P Clips, Fuel Lines & Brake Hoses

[GreatOldOne]

Hi guys,

Over the weekend I managed to get the front discs on and all of the calipers bolted on. In doing so, I've started to install some of the brake lines.

The rear ones have gone on OK, but more about that in a minute. The line that goes from the master cylinder through the transmission tunnel to the back will require clipping up - with P Clips. I ordered some with the chassis, but the internal diameter of them is too small (even taking the rubber off them) from the braided hoses, so I've got to get some others.

I've seen a few on eBay, but for the most part they're plastic. Are these OK? or should I get the metal type? I'd be getting several sizes, as I'd need some for the fuel lines as well... Which leads me to my next question.

I'm going to get some fuel hose and install the run from the rear of the car to the engine bay now, as it'll be easier to whislt the engine, box & prop aren't in the way. I assume that I'll need to run two pipes (supply & return), but what diameter pipe do I need? Will it be the same size for both runs?

Finally, back to those rear brake lines. I've got them all clipped in nicely, and run to the back bulkhead. I'm not entirely sure that they're long enough though (maybe due to the way I've run them, but they're following the path of the old lines...)

What I think I may have to do is run a piece of hard pipe from one side of the car to the other with connectors, like so:

                |
                |
                #
                #
----##========#####----

--  flexi
== coper / hard pipe
## connectors

The copper pipe would run under the prop shaft to the left hand side, and the have the correct connector on the end for the flexi to screw in to. The other end would have the correct connector to go into the three way union that I have.

I need to have a measure to be sure - but If I do need something like this to make the distance up, a) do you think it'd be OK, and b) Would someone be willing to make up the pipe for me? I know a lot of you have done you're own pipes so have things like brake flaring tools and fittings, and possibly a couple of feet of pipe spare. Obviously I'd reimburse anyone who can do this for me.

I'll try and take some pictures of the problem area later on so you can see what I'm going on about.

Cheers,

Jason

[MartinClan]

Originally Posted by GreatOldOne

I've seen a few on eBay, but for the most part they're plastic. Are these OK? or should I get the metal type?
Jason

I used stainless p-clips, you can get them from Namrick amongst other places.

Originally Posted by GreatOldOne

I'm going to get some fuel hose and install the run from the rear of the car to the engine bay now, as it'll be easier to whislt the engine, box & prop aren't in the way. I assume that I'll need to run two pipes (supply & return), but what diameter pipe do I need? Will it be the same size for both runs?

You will need 2 fuel lines. I used 8mm supply and 6mm return - both in copper. I thought that 6mm for the supply might not be big enough.

I made my own brake lines up - I have plenty of fittings and pipe left. The only thing I would say is the tool I used produces imperial flares. As far as I can see they look exactly the same as metric ones - but I haven't put any fluid in my system yet lol

BR

Robin

[GreatOldOne]

Thanks for the advice Robin.

I had a poke around when I got in from work, and by re-routing the brake lines (I had them going through the eyes in the arms and the brake shields that used to be the transition from the hard pipes to the flexi ones) I've got enough slack to join the pipes with the t-connector and fix it to the rear bulkhead.

Should have thought of fiddling with the pipes earlier... I'm as dumb as toast sometimes...

[jeremy]

Before you decide on you fuel line dimensions, have a look at your planned fuel set up.Check the width of pipes on your marlin tank;mine are 10mm.Next decide if you are using a facet low pressure pump at the back;if so this is supplied with 8mm inlet and outlet fittings;next look at the front setup; if you are using a marlin swirlpot, this has 10mm fittings; followed by a high pressure filter and pump which have 8mm fittings........you can see were i am going with this..try and draw you system on paper and minimise the amount of reducers and clips involved..reduce the risk of leaks.\europa have a great range of fittings for their pumps and car builder solutions have a great range of in-line fuel hose reducers. good luck!

