re: wiper vacuum source
 

After reading the discussion on boosting wiper vacuum isn't there a 12 volt electrically powered vacuum canister available? I'm looking at replacing my vacuum wipers in my 50 merc but it would be a lot easier work wise and possibly cheaper to hook up an independent 12 volt vacuum source and I assume it might give me wipers with some variable speed capability. Any ideas?
Thanks. Lefty Rodan

Re: wiper vacuum source
 

Here's one.

https://cdn.sparkfun.com//assets/par...4/10398-02.jpg

Available here for $14.95: https://www.sparkfun.com/products/10...dMEaAr4v8P8HAQ

A bunch more here: https://www.google.com/?gws_rd=ssl#q...mp&safe=active

Here's what looks like the same one in 6 volt if anyone's interested (I might even be): http://www.alibaba.com/product-detai....12.kz1Heb&s=p

More choices here: http://www.alibaba.com/showroom/vacuum-pump-6v.html

Re: wiper vacuum source
 

How would a person determine the capacity required for a vacuum wiper setup to see if one of these vacuum pumps would work?

Seems like a great addition, IF the capacity is there

Re: wiper vacuum source
 

"After reading the discussion on boosting wiper vacuum isn't there a 12 volt electrically powered vacuum canister available? I'm looking at replacing my vacuum wipers in my 50 merc but it would be a lot easier work wise and possibly cheaper to hook up an independent 12 volt vacuum source and I assume it might give me wipers with some variable speed capability. Any ideas?
Thanks. Lefty Rodan"

Lefty,
Do you possibly have a dual action fuel pump on your Merc now, and that and your manifold vaccum combined are not sufficient to power your wipers? If you are just operating off the manifold vacuum now, you could check to see if a dual action fp would fit on your Merc, and give that a try before going in other directions that have been suggested. Now maybe the cost of a dual action fp would be more than some of the other suggestions that have been made, I am not sure.

ps...I still have that nice 4" Merc crankshaft in my stash :) just waiting for its chance to get back into a nice newly built flathead, but the only poesibility I see for it now is to maybe use it in an early 21 stud 36 LB engine :) and it just might happen :)

http://www.ebay.ca/itm/1951-ford-dou...-/400116863720

Re: wiper vacuum source
 

One way to find out what it takes to power the wiper is to measure the volume of the wiper vacuum chamber and then multiply with desired speed of the wipers.

Re: wiper vacuum source
 

The pump I found (Post #2) moves 12-15 LPM. I'm assuming that's liters per minute. That sounds like quite a bit without knowing exactly how much a vacuum wiper motor takes. I'll probably order the 6 volt one for my car and try it out and see. I won't use it full time but as a "booster" on a long climb in heavy rain or snow to keep the vacuum wipers going.

Re: wiper vacuum source
 

Wonder how much the diaphragm of the pump can take, so running it in series and engine braking dont break the pump.

Re: wiper vacuum source
 

Vacuum can't brake the pump because vacuum maxes out at the ambient air pressure of about -16 psi. The biggest strongest vacuum pump in the world (including a flat heat engine) can't create any more vacuum than that, just higher volume.

For a booster, I will connect my electric pump to the regular wiper vacuum line with a T such that the engine provides the vacuum most of the time. Then, when it doesn't provide enough (long climbs or acceleration) I'll switch on the booster pump to supplement. The one way valve at the carburetor will keep the electric pump from sucking air backwards out of the carburetor or manifold. That's already a stock item in the system.

Re: wiper vacuum source
 

I would be interested in a 6 volt unit. Does anybody have the scoop on "Ali-Baba"? This is not the first time I've run into them; they seem to be reps for various Chinese manufacturers. Can you order direct from them? When I tried to go further on their site, I got in to a manufacturing quote request area. I didn't go any further for fear of inadvertently ordering 100,000 of something.

Re: wiper vacuum source
 

Try ordering "samples" that usually makes them interested in selling a single unit and of good quality to have you return ;)

Re: wiper vacuum source
 

Ali-Baba is supposedly a Chinese AMAZON-like outfit. I steer quite clear! DD

Re: wiper vacuum source
 

Im not sure how much vacuum that pump can create in reality and if it can take more then that.
Next is how well it handles oil and other leftovers from the wipermotor.

Re: wiper vacuum source
 

Alibaba is the distributor, not the manufacturer. The manufacturer is Emily Xiao Shenzhen Yanhua Faith Technology Co., Ltd. and can be contacted directly. I haven't tried that. Although many of the pumps Alibaba sells have minimum quantities of numerous, this pump is listed only requiring a minimum order of 1 with a price from $3 to $20. I've sent a request for a price. The request form provided a box to check for other distributors to contact me if this one doesn't in 24 hrs. We'll see what happens. I did have to put down a company name, which I have, so, they may just sell wholesale to businesses for resell.

Re: wiper vacuum source
 

The pump creates up to 16" Hg of vacuum. I intend to try one out and see how it works and report.

Re: wiper vacuum source
 

Just a thought. If you had a vacuum gage hooked up in the car, you could determine at what reading the wiper motor quits. Knowing that, any pump would have to attain a vacuum pressure that is better, and the key thing, have sufficient volume.
For ha-ha's I connected an auto vacuum gage to my shop vac.and the best it would do is 2lbs. vacuum.
A rough estimate of the volume of the wiper motor is .128L If the electric pump is rated at a volume of 12-15LPM a rough estimate is that should provide appox. 93 strokes of the motor per min. (but don't take it to the bank) Hope it works as it could provide a relatively cheap solution to many.

Re: wiper vacuum source
 

Hmmmmm.......I'm used to seeing vacuum readings in inches of water, or inches of mercury. Never seen one measured in lbs. of vacuum. DD

Re: wiper vacuum source
 

Can we be sure that Chinese vacuum meets US standards, though? ;)

Re: wiper vacuum source
 

Duly noted (Dam Chinese gauge):D

Re: wiper vacuum source
 

I'm used to watching the manifold air pressure gauges on the helicopters. They likely correlate to some degree on normally aspirated engines. The vacuum in inches HG is usually around 10" HG at idle but increases closer to ambient pressure at wide open throttle. That's why they put the boosters on there was so you would still have enough vacuum to keep the wipers motoring when running down the road at highway speeds. I remember having to let off the throttle now and then to get some vision back when driving in a hard rain. I figure the wiper motor needs around 16 to 20 inches HG in order to operate. The closer to ambient, which is average 29.92" HG at sea level, the slower the wiper will work. Most folks that have ever driven a car or truck with vacuum wipers usually note that they don't motor at all at higher power settings since there is just not enough vacuum there.

If a person uses a vacuum source other than the engine, you could have wipers that work all the time as long as the thing has enough vacuum pumping capacity. A person could use a regulator or an adjustable vacuum bypass bleed if the source put out too much vacuum. This would control the wiper speed to some extent if it was easily adjustable.

Re: wiper vacuum source
 

Yeah, let us know. I would be interested in one if it works okay.