Working ignition distributor

[AdmiralSenn]

Looking for an ignition distributor to make into a sacrifice to Megasquirt's ignition system.

I'd rather not spend $275 at DMCH for a new one, so if someone's got a spare (better if the advance mechanisms are broken as I don't need them anyway) I am interested.

All it needs is a working shaft and impulse coil, I have a cap and rotor and tach wire already.

[Texas Twister]

I am doing the conversion right now and just put on the modified one on the car lat night. Until I get it dialed in I plan to hold on to it, but once finished I will be willing to give it up. I haven't even converted the unit for fuel and ignition yet. Are you in a big hurry? I am converting a stage two engine and the cams seem to be giving me a vacuum problem. We did the conversion on a stock engine and it idles like a sewing machine. Spittybug has kept the thread going on this.

[AdmiralSenn]

Not a huge hurry, no. I've already missed about six deadlines on this project, so I'm clearly not being very proactive.

I can probably wait till you're done. I do need to have my spark control done before my next major project, though, so hopefully it's not TOO long.

Have you considered asking Mike Lund (opethmike) for advice? He just dialed in a DPI Spec 2 cam and exhaust package which is even more aggressive than the DMCH stage 2, and he got around several issues related to the aggressive cams.

[opethmike]

The two biggest issues I had with tuning my Megasquirt after installing the Spec 2 package were the idle, and acceleration enrichment.

For the AE, you pretty much can't use MAP based at all; too much natural swing in the MAP. I made mine entirely TPS based, and it is fine now.

With bigger cams, you are going to get less vacuum at idle. The bigger the cams, the less the vacuum, and the worse the quality of the idle. There is only so much that can be done here (and that's why factory cams are almost always quite mild). My idle vacuum swings between 50 and 60 KPa, so unlike with a stock cam set up, the little dot is constantly moving between cells in the VE table.

The trick is to watch which cells it is going between, and set them all to the same VE value. If you don't do that, you'll get a hunting idle, and have horrible K-Jet flashbacks. I found that I could achieve the best idle quality be running a tad bit richer than the car was when it was stock.

[Farrar]

Checked for a Volvo equivalent in a junkyard? May have a slightly different vacuum advance curve, but that doesn't matter if you're not using vacuum to advance spark.

[AdmiralSenn]

The last few times I've been, there have been no odd-fire V6 Volvos. I've only ever seen one V6 in the local yards and it was a B280. Not a lot of them down here, or maybe they're all still running.

[AdmiralSenn]

Le bump.

Texas Twister, are you still waiting on your conversion?

[Spittybug]

Adam, Texas Twister is Ian, one of the two cars I'm helping do the stock conversion on. He came over yesterday and we were using the dizzy in my drill press to drive his 3.57 box. My oscilloscope clearly shows a clean VR signal, but once it gets up over ~4,500 RMP (seems to vary) the resulting squared wave signal from the VR conditioner seems to break down and cause sync issues. We can make that go away by tweaking the threshold voltage pot, but then we get sync loss at idle and below! Very frustrating. Something changed in the 3.57 boards since my 3.0 has no issues on the same test rig.

I don't know if Ian frequents these boards much, that's why I jumped in to let you know what's going on.

[AdmiralSenn]

Oh, THAT's who he is!

I wonder if something in the SMD components is different. I have no idea where to even begin with that issue.

Anyway, cool.

It doesn't really matter that much since Christine is still grounded until I bust up the rest of that broken tap. I was just wondering.

[AdmiralSenn]

Ka-bump. Gathering parts for when I get to the head work this month. Would like to reassemble with electronic ignition so a distributor to modify would be cool to have right about now.

Thanks.