Getting OGU roadworthy again

[UAB807F]

Can I take it that you're pleased ?

It's a great feeling when something you've worked on for so long comes together, so well done. You'll fly through the few snags you've picked up now the main job is over with, grab yourself one of those free tax discs and you'll be amazed how quickly you'll sort out the niggles once it's running on the road.

Brian

[billwill]

Tuesday:

I haven't done much since last Friday. I was going to set idle mixtures & balance the carbs yesterday,, but it was all wet & drizzly here, so I did the electrical stuff instead.

The un-lit headlights problem proved to be the main beam headlight relay. So I opened the can carefully, cleaned the contacts & adjusted (i.e. bent) the metal work inside until it was contacting nicely. Then I put it back in its can with a bit of silicone sealant. Now working correctly. I did notice that if I connected the wire from the bulb, direct to the blue/white supply, i.e. missing out the relay the light bulb still went on/off according to the steering column switch. At first thought that doesn't seem right to me, the purpose of having a relay is so that the heavy current for the bulb does not run through the control switch contacts. Needs investigating later.

A dicky right-rear trafficator proved to be a broken contact tip in the bulb holder. These are rare now, so a bit of metal bending of the remaining part of the connector, sorted that for the time being. Its a rather crappy design there & could be improved. A loose & flickering rear sidelight, cured by putting a large rubber washer around the prongs that hold it into the caseing (from inside the boot) so it is now held firmly with no flicker.

I'm not sure if the tank sender circuit is working correctly, the dial shows empty, but the dipstick shows the tank a third full, Could read more when I put more fuel in.

Incidentally she starts OK on the OLD petrol that has been in the tank for about 2-years. I was wondering if I needed to buy a new jerry can & drain that lot into it, and get fresh petrol, then later use it up a bit at a time. Much of the fuel that had been in the car when she stopped being usable had already been transferred to another jerry can. I reckon you won't get evaporation of the lighter elements when it's sealed in a jerry can; after all they were invented for carrying fuel around in hot deserts.

I'm still getting a baffling smell of petrol in the car though. It doesn't/didn't seem to occur when actually driving the car, but after stopping & locking up (it's a coupe) there was/is a strong smell of petrol when I get in next time. I've checked & checked but can't find any trace of a leak. This has only occurred since an electric pump & new fuel line were put in for me, some years ago. The new line is a stainless steel braided flexible pipe that runs all the way from the pump in the boot, down behind the panel under the right hand door up by the accelerator pedal and into the engine compartment from the side near the air box. It then goes to a fuel pressure regulator.

After stopping there is no significant fuel smell near the carbs & the pressure regulator and no significant fuel smell in the boot. There is a bit of a fuel smell in the cabin, which seems stronger the lower I try. Taking the seat out and pulling the side panel away, there 'seems' to be fuel smell there, but there is absolutely no indication of any fuel dampness and that is one-piece of high quality tube there. The stronger smell there may just be due to the fuel vapour being heavier than air and therefore tending to smell stronger near the floor of the cabin.

All rather baffling.. the only theory that fits the facts is that that section of the fuel pipe is porous, but that seems highly unlikely. Simply replacing it as a test, with the same Goodridge piping stuff, from Burtons would cost about ?90, so I'm reluctant to do that without further proof.

[prezoom]

When I rebuilt my race car a number of years ago, I attempted to reuse the main fuel line from the fuel cell/fuel pump to the regulator in the engine compartment. When I first switched on the fuel pump, the AN fuel line, stainless over rubber, leaked like an old soaker hose, over almost its entire length. Not sure if the degradation was due to the type of race fuel I had been using, the rubber drying out over the two year rebuild, or just age. I replaced it with a teflon lined hose, not as flexible, but it made me feel better.

Rob Walker
26-4889

[batfish]

Bill

I recall reading in the past that some types of fuel tubing are not suitable for internal installation as you will get the smell of fuel. It maybe worth contacting some one like Exact Hoses and Fittings in Totnes to confirm which hose is suitable.

regards

Andy

[billwill]

Aha, excellent Info Rob and Andy..

I was going mad thinking that it can't be this high quality pipe leaking, but if other people have seen this symptom it can be true, after all.

It could be that Vegantune of Finchley, re-used a pipe that had been on one of their race cars when they did this modification, not realizing that it could be damaged in that way.

Well that gives me courage to do what I was contemplating, i.e get two new short flexible pipes, one for the pump end and one for the pressure regulator end and then buy a length of brake pipe to use for the in-cabin section.

I think copper brake pipe was more-or-less what Lotus uses for the fuel pipe inside the box chassis, is it not? Does anyone know if that is OK and what diameter I should use? Standard brake-line diameter seems to be 3/16. Is that large enough; I don't know offhand what the inside diameter is?

