Quote:
Originally Posted by ltrrtl
Bruce,
You bring up valid points... Since originally posting my question I have purchased the R&M - 1101S wire loom set... I am installing the new smaller A/C compressor and it appears "from pictures" that the loom will fit. Heads are straight out plugs, no angle......... Loom set is expected to arrive on Tuesday.
Yesterday, I installed the headers, plugs and test fitted some old 90 degree wires. Driver side looks good, maintaining 1/2 clearance. Passenger side is not so good, 2 plug ends are right next to the header tubes. Does not matter if I use 90 or straight cables, I will not get more than 1/8 -1/4 clearance at the wire cap/ plug. This is my 1st build with headers and I understand the heat and all but, what is one to do when the clearance of 1/2 can not be achieved? BTW, returning the headers is not an option I want to go with  |
Not all the spark plug wires on an engine need to be straight or 90 deg, use one that gives the best clearance. So you could end up with let’s say (3) 90 deg and (5) straight spark plug ends or any combination on one engine. The fit and clearance is more important than the aesthetics of all the spark plug ends being the same on each spark plug.
If the clearance that you’re talking about is the clearance between the spark plug wire boot and the header tube it’s just something you’re going to have to live with but there has to be some. I’ve seen this happen with 90 deg boots but with straight boots you need to maintain the ½ clearance or switch to 90 deg boot.
A few tips on running the spark plug wires, you should hold to a minimum any twisting of the wire and do not bend the wire to have a bend with less than ½ inch radius bend (no sharp wire bends) and make sure that the wire is not riding on any sharp edges of the block. The spark plug wires have a carbon core that conduct the electricity to the spark plug from the distributor and any sharp bend or excessive twisting can cause gaps/breaking the wire core and making the wire have a higher resistance to conduct electricity. The spark plug wires now a day are better than the old days but I still want to keep all the wires as separated as possible (using wire spacers), let’s say any run over 4 -5 inches with the wires touching each other and parallel can induce current in one of the other wires or jump from one wire to another, this might not happen right away but the possibility down the road does exist (then you’re trying to figure out why your engine isn’t running right).
I generally use universal (you cut to fit) wire kits. That way I can have the correct wire lengths for my application. One thing to note is do not and I will say again do not cut any wires till all the wire runs are set from all the spark plugs to the distributor. Not all the wires in the kits are the same length and if you cut one to short you may end up buying another kit. I would not recommend any solid wire core wires for a street application they are generally for racing only. One problem you might run into is the kits normally come only with all 90 deg boots at the spark plug end or all straight ends, if you need to have a combination of both ends you might have to buy two kits. Some kits come with a crimping tool that can be used with a vice and others don’t. I’ve found that the (MSD 3503 Mini-Stripper Crimpers) work well with a vice and relatively inexpensive if you need one. Also the distributor should be set close to what would be you normal set timing and allow a little extra length of wire at the distributor for some timing adjustments if needed.
Hope this helps you out in setting up your ignition/wire runs
Bruce