Questions about wiring loom for engine

I am in the phase where i am starting to wiring the looms for the car, power, lighting, auxiliary etc.
But i haven't decided whats best yet in two regards and would need some of your thoughts and pictures please.
1. Engine harness, wich way to approach the engine? Was thinking about approaching from the rear side at the bellhouse to get a cleaner look, but the heat from the headers is an issue.
2. I will run separate ignition coils, was thinking about putting them on each side of the oil pan on the chassi and then just let the ignition cables connect to the engine from underneath, this would mean less heat for both coils and cables. The only thing talking against this solution is the instruction for EFI system that states that the header ground wire from the coils need to be as short as possible to the head it will ignite into.

Would love to hear your thoughts and ideas, and also see some lovely pictures of engine bays with different solution for both engine harness and ignition solutions with separate coils. :)

The general concept about the enginebay is that "neat and invicible", meaning i want as little as possible of wiring, and other cluttering things as brake lines and hoses to be visible.
I have already gone thru the pain of having all brake lines routed behind panels.
The same will be done for wiring and hopefully hoses too.
A couple of example pictures to visualize what my thoughts are about.
First picture is of coil placement, each side or firewall, second is engine harness, front or back approach? Low or high.


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Randy V

Staff member
Lifetime Supporter
There are many examples of coil & fuel pump placement. However, since these cars are generally built to replicate the originals and those were racing cars, I doubt that you’ll find many examples of those being hidden away along with wiring. The idea in building racing cars is to make higher failure items accessible so they can be easily exchanged. Therefore, most examples will show the coils and pumps mounted to the firewall.
Here's some pics for what how I hid the ignition coils on an LS in a homebuilt Ferrari 250 GTO. I thought about remote mounting the coils but opted to go this way instead. Yes, this is an LS converted to SOHC but I still found the coil mounting up top to be best compromise.

P1000249 - web.jpg

Valve/cam covers I fabricated from .050 3003 aluminum sheet. Ferrari script was bought off the Internet. I put holes in the side for ventilation and also for spark plug wire access to the coils.
P1120729 - web.jpg

P1120736 - web.jpg

If you look closely, you can see the spark plug wires exiting the covers. The reality is that it's so subtle that no one notices. I guess if I'd have thought about it, I would have probably put the wire harness under the covers as well. More work but would have made the look even cleaner.

The vast majority of people just think this is a Ferrari engine versus just another LS in a hotrod.
Thanks for the replies, and yes Randy, you are probably correct, didn't think of that

I would like to see pics of the wiring looms going from chassi over to front/rear clam also, havent figured out a good point to drop over yet because of the high pivoting hinges wich in turn means alot of twist in cables going over.