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Ignition wire routing

Old 11-14-2018, 04:14 PM
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RJTCorvette
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Default Ignition wire routing

I am a new member with a 1977 L48 350 engine. I have owned the car since new but let it sit for a long time. Now in the process of getting it back in running condition. My "helper" removed all of the ignition shielding and spark plug wires. The new wires are in the correct positions but just routed the easiest way to get the engine started (which it did!). So now I am trying to put it back together myself. Does anyone have a photo or diagram that shows exactly how the spark plug wires need to be routed? I have read that they need to go through an engine mount and the boot won't fit. I hope that I can remove the distributor boot to get the wire through the mount and put back on without causing a problem with the new wires. Any photos of the shield installation would help also. I am just sick over this since I would have routed each wire one at a time if I had done the work myself. Other work that I plan to do soon includes replacing all rubber and fluids. I would also like to install an inline fuel filter (temporary) to protect the rebuilt carburetor. Thank you for any help you can offer me.

Last edited by RJTCorvette; 11-14-2018 at 04:16 PM.
Old 11-14-2018, 04:47 PM
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Originally Posted by RJTCorvette
I am a new member with a 1977 L48 350 engine. I have owned the car since new but let it sit for a long time. Now in the process of getting it back in running condition. My "helper" removed all of the ignition shielding and spark plug wires. The new wires are in the correct positions but just routed the easiest way to get the engine started (which it did!). So now I am trying to put it back together myself. Does anyone have a photo or diagram that shows exactly how the spark plug wires need to be routed? I have read that they need to go through an engine mount and the boot won't fit. I hope that I can remove the distributor boot to get the wire through the mount and put back on without causing a problem with the new wires. Any photos of the shield installation would help also. I am just sick over this since I would have routed each wire one at a time if I had done the work myself. Other work that I plan to do soon includes replacing all rubber and fluids. I would also like to install an inline fuel filter (temporary) to protect the rebuilt carburetor. Thank you for any help you can offer me.
I also have a 77 L48. If you want the wires to follow the stock path #3 Left side and #2 wire right side will be the longest wires of the kit. They do this so the wires are on the front side of the distributor as shown.
One shot of my left side L48.





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Old 11-14-2018, 05:33 PM
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Thank you! I will be working on the car this weekend. Do you happen to have the drawing for the left side? I used to work as an automotive engineer at GM, so I really appreciate the accurate information!! I want to keep my car stock and the service manual has no details at all in this area.
Old 11-14-2018, 06:10 PM
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Default Does this help?



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Old 11-14-2018, 06:56 PM
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Thank you! This Forum is amazing!
Old 11-14-2018, 09:16 PM
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Here's the left side with manifolds installed.


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Old 11-15-2018, 11:00 AM
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Thank you! I really appreciate the help!
Old 11-16-2018, 07:28 PM
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The photo was very helpful! Can you send me a photo of the right hand side also? Great to see the exact same engine and that will help me figure out how to put this puzzle back together! Thank you
Old 11-16-2018, 09:00 PM
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Right side plus one more of the left rear.




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Old 11-16-2018, 09:01 PM
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One more
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Old 11-18-2018, 06:36 PM
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Not that it matters to some people...but actually when you look at the rubber grommet that holds all four of these spark plug wires in the bracket. There are raised numbers on them for the place for the spark plug wires need to go.

On this side the YELLOW arrows are obviously pointing to cylinders #1 and #3. And the RED arrows are pointing to cylinders #5 and #7.

By the way the numbers cast into this rubber grommet are positioned., Cylinders #5 and #7 need to be at each END of the grommet adn cylinders #1 and #3 are in the middle....due to cylinders #5 and #7 fire right beside each other in the firing order ....1-8-4-3-6-5-7-2

like I said...many people do not care or worry about it....but it is something I do so I do not have to go back and correct it if I am having an issue with the way the engine is running due to these cylinders are doing as well as they should.


Not meaning to be picky but I seem to look for things like the fine details this and if I see something.... I can not just say nothing.

DUB
Old 11-19-2018, 01:02 AM
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WOW! Great pictures and detailed instructions.
Learned something today!

Now you got me curious, I'll have to check my wires out.
Old 11-19-2018, 05:36 AM
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Originally Posted by DUB
Not that it matters to some people...but actually when you look at the rubber grommet that holds all four of these spark plug wires in the bracket. There are raised numbers on them for the place for the spark plug wires need to go.

On this side the YELLOW arrows are obviously pointing to cylinders #1 and #3. And the RED arrows are pointing to cylinders #5 and #7.

By the way the numbers cast into this rubber grommet are positioned., Cylinders #5 and #7 need to be at each END of the grommet adn cylinders #1 and #3 are in the middle....due to cylinders #5 and #7 fire right beside each other in the firing order ....1-8-4-3-6-5-7-2

like I said...many people do not care or worry about it....but it is something I do so I do not have to go back and correct it if I am having an issue with the way the engine is running due to these cylinders are doing as well as they should.


Not meaning to be picky but I seem to look for things like the fine details this and if I see something.... I can not just say nothing.

