questions on combinated fuel and vacuum pump

[Cpt.Fred]

Hi everybody,

 

i intend using a Carter M750SA combinated fueal and vacuum pump on the new engine in my Plymouth P10.

bought this NOS quite a while back since i do not want to drill and tap the intake and thought i'd get much better wiper action

when stepping on the throttle.

as you can see it's all pretty tight down there with the split manifold.

the fuel part of the pump will just be filled with fuel to keep the diaphragm moist and intact and then i'll just connect a hose from

the OUT back to the IN port to circulate it.

 

i thought the vacuum side of the pump would be similar, IN on the front and OUT on the back, so i hooked it up that way,

but i looked closer yesterday i saw lettering on the front port saying MAN and the rear port says WIPER...

 

does anyone have one of these in the car and can tell me what is originally connected to the MAN port and what it means?

can i hook the wipers up to the MAN port and just block the other one, or is it needed to suck in fresh air?

it's pretty close to the front exhaust dump, and despite the modified heat shield it will get pretty warm down there.

 

i heard rumours these pumps were used on ragtops to move the folding top, but i cannot really believe that.

 

any info would be greatly appreciated!

 

here's some pics of the pump:

 

 

 

 

 

 

 

thanks,

 

Fred

Edited July 5, 2016 by Cpt.Fred

[Mark D]

Man = possibly manifold?

Edited July 5, 2016 by Mark D

[Don Coatney]

This might or might not help. Follow the link and read the entire thread.

 

http://www.stovebolt.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=51528&page=1

[Cpt.Fred]

thanks! kinda sad though...

that would mean i still need a connection to the manifold... which i do not want to drill a hole in.

 

i wonder why it has to be connected to the manifold. doesn't it create a vacuum by itself?

guess i will take the plugs out, spin the starter and just try out what it does then...

[Don Coatney]

Fred, I have never used a dual pump. All I know is what I read in the link. I was not able to get any more information in my search. Hopefully someone with experience will chime in.

 

On another note is the gasoline in Germany enriched with Ethanol as it is here in the States? If so you may want to replace all the rubber parts in your NOS fuel pump as Ethanol and old rubber do not get along well. 

[Cpt.Fred]

yeah, i thought, when it says 39-50, there should be a lot of them out there...

not so, apparently. if the pump is connected to the manifold it would seem it is only used as a booster

for manifold vacuum. that would mean it's not very strong. i guess i just hav to try it.

 

we have ethanol fuel here, but it's low percentage.

i am using an electric pump to feed the engine, but still it would be nice to have this one intact.

if the diaphragm gives in i will replace it with a new one, if i can find any.

[knuckleharley]

First off,I want to say like Sgt Schultz,I no nutting about your fuel pump.

 

What I do know is that whoever split and welded up your exhaust was a craftsman of the 1st order. Do you know who they are and how I can contact them?

 

Finally,I am probably wrong about this,but I THINK that someone makes small vacuum pumps that work off of 12 volts that you could wire up independent of your manifold and fuel pump,and solve your problems. If your fuel pump is as rare as I suspect it to be,you could easily sell it for more than enough to buy and install the vacuum pump. I would be surprised if someone didn't also make them for 6 volt systems considering all the millions of 6 volt cars sold over the years.

 

Or you may even be able to find one powered by AA batteries if you look around. It's not like you will be driving in the rain every day.

 

Wish I could remember more about those pumps other than that they exist or existed,but can't.

 

BTW,if you want to leave your fuel pump on your engine instead of using a block-off plate,I think I would use thin oil in it rather than ethanol gas. Oil will preserve the diaphragm and ethanol will dry it out and eat it. Maybe not engine oil,but I am sure there is a form of oil you can buy that preserves material like diaphragm's without rotting it.

Edited July 5, 2016 by knuckleharley

[Captain Neon]

What percentage ethanol?  We have 10% ethanol in the US, and it can be hard on old neoprene.  There are still a lot of people in the US that are convinced that their cars are going to explode from ethanol in the fuel, MTBE (now illegal) was the real culprit, and pay a hefty premium for non-enriched gasoline. 

