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Spark plug wire routing
https://slantsix.org/forum/viewtopic.php?t=58173		 Page 1 of 2
Author:  Sam Powell [ Mon Aug 03, 2015 3:57 pm ]
Post subject:  Spark plug wire routing
The park plug wires on the slant are far from ideal. They touch the fender, and each other. I feel there is bound to be some cross fire between them. Today I put convolute tubing on each wire, and paid special attention to where they ran, trying to avoid any contact between then. In some cases I used wire ties to keep them apart. In looking this over, it seems there must be a way to route the wires so they are neat, and do not touch one another at all. I have noticed most of the V-8 engines at the cruises have very neat wire looms where the wires not only look good but are kept apart as well.

I am thinking of fabricating a loom that bolts to the rocker cover hold down bolts that would route the wires neatly into two sets, one for the -1-2-3, and one for 4-5-6, where the wires come more or less upward, and then peal back for the rear ones and forward for the front ones. This would require custom wires that were of differing lengths from the standard set. I was wondering if anyone can recommend a universal set of wires that I could configure to my specific lengths, that also included boot of various styles, some angled at 45 some at 90 and s ome straight. I would like radio pressing type.

For what it is worth, I thought it ran smoother when I was done with the initial covering and routing. Thanks.

Sam
Author:  SlantSixDan [ Mon Aug 03, 2015 10:57 pm ]
Post subject:  Re: Spark plug wire routing
Quote:
The park plug wires on the slant are far from ideal. They touch the fender, and each other.
Neither thing matters much as long as the wires are of good quality and in good condition. What you want to avoid is poorly-shielded wires running parallel in close proximity for more than absolutely necessary -- that's what causes inductive crossfire.
Quote:
wondering if anyone can recommend a universal set of wires that I could configure to my specific lengths, that also included boot of various styles, some angled at 45 some at 90 and s ome straight.
www.magnecor.com and www.auroraignitionwires.com both have technical pages well worth reading and any variety you might want of very good quality ignition wire.
Author:  Reed [ Tue Aug 04, 2015 12:39 am ]
Post subject: 
Magnecore set that fits a slant $60 with shipping. 7mm. Auction title says fits Chevy, but scroll down to the description. It fits slants. :)
Author:  Sam Powell [ Tue Aug 04, 2015 5:59 am ]
Post subject: 
Thanks to both. Never heard of Aurora. They appear to be Canadian. Will read some more on this.

Sam
Author:  Sam Powell [ Tue Aug 04, 2015 3:54 pm ]
Post subject: 
Thanks again for earlier comments. I did a bit of searching on the net for further information and found many TSBs from all manufacturers on the subject of induction misfires, as well as quite a few articles on how to make spark wires look pretty. The cosmetic articles all found various ways to route wires parallel to one another, making no mention of the misfire danger. However, the TSBs made it clear you can do this safely ONLY if you make sure cylinders which fire sequentially are not near each other. On SBC and BBC this required keeping wires 7&8 seperated by one or more wires in the loom. On 5 litre Fords of multiple vintages, there are consecutively firing cyliners on both banks requiring attention. I found similar such TSBs for various Chrysler engines. On one of the Ford TSBs they pointed out the importance of keeping wires at least 3/4" from ground potential such as the dip stick.

I will go study the firing order and wires for the slant and see if there similar pit falls to avoid.
Sam
Author:  Reed [ Tue Aug 04, 2015 4:18 pm ]
Post subject: 
Back when Napa still carried Belden plug wires that were tailored to the slant, the wires came in sets of two long wires, two medium wires, and two short wires. I found that when the #1 plug tower was put in the customary location by the vacuum advance pod, the following arrangement made a nice clean installation of plug wires:

1 = long wire
5 = medium wire
3 = short wire
6 = long wire
2 = medium wire
4 = short wire

