C3 Fires?

[zgator]

A good friend of mine(who has passed)Had a brand new 78 silver anny.oyster int.Car was maybe a year old.It burnt to the ground one night.Never quite knew why.Might have been electrical who knows.

 

[JohnZ]

You can buy either high or low pressure fuel grade hoses by the foot cheaply at parts stores. But like I said millions of cars have been produced without a reputation for fires and depend on rubber fuel hoses AFTER the fuel pump and before the carb up to the end of the carb era in the mid 80s. And continue to use pressurized rubber hoses w/ EFI since. Somehow I have a hard time thinking of the engineering done by companies from Detroit to Japan and Europe as 'jury rigging'.

The problem is that most folks who plumb one of those in-line filters into their pump-to-carb pipe just go to the auto parts store and buy some "gas hose" (NOT the higher-pressure variety designed for pressure-side applications like EFI), and they get the garden-variety hose designed for the vacuum-side applications (which is what comes in the cheapo filter kits as well). Using cheap hose designed for vacuum on a pressure-side application is "jury-rigging". I know just a little about fuel system design; see my profile.

 

[AUSSIEVETTEMAN]

...The key issue is maintaining the original steel fuel line from the pump to the carb, which has SAE inverted-flare fuel line fittings at both ends. You do NOT want ANY rubber hose in that line, especially if someone has "Bubba'd" one of those cheapo plastic/glass fuel filters into it with rubber hoses and clamps. There's a reason that OEM fuel line is all steel....

Yeah, John has something here.
The previous owner of our Vette installed a Holley 650 CFM carb and cut the original steel lines from the pump to the carb! He replaced the fitting he cut off with a piece of rubber hose to fit the Holley. This was due for replacement as soon as we got the car home, but I opted to buy an Edelbrock QJet carb and replace the cut line with another steel line as per the standard specs. These carbs just blt straight on with an original line. As well as HP increases after ditching the Holley, the fuel smells went away!

Some may say that steel lines heat the fuel up before they get to the engine, possibly starving it, but I have never found that to be the case on the older engines with a mechanical pump. Don't know about EFI engines, which run higher pressure.

I think it is safer to have a steel line running up to the carb. That way the only rubber lines in the system are on the pump.


Tony

 

[pgtr]

The problem is that most folks who plumb one of those in-line filters into their pump-to-carb pipe just go to the auto parts store and buy some "gas hose" (NOT the higher-pressure variety designed for pressure-side applications like EFI),

That's NOT actually correct.

A) The generic 'gas hose' as you call it or rubber fuel hose most auto parts store sell cheaply by the foot is either 'standard' (low pressure for carbs) or 'high pressure' (EFI) and both are usually offered in brands like Dayco, Goodyear and Gates. The standard rubber fuel hose stuff IS designed and intended SPECIFICALLY for low pressure carbs applications.

B) The purchase of add'l rubber fuel hose is not required w/ non GMs. An inline fuel filter is simply spliced into the EXISTING factory installed OEM standard "gas hose" as you call it. (yes many automakers are themselves guilty of what you call 'jury rigging').

and they get the garden-variety hose designed for the vacuum-side applications

Huh? Vacuum hose? Nobody said anthing about using vacuum hose or evap hoses for fuel - We're talking about rubber fuel hose that manufactures (not GM) have used for decades to the supply side of carbs (and later EFI).

I think you are confused. Yes there are vacuum hoses and yes there are hoses used for things like evap/emissions - what most people as well as manufacturers use for delivering fuel to carbs (yes after the pump) is standard rubber fuel hose. Not talking about EFI hose either - that's ridiculous overkill for a carb and no manufacturer used it for fuel hose on a carb'd vehicle AFAIK.

(which is what comes in the cheapo filter kits as well).

Do you know this for a fact or are you presuming? Some of those hoses are cut pretty short so as to not include SAE stampings. The packaging clearly states these chrome googahs are not intended for fuel injection but intended for splicing into the supply side of carburetors and that would imply they are including not vacuum hose but fuel hose.

For cars w/ (gasp!) w/ factory original (jury rigged?) rubber hoses to the carb - it's simply a matter of cutting a rubber line in half, maybe shortenng it, and sticking the filter in line.

