cheers snotty seems to run ok so i would take it 'po' has blocked them off.if i unblock and reconnect to filter box what then needs adjusting if anything. ill post pic of carb later if you could look at it and give opinion. 1600 tp single carb no vac distributor. cheers
I have nothing between the plastic t piece and the airbox on my bus. What pipe should I use and where can I get the adapter visible in the pictures above? Sorry to threadjack
A length of plastic washer hose of the right size should do the trick. A spark plug boot may be ok to connect to the air box, with a length of metal brake pipe to connect the hose to the boot.
hi snotty got some photos of carb, it has 2 pieces of pipe with screws in ends, if you can have a look and chuck me an opinion. as it runs ok should it be left alone!!! cheers
right when I took my engine out, the previous owner had only had 1 of the hoses connected which was the link from the front and back of the air box. the take off from the carb was blocked off with a screw like most peoples that have been fiddled with, when I put my engine back in, I reconnected my vacuum hoses in a way that seemed the most obvious from the T piece of the petrol tank breather hose (ceiling of engine bay) to the large single inlet on the air box (the inlet with and adaptor) from the domed shaped flap cover on the front of the air box intake to the rear of the air box (1 of the 2 connections) then from the carburettor to the other intake on the back of the air box (2nd of the 2 connections) that should fill all your holes (pardon the expression)
Wendygun: splendid . The pipe on the RHS (viewing from rear) goes to your distributor vacuum connection (if you've got one). The pipe pointing straight back at you is the one that drives the warm air flap. So...pipe from carb to one of the airbox connections, another pipe from the spare connection to the round diaphragm on the air box. The thing with two vacuum connections is a thermostatic valve.
cheers snotty so take off pipe that is pointing straight back out of engine bay and fit new pipe from that to one of connectors on rear of filter box does it matter which,other connected round to front. does it matter what type of pipe, i take it is only low pressure vac. will it change any settings on the carb/ignition or tickover. what are the benefits of doing it.. i think on the smilies page we need to add stars
I won't change any settings as it's a blind vacuum system. @snotty meant left for distributor, he's getting old and muddled.
Yep, as you say: use the rear carb connection, which is raw manifold vacuum. I can't remember which connection to the vacuum switch, but I doubt it matters. The other connection goes to the round air box diaphragm (worth sucking on the tube first, to make sure you've got no leaks). The thermo valve inside the airbox determines the air temp: if cold, the vacuum moves a flap valve (look up the airbox "nozzle") to pick up heated air from around the exhaust to prevent manifold icing and warm things up quicker. When everything's warmed up, the flap moves so to pick up cooler air from inside the engine compartment. All pretty standard stuff on carb'd engines of the 70s/80s. 3mm vac hose should do. Should have no effect on anything else.
i didn't want to say that you didn't know your left from right...still a star to me...if you have a clear sky tonight go and watch it
The other thing that isnt clear is that there should be a 50 mm hose coming down from the air inlet through a hole in the tinware near the dipstick to a "stovepipe" which pulls hot air from No2 cylinder head cooling fins. If you dont have a stovepipe you can just point the end of the hose at the cylinder head. The whole idea is that at idle the carb shuts the inlet. There is vacuum in the inlet manifold because the engine sucks, rather than because there is a high airflow through the venturi (that second vacuum one goes to ignition advance) . If the air in the filter box where the two little spigots poke out is below 30 degrees C , the vacuum from the inlet manifold goes to the dome which then pulls the air flap to let hot air up from below. Once its warmed up or you have the throttle open so the manifold vacuum reduces the flap will remain shut and the air comes from the upper inlet pipe in the engine bay. If you have never driven your bus at around 0 degrees C you will not have experienced the difference that this setup makes to running and stopping carburettor icing. I have refitted all of the stock air cleaner and preheater kit with my progressive carb, even drilling and JB welding a new vacuum spigot on the inlet manifold for the purpose of reconnecting the correct vacuum that is there at idle. This definitely reduces 'flat spot' on cold days. In the summer time you will barely notice the absence of the correct connections so if you only ever drive your bus on warm days it doesnt matter. Getting the vapour lines from the top of the engine bay all connected up and into the air filter is definitely a good thing.
hi i have pipe going down through tinware to above exhaust. i am working at getting things back to standard but with improving things when for the better. somethings are not clear what the standard is though. want to go back to standard type exhaust probably a bluebird type....
Check you've got the banana-shaped "stovepipe" bit under the tinware that the pipe connects to. When it's all hooked up, worth checking that it does actually work . Your engine hates breathing hot air when it's warmed up, and power will likely be down. Sometimes the flap actuator rod inside the airbox snout rusts through.
