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i have a 82 olds delta 88 with a 305 v8 5.0 engine with the original carb(quadrajet). i have the standard air filter housing(case)and i wanna do a stand alone air filter but i have several hoses connected to it.What do i do with the hoses? i have something like the left picture and wanna make it like the right picture. thanks for any help i can get.
Location: I moved to pittsburgh so I can be near Primantis
Posts: 405
the hoses are for the ThermAC which is a heat riser to aid it warming the intake air early, you can plug them off as one of the hoses comes from a manifold source somewhere. there may be another temp sensor for the choke pulloff as well (snap a picture of your VECI and post it.)
Is it really a 305 or a 307? fast way to tell: where do you dump oil in?
Location: I moved to pittsburgh so I can be near Primantis
Posts: 405
ok, whatcha got....
on the air cleaner that little thing inside, on the base, with the 2 hoses connected from the very bottom are for the thermac - when cold it opens a vacuum motor that draws air in past the 2 inch diameter silver dryer vent style tube to warm incoming air. when the engine is warm, that little sensor stops it and the vacuum motor lets go, if you go to an open aka 360* air cleaner, you have not place for this. the other large 3/4inchish hard line from the valve cover is the breather for the pcv system, you really want this working.
the sensor that looks like a temp sensor sticking from the side of the air cleaner goes to the thermac but also routes vacuum to the secondary choke pulloff. a lot of people just yank that from the car anyway and set the choke for early release - like if they know it will be summer running only....show car stuff
not sure what the other large hose was, I suspect the other side of the pcv, and you had a pic of the egr in there, something else you want, it should be routed thru a vacuum delay and to a ported port on the front of the carb. actual routing is on the VECI I asked for - which should be on the radiator valence
You really need to understand what those parts and hoses do before you arbitrarily remove them. GM isn't in the habit of installing unneeded parts just to increase production cost.
Quad has it mostly correct. The Thermac system is designed to divert warm air into the carb when the outside air is cold. The blue vacuum fitting in the air cleaner is the thermal switch that opens and closes with air temp. When cold, it opens the valve to allow engine vacuum to operate the flapper in the air cleaner snorkel and pull warmed air from the silver convoluted tube connected to the heat stove on the exhaust manifold. Deleting this function may result in rough running on cold days.
The broken red plastic thing in the valve cover is a cheap replacement breather. The factory one is metal painted black. The breather pulls air from the air cleaner housing that gets pulled through the engine via the PCV valve. You can replace the red breather with a generic breather that doesn't connect to the air cleaner.
The large rubber tube is the dump outlet for the A.I.R. system (smog pump). At certain times (primarily when you let off the throttle quickly) the A.I.R. system needs to dump excessive air output from the pump. This hose simply dumps the excess into the air cleaner housing as a muffler. Early A.I.R. systems had a separate muffler housing that did the same thing. Leaving this disconnected can lead to farting noises when you let off the gas.
Please excuse me while i hijack your thread for a moment,
Joe, would you be able to guide me in finding where my blue vaccum fitting connects to? Ive always noticed it isnt hooked up to anything but it as well always seems to slip my mind to look into it, and since were on the topic, who better to consult than the master?
Please excuse me while i hijack your thread for a moment,
Joe, would you be able to guide me in finding where my blue vaccum fitting connects to? Ive always noticed it isnt hooked up to anything but it as well always seems to slip my mind to look into it, and since were on the topic, who better to consult than the master?
I believe I misspoke above. The blue vacuum sensor isn't the Thermac control, I believe it is a Choke Thermal Vacuum Sensor (CTVS), used in the late 70s and early 80s to control the choke pull-off vacuum diaphragm. One side is connected to manifold vacuum, one to the choke pull-off and one is a vent that goes to the air horn to dump vacuum and release the diaphragm when the sensor closes. This function was replaced by a vacuum solenoid controlled by the ECU as the CCC system matured in the 1980s.
Is there any way you'd take on an apprentice.... I'll work on all your stuff for free if you tell me how to do it.... Your like a search engine of actual relevant information....
The info I posted in Post #7 above apparently applies to the late 1970s cars. The 1981-82 cars have slightly different vacuum plumbing of the CTVS. The photo below is from the 1981 CSM and pretty clearly spells out the connections. Once again, sorry this took three tries to get right. This is a pretty obscure emissions control part that was only used for a few years.
The info I posted in Post #7 above apparently applies to the late 1970s cars. The 1981-82 cars have slightly different vacuum plumbing of the CTVS. The photo below is from the 1981 CSM and pretty clearly spells out the connections. Once again, sorry this took three tries to get right. This is a pretty obscure emissions control part that was only used for a few years.
Hahahahaha even with the misinformation i still figured out a few things that were stumping me, so on target or not your info helped as always. Thanks!
I think one of the reasons that a lot of people are all "let me pull all them hoses and **** off that engine and it will look and run better" is that they think it's all emissions based stuff and can all go away with no negative, and possibly even some positive, impact.
A lot of the stuff in the 80s is the pinnacle of carbureted engines in terms of driveability and performance (as in reliability and manners, not horsepower) during adverse conditions. Of course, the problem with that stuff is that, when it breaks, the engine barely runs. I'd rather have an engine with some occasional bad manners that is rock solid reliable. On the other hand, my current driver is almost 200k on the original plugs, so go figure.
Location: I moved to pittsburgh so I can be near Primantis
Posts: 405
Originally Posted by joe_padavano
This is a pretty obscure emissions control part that was only used for a few years.
sez you, we had to train on these things! ;-)
That part is one of those 'not really entirely needed parts' applied to satisfy an emission law in name only. At the time no state tested emissions on a cold motor simply because there was no positive engine control and the point was to gauge system compliance, so by the time the motor was up to operating temp, all means to remove any and all choking were fully in play. most guys I know who have a 360* air cleaner and a nice and shiny coated qjet have that whole system gone and the manifold plugged.
July 7th, 2016, 07:27 PM
