Vacuum Wipers and Voltage Choices

[Loren]

When I bought my 49, the seller told me the wipers didn't work.

Being a business coupe, the cheapest Mopar made, I knew they'd be Vacuum powered.

In the box of spares that came with it were old wiper blades and arms. That should have been a clue as to the problem.

 

This last week I decided to renovate a Wiedenhoff Distributor Machine I've had for years.

Inside there is a robust Vacuum Pump to test the vacuum advance units. So I removed the Vacuum Wiper Motor from the Plymouth figuring it would be a good test of both.

In all of my Mopar shop manuals there is nothing on Vacuum wipers. I suppose there were so many of them for so long they saw no need to tell the mechanics what they already knew.

When I had done the TLC job on the pump I tried it out. The thing works perfectly...both of them.

The first thing I did before pulling the Wiper Motor was pry off the wiper arms.

Once I got the motor re-installed I hooked up a new hose to the engine and tested the linkage.

I didn't realize it but vacuum wipers have a park position and an infinitely variable speed control.

Electrics of the era had two speeds, too slow and way too slow.

The next step was to mount the blades. I figure someone wanted to change the blades and could not figure out how to get them back on right.

Park is achieved by going a little backwards when the vacuum is relieved.

They must have given up and plugged the hose.

 

Now of course vacuum wipers don't care what voltage the car runs.

My car is so original (and low mileage) that it still has the Bull's Eye Head Lights and other stuff I am loathe to change for 12 volts.

So I've decided to keep the 6 volt system intact. Vacuum Wipers of course run nearly acceptably fast enough at idle but the wider the throttle opens the slower they become until they sometimes stop altogether. There was an extra cost fix for that problem. You could buy a Dual Diaphragm Fuel Pump. The manual says very little about them but has one exploded view. A quick scan of eBay and I found two! The top chamber pumps vacuum, the bottom pumps fuel. So when you accelerate the wipers speed up and when you encounter a hill they just keep going at whatever speed you set. That infinitely variable speed control sounded real good.

There is a consequence to this fuel pump. You can't run the Cast Iron Headers. In fact you can't run any stock fuel pump with them. Which means you have to go to an electric pump and since there are not that many 6 volt pumps....you're back to 12 volts again.

So...When I get around to putting my Thickstun Twin Stromberg manifold on I am going to carefully work over the stock manifold with the Rusty Hope kit.

However, I will braze in a divider. Rusty Hope adds a second exhaust flange under the carburetor heat stove area but makes no provision for divided exhaust.

So that's my wiper story...and I am sticking to it.

[DJK]

I have a Carter 6v + ground pump, love it.

[Sniper]

6v electric fuel pump

 

https://www.summitracing.com/parts/crt-p4259

[chrysler1941]

10 hours ago, Sniper said:

6v electric fuel pump

 

https://www.summitracing.com/parts/crt-p4259

I prefer the Airtex E8902 for 3 reasons. 

1. It's a flow through model meaning mechanical pump (if Installed) can continue pumping even if power is off.
2. It delivers max 4.5 PSI. same as mechanical pump, thus no need for pressure regulator or needle change.
3. It's half price and more quiet.

[Sniper]

6 hours ago, chrysler1941 said:

I prefer the Airtex E8902

The Carter has the benefit of being available. 

[Plymouthy Adams]

I personally cannot see the benefit of adding dual carbs, split headers and a few other favored mods on a flathead 6....the added performance verse the cost is so low in bang for the buck.....there are the few oohs and ahs one gets that boost the ego a bit and well, that is okay...something for everyone and well I am guilty of a few things in this hobby causes some to point directly at me and scream     "blasphemer.."

[kencombs]

9 minutes ago, Plymouthy Adams said:

I personally cannot see the benefit of adding dual carbs, split headers and a few other favored mods on a flathead 6....the added performance verse the cost is so low in bang for the buck.....there are the few oohs and ahs one gets that boost the ego a bit and well, that is okay...something for everyone and well I am guilty of a few things in this hobby causes some to point directly at me and scream     "blasphemer.."

Yeah, bang for the buck is low, but still a lot cheaper and faster than a late model electronic engine/trans upgrade,  IF you don't have to buy new parts.  New manifolds, carbs and esp headers are spendy.

 

I was reading another swap tale, started simple but last I read, it is a late hemi, trans, computer, harness AND full rear suspension cradle.  Talk about project creep!

