Ferrari Mailing List: Re: Carbs, fire and costs

[Matt Boyd (ferrari308driver]

Rick,

I thought I'd comment on only one piece of your discussion.

>> The CIS injected cars with brittle injection lines are a more
>> likely candidate for an engine fire.
>
> I don't believe this is an issue unless the lines have been abused (e.g.
> crimped). The lines are very rugged, as are the banjos. But remember, these
> cars are about 30 years old too! And a K-Jetronic system operates at more
> than an order of magnitude higher pressure than do carburetted systems.
>
> New hard lines installed with new copper crush washers at the banjos, is a
> manageable expense during any major service. Probably needed only once
> unless you keep the car for 30 more years.

On a Bosch CIS K-Jet system in the 308s, I don't think that the
original author was talking about the hard lines. I'm guessing they
meant the hard black plastic lines that allow a little slack. About
ten years or so ago, perhaps more, I decided to spruce up the engine
compartment. I removed all the injection lines to have the hard lines
replated with yellow zinc dichromate. I knew that separating the hard
lines from the black plastic lines would likely destroy the plastic
lines, so I sourced new for those, and not from the dealer network. I
can't remember the specifics, but I do remember the term "black
polyamid" when I searched for the right sized fuel lines. I also had
to order a special tool -- it was listed as a Porsche tool -- and as I
recall it was from a place called Baum tools or something like that.
This tool held that black polyamid line perfectly so that I could then
slide the hard lines in. No clamps. It was very difficult and time
consuming, and in retrospect I might should have used a heat gun/hair
dryer to soften up the ends of the black polyamid before trying to
insert the hard lines in.

In any event, I'm guessing the original author was referring to the
black polyamid -- something I've never thought of as a maintenance
requirement to replace (I did mine only because of the cosmetic work
detailed above), but I do concur that over time it is likely that this
hard plastic in a hot engine bay might become brittle. Are there
documented episodes of these failing?

-Matt
'85 308