Greg, We "re-hose" a couple of Ferrari's every month. Although the hoses that you should be using are expensive, they are far cheaper than an engine fire. Here's what we do: SRI hose kit: Includes filler neck, tank to pump and two crossover hoses-Cost about $360. These hoses are better and will last longer than anything out there. All of the other 6mm or 8mm hoses: Goodyear or equivalent SAE R13 hose. I buy this stuff in rolls. Again, not cheap, but dropping in price...SAE R9 is the minimum standard hose that you should purchase. The yellowish-green plastic type tube that connect the top of the fuel tanks: Available from Ted Rutland's. On the Cohine injector lines, there is no reason to replace them unless they are physically damaged. The material that they are manufacturered from is impervious to fuel and still used to this day in virtually every modern car. These should be inspected very carefully, however. The "hose" job is easiest if the deck lid and AC compressor are removed. This is a moderately expensive, time consuming job.
Steve, You are correct. SOUTH of the fuel pump on the FI cars there are NO rubber feed or return fuel lines. ABOVE the fuel pump are plenty of rubber lines for the bulk fuel storage, transfer and fuel vapor systems. The hard plastic lines are DEFINATELY suseptible to rot. Nothiing lasts for 25+ years unscathed in a Ferrari engine bay. NOTHING. Again I had 8 kinks that were ONLY observable upon removal. Each could have led to fire with essentially a Flame Thrower ini the engine bay as the fuel in all those lines except one, maybe two, is under some serious pressure. Verell's kit has all the line you need. He is probably on "Christmas Break" with family. He was this time last year as I recall.
Know you are a Pro, however; on my 308 GTSi I was able to everything with the engine deck lid in place with no real effort. Did not take my AC off either. A 328 MAYBE somewhat different though, as I have no experience there. I 100% agree as you advocate; however, the inner fenders really should come off and the cross-overs and plastic line that runs between the accululator and filter(s) can only be reached from underneath.
With the (typically three) tank nipples on the USA-spec cars, I just find it easier. Then again, thinking about it, I try to do the hose services when cars are in for major services...Less labor duplication. I forgot to mention the fender liners (Ooops). Thank you, as that's a "given" on just about anything on these cars.
That's why I put the "question mark" at the end...I have no idea.....I don't drive injected cars..well, maybe my truck. Not sure where the system converts to injector delivery pressure, but I doubt the fuel pump is at 75PSI???
He went to great effort to engineer and produce it. He had to they put so many additives into winter fuel in the mountains!!! Pass the ski wax......... Image Unavailable, Please Login
On my '85 308 QV and the 328 parts diagram, which my 308's fuel system more closely resembles, there is an approximately 10" long section of rubber fuel line (with the braided cloth jacket) that connects the metal return line from the fuel distributor to the nipple on the right side fuel tank. 328 parts catalog:Tav 12, part #26 This probably never runs at FI pressure, since it should dump unobstructed into the tank, but it probably has a high volume potential and will flow whenever the fuel pump is running and fuel is bypassing the distributor.
No, the fuel pressure really is that high on Bosch CIS -- one of its downsides as the current needed to run the fuel pump gets crazy high. One advantage of EFI systems (besides being way less mechanically/hydraulically klugie ) is that they operate at only about 1/2 that pressure (so the fuel pump current is about 1/2 too).
I truthfully threw that out there because "I didn't know" as well as "no one was posting to help Greg328." It was during the work hours when most of them are off under a Ferrari. I thank all of you, that work on the cars built since 1977! Warmest wishes to everyone. Don't catch fire tho, not THAT warm.......
Thanks everybody, I appreciate all the voices that are sounding off here. Always learning.. I'll be posting progress.. Greg
No argument that a "kink" qualifies as "external damage" and should be replaced. Yes, that's the infamous fuel return line that often weeps/leaks in a not so obvious way (because it is at near zero pressure so fuel doesn't squirt out ). I should've more carefully worded my original comment and said "there are no rubber lines in the high pressure portion of the CIS system so no FI-rated rubber hose is needed". Definitely a prime candidate for the OP to look at for replacement because the outer braid can act like a wick and soak up a small leak that evaporates (so no liquid leaks to the ground) but a big odor source.
I really think $350 for 4 pieces of fuel hose is typical Ferrari excess. None of these hoses is on the high pressure side of the fuel pump so pressure is not the issue. The motivation to replace these hoses seems to be driver by present day fuel mixtures and general age. Given that, I can not imagine why anyone would conclude that anything other than hose rated for current fuel mixtures would be required. If I did have to use this kit because of no other source the first thing I would do is to remove the spiral cage from the hose between the tank and pump inlet. I believe I know what it is supposed to be for but I think it is ill conceived. I presume it is there so that the hose is straight onto the nipples at the tank and pump. Sound like a good idea, but I don't think it really is. Those spirals force the hose into a bend that it would not take naturally and they are thus applying pressure to the hose. With vibration all the contact points between the spiral cages and the hose will generate wear that would not be present if the hose was free, as it is originally from Ferrari. As far as failure at the nipples goes, that arises primarily due to vibration. The spirals will do little to reduce that vibration and may, due to the added weight (small as it may be) may actually make the amplitude of the vibrations greater. It looks neat and serves to visually justify the high price, but for me the functionality is highly questionable. But tht is just me and I never been one to follow.