[Plymouthy Adams]

to that end...I have to beg to differ.....a low mileage donor car can be had for little money and if you chose the right donor in the get go....stick the course...do your own work....very low cost to  have all the bells and whistles and safety devices to boot.  Where most fail is buying a crate engine....$$$$$$  buying a slick shift tranny...$$$$$$$  sending out a brand x rear gear for special sizing and gearing...$$$$$$$  frame enhancements like 4 link rear.......$$$$$$$$$  then the front supsension upgrades usually in a Heidt or similar $$$$$$$$$   and to set that in most old mopars you need special front frails.....$$$$$$$$$$   and $$$$$$  if you do not weld.....buying a harness for plug and play retro if you can find one some times....also big $$$$$$$$$  then with all that the high cost of paint and body...$$$$$$$$$$ then we got to have the interior to speed also.........$$$$$$$$$$   it is no surprise that folks are upside down before they even turn the key...at this time we have not even discussed the install of things like tilt wheel, PS, AC, ABS brakes, Air bags.....zero emission fuel systems very large disc brakes and other amenities including 3 point seal belts and many other things that are all included with the donor car.   Again, you would be totally amazed at the low cash outlay.

[kencombs]

19 minutes ago, Plymouthy Adams said:

to that end...I have to beg to differ.....a low mileage donor car can be had for little money and if you chose the right donor in the get go....stick the course...do your own work....very low cost to  have all the bells and whistles and safety devices to boot.  Where most fail is buying a crate engine....$$$$$$  buying a slick shift tranny...$$$$$$$  sending out a brand x rear gear for special sizing and gearing...$$$$$$$  frame enhancements like 4 link rear.......$$$$$$$$$  then the front supsension upgrades usually in a Heidt or similar $$$$$$$$$   and to set that in most old mopars you need special front frails.....$$$$$$$$$$   and $$$$$$  if you do not weld.....buying a harness for plug and play retro if you can find one some times....also big $$$$$$$$$  then with all that the high cost of paint and body...$$$$$$$$$$ then we got to have the interior to speed also.........$$$$$$$$$$   it is no surprise that folks are upside down before they even turn the key...at this time we have not even discussed the install of things like tilt wheel, PS, AC, ABS brakes, Air bags.....zero emission fuel systems very large disc brakes and other amenities including 3 point seal belts and many other things that are all included with the donor car.   Again, you would be totally amazed at the low cash outlay.

You're absolutely correct.  My Dad owned a salvage for 30 years and I had the advantages that came from that.  Your description sort of reinforces my view.   All those mods, done in your 'spare' time require the car you'd like to be driving to be laid up for a while.  How long a while depends on your 'spare' time, and cash.  A few mods on a stocker can be done in a few hours and the car can be driven in between projects. 

 

There is a place for both types.  One can review the completed insurance auctions for donor pricing and assess their skills as related to adapting the parts and make their decision.

[Loren]

5 minutes ago, Plymouthy Adams said:

I personally cannot see the benefit of adding dual carbs, split headers and a few other favored mods on a flathead 6....the added performance verse the cost is so low in bang for the buck.....there are the few oohs and ahs one gets that boost the ego a bit and well, that is okay...something for everyone and well I am guilty of a few things in this hobby causes some to point directly at me and scream     "blasphemer.."

 

Hey you might be right!

 

I was working on a Model T Ford and I was not impressed with how it ran. It had a high compression aluminum head and I would have expected it to run much better but it didn't. I put the original iron Ford head back on and guess what? It ran much better!

 

The great Ed Winfield had a charming term for such stuff that guys buy without proving they work first: He said, "They Hop their engine DOWN."

Staying with the Model T theme, Winfield was the guy who beat the 16 valve DOHC Frontenacs with a flathead. Arthur Chevrolet (the Indy racer and Frontenac manufacturer) said "I see it but don't believe it!"

 

Tommy Thickstun was a protege of Ed Winfield (like so many) and he knew all about the flathead T Ed built. The concept Winfield imparted on him was separating the intake pulses 180 degrees if you can and if you can't, build a manifold that will help the flow not hinder it. That's why the Thickstun Manifold looks like it does. If it works it stays if it doesn't, it goes on eBay.

 

When I started this post I was talking about Windshield Wipers. Somehow the virtues of electric fuel pumps captured it. However, electric fuel pumps can do nothing to help Vacuum Wipers so on this car I'll use a mechanical pump.

[kencombs]

50 minutes ago, Loren said:

 

Hey you might be right!

 

I was working on a Model T Ford and I was not impressed with how it ran. It had a high compression aluminum head and I would have expected it to run much better but it didn't. I put the original iron Ford head back on and guess what? It ran much better!

 

The great Ed Winfield had a charming term for such stuff that guys buy without proving they work first: He said, "They Hop their engine DOWN."

