70 battery vent tube

[Bill C.]

Re: 70 battery vent tube

i was mostly just trying to raz Paul a little - was not being serious about orientation. :-))

My real feelings for the angle cut - a hell of alot easier to slip through a tight hole.
The cut end will compress and fit into the hole better ...

[Dave S.]

Re: 70 battery vent tube

i was mostly just trying to raz Paul a little - was not being serious about orientation. :-))

My real feelings for the angle cut - a hell of alot easier to slip through a tight hole.
The cut end will compress and fit into the hole better ...

All original cars that i have seen have the angle facing the rear as Ron indicates and one smooth and one ribbed hose.

If you can't find a smooth hose then a fine/medium piece of sandpaper will make the ribs go away.

[Jeffrey S.]

Re: 70 battery vent tube

Jeff,
Attached are 2 photos of an extra smooth hose I have (if they are not there I will try again). The length is 16". The angled ends on this one and the 2 on my '69 are very crudely cut.
Jeff

[Mark D.]

Re: 70 battery vent tube

I thought the air flow had to cut across the angle cut to cause a pressure drop?
Kind of like a air foil section of a wing. Faster air over the curved section, slower air on the bottom (flat), lower pressure up top.

So, that's how that works.

I read about Bernoulli (Bubba Bernoulli from Bugtussle, MS) but didn't know he came up with his theory as a result of battery vent tubes.

[Paul O.]

Re: 70 battery vent tube

Guy,s it is like Thud"s law of opposition if you push something hard enough it will fall over.

Just like Ron and Dave,s observations over the years originals i have seen always had the angle facing aft.

[Dave S.]

Re: 70 battery vent tube

DSCN4877.jpg

Guy,s it is like Thud"s law of opposition if you push something hard enough it will fall over.

Just like Ron and Dave,s observations over the years originals i have seen always had the angle facing aft.

I got to thinking after I made my post and rechecked my 3 Bowtie cars. (1 - 70 and 2 - 71's) and I was incorrect in agreeing with Ron. All my cars have the angle cut facing the front and the angle of the cut is very low as per attached sketch. This is from a 70 but the 71's look similiar.

[Terry M.]

Re: 70 battery vent tube

The angle cut facing the rear (or aft as those flying machine people like to say) makes sense -- with a bow to Mr Bernoulli. But I can't imagine the line workers were anywhere near as anal as we are, or as Mr Bernoulli would require.

[Paul O.]

Re: 70 battery vent tube

Paul, until he rings back in, are you saying you think Ron G. was referring to the angle of the cut off ends when he said "Also those hoses face the rear of the car." and not the vent tube install orientation itself? That does make good sense.

Whether or not they were intended to face rearward, the AIM fails to show any detail regarding orientation of the cut that I could see. Right or wrong, mine face reward. I've attached a photo that I took tonight, standing under the center of the car, looking outboard. You can see that the ribbed vent tube is in the aft position. Smooth in forward position.

Frankly, I struggle to see how the line operator(s) would spend the time it takes to ensure specific orientation of the beveled cut, regardless of work instruction or spec, no? Does anyone know the elevation of the body during this part of the assy. process?

BTW, Jeff - if it helps, I also measured my vent tubes tonight. ID = 1/4". OD = 3/8" (both tubes).

Hope this helps...

Don
The angle cut of your hoses do not look typical factory just my observation.

[Joe L.]

Re: 70 battery vent tube

All-----


Attached is a photo of the absolutely known-original hoses on my original-owner, September, 1969 built convertible. I left the hoses in the battery compartment after I changed to "sealed" type batteries years ago. The rearmost hose is ribbed and the forward hose is smooth. Note there is no sign of any "beveled end " on these hoses. These hoses do not seem to me to fit so tightly in the holes that, even if the bottom end were beveled, the hoses would remain in any particular orientation over time.DSCN2753.jpg

[Paul O.]

Re: 70 battery vent tube

All-----


Attached is a photo of the absolutely known-original hoses on my original-owner, September, 1969 built convertible. I left the hoses in the battery compartment after I changed to "sealed" type batteries years ago. The rearmost hose is ribbed and the forward hose is smooth. Note there is no sign of any "beveled end " on these hoses. These hoses do not seem to me to fit so tightly in the holes that, even if the bottom end were beveled, the hoses would remain in any particular orientation over time.[ATTACH=CONFIG]42509[/ATTACH]

Joe

That is the reason I wrote typical down as to what I or other may have seen and I agree with you on my 71 they were very tight and would not have moved over time.
Here are a photo or 2 of other I have noted over time. Plus looking at my old photos my hoses were facing inboard or toward the drive shaft me then incorrect in my statement. I would add that for the pressure drop to work the hose should be positioned aft, left or right but pointing forward would act like an air scoop forcing air into the battery.

[Mike F.]

Re: 70 battery vent tube

Mine face forward (70 Coupe)

[John H.]

Re: 70 battery vent tube

Bill,

I meant that the open part of the angle faces the rear portion of the vehicle.

The same design principle was used for the C1 crankcase road draft tubes, to maintain a low pressure area at the end of the tube when the car was moving; original '57 tube shown below.


RoadDraftTube57Orig.jpg

[Jeff S.]

Re: 70 battery vent tube

Jeff

If I am reading your post properly you are saying you have the two hoses I need. If they are available I would be very interested in them. Thanks Jeff

[Jeffrey S.]

Re: 70 battery vent tube

Jeff,
I have a smooth hose but it is not for sale. I want to keep it. Sorry if I led you to believe it was available for sale. I just wanted to show you (and others) how crudely it was cut and give the length information.
Jeff

[Joe L.]

Re: 70 battery vent tube

All-----

Completely peripheral to the primary topic here, there's something really curious about these tubes. First of all, as back ground, understand that the ribs seen on rubber tubing usually represent a code that identifies the manufacturer of the tube. Also, the same tubes, GM #3812819 and GM #3769512, were used from 1968 through 1975. The fact that there were two part numbers tells us that neither number represented bulk tubing. If the tubes were cut at St. Louis from bulk tubing, only one part number would have been necessary. In addition, the fact that one hose had ribs and the other not indicating different manufacturers is also consistent with each tube being a discrete, pre-made part.

Now, the curious part. The tube of part number 3769512 was released sometime in 1958. The tube GM #3812819 was released sometime in earlier 1962. So, both these tubes were originally released long before they were first used in any Corvette. Consequently, they must have been used for some other Chevrolet application. However, since they were PRODUCTION-only pieces, I cannot determine what those applications were. Perhaps windshield washer hoses for some application?