Fuel Tank Fitting

[Tim Jobson]

Had a win this week as I managed to obtain a good second hand tank from a sedan which I will clean up and cut its filler neck off and put a fuel hose on it to join the original filler neck.

The original tank had some sort of rubbery gasket that separated the tank from the body of the car, what have other members used to replace this gasket with, any suggestions?

cheers Tim

[1750GTV]

Tim,
From one of the other bulletin boards and posted by a fellow Australian -

"The original seal is made of rubber, hence the deterioration.

I replaced mine with closed-cell Neoprene strip. You can buy it from hardware stores and rubber suppliers. You buy it by length, so you'll need to run a tape measure around your tank first.

The advantage of closed-cell Neoprene is that it is water proof and air tight, and if it's a good quality one it should be acid and oil (fuel) proof too.

The Neoprene strip usually comes with adhesive on one side. The adhesive is a little weak and mine kept letting go when I put the tank in, so I ended up brushing on some contact adhesive first to hold the seal firmly in place."

Post some photos sometime.
I, and many others no doubt, would like to see the car and the restoration.
Chris

[Tim Jobson]

Chris you can see from the pictures how bad my tank was.

Not much luck this week.   Installed a new filter, fuel pump and hoses, rigged a temporary tank in the boot and tried all weekend to get her to start.   Even with a squirt of start you barstard it would only fir for a couple of seconds.     Even after pumping the accelerator pedal the plugs remain dry.    I took the main jets and tubes out and blew them the carby bowl looked clean yet there still is a problem, can any one help?

I have checked that the plugs are sparking but cannot check the timing because I cannot see any marks on the crankshaft flywheel, what are they ment to look like?

A disappointing weekend all up

Cheers Tim

[1750GTV]

That is a fairly ugly tank.

The timing marks on my car consist of a single vertical score, |, across the crankshaft pulley for the fixed advance and a double mark, ||, for the maximum advance. Though the manual says that there is also an "F" (or "P" !) and an "M" scored on the pulley, I've never found these on mine.

The pulley can be fairly grubby with all of the oil, dirt and general sh*t that accumulates over time so it pays to clean it well. This is easiest done by spraying it with a reasonable jet of degreaser, giving a scrub with a toothbrush and hosing it off carefully. Rotate the engine to get to all parts of the pulley and clean it as you go.

Once clean and dry, find the timing marks and use some white chalk to mark them rubbing off the excess so that the scored marks are now white - makes them easier to see with a strobelight. Position the pulley by rotating the engine by hand so that the single score is opposite the marker fixed to the water pump. This now has cylinder #1 at TDC on the compression stroke. The distributor rotor should be pointing at the HT lead going to the #1 cylinder.

If you wish you can also remove the cam cover and make sure that the cam lobes for #1 are pointing outward. The fronts of the cams and the front cam journal bearing caps are also scored and these marks should also line up.

Pull the distributor out and check the points and the gap. Check that the plug leads follow the firing sequence (1 3 4 2). Replace the condensor if it looks suspect - probably replace it anyway.

It may also be worth getting a torch and mirror and having a look down the carby throats while you push on the throttle linkage. You should see the butterflies open and a squirt of fuel come from the accelerating pump jet.

If you're getting a decent spark at the right time in the cycle and you've got fuel and air in an approximately stoichiometric mixture, it should start and run even if it is rough as bags.

It's difficult trying to help from the other side of the nation but give this a go and let us know how you get on.

I don't know how much literature you have, so I've attached a couple of photos from the users manual.
Don't give up, it's just a mechanical device with problems that can be solved - it will start eventually and then the real fun will begin.

Regards,
Chris

[Colin Byrne]

That's good advice from Chris,  to make it easier to find the marks on the crank pully you can also pull out no. 1 plug and carefully using a  screw driver find TDC by slowly rotating the engine, and like Chris said, if you do this with the cam cover off by checking that both cam lobes of no 1 are facing out you can be sure you are on the compression stroke.

Once clean and dry, find the timing marks and use some white chalk

White out pen works well also

Tim when you took the top off the carbies was there any fuel in the float bowls ?

[Tim Jobson]

Thanks guys i will try that, however I think I will be up for a complete rekit and clean job of the carby in the near future.   

Can anyone post info on how best to clean and rekit these carbys.

Thanks Tim

[graemericardo]

tim
go back to basics check you have spark,check you have fuel
is it 2ltr if all else fails pull rocker cover off and align cam marks on the front of cams you shouldthen have top dead centre there shouold be a link on the timing chain atbthe top near the r/h cam
regards graeme ricardo

[1750GTV]

Thanks guys i will try that, however I think I will be up for a complete rekit and clean job of the carby in the near future.   

