ned
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| posted on 4/4/05 at 10:17 AM |
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Hose & fittings explanation required...
As my chassis is now read for powdercoating I'm turning my attention to the plumbing of fuel and brake lines as these will be some of the first
jobs when I get the chassis back.
Having had a quick look at thinkauto, merlin motorsport and other usual suspects I am completely confused as to what size and type of fittings I
require for my fuel and brake systems.
All the hose sizes are easy enough but seem to be quoted everywhere in both metric and imperial, but the hose fittings are listed by metric, imperial,
thread sizes, id/od, jic, npt and I have no idea what the main differences are. Can anyone help me out with an explanation?
I have some braided brake lines form a westfield and I plan to use sierra rear calieprs and eventually hispec 4 pots at the front.
My injection fuel system will include a swirl pot, so I need a few fittings to include this, a pre injection pump filter, not to mention the low
pressure pre swirlpot line.
Can push fit/jubilee/hose finishers be used on injection pressue lines?
Any help/explanations/pointers appreciated.
Ned.
beware, I've got yellow skin
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Hellfire
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| posted on 4/4/05 at 10:51 AM |
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Fuel lines - we are using 10mm OD copper pipe - available from Wickes, B&Q et al.
Brake lines - we're using 5/16" IIRC copper pipe, though I think the metric equivalents are interchangeable. Get a connection and take it
to your supplier to ensure it's compatability. Use someone else like 'STATUS' to resolve pipe sizes before commiting to purchase.
Our's is fuel injection running at 40PSI real line pressure and all of the clips were the spring clips (the single wire jobbies) as fitted to
the bike. I see no saftey issues there as we are not altering any diameters etc. I think we may alter this to jub's but either way it's of
little consequence.
HTH
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NS Dev
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| posted on 4/4/05 at 11:55 AM |
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Hellfire - You'll be using 3/16" brake line, not 5/16"! That's a bit big!!!
Normal car fuel injection lines are around 5/16". When rebuilding Opel Mantas etc with fuel injection I use 5/16" cupro-nickel line for
the fuel feed and returns, but have recently gone over to using plain cheap copper 8mm microbore from screwfix.
Ned, fittings wise, 99% of all the bake line threads you will come across now are m10 x 1. It makes sense to base your lines on these threads, and
then adapt to the right ones at any ends which are not this thread, if you see what i mean. The main ones which are not are the girling (or wilwood)
master cylinders, which are 3/8 UNF, and some brake calipers, typically the USA made ones, which again will be 3/8 UNF.
Other than that, yes, push on and jubilee clip is fine for fuel injection lines, as long as you make a proper job of it (it's what i always use)
I get the copper 8mm microbore and put a single flare (convex one) on each end so the hose clip attaching the rubber line to it has something to get a
purchase on. If you use 5/16" rubber injection hose it will push straight over 8mm microbore with a perfect fit.
The fittings for oil lines etc are quite confusing as in the UK, we use BSP (or NPT/NPTF, basically all the same threads, just different (or not
having any)sealing tapers on the threads.
The americans use a lot of "AN" (American Navy, I think!) fittings, and as most braided line originates from the US, the terminology
carries over. Basically fuel lines are "AN-6" which is 9mm ish, oil lines are AN-8 or AN-10 (and so is the feed ine to Bosch injection
pumps) The "-" notation is the number of 16ths of an inch bore!
The USA then usually couple these up with JIC fittings, which are Convex on the male parts, again the reverse of BSP which is usually convex o the
female part.
Basically, if you are using aeroquip lines (or equiv) then pipe all fittings in JIC until you get to the end that needs to connect to something (like
an oil cooler, which will be BSP if it's Mocal!) and then use a JIC to BSP adaptor at the end.
Hope this all helps
Nat.
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v8kid
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| posted on 4/4/05 at 11:59 AM |
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Ned, Like you I'm flummoxed by all the different standards. I have twigged however that -(dash) 4 is four sixteenths if an inch and other sizes
pro rata. I'm using -3 for brakes which only have to cope with pressure and larger -4 for the clutch which has a larger flow requirement. As far
as I can gather this seems to be pretty well standard. The metric and imperial end fittings both fit the pipe as I discovered with imperial master
cylinders and metric slave cylinders.
As to the different threads I obtained a selection and swapped untill I got one to fit. Watch out for mixed single and double flares they appear to
fit but leak.