For cars w/ metal lines like C3s I don't know what the install method is (I personally wouldn't do it). If the method is to 'saw off' the metal line and splice the rubber joints in for the filter - yes I agree that would be questionable. But again you are in error by citing the problem as being the rubber hoses. The fault is that 'smooth' metal lines are not ideal for rubber seals - normally the metal line should have a beveled edge and extruded ring like a nipple at the end or about an inch from the end for the rubber to conform around. It might work fine - but no OEM attached a rubber hose to a metal line this way.

Using cheap hose designed for vacuum on a pressure-side application is "jury-rigging".

Again, nobody ever said anything about "vacuum" hose - I've cleary stated rubber fuel hose - that only comes in 2 varieties, A) standard (low pressure for carb) and B) high pressure (EFI) and meets specific SAE requirements in both cases. Millions (with an 'M') of non-GM carbureted automobiles have been produced and successfully delivered Billions of non-fire laden recall-free miles using common 'standard' low pressure fuel hoses on the supply side to the carb IDENTICAL to what can also be purchased cheaply by the foot at the corner autoparts store that you dismiss as 'cheap' 'garden variety' and labeled 'jury rigging'. Using high pressure (EFI) rubber hose to the carb would be overkill and never done by the manufacturers originally.

Now if some idiot wants to slap on vacuum hose or evap hose to deliver fuel from the pump to the carb - fine I agree that's jury rigging - but to categorically label rubber fuel hose plumbing to carbs as 'jury rigging' is close minded hogwash.

I know just a little about fuel system design; see my profile.

Interesting background but I suggest you consider further the application of rubber fuel hoses because here you pontificate that rubber hoses are 'jury rigging' simply because the General didn't do it 30 years ago. You don't provide a technical fact based rationale to refute rubber fuel hoses for fuel delivery (and what about C3 fuel returns). I would be interested in seeing that because it would fly in the face of OE accepted rubber hose fuel delivery to carbs used for decades by manufacturers around the world. THey did NOT use high pressure EFI hoses, vacuum hoses etc. - they simply used 'standard' rubber fuel hose still commonly available down at the corner by the foot. Further, with the modification of increasing burst pressure - rubber hoses CONTINUE to be an acceptable method today with EFI.

 

[JohnZ]

If you'll stop pontificating long enough to re-read my post, you'll see that I wasn't talking about "vacuum hoses" - I was talking about "gas hoses" that are designed for application on the "vacuum side" of the fuel pump (common parts store "gas hose"). NO OEM puts that kind of hose on the pressure side of the pump any more; hoses in that application are specifically designed for higher pressure, and are frequently multi-layered and have a protective outer cover.

I don't know who you're trying to impress with your uninformed ramblings - unless you've designed and released OEM Chevrolet fuel systems (as I have), you simply don't know what you're talking about.

 

[pgtr]

If you'll stop pontificating long enough to re-read my post, you'll see that I wasn't talking about "vacuum hoses" - I was talking about "gas hoses" that are designed for application on the "vacuum side" of the fuel pump (common parts store "gas hose").

Well, yeah, I know what you wrote - I was just trying to give you a face saving 'out'.

NO OEM puts that kind of hose on the pressure side of the pump any more;

Well uh like duh - nobody uses carbs anymore in new cars either dude - so yeah like that's a real revelation.

Anyway automakers DID 30 or more years ago and continued to do so up thru the advent of EFI in the mid 80s and today you can go to a dealer and buy a new OEM replacement that is the SAME low pressure fuel hose the car was originally equipped with or is availalbe at the parts store by the foot.

hoses in that application are specifically designed for higher pressure, and are frequently multi-layered and have a protective outer cover.

High pressure fuel hoses as defined by modern EFI did not exist on any scale in the 70s or early 80s when standard low pressure fuel hoses used by manufactures on (then) new cars was commonly implemented for fuel delivery by manufacturers and is still available in their parts systems or at the local parts stores by the foot relativley cheaply. Have you every actually looked at a standard low pressure (carb) rubber fuel hose from a parts store or popped the hood on something other than a GM w/ a carb?

I don't know who you're trying to impress with your uninformed ramblings - unless you've designed and released OEM Chevrolet fuel systems (as I have),

Well let's just say not folks that are easily impressed by resume thumping vs verifiable facts to support the subject at hand.

you simply don't know what you're talking about.

