Dellorto DRLA40 carburetor non linkage return Issue.

27th October 2009
I had been noticing that my left carburetor was not returning to its stop since the rebuild process for the turbo seals whilst I was installing the new linkage kit. I was not entirely happy with the shaft when I put it back during the turbo rebuild and it appeared now I was right and the non return issue on my left carburetor was due to the spindle being bent. This resulted in the shaft rubbing in the carburetor. The only solution I found was to renew the shaft. Its quite tricky to do as you need to be comfortable with stripping the carburetor. The best way to do this is to photograph each stage if you haven done this before. You need to remove the paraphernalia on the top of the carburetor Air cleaners or trumpets. There are 4 screws on the op of the carburetor that hold the float cover on. If you remove these you will most definitely need a new gasket so don't skimp. With the top loose gently remove the top carefully as the float is underneath put these items somewhere safe in a backing tray.

Next remove the two screws either side of the carburetor this locate the spray bar it only goes in one way make sure when you take it out you recognise this. The screw is usually held with a locking nut. With this out the chokes can be removed sometimes these grow in here and will need carburetor cleaner to get the loose and maybe a soft tap. Again look at the orientation how the come out. Record everything

Next remove the nuts on the spindle and remove the control arms these must go on the right way round. Its important that you note which side the longest part of the spindle protrudes from it is imperative it is put back exactly the same for your linkage kit to work.

Next turn the carburetor over you should see the two butterfly valves two of them in each carburetor throat they are held with two brass screws which are peened over on the back so they don't fall out. Once you have the screws out you can twist the spindle vertically so that the butterfly can be removed by sliding them out of the slot. Repeat 4 times noting which way round the butterflies come out and which hole and which way up they will only come out one side. With the butterflies out Put one of the spindle nuts back on the spindle and use a soft rubber mallet like a camping one to remove it. The bearing may come out too don't worry. Use a thin screwdriver to drive it all the way out. You can knock out the bearings whilst your there and remove the plastic covers with a small watchmakers screwdriver and grease the bearings replace the plastic cover.

Put it back is same as dismantling it. Make sure the new shafts the right way round (imperative) I used a couple of sockets or tubing at ether end of the spindle to drive the bearings into their correct seating.

The butterflies can only be inserted from one side of the spindle they wond go in from the other side. Use 4 new brass screws for the butterflies. Peen them from the other side once their tightened by putting a screwdriver across the back of them and tapping the screwdriver with a light hammer ensure you support the shaft underneath with something so as to not bend it again.

Now I did this I now need no springs at all. A carburetor schematic can be found on the www.dellorto.co.uk web site you can buy parts here or on ebay.

Locating Induction inlet pipes & Pressure Covers

20th September 2009

I have been having trouble locating the parts that I needed to complete the turbo 1600 engine I was building. After exhausting every VW specialist in the UK. It was obvious that I would have to spread my search further. Volkzone had initially turned up nothing either as most of the turbo parts come from CB Performance in the USA I knew that with carriage prices currently over $100's I would have to get a UK dealer to order them for me. VWSPEEDSHOP came up trumps again he stated that he could have them here with a month . In the meantime I scoured Vzi and eBay in the hope that something might be available faster. Finally I found someone on Vzi selling a turbo kit that he would split . He had the CB Performance Inlet pipes but no pressure covers.

You can see that the inlet pipes are in two parts they are made from steel which is prone to rust. I painted them as soon as I got them delivered and decided that at a later date I would have them chrome plated.

The VWSPEEDSHOP cover plates were not forth coming as fast as I would have liked. I luckily managed to get an answer to my wanted add on Vzi ,which meant they did not need to come from America, which was causing the delay. I was still not sure whether to fit an inter cooler or cooler to the turbo output. I would have to start connecting up before I would now how much room I have to fit a cooler in. I had also managed to order the silicon connectors from eBay at a substantially reduced cost. I chose the humped connectors as I thought it would make a stronger connection to the pressure covers.

The next problem was going to be assembling all of these components and see weather there was enough room for a water cooler or inter cooler to reduce the turbo air pressure temperatures going in thorough the Dellorto DRLA 40 carburetors.

Linkage kits - Empi - CB and turbo installations

5th September 2009

I had bought a brand new Empi linkage kit a few months back as I already had some inlet manifolds that I was going to use. Unfortunately I had forgotten that the CB pressure covers that were designed to capture the turbo boost and channel it into the carburettor would only fit on the CB linkage kit. This was a major foobar as The Empi Linkage kit had cost quite a lot of money and was a major piece of equipment to get wrong. Fortunately I managed to sell some pieces of beetle parts that I had in the garage that allowed me to purchase the new CB linkage kit and manifolds that I managed to get at a very good price.

The Empi linkage kit uses base plates to sit under the filters and can be seen in the photo right. It is generally quite a good piece of kit with high quality heim joints and aluminium hex cross bar , linkage bar and throttle. The package was very easy to assemble and I was pretty disapointed not to be using it but as there was no system for getting the boosted air into the carburettors with this linkage kit it had be replaced with the CB performance Linkage Kit pictured right. I had negotiated with my dealer not to supply the filters and filter caps as I was not going to use them as I would have to buy turbo pressure caps instead that the dealer had to order specially from the USA which would take a month to arrive.

The most notable thing about the CB kit is the quality of the equipment. Secondly you will notice that the manifolds place the cross bar horizontal to the engine without needing a modified plate like the EMPI system used. This seemed in my opinion to make the engine look more balanced. The fitting instructions see picture right that come with the kit do a pretty good job of explaining how all the parts go together although it did not seem to informative about the hiem joints and I had to purchase some adapters separately to bolt onto the Dellorto throttle levers to enable the adjustment bars to work well. The plates that hold the linkage bar need to have the screws screwed into them to fix the pressure covers it is a good idea to thread lock them into the base, as I have seen a number of these in the past come unscrewed with the bolt locked onto the shaft. The manifolds were an excellent design however no provision for the fitting of a vacuum line to feed the dump valve comes as standard. I found an old pump that had brass feed pipework integral to it. These were extracted from the pump and where fitted into the edge of the manifold by drilling a 5.5mm hole and then with thread locking them in to make a sealed joint. A 3mm silicon hose can them be run to the dump valve . repeated this for both manifolds and used a nylon tee piece to join the two manifolds making one feed to the dump valve.

With the carburettors waiting for the pressure covers to arrive so I could fit the boost system . I would have to turn my attention to the oil system and make some decisions about cooling and supplying oil and retuning oil to the turbo, I would also need to make a bracket to hold the weight of the turbo on the exhaust system.