Derek Posted December 21, 2015 Author Share Posted December 21, 2015 If ignition timing is based off of crankshaft position, as an indirect measure of piston position, and if lash in the system is important to be accurate, why would a cam sensor be better than a crank-mounted sensor I almost posted this earlier. No really:) But I decided to machine an oil cap instead. It seems to me the events relating to the piston are the most critical. And a crank fire system will give you that. Timing chains stretch and distributer gears have lash and wear. On my CNC conversions I use all kinds of optical encoders and slotted optical sensors. By the looks of the wheel that DIY auto tune sells that is what the ZXT dizzy uses. An slotted optical sensor. I also use proximity switches for positioning verification on my tool changer. The slotted sensors and a slotted wheel are far more accurate than the proximity sensors. So My gut feeling is a slotted sensor with a slotted wheel crank driven will give you the most accuracy. Don't forget there is nothing stopping you from stacking multiple wheels and using dual sensors to accomplish what ever counting you need. Put it in a sealed housing and drive it off of the crank bolt and away you go. For now I'll be sticking with my EDIS:) Quote Link to comment Share on other sites More sharing options...
Dan_Austin Posted December 22, 2015 Share Posted December 22, 2015 Funny you mention using multiple sensors, as that is actually what the DIY Auto Tune wheel does. it just happens that both sensors are in the dizzy housing. The outer ring of slots is two groups of 11 (looking like a 12-1 wheel to the ECU), the inner ring is a single larger slot that indicates the engine is in the first half of the cycle. Mounting a hunk of metal on the front of one cam gear that covers 180 degrees could be read by a HALL effect sensor and relatively tolerant in alignment, certainly within the range the valve cover would vary. The truly pedantic could install pins between the cover and head to encourage consistency. This half-moon CAM wheel with a 36-1 crank wheel (a-la EDIS) would be 3X as accurate as the DIY wheel and less prone to valve train slop issues. If the hardest part of installing the head is figuring out how to mount a cam sensor, assuming the CAS no longer fit, I'd be a happy camper. Quote Link to comment Share on other sites More sharing options...
Derek Posted December 22, 2015 Author Share Posted December 22, 2015 If the hardest part of installing the head is figuring out how to mount a cam sensor, assuming the CAS no longer fit, I'd be a happy camper. Well as long as Rossman's measurements are correct it will fit. Do you like how I set him up for the blame if it doesn't fit. That's the mark of a true businessman:) Actually there is plenty of room if you don't run a traditional cap and wires. If you do run a cap and wires it may get a bit tight but it will work. Quote Link to comment Share on other sites More sharing options...
rossman Posted December 22, 2015 Share Posted December 22, 2015 Wait...what? No, I don't think so! Here are the dimensions, for the record... Quote Link to comment Share on other sites More sharing options...
Derek Posted December 22, 2015 Author Share Posted December 22, 2015 Thanks for the visuals. I'll double check them tomorrow but I'm sure we have plenty of clearance. Quote Link to comment Share on other sites More sharing options...
TimZ Posted December 22, 2015 Share Posted December 22, 2015 (edited) I almost posted this earlier. No really:) But I decided to machine an oil cap instead. It seems to me the events relating to the piston are the most critical. And a crank fire system will give you that. Timing chains stretch and distributer gears have lash and wear. Agreed. The only thing that you should be using the cam sensor for would be to answer the question "which 360 am I on?" As I already mentioned, you don't have to be very accurate to be able to answer that question reliably. Trying to use it for anything more than that is folly. I'm advocating foregoing the sensor inside the valve cover altogether, and using a modified stock distributor pickup to tell you that. It's a much less harsh environment for the sensor to live in, you don't have to figure out how to mount it and get wiring to it, and there's already a reliable solution for it. If you really hate having a distributor still hanging off the front cover that much, then engineer a more compact unit that mounts in its place. Edited December 22, 2015 by TimZ Quote Link to comment Share on other sites More sharing options...
jacky4566 Posted December 23, 2015 Share Posted December 23, 2015 Madkaw was talking about cam angle sensors here: http://forums.hybridz.org/topic/113728-ms3x-install/page-7?do=findComment&comment=1150574 I dont think he finished it yet but the jeep 4.0 L6 cas looks like a close bolt on. That plus a 36-1 and your golden. Quote Link to comment Share on other sites More sharing options...
Xnke Posted December 24, 2015 Share Posted December 24, 2015 Yeah, Yeah, I know-No new photos of the headers yet. I have had to strip my own car instead of using another local guy's partially assembled Z to check fitup, so that's what's been the extra delay this month. I've got the SuperZ stripped down, the adaptor plate bolted up and the header bolted to it. Photos tomarrow when it's daylight. Part of the long delay has been making sure that when the engine gets rotated by using a Z series or KA series bellhousing, the header doesn't hit the steering shaft-but then Derek has no plans for that so I quit wasting time on that and decided to just build the header and get it done. I'm the guy holding up the show now. If the production head gets some orders, I'll have to buy one and jig it properly for all three bellhousings so there are no issues. Also, questions like "Will it fit a ZX?" All those questions I've just thrown out the window for this prototype header since I know the car and the position it'll be in...has taken me too long to quit jigging a production piece and just get on with it. I'll try to get you more timely updates on this, guys. Quote Link to comment Share on other sites More sharing options...
Xnke Posted December 24, 2015 Share Posted December 24, 2015 Checking clearances, I'll be able to weld the other two rearmost tubes in this evening. (they're tacked up, but I didn't fit them on in case I needed to move them a bit) Plenty of clearance here, so will be easy to use the same header on the Z-series truck bellhousing to get the engine standing straight up and down, and will be doable to use the KA housing...might be a bit tight on the steering shaft but very workable I think. The two rearmost tubes won't encroach on the stock bellcrank or the brake booster much at all. I was initially worried they'd be a difficult fit, but this header will still actually fit in a ZX with rack-and-pinion steering, I don't have a recirculating ball steering box to check against yet. 1 Quote Link to comment Share on other sites More sharing options...