No, the only function of the "cages" is to help the (straight cylindrical) hose hold a round shape cross-section when bent into a radius, and not kink like this: Image Unavailable, Please Login Image Unavailable, Please Login Can a hose be found with properties that when cut to the perfect length and bent into this shape doesn't kink -- maybe. You can read the patent abstract here (this is not an SRI patent): http://patft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=6557589.PN.&OS=PN/6557589&RS=PN/6557589 (US Patent No. 6,557,589) With regard to: "...why anyone would conclude that anything other than hose rated for current fuel mixtures would be required", the tricky bit is understanding what "current fuel mixture" means vs the manufacturer's testing. If you have a daily driver where you are always putting fresh fuel in and not letting it separate, and replacing the hoses fairly regularly = probably no problem; but if the fuel separates into a gasoline/water/100% ethanol layer cake, and you're not replacing the hoses every few~5 years, that's a more difficult situation. JMO -- to each his own...
That particular hose is also hard to see under the top of the frame rail. It's also hung on the end of a metal fuel line, so it's sort of a "stealth" rubber line. The section on my 308 was so brittle that it snapped in half when I was removing it. It is actually the current TREND in fuel mixtures that is the driving factor. What is good today, might not be tomorrow. Hopefully, Dave has been forward looking enough in his hose design that it will be ahead of the additives for quite some time. General age? Of the car or owners? As I get older, my tolerance for replacing things that should be non-wear items is diminishing. Changing a clutch or brake pads isn't a problem, since I probably had a lot of fun using them up. Changing fuel hoses because someone decided that moonshine was a motor fuel...not so much.
Max pressure anywhere in the system can't be higher than the pump pressure (without external force). The pressure is reduced to primary pressure (~75 PSI) in the fuel distributor, and a part of the flow is further reduced to control pressure (~60 PSI Bar) by the WUR. Pump pressure must be at least 75 PSI + losses between it and the fuel distributor. The CIS is effectively a miniature hydraulic system with the air sensor acting as a servo valve controller. Unlike diaphragm pumps, the CIS fuel pump is a positive displacement pump that could be used to drive small hydraulics.
http://www.autohausaz.com/search/product.aspx?sid=zmmbqv45uowtwa553mdzo4fg&makeid=800016@Mercedes&modelid=1193420@280SE&year=1980&cid=22@Fuel %26 Air System&gid=6352@Fuel Hose/Line If that link does not work, got to autohausaz.com and Mercedes/1980/280SE/Fuel-Air System. All the correct METRIC sizes are there. The 5/16" hose is to large (at least for my 77 it was). The 7.5mm ID is correct and the clamps work on that b/c the wall is also the correct thickness. It is rated for EFI with internal bracing. 14mm ID is also sold. That will cover most of what you need. EDIT: I bought just the cross over hoses from Dave with clamps. Great stuff and no more worries for me.
Thanks for setting the record straight on the function of the cages. I would still say it is ill conceived as the cage exerts pressure on the hose (to bend it) where there should be none and it will cause wear which could potentially be more of a concern than a kink. And if the cage is preventing the hose from kinking then it is also exerting force on the hose to hold its round cross section. Again, something that is just going to initiate wear at the contact points. FWIW, I have no problems with kinking of the hoses on my '85 308. So I don't think it is a big issue. I mean, let's get real here. It's not like rubber hoses bent in different directions are unique to Ferraris. If a hose kinks it is probably an indication of being poorly installed or that the hose is damaged or weak, and it should certainly be replaced. As for the fuel separation problem, I have a bottle of summer mix fuel sitting in my garage and I'm waiting for something to happen. We'll see how long it really takes. I'm not trying to be argumentative (well maybe a little ) but it often seems that when the name Ferrari is involved common sense goes out the window.
I am not so sure how a device like that can prevent a kink in all cases. I remember coils INSIDE the hoses to prevent kinking. I don't remember them on the outside except to protect hoses from rubbing damage. That said I am not referring to fuel hoses but to some gas hoses used in the lab. I would assume that the principles would be the same. By the way Dave's hose&coil look very cool as far as hoses go.
Hose mfrs specify a minimum bend radius dependent on their construction and size. They can be forced into tighter bends by using mechanical restraints, like springs, to prevent collapse (kinking), but they over-stress the wall fiber, considerably weakening the hose. The problem with no-name components like hoses is there's no way to verify specs...you have to trust the vendor.
Darn, I believe your are right. My apologies. THAT one was a BEYOTCH to change out with lots of time and blood (and half a bottle of Canadian Mist afterwards (it is MY car after all)) as I did not remove the rear deck lid or inner fender when I changed it out. The experience was SO tramatic I blocked it from memory ....... (only HALF kidding).
Just food for thought. WHY did BMW early this year with the ethanol BS going on over here (We crushed E10; it is actually harder to buy now than E0 or E5) say that, "Ethanol is UNSAFE in any mixture for automotive use?" Why did G___S Hose say NOTHING when a NEW six month old rotted hose from a Ferrari was dropped on one of their engineers desks? Is one paranoid when all the evidence says, "they really ARE out to Get You?"
