TheSamba.com :: View topic - Any carburetor recommendations for a 1973 bus, 1700cc?

Wed Apr 28, 2010 9:07 pm

I recently bought a 1973 camper bus and I was wondering if anyone had any ideas for a good carburetor. I am looking for something that gets good gas mileage and performs well, and is something that is easy to maintain. Ive read some guides and a progressive centermount 2bbl one seems like what I would want, but since I am a newcommer to all of this I really have no idea. A stock carb also seems reasonable to me as well.

Wed Apr 28, 2010 10:41 pm

Hi!

The stock solex carbs were really hard to find locally(no one had them) and when I asked about it everyone always asked why I'd ever want one. If its not already installed it would be a real big hassle setting up.

Don't go for a single carb. My 72 bus had one from the previous owner, and when I moved to the Nw I experienced severe carburretor icing. The manifolds were just too long and there is no provision for carburretor heating like the older type 1 engines. Dual carbs sit closer to the engine and the fuel/air has less distance to travel and I have yet to experience carb icing for the last 5 years in Oregon.

Although they weren't cheap for me I bought Kadron 40 dual carburretors. They don't work well out of the box(in the bus) unless someone can re-jet the carb and possible add a vacuum port for a SVDA distributer. I am using a 009 distribuiter with no ill effects but many Bus owners say to shy away from them. You will also need a fuel regulator. Very important for fuel milage!

I went to www.lowbugget.com to buy the jets for the carb. A.J. Will ask you about your combo, what engine your using, what vehicle, and at what elevation you'll be driving at. higher altitudes the air is less dense and you need a smaller jet to maintain the same ratio of fuel to air. A.J. asked what my fuel pressure was. I had no idea, my 1800 engine had an electric fuel pump and I figured 4 or 5 PSI. That was no good as the carbs overfill and run in an extra rich condition and waste fuel fast. I ran my bus like that for 2 months. It was a fuel hog.

The fuel regulator makes a difference! I had re-jetted my Kadrons(from A.J at lowbugget) and didn't install the fuel pressure regulator he had me buy. My fuel milage was 12.1-13 MPG! I installed the regulator and my fuel milage bumped up to 15 or 16 mixed town and highway. With a vacuum port on the carb and an SVDA distribuiter I'd maybe add another 1 or two MPGs. I still use a 009 distribuiter mechanical advance only. Runs great but I do want to improve my MPG just a bit.

Enjoy your bus!
Matt Davala

Wed Apr 28, 2010 11:13 pm

I don't think there is a prefect fuel system for a bus. Single, dual, or FI. They all have their pluses and minuses. That said, installing FI on an early T4 powered bus is really pretty easy and may be easier than either a single or dual carb install. You would need to weld on a mounting bracket for the air cleaner and come up with a return for the fuel pump. Other than that its just 4 wires to splice or add to do the install.

Done right (which takes a lot of knowledge and can be a lot of work) the progressive seems to be able to give the best gas mileage and the same or better power than other systems. It has draw backs on running during cold rainy weather.

Wed Apr 28, 2010 11:48 pm

I'll give an honourable mention to weber 34 ict's. As simple as it gets, reasonable power and gas mileage, cheap to buy.

I'm same year and capacity - from what I've read, driven in other buses - I rekon 36 IDF's or DRLA's are the answer to most of the question. I have no knowledge of FI.

I ran a weber progressive for 2 years in a climate which is probably similar to yours in oregon - cold winters and maritime air - and it was never better than almost good enough. I tried IMDU's, jetting etc...hot air in is the key, I think, but this takes quite a bit of thought and engineering which isn't in the kits.

Just my 0.02

Thu Apr 29, 2010 5:44 pm

I HAVE a weber carb on my 1973 bus and I could not be happier.IT gets 23 miles a gallon.starts right up, but I dont drive the bus in the winter here in chicago. to much salt..

Thu Apr 29, 2010 6:45 pm

I have a progressive on mine as well, and have been happy with it..except for when it's cold. That's why I'm collecting all the necessary parts to go back original.

Fri Apr 30, 2010 11:27 am

awesome, thank you for your responses. I think at this point I am going to just rebuild the weber carb I have in there and use the money I would save on other parts of the bus.

Tue May 04, 2010 6:08 pm

Hey guys I have the venerable Webber progressive on my Bay. And every type 4 owner that has had one will all complain about the same thing. Intake icing. The 914 guys just shudder at the thought. Well I'll give you some insite as to what I have done to solve this problem. My bus will idle perfectly fine and drive around like it should on a -30C day. Before without my improvement, it would be a pain in the ass already at +5C. I would have to raise the idle for it not to stall every time you took your foot off the gas pedal.

On the 72-74 the firewall engine tin there is a provision for the heat riser that collects off of the lower cylinder tin right behind the mechanical fuel pump and makes for a heater pipe that comes into the engine bay to connect to the then... oil bath air cleaner pot that used to sit directly on top of the motor. You now have carb heat if you can collect these parts.

