davek Posted December 19, 2013 Share Posted December 19, 2013 Staring at my L28ET in 100 pieces last night I started thing about how I was going to mount the trigger wheel for crank angle sensing. Then I noticed the harmonic balancer looking right back at me. This is a balancer right?? There is plenty of meat on that back side flange/disc I could easily machine the 36-1 notches. I have access to CNC mills and wire EDM. Of course this changes the balance of the unit right? Well doesn't mounting a seperate 36-1 wheel on the crank change the balance as well? Am I thinking way to far out of the box? Anybody done this? Quote Link to comment Share on other sites More sharing options...
mobythevan Posted December 19, 2013 Share Posted December 19, 2013 Can you get away with less teeth and save some machining time? Quote Link to comment Share on other sites More sharing options...
davek Posted December 19, 2013 Author Share Posted December 19, 2013 I could save a little machine time. The real question is this a good idea or not. I see the trigger wheels have a balance hole in them opposite the missing tooth so my original post is not correct. I'll call the engine shop and ask about rebalancing. Quote Link to comment Share on other sites More sharing options...
str8pipez Posted December 20, 2013 Share Posted December 20, 2013 This is something that I have been considering as well. I'd like to keep my A/C and possibly do the same thing on the front side. I guess I could do the back side as well. Surrpised if this hasn't been done yet. Quote Link to comment Share on other sites More sharing options...
madkaw Posted December 20, 2013 Share Posted December 20, 2013 Suprised more folks don't go this route.... http://forums.hybridz.org/index.php/topic/90889-wasted-spark-ignition-no-edis/ Quote Link to comment Share on other sites More sharing options...
mobythevan Posted December 20, 2013 Share Posted December 20, 2013 I remember that setup that you linked. That is why I was curious why someone would do 36-1 if making their own custom setup instead of 6-1, but there may be reasons. Anyway, there are several options so maybe other people will chime in. Quote Link to comment Share on other sites More sharing options...
Metro Posted December 20, 2013 Share Posted December 20, 2013 I used the flywheel method and it pretty well. The flywheel is large and stable so theoretically should give the best signal if the divots are positioned correctly. I just had problems with my sensor and possibly the positioning of it in relation to the divots. Currently I'm using a 30-1 wheel made out of the '81 l28et's 90 tooth wheel with a hall sensor, I think this is probably the easiest way to go with stock parts. Just have to remove the pulley and grind two teeth for every one. I think there's enough material and it sticks out far enough that you could grind down all the teeth and make wider teeth like an OEM 36-1 wheel has. I haven't had any issues with the little nubs losing the signal though. Quote Link to comment Share on other sites More sharing options...
madkaw Posted December 20, 2013 Share Posted December 20, 2013 I used the flywheel method and it pretty well. The flywheel is large and stable so theoretically should give the best signal if the divots are positioned correctly. I just had problems with my sensor and possibly the positioning of it in relation to the divots. Currently I'm using a 30-1 wheel made out of the '81 l28et's 90 tooth wheel with a hall sensor, I think this is probably the easiest way to go with stock parts. Just have to remove the pulley and grind two teeth for every one. I think there's enough material and it sticks out far enough that you could grind down all the teeth and make wider teeth like an OEM 36-1 wheel has. I haven't had any issues with the little nubs losing the signal though. Can you elaborate on the issues you had with the crank sensor and position. I have not tested mine yet, but I am hoping it will work. If you are still at assembly stage on your engine, this method of using the flywheel is the cheapest and easiest in my opinion. A 20$ sensor and a drill press. Granted-you should have the flywheel balanced afterwards which adds to cost. Quote Link to comment Share on other sites More sharing options...
Metro Posted December 20, 2013 Share Posted December 20, 2013 (edited) I think the problems I had were my own. I would lose the signal over 5800rpm and that might have something to do with the specific sensor I was using. My dad gave me a stainless steel Caterpillar VR sensor. It looked nice, so used it. Originally it was made for reading the teeth of a flywheel to get the engine rpm. I don't know the specs on it, but it might be possible that 5k+ rpm was outside its operating range. Up until that point, it was fine. It was really finicky about the gap too, I pretty much had a 1/2 a turn range where it would and wouldn't work. There's also the chance I mounted it slightly out of position on the cover plate. By easier, I meant you don't have to drop the transmission, it's my least favorite thing to do. Edited December 20, 2013 by Metro Quote Link to comment Share on other sites More sharing options...
davek Posted February 1, 2014 Author Share Posted February 1, 2014 (edited) Back to my question--Balancing the unit becomes very simple. I'll make the depth of 2 teeth deeper opposite the missing tooth to make up for the missing weight. Correct?? 2 more questions. a) Using the hall effect sensor from DIY--Will it matter if I leave the crank angle indicator knotch on the harmonic balancer. I would like to leave the notch on a tooth to be able to strobe the ignition angle. I don't know if the small notch would have any affect on the hall effect sensor readings. b)What is the length of line for a tooth? The edge the sensor is reading. I'm thinking the space between teeth is more important. And depends on size of the sensor. The Teeth on the harmonic balancer I draw up are 0.26" with 0.35" between teeth. looks good but I'm no sensor engineer. Edited February 1, 2014 by davek Quote Link to comment Share on other sites More sharing options...
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