Sunday, 17 January 2016

Only You Can Prevent Engine Fires!

The 1983 Porsche 928s is a beautiful and cool car no question but after 32 years she will be showing her age and that is OK.  A few things that extend beyond just routine maintenance will need to be done. After combing through 928 community forms and various other group support systems it became obvious that one action was required first and foremost.  The rubber in the engine bay would need to be replaced. I spent the better part of  two days of looking for a condom in the engine bay to no avail before I re-read the posts and I learned the errors of my ways!  Fuel hoses, rubber fuel hoses that is what they were referring to. I always thought of the car as a female anyway finding a condom in the engine bay would have just been, well, wrong.  

It is just a fact of science that all compounds breakdown and ultimately fail over time. Compounds such as rubber.  When that rubber is a component in the fuel lines it becomes a larger concern. 30 year of passing fuel under pressure through the rubber components will take a toll.  Especially in North America where our petrol is contaminated with ethanol. This ultimately makes a bad situation worse. If this is not concern enough the majority of these rubber hoses live in the engine bay.  If any of these hoses rupture it mean an engine fire.  In technical terms this is what mechanics refer to as "bad!". To avoid this all of that rubber needs to be replaced with proper rated hose and the appropriate type of clamps.  The 1983 Porsche 928 fuel system runs a pressure of approximately 2.5 bar or 55 psi. It is critical to use an appropriate hose with a specification can support this application.  The same goes for the clamps.  It would be a damn shame if you spend all this time replacing the rubber only to cause exactly what you are trying to avoid by using the wrong hose or clamps.  So how do you sort this?!?

When you find yourself obsessing over a Porsche 928, the first thing you need to realise is that no matter what you are seeing or needing, someone else has already been there and done that. So when you require information you will find that there are some great 928 resources on the web, teaming with fellow believers just dying to initiate people into the our "not-so-secret-society" and teach them the secret hand shake. As tongue-in-cheek as that was meant to sound, it is not actually far from the truth and as a recent convert to the Church of 928 I can whole heartedly testify that you are not alone!  Ask and ye shall receive!  To do that there are two forums that are a must to be a member of. Rennlist and Pelican Parts.  These forums both have specific areas for 928 enthusiasts where knowledge is past, documented and problems solved.

There are also two friends you need Carl Fausett from 928 Motorsports and Roger Tyson from 928sRus.  These two men are the Grand Poobahs of the 928 community and a touchstone for parts, technical information and advice.  Carl's site focuses on performance and racing aspects of the 928 platform as well as speciality items. If you plan to take your Porsche 928 on a track he is the man to talk to.  He sells a variety of parts that make your 928 even better and more fun on a track. Even if you are not taking your 928 on a track I highly recommend the chin plates to protect you from damage due to bottoming out.  Roger is a source for basically everything you need to keep your 928 running and healthy.  If you tell Roger what you are doing and what you think you need, he will hook you up and make sure you are not missing anything. The customer service I have experienced with both gentlemen has be absolutely stellar and I could not have gotten as far as I have without their help.

In the specific case of the rubber replacement I ended up getting the High Pressure Fuel Line and the Fuel Line Clamp Kit from 928 Motorsports.  This way I knew I had the right line and the right clamps for the application.  Also knowing Carl has used this combination in several cases in the past made me comfortable that this was a tried and true method.  Carl even has a PDF document outlining how to work with the clamps and line. The images below indicate with red arrows the hoses that need to be replaced for the 1983 928s.


The image to the left shows a selection of the key hoses that need to be address as a bare minimum. The lower two hoses connect the fuel distribution system in the engine bay to hard fuel lines that come form the rear of the vehicle.  In the middle you see the injectors (total of 8) still connected by the little 2 inch rubber hose to the fuel rail. The hose at the top is from the rear of the car, used to interconnect the hard fuel lines to the fuel filter.  This was the only hose that we actually could find an OEM replacement for.  We kept the original for the sake of the fittings.
The image to the right gives a clearer look at the hoses from the injector to the fuel rail.  The OEM clamps on these things were quite a pain to cut off. It was all about the sharp tin snips and a whole lot of patience and liberal application of single malt.
The image to the right is what things look like once your have changed all the rubber.  I did a little clean up on the fuel rails, that the injectors connect to as well, before replacing them in the engine bay.  The re-installation is pretty straight forward for the injector rails but the interconnection hoses between the fuel distribution system in the engine bay and the hard fuel lines to the rear of the vehicle were annoying to get to and frustrating to disconnect and reconnect on the hard fuel line side.  A combination of tight access and the tight lock of the nuts managed to coax more than a few curse words and an equal number of beer breaks before we were able to get them release and then back into place.  Thank god I have a strong liver and sound proof  (mostly) Garage. Some clean up was done prior to replacing the injectors but I will save that for another post.

With these hoses now replaced the fear of engine fires has been mitigated as much as possible. With any vehicle it is always a risk but now the probability has been drop substantially and the possibility of a hose rupturing is as close to zero as possible.  We can now drive the 928 with no fear, although we still keep a fire extinguisher in the car at all times.

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