Cheers
David
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NS Dev
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| posted on 4/4/05 at 12:06 PM |
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Just to clarify, as my last post went on a bit!!
For BRAKES -
Pipe everything up apart from the flexy lines in 3/16" cupro-nickel pipe. Use Female nuts on the ends of this pipe to attach to male bulkhead
fittings on the ends of your aeroquip type flexy lines (with locknuts to secure the bulhead fittings to chassis tabs)
Sierra calipers have M10 x 1 theads, as do M16 calipers. I guess the HiSpec's are also M10 x 1, but american calipers will be 3/8 UNF.
Your master cyls (assuming you are using twin girlings on a balance bar) are 3/8 unf so just get the appropriate end fittings for your copper line,
the M10 x 1 and 3/8 UNF both fit the 3/16" line, and all available from your local brakes place (if you struggle, try your local brake and
clutch fast-fit place and a bit of cash to one of the mechanics in there!
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v8kid
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| posted on 4/4/05 at 12:12 PM |
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Nat,
Our emails crossed can you expand on the sealing tapers? Are both the male and female tapered and should ptfe tape be used or is the metal to metal
joint ok?
I found when forming brake flares that the process formed tiny pieces of swarf which I was a bit neurotic about cleaning out - even more I suppose
with injectors - have you experienced any problems?
Cheers
David
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NS Dev
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| posted on 4/4/05 at 12:23 PM |
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Tapers are only applicable to NPT and NPTF plus BSP(F) in common auotmotive applications.
NPT is not completely self sealing, needs ptfe tape.
NPTF IS a self sealing taper version of NPT, and most common on oil pressure senders etc.
BSP is available in parallel and taper threads. In hydraulic (higher pressure) applications, it is usually parallel, and seals onto a conical seat or
with a sealing washer.
It is also used for conduit threads and plumbing etc, in taper form (BSPF) but this is unusual on cars.
All of the (tapered versions) above are basically compatible, as long as sealant/ptfe tape is used!
Again, none are used for brakes etc, and to be honest, most USA sourced oil line fittings (most of them!) are JIC (i.e. the biggest range is available
in JIC) and you just use an adaptor at the end of each line, but any bulkhead fittings etc mid-line are best left as JIC, as they are common and
cheap!
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ned
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| posted on 4/4/05 at 12:37 PM |
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NS Dev,
that seems very comprehensive, thanks!
one last thing, i was pondering the idea of a dry break connector for the clutch to save having to disconnect and bleed the whole system if i ever
wanted/needed to take the engine/gearbox out, is this a bit ott and if it is a goer, any specific type of dry break connector to opt for?
cheers,
Ned.
beware, I've got yellow skin
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NS Dev
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| posted on 4/4/05 at 12:40 PM |
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A bit ott perhaps, but only because the ones that don't let any air in are expensive. Certainly very convenient!!
Think Automotive do a good range, look for the ones with low cc leakage and non-air inclusion, but they are £75-£100!!
here's a good link for explaining pipe fitting tapers etc.
hydraulic fittings explained!
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chrisf
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| posted on 4/4/05 at 01:19 PM |
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Hey Ned:
Just to expand upon the Army / Navy (AN) fittings...The AN flares are different from the NPT flares. I cannot remember the exact number right now, but
the idea was to design a flare with more surface area on the flare. This means that if you use the AN fittings for the fancy braided line, you need an
AN flare tool.
I'm currently dealing with this as my fuel cell came with an AN fitting. I'm going to have to use AN to NPT adaptors.
--HTH, Chris
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NS Dev
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| posted on 4/4/05 at 01:58 PM |
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The "AN" flares are JIC, and adaptors are available off the shelf from Think Automotive.
(as such, NPT fittings don't have a "flare" they seal with washers on the faces or self sealing threads (NPTF)
The actual flare is pretty irrelevant, as you wont be flaring solid line to fit them.
All you need to remember is that most of the Yank stuff is JIC, and as I said, keep all the line fittings as JIC, then convert to BSP, NPT etc etc
where you need to attach to something that doesn't have/cannot be fitted with JIC fittings!
[Edited on 4/4/05 by NS Dev]
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cidersurfer
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| posted on 4/4/05 at 02:32 PM |
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More threads pages...
Threads
More Threads
shimming solid lifters is a job for a friend...
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