Hi recently bought a 1975 Bay with a type 4 engine. What is people's opinion on Carb set up. It has a centrally mounted webber at the moment but the manifold boots are perished so just wanted some advice before I started spending money. Any one running twin carbs or have any for sale? Thanks in advance
I’d find a pair of original PDSIT 3/4 and rebuild them. Better fuel economy compared to aftermarket ones and starts on the button. But I like original things.
If you go down the weber ICT route (a reasonably common choice apparentl), make sure that the carbs are jetted correctly for your engine. The make and length of the inlet manifolds is important as is the linkage between the two. Do you have a budget in mind for this?
For a standard Type 4 engine the standard Solex PDSIT 3/4 carbs are probably best, a centre mount progressive is the worst possible induction so almost anything else would be better. Weber 34 ICT’s are a popular twin carb set up, 40 IDF’s work well on 2.0l+ and okay on smaller capacity engines if the chokes are small enough. Dells are arguably better carbs but they are not available new and used would need to be overhauled, and that can be spendy.
These stock carbs can be great, I loved mine after they were refurbed, but it's a minefield if you don't know them. For example the carbs on you link have had the idle fuel solenoids removed and replaced with "something". Pretty sure they never came like this. Another set on ebay has lost it's idle enrichment. And they're not the most obvious carbs to setup.
Hello, a lot of carbs you could buy today are not that quality you expect. Newcomers that ask how to fix this ugly running setups are common. Also current repro Weber need to be modified to be used. So for the original engine setup the original carbs are the best - today rare and somehow expensive. If possible refurbished by an expert with new seals, shafts, nozzle needles - in general this is very expensive. And take care to have the correct one with fitting needles for your engine size - there are different sizes and models of type 4. regards,
ICT's most definitely . Simple and easy to set up . Eurocarb i find are really helpful and WayoutWestie have a great section on jetting etc .
Indeed but they also have some known problems like filling your case with fuel. The point I'm fumbling to make is that I think whichever way one goes with carbs it's unlikely you'll be able to just bolt them on, balance and drive off into the sunset... but... you should be able to IMO because several times I've taken carbs off one engine and put then on a completely different (CCs/t1/t4) engine and they've been bob on including the idle mix being within a whisker. "Carburettor Exchange" managed this feat by setting up my Solex carbs on a "similar" engine when they refurbed them. This is no mean feat with the complexity of these carbs but additionally there's no messing with jetting to be done because VW did it for us.
e.g. at today typical 40 IDF 70 these need additional bypasses at low throttle for smooth acceleration - also to reduce consumption - etc. Ask your local engine experts...
Thanks for reply . I have been to the odd show and a few buses seem to cough and splutter while slowing moving in the queue.
Mike over at WayOutWestie is a good guy and has spent a lot of time looking at ICTs on aircooled engines. He even offers different packages of ICTs, manifolds etc. If you go down the ICT route (this may apply to other carbs as well), you must ensure that your fuel pump is working at the correct pressure and that you have a fuel cut off valve or one day, you will probably find your engine full of fuel.
@Pdjordy i don’t have experience with multiple setups but i did have to go through the same decision process as you. My bus had progressive carb which was rubbish. considered all the options and went for ict kit from eurocarb (genuine webers, brand new not needing repair/refurbishment etc) as they were affordable and relatively easy to setup took a lot of time and effort to get them right but I think I’m there now. I also have a cut off valve plus a huco low pressure pump. I also rigged up a lambda sensor and afr gauge and spent a bunch of time re-jetting to get them running as good as possible. The out-of-the-box setup wasn’t great, wayoutwestie setup was an improvement but every engine is different and unless you have a gauge you’re just guessing.
just looked up drla 36 kit on eurocarb website- they are now 1,700 quid plus vat - ouch! And that’s for refurbished second hand carbs .. Are they worth 3x the price of the icts?
