Distributer question

[Oldbones]

Hi all

A little advise please

I am fitting a pair of delortos via a guy croft inlet manifold to my 2.0 beta spyder when I bought the car 7 years ago it came with a box of spare parts including a distributor that looks identical to the one fitted to the car but without the vacuum advance unit attached to the side of the dissy.
Question- as the manifold does not have an outlet for the dissy vac pipe can I fit the none vac dissy? Does anyone know why there is no vac unit?

If this none vac dissy is not suitable then I will drill and tap the manifold and fit a spout for the vac pipe and use the one currently fitted

Thanks for you help

John

[Thotos]

The twin-cams when fitted to Fiats (except for the American, Swiss and few other markets) do not have vacuum advance on the distributor. The vacuumless distributor on my Fiat 131 twincam with Guy Croft manifold and twin 45 DCOEs works very well indeed    So I'd say fit the distributor without the vacuum advance and see how well it works before you start drilling and tapping.

[lukasdeopalenica]

My beta also has a distributor without the vacuum unit and works fine, but some betas have it - see spare part catalogue etc. In my distributor there is a plastic plug covering an opening for the element.

[75coupe]

I have a Bosch electronic ignition distributor without vacuum advance on my modified Beta with GC inlet, twin 45's and it works  fine.

[Oldbones]

Thank you for your prompt advise. I have decided not to drill the inlet manifold but I will reassemble everything with the vacuum dissy in place but not connected then when I have everything working in a fashion, swop to the non vac dissy. This is cos I know the vac dissy works but the non vac dissy has been in the bottom of a box for last 100 years!

Didn't realise when I started this refit how difficult it would be to get the twin choke webber manifold off and the guy croft on in fact nut and bolt head access is almost impossible!! Hope it's going to be worth it

How have you 2.0ltr lancia guys with the twin carb mod found the difference from the standard

Cheers

John

[75coupe]

Hi John

To fit the GC inlet you need to use cap head bolts and I found it easier to remove starter as well, then I used  a 1/4" drive 6mm Allen key socket with wobble drive and just manged on get it on..... Not easy you have my sympathy there!

Have you done anything else to the engine? Are you using an electric fuel pump?

Fitting twin 45 DCOE /DHLA carbs can be worth up to 10-18BHP with no other mods, provided they are jetted correctly. Throttle response will be better, cold running better, improved part throttle response/economy, and generally you don't need to use the choke, 3 prods on the accelerator is enough to squirt some fuel in to start, remember you have 4 accelerator pump jets now instead of 1!

Make sure you have a cold air intake, sucking hot air from the radiator is not good, it will rob power and also cause detonation in hot weather, I have made an airbox out of alloy, insulated it and have a remote pod type air filter that sits behind the passenger side headlight, it also reduces the induction roar, which will be very LOUD! (a great noise but can be a little wearing in a road car).

A fuel injection type in line filter does wonders for stopping crud getting into the carbs.

The key with twin carbs is to make sure they are jetted and setup correctly. It is a myth that they need "constant tuning", I find them less hassle than the standard carb, but I am biased......

Good luck!

[mangocrazy]

Make sure you have a cold air intake, sucking hot air from the radiator is not good, it will rob power and also cause detonation in hot weather, I have made an airbox out of alloy, insulated it and have a remote pod type air filter that sits behind the passenger side headlight, it also reduces the induction roar, which will be very LOUD! (a great noise but can be a little wearing in a road car).

Would you have any photographs of that setup? I've got a set of DCOE 45s squirrelled away that will be fitted one day, and I've been fretting over what to do with the intake. I know the intake roar/howl can be addictive in the short term, but longer term (and on long journeys) it can get quite wearing. Also, as you say, the carbs really need a diet of cool air, not pre-heated by the radiator...

[75coupe]

Hi if you check out the tuning and competition section and look for 2litre uprated engine rebuild there are some pics there. I will try to upload a few more later when I have access to my PC.

[75coupe]

Here are the pics of the engine bay and air intake setup

[mangocrazy]

Very nice work there; very clean layout and excellent attention to detail. The photos give a really good idea of how the layout works. Was fabricating the airbox/plenum chamber much work? I'm presuming there's nothing available off the shelf for that kind of application. Did you just make the airbox up based on available space, or did you work to some calculations?

