Tom, its there in the engine harness up to the two round connectors. I didn't continue it from there. Will that be sufficient to get the bench test done - that was my plan?
914-SHO Project Thread
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Tom, its there in the engine harness up to the two round connectors. I didn't continue it from there. Will that be sufficient to get the bench test done - that was my plan?
Off Road SHO
Moderator
Probably. it's there to shield the sensitive pick-up wires of the two Hall Effect sensors in the Cam sensor and the crank sensor from EMP of the spark plug wires and starter cables.
Tom
Tom
hawkeye18
Sorta cares
Off Road SHO
Moderator
Isn't it still an EMP that causes the EMI?
Tom
Tom
hawkeye18
Sorta cares
Lots of things cause EMI. EMPs produce a large amount of it. EMI does not generally produce an EMP, however, unless you manage to compress several megawatts into several microseconds. There are research labs where precisely that is done. I believe the Mythbusters visited one such facility once.
EMPs are a very specific form of EMI. EMI, or ElectroMagnetic Interference for those not sure of what we're talking about, is any radiated energy that causes undesirable operation in other electrical equipment. Any of you old enough to have seen your tube TVs' pictures wobble when the microwave or even vacuum cleaner was turned on know this effect.
It works on the concept of induction - any length of wire or circuitry will act as an inductor [antenna], and will transform radiated energy into voltage. Radios and radars depend on this concept for their operation. The crank sensors, if not properly shielded, will transform the radiated energy of the spark plug wires and alternator into a very small voltage, but voltage sufficient to confuse the PCM and cause a poor-running engine.
The foil shield acts as a RF blocker, and the ground attached to it shunts that radiated energy back to the battery and away from the hall effect wires.
An EMP (ElectroMagnetic Pulse) is an altogether different flavor of ice cream; at its heart it is still EMI like any other, but if EMI is a large sparkler, an EMP is a quarter-stick of dynamite. It is most commonly associated with nuclear weaponry, which releases enormous amounts of energy in nearly every conceivable band, including radio frequencies. More importantly, it does it very quickly.
The effect of this is that while EMI caused by an errant or poorly shielded motor may induce anywhere from .01 to 1 or 2 volts in a nearby system, which would cause annoyance and slight malfunction, an EMP burst will introduce hundreds or even thousands of volts into every circuit path of every piece of electronic equipment nearby (and nearby might mean within 100 miles), and at not insignificant current.
Naturally, introducing that much power into the tiny, tiny little transistors and ICs that run our modern life will make them go kerplooey. Everything that relies on voltage will cease to function (from PS3s to Pacemakers), and that especially goes for radios and radar sets, items which depend on sensitivity to radiated energy.
I have a vested interest in this as my particular field is in naval aviation - and avionics in particular. As my signature suggests, the particular type of aircraft I work on is a little more sensitive to the effects of an EMP burst than most; a lot of our work entails ensuring that pieces of gear are properly shielded from EMI and EMPs.
And that concludes the lesson for today.
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intimdatr
Got Cams?
dayum, i learned something 
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Off Road SHO
Moderator
So was I right or not?
hawkeye18
Sorta cares
You were correct, if not entirely accurate. I'll give you a B+. :laugh_ti:
Shoaz
Studly dood
Unless there are bombs going off in the engine bay you meant EMI, not EMP.
Sorry. I thought I was wrong once, too, but it turns out I was mistaken about that.
Been a busy week at work so not gettin much time for teener stuff. Did get my PCM (ECU) wiring harness spec'd out and labeled. All items marked in blue will go, but nothings getting cut until the test run is completed.
I will also want to complete the test install of the engine before deciding where other engine components will go. So this harness is a rough draft. There are several components like the DIS that get mounted in the engine bay.
Big question is locating the battery. I'm planning on using the power distribution box from the SHO and the new style 914 fuse/relay panel. (Thanks Engman) I want the fuse/relay panel somewhere other than under the front dash - so I was thinking - front trunk/drivers side.
If the distribution box is up front also, then it makes sense to put the batt up front. If the distribution box is in back (engine bay or trunk) that makes a long run for primary power to the fuse/relay panel - but not that different from stock arrangement.