All I am talking about is pointing to a SIMPLE VERIFIABLE OBSERVABLE FACT that MILLIONS of cars were produced by automakers from Japan, England, Europe and North America that utilized standard/low-pressure rubber fuel hoses to deliver fuel to the carb well before the advent of EFI and existance of high pressure fuel hoses. All anyone has to do is pop the hood on one of any number of cars of the era to see plain ol' low pressure rubber fuel hose right there leading up to the carb supply side just the way the factory installed it w/ a fuel pump pumping gas thru it. Or simply review how many hot rodders with aft located electric fuel pump(s) have done it safely and absolutely leak free for years.

To sit here and label any car that has factory installed or owner installed standard low pressure rubber fuel hoses a 'jury rigged' car w/out a basic understanding of how non-GM makers did or do things is about as insular, righteous and arrogant as I've experienced. This intolerance to factory originality deviations is precisely the kind of stuff that gives your corvette society a bad rap. And I kinda suspect if this arrogant 'inside-the-box' 'my-way-or-the-highway' no matter what the truth attitude is prevalent among your peers - reveals how a company like GM arguably got it's market share waxed by imports decades ago and has had to since recover from those times. At the least it suggests an unhealthy mix of complacency and arrogance as to engineering.

I don't care what your resume says or what kind of chairman you are for some Corvette society that is intolerant to any variation to factory original configuration - you've amply illustrated you are completley ignorant of how millions of carb'd cars produced by other manufacturers have done things with respect to fuel delivery thru the 1970s and early 1980s prior to EFI with a stellar safety record regarding fires. Nor in your prior position did you seem knowledgeable of specific SAE white papers and standards on the subject of rubber fuel hoses.

Again you've failed to elaborate on the rubber return hoses on C3s. And again you've failed to provide any specifics or facts about WHY you insist you are right and everyone else from the millions of cars produced using low pressure rubber fuel hoses or DIYer hobbyists/hotrodders or Dayco or Gates or the corner parts store are all wrong other than to thump your resume as if that is enough. If nothing else our present litigious society would likely prevent the parts store from selling the wrong hoses for carb fuel delivery. The bottom line is you are wrong to label the usage of low pressure rubber fuel hose as mere 'jury rigging' with unsubstantiated and vague accusations simply because GM's Corvette didn't implement it between 68-82 (while other competing automakers did).

Please feel free to provide some relevant FACTS about rubber fuel hoses beyond mere posturing based on a resume. It's far more constructive to members of this forum and readers of this thread than bragging about one's background.

 

[pgtr]

For those of you who want to hear about fuel delivery instead of an exalted resume, are not 'constrained' by a car club that demands nothing but factory originality or whose former employment experience doesn't induce ostrich like behavior as to how competing manufacturers succesfully did things on a mass scale... here are the FACTS (that you yourself can verify) about rubber fuel hoses in simple plain speak hopefully of interest to C3ers with a general automotive interest:

First let's differentiate kinds of rubber hoses that 'might' be 'pressed' into service or confused with the appropriate hose or tube:

1) Vacuum hose - not acceptable for fuel - nuff said.

2) Evap/vapor hose - easily confused w/ fuel hose however for simplicity sake this is often not explicity used by manufactuers to ensure it doesn't get confused or to simply supply chain - same reason parts stores often don't offer it - Some manufactures and most all aftermarketers just substitude #3 below for simplicity/safety.

3) Standard Rubber Fuel Hose. (the so-called 'jury rig' hose or 'gas hose') This was and continues to be intended for the 'standard' pressures one sees w/ an electric or mechanical fuel pump yes even a high perf one! - it's 2 layers nitrile and PVC w/ a fabric reinforcement sandwhiched in between. It will carry an SAE stamping on it. It's designed for long life and resistance to internal and external breakdown. It was originally 'the' standard for (pressurized) fuel delivery usage and pressures WELL beyond even the highest fuel pump intended for carbs. However that was before EFI. When EFI came along this then became what is now known as 'low pressure' fuel hose. (High pressure of course being EFI typically operating at 10X the psi of a carb). This type of low pressure rubber fuel hose is COMMONLY and probably universally available at the corner parts store as 'fuel hose'. It's almost always available in a recognizable OEM brand like Dayco, Goodyear or Gates to name a few. It's NOT intended for EFI - just for supplying to carbs. It's commonly used in the aftermarket/repair industry for other things like evap or emissions hoses too since it's plentiful, practically universally availalbe and cheap by the foot.