Staying with the Model T theme, Winfield was the guy who beat the 16 valve DOHC Frontenacs with a flathead. Arthur Chevrolet (the Indy racer and Frontenac manufacturer) said "I see it but don't believe it!"

 

Tommy Thickstun was a protege of Ed Winfield (like so many) and he knew all about the flathead T Ed built. The concept Winfield imparted on him was separating the intake pulses 180 degrees if you can and if you can't, build a manifold that will help the flow not hinder it. That's why the Thickstun Manifold looks like it does. If it works it stays if it doesn't, it goes on eBay.

 

When I started this post I was talking about Windshield Wipers. Somehow the virtues of electric fuel pumps captured it. However, electric fuel pumps can do nothing to help Vacuum Wipers so on this car I'll use a mechanical pump.

There are electric vacuum pumps available.  Also pumps that attach to the back of an alternator.  Changing to a 12 v alternator to run vacuum wipers seems a bit much though!

 

Addition of a fairly large storage tank, with a check valve,  will help a lot for short burst of acceleration, but not long sustained high load, low vacuum circumstances.  Lots of older cars used them.  A piece of PVC pipe and a couple of end caps will work.

[desoto1939]

I do not understand how a 12 volt alternator is going to improve your vacuum wiper motor.  The  vaccuum  is created by the motor and not the alternator. The alternator is creating an electrical flow to provide better lighting and more electric voltage.  Unles youhave some way that the 12v alternator is running a vacuum pump at a more efficent rate and provide more vaccum.

 

When you put the aluminum head onthe Model T did you also change to a plug that would hav ebeen used with the aluminum Head. I know that when you put the Aluminum Head on our mopar Flatheads you have to chnage to a plug that works properly for the al Head.  Most people just put on  speed equiptment, dual carbs, split manifolds dual exhaust and think that their HP is going to improve significantly.  But to accomplish this there are other thngs that can help like porting the holes inthe exhaust and intake manifold. cutting down the angle for least resistance for intake and exhaust.  So if you want to increase your HP then put in a V8 and make the other chnages to support the HP change. Yes these older cars could do 60-70 MPH. But whne done whne these cars were the normal cars onthe road there was less traffic now aday ever modern car can do over 100mph can handle better. Our older cars were not setup to being doing 60-80 MPH on the average.

 

Rich Hartung 

[kencombs]

1 hour ago, desoto1939 said:

I do not understand how a 12 volt alternator is going to improve your vacuum wiper motor.  The  vaccuum  is created by the motor and not the alternator. The alternator is creating an electrical flow to provide better lighting and more electric voltage.  Unles youhave some way that the 12v alternator is running a vacuum pump at a more efficent rate and provide more vaccum.

 

 

Exactly. Since diesel engines have no intake vacuum, diesel  light trucks use an alternator with a vacuum pump mounted on the back to provide vacuum for the brake booster.  Sort of like the 50 Mopar and GM power steering.

[Loren]

2 hours ago, desoto1939 said:

When you put the aluminum head onthe Model T did you also change to a plug that would hav ebeen used with the aluminum Head. I know that when you put the Aluminum Head on our mopar Flatheads you have to chnage to a plug that works properly for the al Head.  Most people just put on  speed equiptment, dual carbs, split manifolds dual exhaust and think that their HP is going to improve significantly.  But to accomplish this there are other thngs that can help like porting the holes inthe exhaust and intake manifold. cutting down the angle for least resistance for intake and exhaust.  So if you want to increase your HP then put in a V8 and make the other chnages to support the HP change. Yes these older cars could do 60-70 MPH. But whne done whne these cars were the normal cars onthe road there was less traffic now aday ever modern car can do over 100mph can handle better. Our older cars were not setup to being doing 60-80 MPH on the average.

 

First of all I didn't put the aluminum head on the T. I know better.

The issue was that the head was poorly designed. It had too much compression. The valves were shrouded and the pistons touched the head when they rocked at TDC.

Modifying a Model T for more power is much more involved than just slapping on a cylinder head. If you think a Plymouth is a slow speed engine, look into a Model T!

They will go 35 mph and feel like it's 100mph. The crankshaft looks like a piece of bent wire and the oiling system is 100% splash.

 

My philosophy about mods to a collector car go along like this. What would a knowledgable Mopar guy build way back in the day? A period correct car with the best stuff available (say within 5 years of when the car was manufactured). I like the KT Keller 1949-54 Plymouths. I do not want a Chevy powered anything period, full stop.

