm under cranking. I'm used to seeing erratic jumps that you mentally average. This was rock solid timing. Very cool.

[hulken]

(IMG:style_emoticons/default/agree.gif) with both of the above. Every new cam, or more generally, every new motor combo (heads, cam, bore, stroke, CR, etc) will need a new tuning of the FI maps. So yes it's useable, but it still needs to be tuned.

I got a picture of the trigger wheel from the machine shop. A bit of a goof on two of the holes, but that's fixed on the future ones. This trigger wheel will drop on in place of the fan spacer. Once I get this in hand, I'll need to devise a sensor mount. Ideally, it'll be something that could be installed without removing the fan housing. But we'll see about that.

Are you planning to sell these trigger wheels?

[McMark]

UPDATE: JeffK (mightyohm) came by again today and we made another test run of the MicroSquirt motor. It worked really well in fuel only mode.

But it still doesn't like to drive the coil. We're pretty sure it's a feedback/noise issue. So a little more playing and this system will be 100% developed.

And just to cross post, my crank trigger setup is available here.

[chocolate.curry]

I didn't see this mentioned earlier in this thread, but maybe I missed it: are you using an EDIS coilpack for the ignition?