The relays mount to the back - if I can fit all the PCM and 914 relays back there. Otherwise I'll make an extension for the extras.
I will also want to complete the test install of the engine before deciding where other engine components will go. So this harness is a rough draft. There are several components like the DIS that get mounted in the engine bay.
Big question is locating the battery. I'm planning on using the power distribution box from the SHO and the new style 914 fuse/relay panel. (Thanks Engman) I want the fuse/relay panel somewhere other than under the front dash - so I was thinking - front trunk/drivers side.
If the distribution box is up front also, then it makes sense to put the batt up front. If the distribution box is in back (engine bay or trunk) that makes a long run for primary power to the fuse/relay panel - but not that different from stock arrangement.
The relays mount to the back - if I can fit all the PCM and 914 relays back there. Otherwise I'll make an extension for the extras.
Nice looking work. I assume you know can use a piece of brass or copper on backside to weld up holes. [That is if you have access to the backside] I picked up a old drain pipe plug at scrap yard for that purpose. The weld will not stick to it. Maurice
Maurice,
yep use that trick as much as possible - especially with my flux wire welder that only has Low & High. I stumbled across that trick on one of the DIY welding sites. The internet actually has some useful information occasionally.
intimdatr
Got Cams?
If you move the Batt. to the front its going to gain some of the original 50/50 weight distribution back and open up some work space on the motor and will allow you to get a bigger battery which is always good.
On the fuse panel, coming from someone who has traced wires from the original fuse box outward and around the STUPID aftermarket A/C stuff i say PLEASE move it to trunk. Lol.
But other than that its looking really good! Cant wait to see this thing out on the road!
On the fuse panel, coming from someone who has traced wires from the original fuse box outward and around the STUPID aftermarket A/C stuff i say PLEASE move it to trunk. Lol.
But other than that its looking really good! Cant wait to see this thing out on the road!
Yeh, I don't know what possesses engineers to put this stuff where they do. I can't think of a single person that looks forward to climbing under the dash, upside down, cramped, feet hanging out the door or over the seat, no light, trying to work on electrical circuits.
Sorry for the rant - but its just DUMB!
My other fav is the oil filter mounted sideways - DUH? How many times will you enjoy that? It's early, I'm tired and going back to bed.
Sorry for the rant - but its just DUMB!
My other fav is the oil filter mounted sideways - DUH? How many times will you enjoy that? It's early, I'm tired and going back to bed.
Offtopic. Try removing a MG Midget dash. Not much there but held in by some nuts on studs on dashpanel. In tech manual I read says " extremely small hands extremely benificial at this time". You got to be kidding. Maurice
Not much happening today. Finished up some welding and did some running around to get small parts to mount fuel pump temporarily on engine cradle. Also started wiring diagram for fuse/relay panel and how it all ties to the SHO power distribution box. I've got a couple of questions, but I'll post those elsewhere - once I the rough diagram done.
Got a couple hours in before dinner. Love it when the wife is trying new recipes - always takes twice as long. Anyhow, got gear oil in the son's tranny and got the Fuel pump mounted on the engine cradle.
Thinkin about having a start-up party in September for the SHO motor. Won't have time/money to get everything done before then since we're taking my daughter up to WY for college in August. Anyone interested in drinks, burgers, etc in SE AZ?
You all can be my backup if it doesn't start the first time - right!
Thinkin about having a start-up party in September for the SHO motor. Won't have time/money to get everything done before then since we're taking my daughter up to WY for college in August. Anyone interested in drinks, burgers, etc in SE AZ?
You all can be my backup if it doesn't start the first time - right!
rbruso
unlikely
I'm in, as long as it's not my wife's birthday (the 22nd of September)
The parts car still has the two pin ground connector if you're interested. If it's not absolutely dumping I'll likely be pulling stuff this weekend so I will put it aside for you.
The parts car still has the two pin ground connector if you're interested. If it's not absolutely dumping I'll likely be pulling stuff this weekend so I will put it aside for you.
