Lancia Motor Club

Hi,
Can anyone offer me advice on options to upgrade the spec/performance of the air filtration system, fitted to a set of Dellorto DHLB carbs on an S3 1.3 Fulvia?
Might be a more efficient filter element within the exisitng air box; or replacement of the air box with performance filters and/or trumpets plus gauzes.
Any suggestions welcome, including advice on suppliers for components.
Thanks
Robert

On my 1600HF I use PiperCross socks on trumpets, seems to work well. And sounds great.

The standard airbox is not to be sniffed at and has the added flame guards...

Demon Tweaks

You'll find trumpets with or without mesh on Italian ebay at about 25 euros each. However just bolting these on in place of the standard box will mean you'll lose the bracket for the carb support bar which will mean the sheer weight of the carbs are hanging from the rubber mount which will speed up cracking and lead to poor performance. Even the type with mesh will keep flies etc out but easily let through fine grit floating around on a dry summer road so socks are recommended. Here's a nice set up which comes with a proper support and very fine mesh if you can stretch to the price - http://www.ricambilanciafulvia.it/fulvia-corsa/carburatori/tromboncini-solex-35.html

This was what I bought as I didn't want to lose the support!! Dont think I paid that though but it was 5 years ago. I put piperscroos socks on as a precaution to grit etc.

They're on my shopping list..................one day. I would add socks too.

are you running standard solex carbs like this, if so have you had to rejet? are you also using the original trumpets, or if not what length trumpets are they? thanks Roger

Roger

Standard 42mm Solex which I think the main jets from memory have been opened up by005. Trumpets are twice as long as standard (approximately).

Tim

Do you mean DHLA's as I would have thought that DHLB's were too small for your 1.3 as I have DHLB's on my 1091cc 2c?
Brian
8227 8)

DHLB's go to 35mm and fit the Lancia manifold - or have I got this round the wrong way??

Forgot - there is also this cheaper option that offers the carb support but doesn't have mesh. If you run with socks it shouldn't make much difference I wouldn't have thought - ebay item  250995639082

Fantastic response.

Many thanks to all.  Seems all options are pricey - but you get what you pay for.

Robert

There is a very cheap option you could try. I used to sprint and hillclimb my Fulvia and messed about with various ideas. The one that I thought improved it most in standard form (and I'm sure it wasn't my imagination) was to keep the standard box but remove the filter and the baffle from in front of the trumpets. I then placed a sock over the intake pipe secured with a cable tie. It seemed much livelier to me. So much so that I've ran it like that without problems for the past 12 years. I don't have the warm air hose fitted to my air box so I just made sure the flap was in the closed position to stop air bypassing the filter sock. I've been tempted to cut away the diverter plate and the plate behind that on the outer part of the air box but I don't like to destroy things that can't be replaced. Be interesting to see what a completely unrestricted box was like though. I've only been looking at different options recently like socked trumpets just because I love the intake noise.

Tim,
Perhaps I've got it wrong on this as I have 32 DHLB's fitted to "Fay" with my 1091cc engine, but I thought you had to go to DHLA's to get 35mm suitable for 1.3's ?

 Brian
8227 8)

Stan,
 if you can find one, early Fulvia 2c's and 1.2 HF's didn't have a hot air intake and valve at all, only a straight tube, I doubt you'll find one off of a HF but you just might find one off of a 2c where you are, or possibly an early 1.2 coupe.
Or if you do want to modify yours and then want to change back, I've got a spare complete air cleaner assembly with the valve going spare.
Brian
8227 8)

Thanks for that Brian. I'll bear it in mind and look out for those versions you mention..

Hi Stanley

I presume the car you ran with the airbox mods was a 1.3s with solex 35's and 31mm chokes?  If so did you retain the standard jetting or make any changes.

Sean

Brian, definitely DHLB 35s on a 1.3, as found on my coupe, just slightly bigger version of your 32s, not the wider bodied DHLAs which start at 40mm (?) upwards.

 Neil.
Thanks for the clarification :)
Brian
8227 8)

Yes - it's a 1.3S on standard Solex 35's. I didn't make any other changes to the carbs. It was sprinted, hillclimbed and was pounded along roads all day long to places like Corsica from the UK - and no horrors like overheated pistons. At the time all those years ago it was based semi-scientifically on lap times around Goodwood and other circuits, speed at the end of the straight etc. For instance I remember trying out just open trumpets for one session and found it couldn't reach maximum revs on the straight. I replaced the filter etc and the revs came back. I've never worked out whether the mixture was too lean or the carbs were sucking in hot air from the rad? I just found this solution quite a good compromise - it just seemed to rev more freely and could still attain maximum revs. Be interesting for someone else to try it just to see if I'm hallucinating.

Maximum revs being what?

From memory it was a self-imposed 6200 I think. Seem to remember it was struggling to reach 6000 - it just reached a point and stayed there even with my foot flat down. The figures might not be exact - I'm going back a good few years and it's only had road use since but it was having trouble finding the last few hundred revs. That was just with the cold intake removed with the standard (quite crude) intake trumpets. Strange thing was some time later I was at a Lancia Club trackday and overheard someone saying they were running their 1600 Fulvia on open trumpets for the first time and they couldn't get top revs on the straight. I told them what had happened to me. What do you think? Intake air too hot, mixture too lean or both? You raced yours didn't you? Be interesting to hear your opinion.

VEry good double mesh Weber filters and a proper Ally support bar underneath for carbs:

And standard jetting ???

They look like a type I saw recently on the Demon Tweeks site I think. Are they a push fit onto the trumpets? Be nice if they existed for properly rounded 35 trumpets.

They look to me like they are fitted in place of the trumpets and bolt directly to the carburettor bodies?
Brian
8227 8)