Is this a vacuum fitting on Graham Paige?

[GrahamPaige29]

Hi guys.  The picture below is NOT  a pic of the engine from my car.  It's one I'm using I found online for reference.

 

In my Graham Paige 612, my manifold does NOT have the fitting/copper tube circled in the picture.  It just has a threaded hole there in the manifold.  I was puzzled by it for a while but now I'm thinking it's for the vacuum operated windshield wiper.  Is this right? 

 

Also, there seems to be an adjustable bolt where the tube meets the manifold.  You see the square bolt head just below the copper tube fitting?  I'm wondering if this is an essential part of it's operation.  Anybody have experience with this type of setup? 

 

When I'm testing my engine out, should that hole be "plugged"?

 

Thanks!

 

Geoff

[Spinneyhill]

Vacuum wipers? Probably. it has a pump so no vacuum tank.

 

The square thing is probably a plug. It looks like a T fitting has been used and one leg needs to be plugged. This may have been an off take for the vacuum tank in a previous model with a vacuum tank fuel system?

 

If you don't have the wipers connected, the hole must be plugged - otherwise you have a big vacuum leak and it might not run well at all.

Edited September 26, 2017 by Spinneyhill (see edit history)

[PFitz]

Yes, very likely that manifold connection is for the vac wiper motor line.

 

The square ended plug is an old style 1/8 inch pipe thread plug that someone used to block off the pipe thread tee fitting that has been threaded into the manifold. 

 

Looks like there is another 1/8 inch pipe plug at the front end of the manifold through the black sheet metal shield.

 

Paul

[GrahamPaige29]

Ok thanks guys.  When I was first examining the manifold i thought "WTF???" to the holes in the intake pipes.  Now it seems to make sense.  I wonder if the second hole at the heat shield has a purpose.  Maybe it's a common hole for another model of Graham which has the manifold reversed.

 

For now I will add a threaded plug in the hole to test the engine.  When I reinstall it I'll be able to work on getting the wipers working again.  Yet another challenge.  Thanks you guys!

[PFitz]

Someone may have added the tee to the original wiper motor take-off on the manifold,  and then drilled/tapped where the front plugged hole is for an inverse valve oiler, like the Marvel Mystery oilers.

 

Usually you see oilers installed with a single line to the middle of the manifold. But on some, where the wiper motor line is nearer to one end of the manifold, I've seen them with a split feed line going to the middle of each half of the manifold. That's to get more even distribution of oil to all the intake runners.

 

If they took the oiler off a setup like that then they just need to put plugs in the manifold hole and the tee like it shows in the picture.

 

Paul  

Edited September 27, 2017 by PFitz (see edit history)

[Rusty_OToole]

Most likely the pipe is for a vacuum wiper as you say. They happened to use a T fitting and plugged one leg that they didn't need. Why did they use a T? Who knows? Maybe they were going to add a vacuum gauge or something, or maybe they had a T fitting handy.

 

You should definitely plug the hole, it will cause a major vacuum leak and louse up your motor, possibly make it impossible to start. You can buy a pipe plug at any parts store, hardware store or plumbing store. You may use an iron or brass one. Put some teflon tape on it, to be sure of a perfect seal, and make it easy to remove if you decide to put a vacuum fitting in there. A bolt will not do, the threads are all wrong, you need a tapered pipe plug.