[c42]

Hi Bill
You really need to use 5/16th - 8mm diameter pipe, I have used Copper but Cunifer is fine also; you can get compression fittings for the ends of the pipe and bespoke lengths of flexible fuel pipe from the likes of Earl's Performance Products etc.
Regards
John

[elj221c]

I think copper brake pipe was more-or-less what Lotus uses for the fuel pipe inside the box chassis, is it not?

No. It was a hard black plastic. I am still contemplating what I will use on my next rebuild. I look forward to answers to your question for a better alternative. I am sure, though, that it has been discussed before and at some length.......

[billwill]

I've taken the plunge and ordered 3 metres of this 5/16 cupro nickel pipe
http://www.holden.co.uk/displayproduct. ... de=015.345

And some of these for flexible ends.
http://www.holden.co.uk/displayProduct. ... de=015.054

I'm assuming it will be OK, to push these rubber fittings onto the hard pipe and do up the clamp; after all the pick-up from the fuel tank is no different than that really.

~~~~~~~~~~~~~~

On a side matter, does the Cunifer pipe look like brass rather than like copper when you polish a bit of it with emery paper. Or is the bit of scrap pipe I found in my metals box a piece of brass pipe?

I assume cupro nickel is the same as cunifer or Kunifer pipe.

[c42]

Hi Bill

Cupro Nickel/Cunifer is certainly more yellow than copper colour but I would not describe it as brass like, you will have to have a polish when the package arrives!

I must admit that I usually make a small rounded flare on the end of the tube - that is just me in belt and braces mood but if you are only sucking fuel through the tube rather than pushing it through under pressure you should not have a problem.

Regards
John

[billwill]

This section will be pushing it from the pump, but at present I don't have a flaring tool.

[prezoom]

My Elan has plain old rubber fuel line from the tank/electric pump to the fuel pressure regulator. Then one of RD's fuel line manifold's to the carbs. I am sure the rubber line will start leaking sooner or later. When I restored my Sabra GT, it had a plastic fuel line from the tank to the mechanical pump, which had become quite stiff after 45 years.

I found some 5/16" plastic line at my favorite hardware store, which used compression fittings. The female compression/male straight thread fitting used the same thread at the AC fuel pump end. The tank end took a little modification, as the fuel pickup tube had an internal BSP, rather than 1/8" pipe, close but no cigar. I wound up soft soldering the male pipe/female compression fitting, as an additional precaution against leaking. The plastic tubing seems to be holding up well. It is routed on the opposite side of the chassis, away from the exhaust. I believe you could purchase the tubing from McMaster Carr or MSC, on this side of the pond. It comes in all sorts of colors.

Rob Walker
26-4889

[c42]

Hi Bill

You could get a couple of 8mm copper olives and solder them onto the pipe one at each end or to flare the pipe I can nip the pipe in my lathe chuck and tap a small taper into the end of the pipe - it does not need to be much of a flare.

All of that said I am sure that there are people here who have just pushed the flexible pipe onto the straight pipe, tightened it up with a proper fuel pipe clamp(not a jubilee clip)and never had a problem!

Regards
John

[billwill]

I think a small flare might be useful here, just to stop the rubber pipe slipping off the copper/nickel pipe. So I might try with a simple metal cone point first and if that doesn't work, get a proper flare tool.

Actually having ordered the pipe I foresee that it is going to be a difficult job, feeding & bending the pipe in the path described above, behind the panel inside the cabin under the right-hand door .

[UAB807F]

I replaced the fuel line on my car with 8mm Aluminium tubing and made a small flare on either end. Because my brake pipe tool only does conventional brake pipes I bought one of those cheap Ebay ones which does from 5 to 16mm tubing. It's not the sort of tool you'd be proud of having, but it does do the job for under a tenner.

Replacing the tube was straightforward but I cheated slightly as it's not metal from tank to carburetors. I fed the Al tube in from the engine bay & used the cut-outs in the chassis to align it with the holes/grommets along the way, but from the end of the tunnel I used fuel injection quality rubber tubing to go over the diff & into the rear boot. (I think if I were doing it again I'd just use fuel injection hose for the lot. )

[billwill]

A few photos of the experimental vent that I have made for my crankcase oil breather, using standard bits of 15mm plumbing pipe and a piece of electrical flexible ducting, as mentioned above.

Experimental vent for the oil breather

The blanked end is held to the airbox by a piece of the same flexible ducting and some hose clips. Not visible in these shots as the carbs and air box are not mounted.

The catcher bottle is an alloy cycling/camping water bottle from the 99p shop. I will probably need to use a Turkey Baster cooking implement to suck out any oil collected there as it is not possible to get easy access once the carbs are mounted.

Experimental vent for the oil breather

Experimental vent for the oil breather goes into alloy drinks bottle