Derek Posted December 25, 2015 Author Share Posted December 25, 2015 Looking good Xnke. Who knows, you may finish before Crane:) Thanks Derek Quote Link to comment Share on other sites More sharing options...
98blackbell Posted December 25, 2015 Share Posted December 25, 2015 We want to here this beast! Great job Xnke. I could afford the headers but not the Head. Hmmmm, May i missed a gift from Santa CLause! I wish say about $15,000, LOL Quote Link to comment Share on other sites More sharing options...
Brad-ManQ45 Posted December 25, 2015 Share Posted December 25, 2015 I am thinking of using the distrbutor only for the single sensor for TDC on #1, then a crank sensor for the sequential needs. Quote Link to comment Share on other sites More sharing options...
Derek Posted December 25, 2015 Author Share Posted December 25, 2015 That Jeep sensor that Madkaw is playing with looks promising. Cheap too. Quote Link to comment Share on other sites More sharing options...
zedric Posted December 26, 2015 Share Posted December 26, 2015 I am thinking of using the distrbutor only for the single sensor for TDC on #1, then a crank sensor for the sequential needs. I thought the the same, crank sensor because it's the most accurate, and modified distributor for TDC reference. No messing with the cams or valve cover unnecessarily, why would you when you already have a distributor hole and mounting setup that you would block off if not in use? and if you're worried about looks I'm sure it could be made a lot smaller and neater than a stock distributor. Quote Link to comment Share on other sites More sharing options...
FricFrac Posted December 26, 2015 Share Posted December 26, 2015 I thought the the same, crank sensor because it's the most accurate, and modified distributor for TDC reference. No messing with the cams or valve cover unnecessarily, why would you when you already have a distributor hole and mounting setup that you would block off if not in use? and if you're worried about looks I'm sure it could be made a lot smaller and neater than a stock distributor. Location doesn't change the accuracy - it's the resolution of the encoder. The stock Nissan optical wheel has 360 slots on the outer track. It's actually too high of a resolution for a lot of stand alone ECUS. If you were going to put the encoder on the cam you wouldn't want to put it inside the valve cover. How to interface to the cam is the challenge. If the sensor could be mounted to the head itself rather than the valve cover it would make lining up the interface a lot more precise. Quote Link to comment Share on other sites More sharing options...
Xnke Posted December 26, 2015 Share Posted December 26, 2015 We want to here this beast! Great job Xnke. I could afford the headers but not the Head. Hmmmm, May i missed a gift from Santa CLause! I wish say about $15,000, LOL At this point, Derek is glad he's not paying labor cost on these! To date I have 49 hours on the clock, so I'll have to pare that down if I am going to actually sell any of the production pieces... Quote Link to comment Share on other sites More sharing options...
Derek Posted December 26, 2015 Author Share Posted December 26, 2015 At this point, Derek is glad he's not paying labor cost on these! To date I have 49 hours on the clock, so I'll have to pare that down if I am going to actually sell any of the production pieces... I'm sure you noticed how fast I said yes when you offered to do it for the price of materials:) I'm no dummy. If you hadn't offered I would have stuck with plan A which was manipulating a set of stock headers to fit. I knew money was going to start getting tight at the end and I was right. Quote Link to comment Share on other sites More sharing options...
zedric Posted December 26, 2015 Share Posted December 26, 2015 Location doesn't change the accuracy - it's the resolution of the encoder. The stock Nissan optical wheel has 360 slots on the outer track. It's actually too high of a resolution for a lot of stand alone ECUS. If you were going to put the encoder on the cam you wouldn't want to put it inside the valve cover. How to interface to the cam is the challenge. If the sensor could be mounted to the head itself rather than the valve cover it would make lining up the interface a lot more precise. Location has everything to do with it! If the cam is rotating @ ½ the RPM of the crank, then 1° out @ the cam is, 2° out @ the crank, that's halved your resolution right there, and that's not counting lash and chain stretch. Like Derek said in post #721 the crank is where you should be timing everything, all the resolution in the world isn't going to help you if what you're reading is wrong to begin with. Quote Link to comment Share on other sites More sharing options...
madkaw Posted December 26, 2015 Share Posted December 26, 2015 (edited) That Jeep sensor that Madkaw is playing with looks promising. Cheap too.Derek, this would be easier for you to finish than me. The only part that was giving me a hard time is coupling the oil drive shaft to the Jeep sensor shaft. I know you could come up with a way to machine the jeep shaft groove to fit the oil shaft tang. I also was going to come up with a bushing to keep shaft side play to a minimum.You can buy these new all day long for 20$. Edited December 26, 2015 by madkaw Quote Link to comment Share on other sites More sharing options...
Tony D Posted December 26, 2015 Share Posted December 26, 2015 Haha I feel like I should qualify sentence and say I was being sarcastic. Got a lot of friends in the trades being in oil country, I just pull out the popcorn when I see these discussions Sorry to de-rail the thread! No, I have never sketched cartoons on the wellhead porta-potty little dumplings happily in mid-frolic around a big oily splotch putting a caption below it "Pipefitter Biscuits dancing for joy in finding a huge puddle of gravy on the rig..." I would never do that. But I would make a mental note of whomever did it and remember it clearly now 26+ years after seeing it out in Bakersfield while doing an Ajax Overhaul! "We all Oil Field Trash!" Quote Link to comment Share on other sites More sharing options...
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