 

The biggest problems with ethanol are carburetor adjustment (float should be lowered 2 to 3/32"), obsolete material failure (gaskets and hoses), and loosened varnish.  There may be old hose and gasket material floating around in old storage buildings or small quantities stashed in garages, but I think most people would refrain from using 20+ year old hoses.  All the fuel hoses and gasket material now sold in the US is designed to resist ethanol.  As for the loosened varnish and sludge, an inline fuel filter can prevent the pieces from making their way to the carburetor.  In the '90s (when E-10 became common in Minnesota), I changed my fuel filter every spring as preventative maintenance.  I never had one clog on me.  I now change it as an afterthought if I remember it.  Most new cars sold in the United States don't even have fuel filters any more because ethanol keeps fuel systems so much cleaner.  I replaced the 20+ year old fuel lines in 2003 when they started to crack, and rebuilt the carburetor in 2008 when the 62 year old accelerator pump failed.  This all would have happened even without ethanol in the fuel.

 

I run all of my vehicles with E-10 year around.  I even tank mix E-50 in the summer time in my Dakota pickup.  I've even been known to top off my '97 Neon and the wife's '09 PT Cruiser with E-85.

[greg g]

Yes the pump is meant to fill the gap when manifold vacuum drops under load or acceleration. Do you have a vacuum gauge? Normal manifold vacuum is 17 to 21 inches of mercury. Hook the gauge to the man side and see what it pulls. If it anywhere near the normal reading then it should work. But you could probably plumb in an accumulator between the pump and the wiper motor. While thinking about this, a little creative plumbing should allow both diaphragms to pull vacuum. However I would plumb the man side to the accumulator, and then the accumulator to the wiper motor. This way the pump would be evacuating the accumulator,and the accumulator would be powering the wipers. Again you can check the motor side using the gauge to query the vacuum developed in the accumulator. This is how the vacuum actuated convertible top worked, not off direct suction developed directly by the pump If all fails there is always rain X.

[Cpt.Fred]

knuckleharley:

engine, headers, tranny etc were built by George Asche.

full story here: http://p15-d24.com/blog/17/entry-107-das-boot-going-the-long-block-route-with-a-1940-plymouth-sedan/

 

thin oil sounds like a good plan, thanks!

 

i rode around with standard manifold vacuum on my previous triple intake with little to no wiper action, so i thought it would be nice to improve that.

 

Cpt.Neon:

E10 is normal here, though i think normal fuel with 95+ octane has 5% in it as well.

 

greg g:

i will spin the crank without plugs and see if both ports are pulling. if so, i put a T in the line and hook the wipers on there.

i don't have a vac gauge, it think, but one of my motorcycle guys might have one.

Edited July 5, 2016 by Cpt.Fred

[Don Coatney]

I installed a vacuum reservoir for my wipers. If you elect to do so make sure you also install a check valve on the vacuum supply line. The white thing in the picture below is a check valve. The check valve allows the reservoir to store the highest vacuum in the system. Without the check valve the tank would go up and down based on how hard you hit the foot feed same as the intake manifold vacuum does. With this tank I can get 4-5 swipes of the wipers after I shut the engine down.

 

[casper50]

I bought a complete electric set out of a 47 chrysler.  Going to switch the vacuum out and the electric in. My first vehicle was a 49 5 window Chevy truck.  I hated the vacuum wipers.

Edited July 5, 2016 by casper50

[DJ194950]

The only real reason to hook up the air source end of the vacuum pump is supply filtered air to the pump. I guess the idea was to get the supply from where the original vacuum source was plumbed as is was the and convenient only.

 

I have had two of these dual pumps on different cars.  One of them had a fitting tapped into the air cleaner as Man. . source and the most recent I just used a paper inline fuel filter as my air filter and it mounted up behind the radiator support. 

 

Both worked great with no slowing down of the wipers even with the gas pedal floored!.

 

Prefer myself to supply vacuum source  to the wiper motor with no fuel fumes in it which is what I believe is the cause of the wiper oil turning to a bees wax consistency over time.

 

I agree with a slight amount of thin plain oil would be better than fuel in the fuel side of the pump as a lubricant.

 

DJ

[Don Coatney]

What am I missing? Why would a vacuum pump need an air supply? Flow is from the wiper motor to the atmosphere.

[Cpt.Fred]

casper50:

is it a 6V postive ground setup? do you have pictures of it? sounds interesting.

 

DJ:

i will try that. i hooked up both ports to a T connector yesterday and it seems to pull,

but if you are running yours like you said with no issues i will switch to your system.

what "wiper oil" do you mean, do have oil in your motor?