DUB
DUB......you're suppose to tell me these things BEFORE I put the engine in the can! Now I'm gonna have to crawl under to fix the routing
Old 11-19-2018, 08:18 AM
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I also say do not fix what is not broke. So if it all good...then leave it. I was commenting on what I saw.

Sorry about this forum members....but I am just 'one of THOSE guys' who often times finds himself stuck in the rut of the fine details needing to be identified and done as it was designed.

Mainly because IF I don't...with my luck....then I have to deal with something that I possibly could have stopped from happening.

NOW...here is where my twisted brain thinks. I KNOW why GM is doing this...( or at least I think I know because they do the same thing on the Tuned Port C4's) BUT what about the two wires down in the hockey stick shaped metal shields that are along side the engine block and the two wires that are obviously touching each other while in that shield. And not only that. They are both clipped into the clip that attaches to the oil pan bolt with NO separation at all. BUT YET that separate them again right where the spark plug wires are attached to the spark plugs. So by this time the inside of my brain is spinning like a flushed toilet and I just have to shrug my shoulders and do it as they did it and hope all is good.

I do know I HATE seeing Zip-ties used to bundle the spark plug wires in a bundle...UNLESS that person KNOWS how to make a spark plug wire separating harness out of several large Zip-ties. YES... the drag car race team I worked on for a while used Zip ties to hold the plug wires together BUT they had a thick heat shielding sleeves on them which kept them apart when they were Zip tied together...so that does not count due to they are not like spark plug wires right out of a box with no added sleeves.

DUB
Old 11-19-2018, 11:24 AM
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Duke94:
Nice photos!
I like the Gray 90* Spark Plug boots.
What brand did you use, or are they Taylor 46081?
Thank You,

Last edited by bmotojoe; 11-19-2018 at 11:31 AM.
Old 11-19-2018, 07:10 PM
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Originally Posted by bmotojoe
Duke94:
Nice photos!
I like the Gray 90* Spark Plug boots.
What brand did you use, or are they Taylor 46081?
Thank You,
The wires are these. Fit was just about perfect.
https://www.zip-corvette.com/78-82-s...s-no-date.html
Old 11-22-2018, 07:31 AM
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I still can’t understand the wisdom of routing wires through the engine mount. This complicates what should be a relatively easy job. In my case, the routing was done while the engine was on a stand. But the next owner won’t be so fortunate. I’ll bet most have rerouted the wires during replacement. Just my 2 cents.

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Old 11-22-2018, 09:02 AM
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Routing the spark plug wires through the engine mount can be a snap. Depending on the engine and what has been previously done to it. Simply remove the spark plug boot and reinstall it when you slide the wire where it need to go and far enough out of this area to reattach the boot. I do it that way on every car that requires it. This is often times due to the missing 2-wire spark plug wire looms that were not put back on,

YES..I may need to either loosen or slightly move or tweak the 2-wire spark plug wire loom so I can cage the wires back into it.

Then I take the plug wire and begin to route it back towards the distributor.

On rare occasions due to the design of the 2-wire spark plug wire loom....because they are not all the same in how they are made. One design it is made out of steel and the end where the wires go is dipped in a flexible rubber. The other design is where they attach a plastic loom to it so the ends where the spark plug wire goes can snap off due to it is plastic.

I loosen but NOT remove the 3 bolts that hold the motor mount to the engine block and raise the engine up so there is a tad bit more room for the wires to be removed and then cage into that 2 wire spark plug wire loom. By using this method I can often times NOT remove the spark plug wire boot end.

If you buy a good set of wires you should have no fear in damaging the spark plug wire when removing the boot for the spark plug if you simply insert a small pocket size thin flat blade screwdriver and run it around the wire to break the seal. The pull it off and reinstall. I have never had a wire get damaged doing this. I obviously use some of the dielectric grease often times provided with spark plug wires to put a very thin film of it inside the area of the boot or on the outside of the wire by the terminal so when I go to slide it back in, it slides in with ease and is also sealed. and no fear of it arcing.

And if some of the wires are way too long and I can not position that additional length of wire adn have it be right.... I can remove the boot and cut the wire and move the terminal and crimp it back on and ohm it out. Having the tools to do this is wise so that if you do not have replacement terminal ends...you have a way to open up the crimp so you can crimp it back as how it was.

DUB
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Old 11-22-2018, 10:03 AM
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Ok I’m going to fess up. I always buy precut ignition wires and I have never attempted to take one apart. Thanks Dub, for the advice. I doubt that I will ever need to replace wires again on this car, at least.
Old 11-22-2018, 10:22 AM
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I also install made up spark plug wires and also install wires from MSD where I can make them up to exact lengths but regardless of that the boot can come off .

Hopefully yours do not need replacing but if they do it is not really that big of deal in my book considering all the other things I need to fix on these Corvettes that is much harder than that. I often times enjoy putting spark plugs wires on for a nice change of pace. As sick as it may sound...it is kind of relaxing to do....in comparison to rebuilding steering columns or a manual transmission or bonding on body panels and doing body work.

DUB

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