[MartinClan]

Originally Posted by jeremy

Before you decide on you fuel line dimensions, have a look at your planned fuel set up.Check the width of pipes on your marlin tank;mine are 10mm.Next decide if you are using a facet low pressure pump at the back;if so this is supplied with 8mm inlet and outlet fittings;next look at the front setup; if you are using a marlin swirlpot, this has 10mm fittings; followed by a high pressure filter and pump which have 8mm fittings........you can see were i am going with this..try and draw you system on paper and minimise the amount of reducers and clips involved..reduce the risk of leaks.\europa have a great range of fittings for their pumps and car builder solutions have a great range of in-line fuel hose reducers. good luck!

Excellent advice!

Robin

[peterux]

Just to add my two pennies to all the excellent advice above.
I used 8mm copper pipe for both feed and return, metal p clips, a Marlin swirl pot upside down on the inlet side (i didn't like the idea of putting the fuel system just above the exhaust manifold) and a whole host of pipe fittings and reducers.

This is an area of the build you can use your right brain and invent your own solution!!

Oh and don't forget to use the proper high pressure rubber fuel injection hose for the high pressure sections. halfords actaully stock quite a good selection of sizes for low and high pressure. A bit more expensive but no postage and packing costs.

[Patrick]

Yup, I'm using 8mm copper too. I had to flare the ends a bit which helped the flow.

It becomes a complete PITA to work on those lines once you've got the engine in! I plan on doing the whole lot with braided flexible pipe at some point reducing the number of connections, but not until the engine comes out for a rebuild.

[Patrick]

I worked out £60-£80 to do the whole lot with braided pipe - another reason I'm using copper to start with. I don't see any reason why the sva folks would have a problem as long as the pipes are of suitable specification

[Will5]

At risk of sounding foolish, what are the pressure ratings for low and high pressure pumps? Would the original BMW pump qualify for one or not if so which one?

I have just been to a motorsports day at Stonelieigh, I asked at several stands if they had low pressure pumps but got blank looks. I must have been asking the wrong question so I decided to give up. Once more confuessed

Can anyone help, thanks.

Will

[PJC]

Will,


I actually haven't fitted a low pressure pump, but a bosch version that's used on injection cars.

This way there's certainly enough input in the swirlpot. I went to the ... (how do you call it where all old used cars are?) and bought one for 5 euro. Cleaned it and fitted it on vibration dampers.

Only problem that can occur is when tight corners and low fuel level give some air in the pump. This must not happen too long otherwise they will be overheated, but friends in Dax Rush which use such pump say that you can hear when this happens through the noise (after the 3th round at a roundabout !)

Peter-Jan

[peterux]

Originally Posted by Will5

At risk of sounding foolish, what are the pressure ratings for low and high pressure pumps? Would the original BMW pump qualify for one or not if so which one?

I have just been to a motorsports day at Stonelieigh, I asked at several stands if they had low pressure pumps but got blank looks. I must have been asking the wrong question so I decided to give up. Once more confuessed

Can anyone help, thanks.

Will

Will,

the low pressure pump is typically used for carburreters and is arounf 4-6psi. It pumps the fuel from the tank up to the 'swirl' tank. From thre you use a high pressure pump designed for fuel injection systems. My donor had a high pressure pump but it was mounted inside the petrol tank so not suitable for the Marlin fuel tank. My advice is to just bite the bullet and buy the pumps direct from Marlin. They are not much more than buying separately and you know you'll get the right spec pumps.
cheers

Peter

[Will5]

Peter,

Thanks for the information, I will have to bite the bullet and put another order into Marlin.

Cheers

Will

[GreatOldOne]

Well, after much prevarication and endless questions, I got my major fuel lines in during the easter break:

Like most of you, I went for 8mm copper hard pipes to do the major runs down the length of the car.



The lines where they pass through the bulkhead at the rear of the chassis:



I then routed the pipes up toward the top left hand side of the rear of the car. My thinking behind this is that it'll be easy to route flexi's from this point to any where on the tank / lp pump, and keep them nice and neat and out of the way of anything moving.

The pipes are finished off with some brass barbs that I got from Woolies Trim. These are just soldered on:



I put some yellow caps on the pipes to keep dirt out of them until the rubber flexible pipes are on.

I'll be sorting out the clutch pipes and the holes that they pass through next - and once that's done the engine will go in. I'm hoping that I can get that done by the end of the month.

[peterux]

Nice progress, Jason.