It was possible to route the wires so there was minimal contact between the sequentially firing wires. It helps that the slant is an inline motor where the sequential firing order always has cylinder on the opposite end of the motor with at least one cylinder in between the currently firing cylinder and the next to fire cylinder.
Author:  bboogieart [ Tue Aug 04, 2015 6:19 pm ]
Post subject: 
I used to go to salvage yards and grab all the wire separators I could find.
GM had a lot of nice thick gray plastic separators.
There used to be dress up kits as well that had wire looms.
I would mix and match until everything looked nice and the wires never touched anything.
I don't know if those are still out there.
Mainly it just takes some fussing and time.
You should have no trouble.
Author:  SlantSixDan [ Tue Aug 04, 2015 7:23 pm ]
Post subject: 
Starting in late '62, four out of the six plug wires had 90° terminals and boots at the distributor cap end. The only ones with straight terminals/boots were the shorties for № 3 and № 4. This spaced the wires away from each other above the distributor cap. I've also seen sets with 90° terminals only on the longest wires for № 1 and № 6, straights on all the rest. But by '73 or so the factory had gone back to all straights, and it's been years since aftermarket sets have come with any 90° terminals. Fortunately, companies like Aurora and Magnecor will put together whatever set you want (or you can do so yourself if you're a masochist with the proper tools).

Tough to avoid plug wire proximity to ground potential (RH inner fender) with a slant motor, unless you're in a B-body, C-body, truck, van, boat, combine, or green bean harvester. Fortunately it doesn't really matter much until the plug wires are past due for replacement.
Author:  NEVjr [ Tue Aug 04, 2015 8:00 pm ]
Post subject: 
153624? alternates front and back with the distributor in the middle. its also not as bad as a v8 because there are not as many firing events per revolution
Author:  '67 Dart 270 [ Tue Aug 04, 2015 8:20 pm ]
Post subject:  universal wires
Hi Reed,

I used MSD 31199 plug wire set. You can cut and form them to whatever length you want. The boots that go over the spark plugs might be long for your special routing needs, but for my purposes they work fine.

See: http://www.summitracing.com/parts/msd-31199

I didn't particularly try to keep them from touching, but I did try to get them "elegantly" and symmetrically arranged. My install: http://s785.photobucket.com/user/67dart ... c.jpg.html

That said, I agree with Dan, if they are good wires, properly shielded, no worries about touching the fender or each other.

Brian
Author:  Reed [ Tue Aug 04, 2015 8:21 pm ]
Post subject: 
Quote:
green bean harvester.
:shock: got any pictures?
Author:  '67 Dart 270 [ Tue Aug 04, 2015 8:40 pm ]
Post subject:  Msd-31199
...doesn't have 45 degree boots though...only 90's for the distributor and 180's for the plugs...but it is a V8 set and has lots of extra wire and some extra parts, and a vise crimping tool...

b
Author:  Sam Powell [ Wed Aug 05, 2015 5:01 am ]
Post subject: 
Since the sperk plug wires are in firing order out of the cap, it is obvious (like duh), that all the wires will be running parallel to each other sequentially for a short while, and all will be parallel to the next one to fire, thus producing the condition for an inductance missfire. It seems the only way to avoid this is to have some of the cap boots be 90 degrees, and some straight.

I am travelling again to the midwest starting Thursday, so will have no time to look into this for a week. But it does not seem like a trivial deal. Several years back my trusted, and well trained mechaninc friend Tommy T watched my slant idling with its relatively minor twitches and tremors. Tommy made the comment slants were not designed to idle smoothly, pointing to the uneven intake runner length. However at the cruise on Sunday another fellow made the comment that inline sixes were inherently better ballanced that v8s.

So how do you reconcile these views? In terms of modern engine design, the slant is pretty outdated, and has some flaws such as head and intake design, that would be very expensive to "fix". However improving ignition functioning requires no structural engineering. While the HEI is a significant step up, maybe there is moreThis business of looking thoughtfully at spark plug wire routing seems like such a simple thing, and yet must be vital if every major manufacturer has issued TSBs on the importance of this. It kind of falls into the same catagory as good grounds and clean connectors; not glamerous but important non the less.

I would like to know if the folks who have worked out the Ford EDIS experience a smoother idle? Especially thise who have set up COP. I think that is Josh, and maybe Pierre.

Sam
Author:  '67 Dart 270 [ Wed Aug 05, 2015 8:01 am ]
Post subject:  idle
Sam, my slant idles really smoothly for what that's worth. brian
Author:  '67 Dart 270 [ Wed Aug 05, 2015 8:19 am ]
Post subject:  parallel
Dan can correct me on this, good shielding aside (which should avoid any issues) I think the wires have to run parallel and be pretty close to each other, in contact, as well. You can see in my setup, for example, there are no such instances of two wires lying parallel and adjacent to each other with only 90 degree boots on the distributor:

http://s785.photobucket.com/user/67dart ... g.html?o=0

Sam, what wires are you currently using (sorry if you already said which)?

brian
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