My Suburban (when I can get it out of storage) will get the 265 Chrysler flathead 6 I have built for it. I don't like T5s so this car gets a Plymouth R10 Overdrive transmission (just got the parts I need for that today). I don't like the idea of changing the rear end, so I have a 3.54 pumpkin from a 56 Plymouth. I don't like the idea of Disc Brakes, so I have a set of 12 inch Chrysler drum brakes. All the kind of stuff a Mopar mechanic would want on his car. That to me has more value than the bragging rights to all that modern V8 stuff. Yes disc brakes are so simple a monkey could fix them. The Lockheed brakes are a little more challenging, you have to read the manual and have the tools. I can do that.

 

[JBNeal]

I've heard rumors that some outfit has available a vacuum to electric wiper motor conversion...?

[Loren]

Yes there are a couple. All 12 volt, all 2 speed.

If you could find the original 6 volt electric wipers there were two versions of those.

If new manufacture 12 volt wiper motors are $275 (plus changing over the car to 12 volts) how much would you expect to pay for one of the 6 volt originals?

A guy could wire in the intermittent wiper control with the electric 12 volt wipers. So there is that.

Or you could use the infinite control on the vacuum wipers to approximate that feature.

A dual diaphragm fuel pump will give you enough vacuum to operate them like the electrics and if you ever feel the need to change to 12 volts, that's one less thing to worry about. Plus that was the period correct solution to engine vacuum loss under acceleration.

This car is so original, I feel that keeping it that way has value. Dual Diaphragm fuel pumps were an extra cost option and are mentioned in the Owner's Manual.

 

This car still has the original upholstery too!

The Owner's Manual also tells you that you can get extra seat springs if needed. That's an option I am going to take advantage of. The seat in this car reminds me of an old cheap mattress. The springs struggling to accommodate your weight when you sit on the edge.

I am starting the installation of the Overdrive transmission tomorrow. More to come. 

[desoto1939]

12 hours ago, kencombs said:

Exactly. Since diesel engines have no intake vacuum, diesel  light trucks use an alternator with a vacuum pump mounted on the back to provide vacuum for the brake booster.  Sort of like the 50 Mopar and GM power steering.

Ken: Thanks for explaining how a diesel alternator uses a vacuum pump. I was not aware of this setup.

 

rich hartung

desoto1939@aol.com

[ccudahy]

Ford diesels have a separate belt driven vacuum pump. They are driven with an idler pulley.

Edited July 15, 2021 by ccudahy

[JBNeal]

I found two complete 6V wiper systems in parts trucks, one I had to liberate in a hurry cuz that truck was 3rd next in line for the crusher (long story)...in my area of rolling hills and sudden summertime downpours, the vacuum setup just doesn't cut it.  I've refurbished one 6V system (write-up pending) and was able to correct its age related deficiencies.  Two speeds on demand is very nice, and the only indication that I'm running elec.wipers is the lack of a vac.hose going through the firewall...I consider this a safety device so it's like spending $$$ on seat belts ??

[chrysler1941]

More than 10 available

 

https://www.ebay.com/itm/254791239548

[Sniper]

Nowhere that I could find does that link claim to be an Airtex E8902.  What it looks like is a cheap, third world knock off.

[Plymouthy Adams]

the only thing American about the ad outside the US Flag...is the statement: ships from US... and the sole reason they get away with the flag I suppose.  But on the other side of the coin....so many of our US name brands are manufactured overseas.....there is nothing that says that this is NOT as you would get if you bought name brand as the maker is going for a larger pieces of the pie on retail verse supplier mass quantities.   Odds are even a US part number will get you to these ads as they know the application as they make the box also....tough buying world today.....

[Sniper]

True, unfortunately. 

[Loren]

I found a Double Diaphragm pump.

I also found a new production rebuild kit for it.

 

I just scanned the manual and it says there is a very strong spring inside which requires special handling.

It suggests replacing two of the screws with longer ones to gradually release the pressure.

That's advise I intend to pay close attention to as I have very bad luck with spring surprises.

Must go back to my early years and Jack-In-the-Box toys. lol

[Marcel Backs]

If a 12 volt wiper motor is available to replace the vac type device, it is very possible to purchase a 6v to 12v converter aka a voltage doubler that will power it with no adverse effects. Street Rod HQ in Vancouver Wa sell this device for a reasonable price. If you have any basic electronic skills, a D.C. voltage doubler can be built using some pretty basic components. Many circuit designs exist and can readily be found online taking voltage regulation and current capabilities into consideration. Hope this helps. BTW the unique sound of a dual exhaust equipped 6 is bloody priceless and I will be soon equipping my Chebby with a set! Duals on your coupe would greatly amplify the cool factor and the exhaust note also satisfying your penchant for the old school go fast parts! Best Wishes! M