1974 Alfasud Trofeo

[Marlow Sud]

The std tank was half full before.
Brgds
Simon

[Marlow Sud]

Just found Bryan's good advice on how much fuel to carry each race. I can feel a spreadsheet coming on. Love spreadsheets!

Fuel consumption wise we used to work on 1 litre of fuel for every 2 miles for the 8 valve engine (only ever run on carbs). I calculate what my lap times should be (allowing for getting up to speed in qualifying or a standing start lap in the race) and from that work out number of laps and therefore likely distance covered in that session - 20 miles = 10 litres, etc. For a safety margin we run a float of 5 litres - we've never run out of fuel

So my foam filled tank is 7 gallons or 30 litres and it has a clear tubing sight glass so I can mark it up in 5 litre increments. Perfect.

It is a standard mini racing tank from Concept so a very cost effective solution. The aluminium sheet for the rear parcel shelf was £10 from a fabrication shop in High Wycombe.

Brgds
Simon

[Veesix75]

I use roughly 2 gallon in a 15 min session.

I keep mine brimmed just to be safe at 4 gallon.

[Marlow Sud]

Thanks Tim.

[Marlow Sud]

Removed the original steel fuel tank today. It turned out to be a very easy job with the rear of the car on axle stands and a trolley jack to lightly support the tank. I removed the nearside rear wheel and both jubilee clips from the filler to tank lower rubber hose elbow. With a bucket under the elbow I prised the elbow off the bottom of the filler tube. The flow of fuel into the bucket was started and controlled by turning the elbow to eventually point downwards into the bucket. The tank still had about a gallon in it but returning the elbow to the upright position kept it all in the tank.
The tank to pump pipe was removed at the pump end. The two 13mm tank strap front bolts were removed and the tank settled onto the trolley jack. The tank was then slowly lowered to the floor. At that point the fuel level indicator spade connections and the bonding strap can be removed and the tank carefully taken out from underneath the car.
The tank straps un-hook from the rear locating positions.

All the best,
Simon

[Marlow Sud]

Hi guys,
At Brands Hatch this morning for a sneaky practice before racing at the weekend. The car should be a little lighter with the smaller fuel tank and no bumpers.
Lovely sunny day for it. Passed the noise test and just waiting to go to the drivers briefing.
I am told I might need a swirl pot but will find out today.

Brgds
Simon

[88liam]

Hi Simon

Car looking well, would be interested to hear the outcome
off the swirl pot, took the saxo to mallory park on a track day
a couple of weeks ago, never had a problem with fuel starvation
previously, drove the car at Angelsey and Oulton Park, Shaws
hairpin resulted in fuel starvation, filled the tank to the
brim and it cured the problem for a few laps then it came back,
what do the regulations say about where you can site a swirl pot on
a race car?

Liam

[Kegsti66]

Good luck for the weekend Simon.
Car looks good without the bumpers.

[Marlow Sud]

Hi Guys,
It was all a bit one step forward, two steps back today. The good news is the shakedown today means I will be ready for Saturday.
The car was popping and banging as I approached 6000rpm. Typical. I put in a foam filled tank and it makes things worse. I called Tom and got some great advice.
I checked the in-line filter which is a filter king pressure regulator. The filter looked a little grey so I removed it and the car ran much better but was not cured. On that run I got black flagged for noise. I was 2db over the 92db drive by limit. The on-site shop had four different sizes of decibel devil but not the 2in one I needed. I spoke to the noise tester and as long as I set the rev limiter to a lower figure they would let me out again but another black flag and my day would be over.
I went out again and got black flagged after four laps.

I have ordered a 2in decibel devil to pick up on Saturday for track days. I won't need it for racing as the limit at Brands on a race day is 102db.

Should receive my new Filter King with new filter and pressure gauge on Thursday. Its a 5 min job to fit it and Tom has given me the correct pressure setting to use. I have looked up Filter King information online. They specifically mention fuel starvation problems at full throttle settings if the pressure is too low. Pretty sure the starvation problems will be cured with the new correctly set Filter King.

All the best,
Simon

[Marlow Sud]

Pics:

Filter King

Internal Filter

Carbs and Carb jets got a jolly good clean

Posing in a charity scarf. It's for a very good cause.

[AlfaCorseChris]

Hi guys,

anyone got a Trofeo kit laying around for my Ti ?

[Marlow Sud]

Hi Guys,

I checked the facet pump filter screen tonight (as advised by Tom) and it was pretty dirty with fine tank residue. I think this could be the cause of a gradual on set of fuel flow problems.

MSV photo from yesterday

Brgds,
Simon

[rsfruitbat]

Part of my pre-event prep was to always strip the carbs and clean them.
never found out where the rubbish came from but it did eevn with inline fuel filters.

rsfruitbat

[Marlow Sud]

Good advice thanks RSFruitbat.
I checked the carb fine mesh filters and they were completely clean.
New in-line filter / pressure regulator fitted. It is high flow so the paper filter is twice the size of the previous one. Set the pressure to 3.5psi and then blanked off the tapping. The car idling is noticeably better.