Can anyone post info on how best to clean and rekit these carbys.

I've rebuilt many sidedraught Webers but have never tackled Dell'Ortos which you have on your car. I would think that the principles would be similar once you've removed them from the car. You'll need a very clean area, the usual tools, spray on and liquid degreaser and a compressed air supply. A book detailing the procedure would also help and will be a handy resource in future - eg: Des Hammill's "How to build and power tune Weber and Dellorto ...." (ISBN 1903706750 and about $30.00). You'll need a gasket kit as well - I get all of my carby bits from Nardek (www.nardek.com.au), though I don't know if they stock Dell'Orto parts. If they don't they should be able to tell you where they are available.

Setting them up when you've finished is a task in itself. They need to be balanced so that each throat is drawing the same volume of air, the idle screws need to be set so each cylinder is running correctly and finally the engine idle needs to be adjusted. The procedure is often repeated until everything is right and the engine is purring.

Having said all of this, personally I wouldn't fiddle too much with the carbies unless there is an obvious problem - leaking fuel, jammed butterflies or obvious bad corrosion when you look at the fuel bowls. Dell'Ortos are good carbies and usually very robust - even if they are not set up perfectly, the engine should still run. At the moment I'd be concentrating on the fuel supply, the electrics from the coil to the distributor and out to the plugs and the timing. Replace the points and condensor, check the cap and rotor, maybe replace the coil, check the leads and put in new plugs. Check the static timing. Make sure you've got fuel flow. As a last resort contact the previous owner to find out when it was running last and whether there were any problems - eg: a badly blown head gasket or a warped head from overheating will make an engine very hard, if not impossible, to start.

I know you've probably already done a lot of this, and I mention it for my own completeness more than anything else, but it's still worth stepping through it logically.

Hope I haven't scared you off. Keep at it and keep us informed. The local WA AROC should be able to help as well.

Failing all, just buy back the 308GTB

Chris

[Mat Francis]

i did full rebuild on the webers a while ago, as they had a huge stutter around 2000rpm, then would pick up again at around 2300. huge difference, pulls cleanly all the way through now!

i'm half way through the dellorto's rebuild as i write this. my chosen method was to completely dismantle ONE of the two, (leave the second as is, it's a good reference if you get lost or forget where something goes), and bag all the little bits and pieces, marking the bags nice and neatly. be very careful when taking out the idle jet screws(?). they have a needle like end on them, very easy to snap.

Once all the gaskets, plastics, anything that could dissolve is off, i left the body and top plate thing soaking for a week in degreaser. probably overkill, but it made cleaning the crap off them very easy.

i bought a kit off ebay from a mob called MLP carburetors, about $60 each. there is probably easier ways to find them.

Also, while it is apart, give the jets a really good clean out.


Putting them back together is simple enough, and if in doubt refer to the owners manual of the car, (mine has a diagram of all the carbies internals), or the kits also usually come with a complete diagram i think.

As long as you are damn careful not to lose any little bits, and there is a lot of them, you should be alright!

Tuning them is the really fun bit, can't offer any advice there as i make dad do it for me.

Here's the difference the degreaser makes!

[Neil Choi]

Hello there

Friday afternoon, 40 mins before beer o'clock.

Just a quick word of cheap chemical advice, you can use acetone (bought cheaply at any hardware store) to clean all that gunk off the carburettor.  Carbie cleaner in a spray can is probably acetone mixed up with some detergent and some nice smelling fragrant.

Neil
Drug Designer extraordinaire

[1750GTV]

Tim,
I found a picture, but unfortunately no legend to go with it. It may be of some help - especially when you have little bits like ball-bearing #51 ....
Gotta agree about the soaking - I use standard thinner and leave the carby in it for about 48 hours. Works wonders.
I've also attached a photo of the service kit available from www.dellorto.co.uk
Regards,
Chris

[Tim Jobson]

Thanks chris and matt your advice, I will go back to basics and check the electrics and timing first, finding timing marks is the first task.   I still feel fuel is not geting to the cylinders, yes colin the carby bowls are full of clean fuel, I will try to see if any fuel comes out of the accelerator pump jets as well.

As for my 308, it had 4 twin throat webbers and I never needed to touch them in the 10 years I had her, I do miss the sound of these carbies at work!

PS:  I did read on one site that if the accererator pump diaphram  was cracked it would leak fuel on to the starter and this has caused engine fires, especially in Lotuses.

Cheers Tim