One set of answers always leads on to another set of questions, unfortunately... 

[peteracs]

Hi

Can you also let me know where you got the strut top brace from?

Thanks

Peter

[75coupe]

Hi

The airbox size was based on space and clearance from the end of the carb rampipes. ideally You need a gap of at least 50mm from the end of the carb rampipe to the plenum cover. the shorter the rampipe the shallower the cover.

I just made my own out of 2mm alloy and 75mm aluminium pipe. it is all hand bent and sealed/riveted together with silkaflex adhesive sealant. I then used 6mm thick self adhesive foam to insulate it. This is available in rolls 50mm wide from refrigeration parts wholesalers and otherplaces no doubt.

I was lucky I picked most of it up FOC from a Bus bodybuilding workshop....(my daytime job is Technical Manager for Thermo King Bus air conditioners...)

I fiited a different radiator fan to the front of the rad which blows through rather than sucks through to give more space behind rad. (Rad is out of a Ford Focus ST170....)

Piper cross do a complete kit with filter, plenum, backing plate etc for twin carbs available from Demon Tweeks and others no doubt.

The strut brace is just homemde from 25x25mm alloy box section from the local DIY store. The strut ends I made from steel sheet and secured to the alloy section with bolts. There is also a right angle bracket underneath that bolts through the side of the strut tower tha cannet be seen in the pic. I will probably make a "stronger" one when I get round to it, but has not given any sign of bending/cracking during my circuit racing with semi slick tyres....

Regards Ian

[archigraphe]

Very nice work in your engine bay,

After the twin carb and the good filter solution, I notice the bar, is it "do it yourself?" made?

Do you have an in head thermostat ?

the top mounting strut are not standard? who is it? have you change camber or toe with this mounting?

It seems ther are minus dirt on race as we have in rally....

[75coupe]

The bar is home made. The strut tops just have large thick washers to reduce rubber movement in the top on rebound when the wheel is dropping.

No dirt in circuit racing unless you come off the track...........:-)

[Oldbones]

Here are the pics of the engine bay and air intake setup


Well I must say your engine bay is the most impressive I've seen, something for me to aspire to!!!

If you ever decide to change your strut brace I would be very interested in it. I have tried to make out out of aluminium but it looks very crude and it does not allow me to remove the water filler cap, I note you have move your expansion tank, was it due to the strut brace getting in the way?

I have fitted my twin 40's now but not managed to get them running as yet. You have me a little concerned regarding the warm air issue I have KN filters fitted an one is directly behind the radiator and therefore will be drawing in warmer air than the other.

[75coupe]

Is your engine standard? If so and based on you being in the UK it will not be the end if the world. The ambient temps where I live are regularly 30 degrees C plus, so the coolest air possible is required. My engine is also seriously modified with an 11:1 compression ratio, so everything is "on the limit" and little details make or break the car...

When I first fitted the carbs I had similar type filters and a standard motor. I had no issues with pinking. If you are using a carb type radiator you can lean it forward under the front panel, I then used the original top mount at the front to secure the rad. You will have to extend the top hose to reach.

I then used some thin ally sheet to defect hit air under the carbs....

[Oldbones]

Thanks for the info, yes it's a standard engine and have picked her up today from the rolling road tuner. Seems to be running well so just waiting for the summer to arrive to the UK to try her out.

Cheers
John

[VXdeMayo]

Dear Ian,
Great work and I bet it sounds wonderful at full chat. However can you or anyone else tell me if anyone makes an air box to fit a SINGLE Weber DCNF. I have one of these carbs for our VX (re-jetted as per Guy Croft's book etc). I also want to use a K&N cone filter as you have to enable getting rid of the horrid standard airbox fitted to the VX. (This will also make plug changing easier). I could put a domed foam/ mesh filter on a DCNF, but am worried about air at the wrong temperature  upsetting the fuel / air mix etc.

Has anyone got any advise please?
Keep up the great work.
Chas and Anne.

[75coupe]

Hi Chas

I am building a modified VX later in the year, but it will use a DCOE. Your best and probably only option is to custom make a cold air intake. Clearance with the top of the bonnet will be the biggest issue.

I think Grundo who is a member of the forum fitted a DCNF to his, maybe you can PM him.

Regards Ian

[VXdeMayo]

Cheers Ian, will do that.
Best of luck!
Chas.