Dellorto twin 40s

Hi, i have recently purchased my first carb'd MK1 1.8 clipper cabby, after more than my fair share of MK1 Cab GTI's i now feel like a novice again as i am only use to fuel injection. Anyway after spending out £325 for a solid 89 clipper cab with 89k on the clock i have just bought a set of Dellorto twin 40s, usually i hear alot about webers etc and i am wondering if these Dellortos are going to be any good and also can anyone give me a heads up and what else i will need to fit these on my car as i only have the carbs.

Thanks in advance  for any information


Andy

Lots…

Inlet manifold,  throttle linkage, fuel lines, fuel pressure regulator, fuel pump…plus sundry parts.

The popular inlet manifold needs porting as they are too small internally. Then, the manifold needs matching to to head.

Im a BIIIIIIG carb fan, but I wouldn't fit them as a first choice mod.

Thanks for the info, hmmmm thought i would need a few bits just not this much! so good job i got the carbs dirt cheap!!!! i like a challenge!

Thanks for the info, hmmmm thought i would need a few bits just not this much! so good job i got the carbs dirt cheap!!!! i like a challenge!

Cheap carbs can mean cheap for a reason. .so beware.

Lots of parts available so no probs to re furb them unless there's something wrong internally. .any pics?

 Make a note of all the jet numbers, including in particular the choke size.

If you like a challenge you now have one!

You'll also need misab plates for mounting the carbs to the manifold, an inline filter, fuel hose, and a heat shield between the manifolds.

Also..the clutch cable will foul the second trumpet in from the left..looking from the front. . from memory a scirroco or diesel cable clears better as it runs tighter to the bulkhead.

Yeah i was planning on getting the kit to refurb then, nice quiet job in the garage, I will get some pics on as soon as i can, the car is off the road at the mo so there is no rush in getting them sorted. Thanks for the tips.

Andy

I am running twin dellortos on mine. I had a few problems like jetting and a cheap throttle linkage. once this was sorted i had them set up on a rolling road.

I must admit a twin carbed engine sound awesome and its interesting to drive.

You might also want to consider making an airbox because the filters play havoc with the clutch cable and they sit above the manifold.
so a small air box with a cold air feed should help performance.

I will attach some pics:

Good call…

Contact developments (Dellorto UK) stock all the parts needed and are very helpfull to deal with.

Thanks for all the info chaps, nice pictures that is looking very good. Cant wait to get mine sorted like that but it is a long way off!

I run a single 40 dellorto, bought a pair and then sold them on again as it looked a whole world of pain getting it all sorted.

The heat sheild is a definate for the conversion as is an electric fuel pump, the mechanical one on the clipper will not deliver the fuel needed.

The air box could be tricky if you are planning on retaining the rain tray in the engine bay!

Are there any guides on the forum for installing and setting up these carbs? 

I'm looking at doing this on an ABF with twin 45 Dellortos

Similar rules apply to an ABF as it does in this thread.

Be careful what you buy used as there's a lot of useless junk out there. Carb jetting is fairly straightforward to get them running nice before a rolling road set up.

Inlet manifolds are important…a poor flowing one will cap back any carb gains. A good throttle linkage is a must.

Carb conversations can often be slated when poor/warn carbs are used on a bad inlet manifold with a worn linkage and incorrect settings. Get the right carbs on a good manifold jetted correctly with a nice linkage and carbs work great.

Get yourself a book on it and have a good read.

https://www.ebay.co.uk/p/How-to-Build-Power-Tune-Weber-Dellorto-D-9781845849597/6020831876?iid=352578011095&chn=ps

Is the one I used.

Cheaper than buying the wrong thing and making costly mistakes. I think there may be a PDF out there too

https://www.mazdabg.com/ftp-uploads/Mazda/RX7/info/carb_book.pdf

JMRacing  got any suggestions for a good linkage?

I have the 'black framed on the top of the carbs' style on my Derby and the return spring is too hard. Makes driving it in traffic a nightmare

Ian

Eurocarb do a couple of good ones, including the newer version with a cast frame and multi adjustment…its around 90 quid from memory. Worth a call to them, always honest and very helpful with any of my fuel system parts in general and the best source for Dellorto bits.

Some of the metal frame linkages are ok when new but can wear quickly.