4) High Pressure (EFI) Fuel Hose. This obviously came along when EFI did since about the early to mid 1980s. This has a VERY HIGH burst rating and is big time over kill for a carburetor. It has something like 800 psi burst strenght! Of course it should work great for a carb too. This type of hose is commonly available at teh corner parts store as well as 'fuel injection' or 'high pressure' 'fuel hose'.


Now using option #3 above to deliver fuel to the carb is NOT as one individual insists - 'Jury Rigging'.

However there are tradeoffs between an appropriate low pressure rubber fuel hose and a metal line.

The rubber hose is less likely to leak at fittings (note the factory uses extruded 'nippled' metal tubing/fittings for rubber hose attachment), it's less susceptible to letting fuel heat from general engine compartment heat, it is far better for vibration and mandatory for movement (between engine and frame) and it is less expensive and easier/simpler to install. However it has limitations as to routing and care must be taken as to potential rubbing or heated metal surfaces or crimping. Example: Look at a typical 1970s or 80s carburated car w/ an electric fuel pump mounted in the rear - typically this type of hose is used by the automaker to 'arch' a connection between teh firewall fuel line and the carb fuel inlet. An identical hose is often used on the return side. Age 'can' cause cracking but only over a very extended period of time.

The metal tube hose can be routed more specifically and is ideal for a mechanical fuel pump since this forces the hose to be routed very close to the engine over an extended distance. With proper routing abrasion is not an issue. The added complexity of threaded fittings can sometimes make these more prone to leakage or misthreading at the fittings and joints. They are completely unacceptable in a situation with vibration or movement. Corrosion can cause leaking depending on metal used but only in more extreme circumstances.

As you can see BOTH can and do function fine and have their places. For a stock C3 w/ mechanical pump the stock type metal line IS appropriate. But for those who for whatever reasons such as a modified C3 w/ electric fuel pump(s) - either the standard (low pressure) rubber fuel hose or high pressure EFI (overkill for carbs) hose work fine delivering fuel to carb (yes that statement will ilicit another response about someones resume but the fact remains). Using this does NOT automatically make one a 'jury rigger' because someone from a club devoted to originality for the sake of originality says so. You are in good company w/ countless competent hot rodders and 10s of automakers employing armies of automotive engineers that have specifically selected and used standard low pressure rubber fuel hoses for fuel delivery to carbs. Billions of safe fire, fire free, recall free miles have been acrued.

Just because we own C3s doesn't mean we can't learn and apply proven techniques used by other car makers or grass roots hot rodders to our projects or consider that fact that there is more than one legitimate way to to skin the ol' cat (gotta love that superbowl commercial!).

 

[Eric]

This thread has somehow managed to take a very negative personal turn. Let's stop the finger pointing and just move on. I don't like the thought of having to close a tech thread.

By the way, this thread is two years old and the original poster hasn't even been here since 07-27-03.

 

[pgtr]

Thanks Eric, my appologies to you, JohnZ and everyone else - (post edited - inappropriate content removed)

I see now it's an old thread - I guess some of us were following up to a recent response that resurrected the thread, hopefully there's good technical info here for many C3ers.

Back to the topic at hand - here's a typical 'buck-a-foot' 'gas' hose from my supplies in the GA bought from some chain parts store or other. This is NOT EFI hi-pressure stuff and is equivalent to the factory original fuel hoses used to deliver fuel to carbs on a number of cars I've owned from the 70s and 80s.

For those of you with say electric fuel pump(s) retrofitted aft of your engine - this would be typical or ideal hose to bridge between the metal fuel lines on the engine and frame.

Funny side note (Do not attempt this at home!) - Out of sheer laziness/cheapness/convenience I remembered I actually used this very hose on a temporary fuel pressure guage I plumbed into a newer car w/ EFI to test fuel pressures at sustained WOT. At ~55 PSI without even bothering to put clamps on the hose it didnt' leak a single drop! However I had to keep cranking and cranking on the threads for the guage ti get it to stop leaking! Ultimately I left it in for several months of driving before I needed the guage for something else and removed it. Just an FYI but definately do use EFI rated hose for EFI systems!

 

[Eric]

This thread has been closed. It headed in a bad direction and I see no sign of it changing direction.

Eric Whitaker
CAC Community Administrator