Hey now! We did get a little off topic for a minute. Anyways, I am committed to help you guys find a good, reliable, economical solution. I'm sure Fast 355 will be just as generous with his time and expertise. (P.S. we know exactly how camshafts function).
Last edited by Tom B.; 09-16-2017 at 04:50 AM.
Then you should know it has nothing whatsoever to do with the engine it's installed in. It doesn't matter how many cylinders there are, if it's an inline or v60 or crossplane v90. In a four stroke engine the intake stroke occurs immediately after the exhaust stroke. End of discussion.Originally Posted by Tom B.
This is a thread discussing the possibility of interfacing a cop setup to a PCM designed for for a distributor. Let's get away from the LS swap economics discussion. The subject has been beaten to death. Let it rest in peace.
I will say this once and then I am done with it. Valve overlap has a lot to do with the way it affects how an engine runs. If your position is to the contrary, I can only surmise you are less experienced than some of us that know better. You and I don't know each other or our personal abilities and experience, so lets not to try to play school teacher.
Back to the subject at hand. As far as this project goes, Andy should have the convertor box I sent him dissected in a timely fashion, and he and Vilefly will have a viable solution.
Last edited by Tom B.; 09-16-2017 at 05:29 AM.
VF, I know those hall effect sensors might be more durable than the optical sensor, but Im not sure. It was hard to find one that had high enough frequency. I think a well sealed opti with no HV will live just fine. Im glad you found a chip that will work so easily.
Years ago, when HEI was all the rage, I had epoxied spark plug towers to HEI coils, had a mirror on the rotor and a IR detector/emitter in the cap. Everyone said I was crazy. I had found the 1-to-8 data distributor chip (as it was called) back then, but I didn't have squat for money, and the internet was not up.
The Opti without the high voltage running through it will be just fine. Just clean it up and seal it. The same sensors seem to run forever in the other cars they are installed in.
Nice project, I think it would be much easier just to use uP for coil switching, we are talking about frequencies of about 25kHz at 8k RPM, that's basically a slow signal for let's say AVR or STM32 running at a few MHz... But I appreciate your effort to make it discrete!
Another point that comes to my mind is that almost all of the optis I had replaced had the optical sensor failing due to high temperature, NOT the HV part. It seems that over time temperature causes the LED and phototransistor to lost alignment somehow.
I think a good solution would be to use vortec style cover with CKP sensor for hi-res signal (180 tooth wheel), and only low-res sensor in the opti. The question remains if the CKP sensor is capable of picking so dense teeth.
I'll agree with you on this one. The optis I've seen fail died in two different fashions. One was the cheap chinese junk replacement off eBay with the Chrysler optical sensor installed that loses high resolution signal when it gets hot. I have one of these and replaced the optical sensor with one from AIP Electronics that meets the specs of the original Mitsubishi unit. The others died because the optical wheel was destroyed by arcing from the high voltage side.
As lionelhuntz mentioned, AIP Electronics makes a sensor that meets oem temperature specs. They're sometimes out of stock, but I've been running one in my triple-c opti from eBay (previous owner installed it) for going on 3 years now. No problems up to 6800 rpm rev limiter.
Last edited by spfautsch; 09-17-2017 at 01:58 AM.
Valve overlap is a measurement in crankshaft degrees of how long the intake valve and exhaust valve are open at the same time. It is entirely controlled by the camshaft, and for most factory cams it's zero or very nearly. Let's get back to discussing what's relevant here. Overlap, whether in an LT or LS block, is not.
I can only hope I will ever have time alone to myself to make a prototype. Hard enough to concentrate these days. I at least hope to post a schematic someday that works.
It still would be cool to have interchangeable optical disks for various computers and such. Laser cut sheet metal. Sounds pretty cheap to me.
Nissan uses such discs, too.
Last edited by vilefly; 09-16-2017 at 05:37 AM.
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