Wiring for an Engine Run Stand with DJet |
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Wiring for an Engine Run Stand with DJet |
doug_b_928 |
May 6 2019, 07:32 PM
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#1
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Senior Member Group: Members Posts: 692 Joined: 17-January 13 From: Winnipeg Member No.: 15,382 Region Association: Canada |
I'm building an engine stand that will serve multiple purposes (transport, storage, installation/removal, and testing/break-in). The one part I have very little clue about how to do is the wiring. I've searched the forum and have seen others express an interest in having wiring info for a test stand, but it doesn't seem to be documented anywhere. So, hopefully this thread will help not only me, but also anyone else in the future who is looking to do the same.
I'm going to have the djet 'computer', manifold pressure sensor (MPS), decel valve, fuel pump, and regulator plate/relay board mounted to the stand. The ground that normally connects the battery/engine to the chassis will be grounded to the stand. The wiring for the MPS will be connected to it and the wiring for the fuel injectors, alternator, and 12 pin connector will all be connected to the regulator plate. In other words, it is as if the engine were in the car with the exception of the wiring connections at the 14 pin connector on the regulator plate. On the stand's 'dash board' I think (please correct me if I'm wrong) I need an ignition toggle switch, a momentary starter switch, an oil pressure 'idiot' light (I'm getting a cheap LED light on sale tomorrow), a tachometer (I have a cheap, generic one from FLAPS), and lever with a cable for controlling the throttle. So the question is, what is the correct way to wire these items? I have the figures from Jeff Bowlsby's webpage and the wiring diagrams. What I'm missing is the theory of what I need to do wiring-wise to make the engine run and get the feedback to the tachometer and idiot light. I'm hoping others who appear to have done this can chime in with their thoughts (paging @StratPlayer @VaccaRabite @michelko @mb911 @barefoot ) and wiring gurus (like @JeffBowlsby ). I assume I run wires from the battery to the two power pins on the 14 pin connector, so that the regulator plate has power. After that, although I think it should be pretty simple, I'm not 100% on how to wire the ignition, starter, tach and idiot light to the 14 pin connector. Please advise. |
doug_b_928 |
May 24 2019, 06:17 AM
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#2
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Senior Member Group: Members Posts: 692 Joined: 17-January 13 From: Winnipeg Member No.: 15,382 Region Association: Canada |
Thanks guys. I didn’t know that about break-in. So once you have the cam broken-in on the stand and the engine installed in the car, do you just do like the new cars and keep it under 4,000 rpm for x number of miles?
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Superhawk996 |
May 24 2019, 06:50 AM
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#3
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914 Guru Group: Members Posts: 5,769 Joined: 25-August 18 From: Woods of N. Idaho Member No.: 22,428 Region Association: Galt's Gulch |
Thanks guys. I didn’t know that about break-in. So once you have the cam broken-in on the stand and the engine installed in the car, do you just do like the new cars and keep it under 4,000 rpm for x number of miles? Break in is a debated topic full of myth, legend and handed down stories. (IMG:style_emoticons/default/happy11.gif) I'd suggest reading various opinions from engine builders and deciding for yourself. Tom Wilson How to Rebuild your Volkswagen Air Cooled Engine book is a good starting point. I'll give you a couple of personal opinions: New cars do really don't need break like we typically think of for vintage engines. I say this as an automotive engineer working in the industry. There are a ton of reasons for this ranging from metallurgy to manufacturing methods and modern tolerances. That said, a mild break in is still called for and isn't a bad thing. Bottom line we design cars knowing that most can't or won't take the time to do a break in. We now do extensive dyno testing and thermal shock type testing that wasn't done in the 70's. We do lots of -40F cold starts and rapid drive away testing that would make you cringe and engines still survive. The list goes on. The reason for varying load and RPM's is to get the rings well seated to the cylinder walls and within the piston groves. Varying RPM and load helps expedite this process. I'll spare you the long form explanation of why this is so. Think rod stretch, thermal expansion, and variances in combustion pressures and you'll be on the right track. The best thing during this process is to get it running, let it run under light load with some variance of RPM's and then to dump the oil after say 20 minutes. Get rid of the fine particles of metal that are shedding from everywhere. Then change oil after about 100 miles driving. Then again at 300. And again at 1000 miles. keep the oil clean during this process. Use Dinosaur oil. It will work better for break in and is cheaper too since you'll be using a lot of it. Now let the controversy begin. (IMG:style_emoticons/default/stirthepot.gif) |
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