 

i put a NOS wiper "motor" in the car, but all it would do was pull the wiper blades up (very slowly and painfully)

and stay there. so i had rain-ex on the glass all the time and when it got bad i let the motor pull the blades up

and switched it off, so they fell back down. that way i had at least one wiper stroke and could go on until the window

had filled with drops again... gruesome, eh?

Edited July 6, 2016 by Cpt.Fred

[casper50]

No photos at the moment.  I can get some in the morning.  Stock setup from a 47 Chrysler.  6 volt positive ground

[TodFitch]

. . . what "wiper oil" do you mean, do have oil in your motor?

 

i put a NOS wiper "motor" in the car, but all it would do was pull the wiper blades up (very slowly and painfully)

and stay there. . .

 

 

There is lubricant inside the vacuum wiper motor if/when it dries out the motor will work poorly if at all. When vacuum wipers first appeared, it was considered a yearly maintenance item to lubricate them. Not sure if that was still true by the 40s or 50s, but it is likely that a NOS wiper would need to be at least lubricated if not disassembled, cleaned, lubricated and reassembled to work well.

 

For what it is worth, I use air tool oil on mine. But I don't lubricate it every year as I am too lazy to disassemble the interior pieces above my windshield to get at the motor, it doesn't rain that much where I live, and when it rains I typically have my car in the garage. Your later car has the motor under the dash which presents different access problems.

 

Here is how you lubricate one of the 20s/30s style vacuum motor where there is one motor per blade: http://www.ply33.com/Repair/wiper

 

Not sure how you do it on the later motors, but I imagine you can find a procedure someplace on line.

[knuckleharley]

i put a NOS wiper "motor" in the car, but all it would do was pull the wiper blades up (very slowly and painfully)

and stay there. so i had rain-ex on the glass all the time and when it got bad i let the motor pull the blades up

and switched it off, so they fell back down. that way i had at least one wiper stroke and could go on until the window

had filled with drops again... gruesome, eh?

 

The diaphragms get dried out and hard,and just don't work properly after sitting for years. Even in NOS pumps.

 

Try spraying a little WD-40 or 3 in 1 oil into the housing and see if that helps it get flexible enough to seal. Usually doesn't take much.

[Young Ed]

Here's a pic of a p15 vacuum wiper setup vs a 46-48 Chrysler elec one. As you can see they look quite similar in size. I haven't crawled under my dash to attempt the swap.

 

 

Edited July 6, 2016 by Young Ed

[Andydodge]

Hi Fred, just finished reading your thread on the 265 engine installation, great read and nice to see another hotroded 1940 mopar...........lol...........but regarding your wiper motor I would have suggested using an electric wiper motor, there are a few different kits around plus being in Germany you'd have access to various small wiper motors including the BMC cable operated ones which are a great setup, I have one in my 1940 Dodge which is mounted behind the glove boxand works well............I intended to do the same swap in the 41 Plymouth Coupe but sold it B4 this happened.........trust you get the vaccum setup working o/k but there is a reason vaccum wipers aren't used any more.............lol..........anyway my regards and I look forward to more pics when the cars finished......Andy Douglas   

[DJ194950]

Cpt.Fred

 

I think the suggestions and those on the link from Todd are the answer about the oil. Very small amount based on usage hours. Very little needed!  A short section of air line hooked up in place of the vacuum line on the wiper motor with few drops on light oil in it-  tied up high under the dash to retain the oil as you work the wiper arms by hand outside the car, perhaps repeat and then re-hook up the vacuum line and give it go.

 

Good luck,

 

DJ

[Cpt.Fred]

hey Andy, good to hear from you!

glad you like it, even with the lack of chromity-chrome, lol...

i have pretty high hopes on the setup, unfortunately i do not move along as fast as i would like...

but the patience will finally pay off, i guess!

 

i will stay with the vacuum unit for now (cause that double pump is so cool in my eyes) but if it

doesn't work properly i will try to go electric.

 

this is how it is now:

 

 

 

the copper line sucks air in, i will put a hose and some kind of filter on it later.

 

DJ: i already followed Todd's advice and oiled the motor yseterday...

during the next text runs of the engine i will try to make those wipers move!

Edited July 7, 2016 by Cpt.Fred