Now... go back way back to the late 70's and early 80's... weber progressives were used on tons of american 4 and 6 cylinder cars. I took the air cleaner from a 81 or 82 Pontiac Acadian. Cut and rewelded the throat of the air cleaner so it would fit properly into the engine bay, mine points close to the firewall to the corner above the heat riser inlet. Now, in this air cleaner there is a temperature controlled flap that needs constant vacuum (off your intake, not a big deal... there's that big ass bolt on the back of the intake... goto your hardware store and get some nylon barbs and make something up for this... I have power brakes so i made a T-fitting and presto... So now you can connect the heat riser to the air cleaner... (don't forget to grab the rubber stud pedestal from the carb you took the aircleaner)

This setup is pretty nice as it takes care of itself instead of piping constant hot air like the dual carb setup. As soon as the engine is running it will produce vacuum and have the flap so that it will be sucking air up from the heat riser. Now once the air cleaner gets warm it will open the flap to suck in cold air... so your intake manages itself. Your heat risers will be nice and warm to the touch.

Ta da. Heated intake for your type 4.

The Weber progressive is one of the most versatile and reliable carbs you will ever come across.

Tue May 04, 2010 6:20 pm

The heat riser pipe is not one of the more common things you will come across since most people blocked it off for unknown reasons... since it is very beneficial.

The Bus Co.
www.thebusco.com

Ken, at the Bus Co. had these parts available for me at a very reasonable cost. He was very nice and helpful.

If you have any questions... feel free to ask away.

By the way Weber 34's I have on my beetle and they are a great carb as well. But I wouldn't change to 34's for the bus. If you were looking for something more of a project then look into CIS injection. The most difficult part would be placing injectors into a customized intake. But that would be the the ultimate in reliable and cheap fuel injection for the bus that would be sufficient in the wildest of engine builds.

Tue May 04, 2010 7:28 pm

pplscar,

Do you have a picture of your set up?

Not to steal this thread, but has any tried to mount a 4 barrel carb on a type IV motor using an adapter like this?

Tue May 04, 2010 10:15 pm

kampalm wrote: Do you have a picture of your set up?

This is my version of what he is talking about. It doesn't use the original 72-74 preheat, but steals heat off the right heat exchanger. The original preheat actually works better than the heat exchanger, so go that way if you can find the parts.

Not really a heat riser, just a preheat. Big difference, having both is the way to go, but takes a lot of work.

Wed May 05, 2010 12:14 pm

kampalm wrote: pplscar,

Do you have a picture of your set up?

Not to steal this thread, but has any tried to mount a 4 barrel carb on a type IV motor using an adapter like this?

I'll take pics and post them shortly. It's nice and tidy.

Wed May 05, 2010 12:17 pm

Wildthings wrote: kampalm wrote: Do you have a picture of your set up?

This is my version of what he is talking about. It doesn't use the original 72-74 preheat, but steals heat off the right heat exchanger. The original preheat actually works better than the heat exchanger, so go that way if you can find the parts.

Not really a heat riser, just a preheat. Big difference, having both is the way to go, but takes a lot of work.

Yes, pre-heat. Thanks for the correction.

Needless to say that the intake risers are warm to the touch... they don't sweat and there ain't no ice on the suckers. It's smooth cruising.

Wed May 05, 2010 2:09 pm

Here is the pic I failed to post a link to above. As I said, this does not work a well as the original VW system on 72-75 bus engines.

Wed May 05, 2010 3:15 pm

I am not buying that the Weber progressive is an acceptable replacement for a decent pair of dual carbs on a type 4 bus.

If you are going to go with carbs, buy a good set, get them re-built and properly jetted for your application, and invest in a good linkage.

You will be ahead in the long run.

Wed May 05, 2010 3:48 pm

Well Randy, you will just never know how smooth and strong a Weber or Weber clone can run and will forever suffer the poor fuel consumption that both dual and fuel injection are known for. Personally I like it that my progressive powered rigs seem to be immune from the normal and all too well know head problems. Setting up a progressive well may not be easy, but once you are there it is a fine system that is probably the most dependable system available for a T4 engine.

Wed May 05, 2010 4:26 pm

And that is because you are a better wrench adn more patient than me.

It takes a lot of tweaking and tuning to get those weber progressives to work in an acceptable manner for a daily driver. I will stick with my FI set up. I have that pretty much figured out.

Carry on.

Wed May 05, 2010 4:29 pm

Wildthings wrote: the poor fuel consumption that ... fuel injection [is] known for.

huh?

Wed May 05, 2010 4:56 pm

germansupplyscott wrote: Wildthings wrote: the poor fuel consumption that ... fuel injection [is] known for.

huh?

When my engine was young, <180,000 miles I would get 24-25 MPG day after day running west across the plains into the wind, never heard of either a set of duals or FI coming close. The engine now has about 220K and the engine is showing signs of age, while the mileage has dropped to 20 mpg.

Wed May 05, 2010 5:36 pm

i get 24mpg in my '79 on the highway.