Brgds
Simon

[Marlow Sud]

Finally got the video uploaded of the car at Brands Hatch showing the symptoms of fuel starvation.

https://vimeo.com/176654405/23f13eff02

Brgds,
Simon

[justsuds]

Hi Simon, - having done what you've done, could the problem be elsewhere ? - does it have a rev limiter ? or perhaps going back to fuel is the pump ok ? - fixing problems is the easy bit, - diagnosing whats wrong is the tricky bit ! - good luck,
John.

[Marlow Sud]

Hi John,

You are quite right. The temptation is to change everything because you just want it fixed. I have been working on the basis that it started with the new tank being fitted so I have been getting great advice and looking at the fuel system from end to end. Clean Carbs, clean filters throughout, correct pressure regulator setting, replaced the fuel pump, filled the tank full and good fuel delivery at both carbs. I just need to measure the flow rates I am getting are OK and
I will also overhaul the carbs though as I noticed that one float chamber needle valve has a brass needle and the other has the brass needle coated in a plastic or rubber?

I disconnected the rev limiter and that had no effect.

Next, I will move on to plugs, leads, distributor cap, rotor arm and coil.

I will let you know what I find.

Brgds,
Simon

[88liam]

Hi Simon,

Might be a million miles away, did your problem occur after
changing your tank ?, could it be a ventilation problem?
air lock?

Liam

[Marlow Sud]

Good thinking Liam.
I did disconnect the breather hose and blew into the breather valve and it was all clear.

Brgds
Simon

[Marlow Sud]

Hi Guys,

The fuel system was done last week:

The fuel tank feed pipe in the boot is now routed through the lower side of the wheel well right next to the pump.
New Facet fuel pump.
Fuel pump switch and power supply checked.
New 8mm copper pipe from the pump to the engine bay.
New fuel hose throughout.
Carbs stripped and cleaned and all jets blown through with an airline.
Float levels sets up accurately.
Overhaul kit fitted to each carb. New filter, gaskets, accelerator pump diaphragm and needle valve.
Carb cold start mechanisms removed and gasket and blanking plate fitted.
Tank emptied.
Flow rate at the farthest point is now 1 litre in 28 secs down from 35 secs before.

The car ran smoothly but completely cut out and stopped if rpm decayed to 1000 rpm.

Brgds,
Simon

[Marlow Sud]

Hi Guys,

Phase 2 today - Ignition.

New spark plugs.
New Magnecor HT Leads.
This is the good bit - New 123Tune distributor that can be programmed from your iPhone. The one you need for your Alfasud is the 123/TUNE+ 4-A-V-V (bluetooth). It says this model replaces Bosch Distributors for VW & Volvo but I measured all the key dimensions of my the distributor drive and its the same.
Very easy to setup and ready for the rolling road guys to properly map.
New Bosch un-ballasted coil.

The existing Marelli distributor, coil and ignition system were all removed.

Replacement coil

The car started immediately. It sounds very different. Picks up nicely and will run happily at 1000rpm!

Rolling road tune-up next.

Brgds,
Simon

[Kegsti66]

Sounds great Simon. Scary to think the power these phones now have.
Good luck with the tuning.

[Veesix75]

Intersting distributor, I'll take a look at that ...thanks.


Keith - take a look at what you can do with a smart watch and a tesla.......we're almost sat in the back seat, not be too much longer.

[Marlow Sud]

Hi guys,
Some pics for you:

It's the new configuration for fuel delivery but I wanted to show the crimp. I saw them In marine use. When you heat it with a hot air gun it glues itself to the wires either end sealing the joint.

My carbs are Italian and the cold start blanking plates are Spanish! Shrew won't like that.

123 ignition in place.

New fan. Only 0.5kg lighter but much more efficient.

New High torque starter. Again only 0.5kg lighter than the original.

I am quite attached to my towing rings so they got a refurb.
Overall, the car has lost another 9kg.
All the best,
Simon

[junior]

All very interesting thank you.

[Kegsti66]

- take a look at what you can do with a smart watch and a tesla.......we're almost sat in the back seat, not be too much longer.

I struggle with a smart phone let alone a watch. Guess I am not that smart.

Simon, new parts look great, hope they sort out your issues. like the Velcro to stop the toe eye swinging.

[Marlow Sud]

Hi Tim,

Well spotted with the velcro.
The car is booked for a rolling road session next Tuesday to check if all is well.

I removed the heater unit today - 3.5KG.

Brgds,
Simon

[Spacenut]

Intersting distributor, I'll take a look at that ...thanks.


Keith - take a look at what you can do with a smart watch and a tesla.......we're almost sat in the back seat, not be too much longer.

Where will it all end? I keep wondering if in the not-too-distant future we will be remonstrating with our cars because they had gone out on their own without telling anyone, hanging around with their dodgy mates drinking cheap oil and not coming back until the early hours...

[KevJTD]

Intersting distributor, I'll take a look at that ...thanks.


Keith - take a look at what you can do with a smart watch and a tesla.......we're almost sat in the back seat, not be too much longer.

Where will it all end? I keep wondering if in the not-too-distant future we will be remonstrating with our cars because they had gone out on their own without telling anyone, hanging around with their dodgy mates drinking cheap oil and not coming back until the early hours...

sounds exactly like Rob now

[Spacenut]

...Except the drinking cheap oil bit I hope!!!