Firewall shields for wires and cables

[RickWoodall]

I have reviewed many builders sites, and talked to several local builders. It seems that many drill holes in the firewall all over and seal up with rtv, sometimes using a set of double snap bushings (one each way locked together, others use things like spruce sells (stainless shields) various types available, and others use safeair type creations with firesleeves etc.

I am trying to minimize the number of holes, and make this as clean and safe as possible. Is there any real consensus from those that have done this on what is "best practices" ?

It seems this is not a smart place to save a buck, but not worth overthinking either. Any help or comments welcome.

 

[D-Dubya]

Best practices...

Well, there's a three-fold purpose in making sure you have a good seal on your firewall penetrations:
1) Prevent fire burn-through (on a really bad day)
2) Prevent oil or other stuff from weeping through (on not as bad of a day)
3) Prevent wires from grounding out on the sharp edge of the firewall (any day)

It's up to you as to how far you want to go. I used the firewall shields from Van's (SSFS-1XPILOT) that have a recess that accepts a rubber grommet on the firewall. A little glob of red RTV at the actual wire penetration helps to seal it up and give the grommet some protection.

As you've referenced, there's more than one way to skin a cat and there are many different methods to choose from. But I wouldn't leave any gaping holes or sharp edges that a wire could ground out on. My two cents...

 

[AltonD]

The LSI install book has this info: Do not run sensor wires with the LS leads to the coils. It is OK to run current carrying wires adjacent to these.

I ended up with three penetrations:
main power
ignition (my b/u alt field does share this one)
sensors