The Stovebolt Site Forums The Shop Area General Truck Talk Any idea what this is?

I'm digging around in the engine compartment today and had to get this thing out of my way to get to the starter. I don't see it in any of the catalogs. The other end of the hose goes to the carb.

[img]http://www.grayinflorida.com/chevy/whatisthis01.jpg[/img]

It,s a vacuum reservoir to help the wipers under acceleration.

ditto

where on "the carb"?
if it's a vacuum can [as it appears] it should have one hose from the intake manifold and one to the wiper motor, and a one way valve inside

Bill

so if i make a contraption like the one pictured or kinda like it, it will help my wipers work better,just a line out of the carb to the canister?

All it is Is a Vacumn Reservoir to increase Capacity.
Quite like adding another tank next to your compressor,to increase volume

10-4,thanx

I'd like to hear a little more about how this works - like how is a vacuum created in a closed container w/o collapsing the container? what happens to the vacuum in the can when you give the engine full throttle? does it suck gas into the can? how does the can have any effect on the vacuum running the wipers [which are hooked to the manifold] when manifold vacuum drops?

there was a vacumm reservoir can on my 57 panel when I got it - had a valve on it w/ 2 tubes, one to the manifold where the wipers would normally connect, one to the wipers - didn't investigate it's function as the vacuum wotor didn't work and I installed electric, but it looked 'purpose made', maybe even GM

Bill

Steve,

You ARE being watched..mind yer P's & Q's buster! :p


Stooo

its a vacume canister off a mercury cougar. what is does simply put is it stores vacume for opening and closing the headlight covers on a cougar. camaros that had hidaway headlights also had a canister similar to this one.

I would not think this item could work without at least a small check valve and another line somewhere.

Their must be plumbing that is not shown, or this was a mad invention in progress!

Stuart

yeah I'd say it was someones attempt to improve the wipers, but the only way to do that is put something in the line to the wipers - that single line wouldn't do anything for the real problem, which is that with extended engine load, like going up a hill, the wipers will stop dead, or nearly - lot different than subtle variations - the hesitation from just punching the gas in normal driving is hardly noticeable to someone used to vacuum wipers, cuz it only lasts a second

I still wonder where the tube actually connects, particularly in relation to where the wipers connect

Bill

I looked at some other pictures I took yesterday and the line comes off the back of the intake manifold and through what looks like a simple splitter, but could be a check valve. I'll get a closer picture and post it tonight. The other line runs through the firewall. I haven't chased that line to see where it goes yet.

No windshield, windshield wipers or engine power to verify if this actually works. ;-) Maybe I can report back in a few months.

i think it is a small alien space craft and if you ever have trouble getting your truck started it is probably from the gremlins that were driving that craft. they are mad because they were abandoned here by their superiors and have decided to infect our bolts with all kinds of little problems that will annoy us for eternity.

A simple vacuum resovoir is not complicated and consist of tank, supply line, check valve and line out to option to be operated by vacuum.Supply is from a source that creates vacuum such as intake manifold,vacuum side of fuel pump or a vacuum pump.The check valve is a one way, in line to storage tank/resovoir to prevent reverse vacuum leak down.
When the option to be operated is turned on the tank furnishes the needed stored vacuum,(hence no delay in option being operated) pressure is relieved from the valve which opens the supply line when the resovoir back pressure overcomes the valve pressure the valve closes which could result in a slight increase in horsepower to the motor driving the source.
Simple, huh?
Hobert

exactly
a tank simply attached to the intake would just provide an effectively larger volume intake manifold - no effect on vacuum supply

Bill

Hey, thats a neat valve cover!!

I'm no automotive engineer, but here's how the one hose "extra suck" thing was explained to me years ago by a one legged black man named Marvin.. who also had a penchent for boons farm and young girls, so don't take anything he says all that seriously.

As the engine runs, their are ports on it that suck air.. as the carb draws air into the engine.

This can thing gets all the air sucked out of it, creating a vaccume in the can.. to a certian point.. then the constant sucking on it prevents any air from rushing back into it.. so you've got a can under the hood that's just itching to suck some air when given the chance.

Now lets say you get the RPMs up like when taking off, or putting some load on the engine.. you loose, for a moment, the natural "suck" from the carb.

When the "suck" level drops from the carb, it's no longer strong enough to operate the vac wipers at "full speed", nor is it able to trap the vaccume in the can.. so the CAN begins to suck air back in.

The suction from the can compensates for the momentary loss of suction from the carb.

The line usually goes into a port on the manifold, or in some cases, into a "Y" adapter that goes to the vac wipers.

P.S. is that a 0 pressure radiator cap? The stock 50 motors I thought needed to have a 0 pressure radiator cap.

Altho with that nifty valve cover, that might not be a stock motor.

I really like that valve cover.

the valve cover is the usual for 55-62 235's

Bill

I can dig it.

I saw his sig said '50 3100 so I just assumed thats what we were talking about.

I like that valve cover.. I wonder if it'll fit on a '46 216?

an original Maxwell House coffee can


we used to use one to increase the volumn of vacuum for wipers. one tube in one out

I think that it is the transmogrification chamber.

Fumblin - no - 216 used the 2 studs thru the top to hold it down didn't it? that late 235 cover uses 2 screws on each side flange, into threaded holes in the head - of course you might be able to fill those 4 holes and put the 2 holes in the top

Bill

The truck is a 1950 3100. Someone just narrowed my engine down to a 1960 235 from a Chevy car. I have no idea about the radiator cap. I have had the truck in the garage for just over a week and have not received my shop manual yet.

But I think the whole engine is coming out soon for a clean-up and revival. Maybe someday it will run again to see if this coffe can actually does anything.

its an "ORECK"

CLIff59

Yea both my '46 216 and 235 have the two "acorn nut" nuts that hold the valve cover on.

I guess what I should have asked is if that valve cover is the same physical size as the older valve cover. I don't imagine it would be a problem to drill two holes in the top to accomidate the posts, so long as they didnt end up comming thru the "chevrolet" script.

Vaccum is a problem on acceleration and is also a problem if you are using any sort of cam- ie howards/cliffords...

At rpms you get less vaccum with a high lift/longer duration cam.

I've switched to electric wipers and added power brakes. So, I'm using a vaccum can and a dual action fuel pump. Hopefully it'll be enough so that I get a second pump on the brakes at higher rpms after the first charge on the diapragm is used.

Pulled the can and three nippled check valve from a lincoln that used it for the headlights. The check nipple goes to the vaccum source, then one line to the can and one line to the booster (or wipers).

(with the checked portion of the valve towards the vaccum source, the reserve in the can won't get depleted/backdrafing to the engine when it isn't producing as much vaccum as is in the can)