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Engine wiring question


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6 hours ago, Ace-Garageguy said:

 

Here's another excellent point: in the real world, you can put #1 anywhere on the distributor cap, so long as all the rest of the wires are in the correct relationship to it.

This can be helpful in tight engine swaps, for instance, where you might have a big vacuum advance can that causes a clearance issue. Simply roll the engine to TDC firing (not overlap) on #1 cylinder, rotate the distributor to where it physically fits, start wiring with terminal #1 wherever you want it...maybe to take advantage of the lengths of the plug wires you have.

The POINT is, to be correct on a non-factory setup, the #1 position on the cap as shown on the firing-order references is NOT carved in stone.

Remember to have the #1 cylinder on the compression (firing) stroke when performing this operation. I used to pull the #1 plug, put my thumb over the hole, and have somebody crank the engine.

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16 hours ago, Ace-Garageguy said:

Or just ask here. We'll be happy to help, we appreciate guys who want to get the details right, and after a while, you'll KNOW.  :D

PS. I added some info to my first post, if you missed it.

I saw that, thanks!!!

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12 hours ago, Ace-Garageguy said:

 

Here's another excellent point: in the real world, you can put #1 anywhere on the distributor cap, so long as all the rest of the wires are in the correct relationship to it.

This can be helpful in tight engine swaps, for instance, where you might have a big vacuum advance can that causes a clearance issue. Simply roll the engine to TDC firing (not overlap) on #1 cylinder, rotate the distributor to where it physically fits, start wiring with terminal #1 wherever you want it...maybe to take advantage of the lengths of the plug wires you have.

The POINT is, to be correct on a non-factory setup, the #1 position on the cap as shown on the firing-order references is NOT carved in stone.

There are limitations to this. Some distributors that are gear driven can have the rotor lined up in several places , but some are slotted and can only be in two positions 180 degrees apart . Not sure which are which but I am thinking that Mopar are slotted. 

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38 minutes ago, Jon Haigwood said:

There are limitations to this. Some distributors that are gear driven can have the rotor lined up in several places , but some are slotted and can only be in two positions 180 degrees apart . Not sure which are which but I am thinking that Mopar are slotted. 

Well, not really.

On some engines, the "slot" is only the oil pump drive, and fits a tang on the lower end of many common V8 distributor drive shafts.

All you have to do to change the location of the "slot" is stick a long flat-blade screwdriver down the distributor drive hole and twist.

It may take a couple of tries to get it right, however, so that the tang slips in the oil-pump shaft just as the distributor drive gears engage the cam.

On Mopars that are built backwards, where the slot on the oil pump drive gear engages a tang on the distributor shaft to drive the distributor, you can orient the oil pump gear with the slot anywhere, if the valley is open. And some Mopar engines will allow you to pull the distributor drive shaft up and out of the pump, enough to rotate it as necessary. Again, re-engaging the oil pump (there's a hex-drive on the pump end of the shaft) can be tricky, but it's easy enough.

Image result for chrysler oil pump drive

And even if you're stuck with the rotor only pointing in one direction, you can still rotate the distributor body to place number one anywhere relative to the body.

Even the "slotted" and offset drive on VW and Porsche flat fours can be tricked into letting you put the distributor in virtually any position.

I've built more than a few engines, you know.  B)

Edited by Ace-Garageguy
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With enough "enginuity " you cab do almost anything with an engine. (not a motor,motors are electric) from cutting them in half to whatever else you can think of.For a 1/25th scale model I think we have surpassed the point of what is correct LOL

Yes I too have worked on my share of engines  Started when I was about 14 in 1964.

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Be sure to do some research on the engine you are wiring.

Twin-cam engines have their spark plugs between the cams.  Pushrod V8s usually have theirs along the lower edge of the head.  Some V8s route the wires directly to the plugs over the valve covers (big block Chevy), while others route theirs underneath the exhaust and reach the plugs from below (small block Chevy).

It all depends on the engine in question.  Fortunately, there are plenty of pictures available.  Enjoy!

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31 minutes ago, Lunajammer said:

Cool conversation, but you guys are gonna have this poor guy so confused he'll be wiring his radiator. :o

:lol:    One of the things I love about this hobby is that it affords so much opportunity to learn: vehicle mechanics, physics and chemistry, electricity and electronics...all available to anyone who has the interest to go beyond gluing parts together.

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27 minutes ago, BigTallDad said:

That's a large bunch of engine pictures...I wonder how many of those engines are available in kit or aftermarket form.

Everything on this page is available, even, I think, a version of the old Merc diesel.

10 of the oddballs on page one aren't available, but would sure make cool one-off projects for an enterprising young man.   :D

 

 

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