mystery part on Twin H manifold

ArtS

I am puzzled about what seems to be an extra part located on the intake manifold compensator tube of my 53 Twin H Hornet. I have had a chance to look at many Twin H manifolds over the past year but none have this particular part. It's a small metal block about 1.0 by 1.5 by 0.5 inches with a small piece of spring steel on the narrow side. The spring steel is fashioned into sort of a flap covering a small hole. The block is threaded into the center of the compensator tube. Any ideas on the function of this part? Thanks for your help and best wishes! Art S.

[Deleted User]

Any chance of posting a picture?

Unknown

probably a n outlet for a manifold vacuum gauge that ran to the dash BILL ALBRIGHT

ArtS

Took a picture but it looks out of focus. Will try again tonight and post ASAP. Thanks. Art S.

dwardo99

Sounds like it is some sort of flapper valve intended to relieve pressure from backfires. Maybe the car had a power brake booster at some time?

ArtS

As requested, I am posting a pix of the extra part located on the Twin H compensator tube of my 53 Hornet. Any ideas about what this gizmo is or does will be appreciated. Thanks. ArtS.

[Deleted User]

Looks like a pressure relief valve to me. If it was a connector for a in car vacuum guage it would have a fitting to connect the line to the guage. I think dwardo99 is right it was put on for a backfire problem. I am going to try and find it in my Hudson lit.

bobbydamit

Ever heard of a "Water Vapor Intake Port"?. It was used on some cars to add to performance and improve mileage. a container of water was installed and the vacuum was pulled through the water to create high humidity. Anyone ever notice how much better older cars ran in the rain? That was back in the days of "Climatic Controls" consisting of nothing more than a choke spring, heated by exhaust manifold gas. Now-a-days a computer does it all for us. We use to make these for racing along with a bucket of ice with copper tube in it for the chilling of the fuel on its way to the carbs. Kids were nutz with ideas to add a mile an hour to "their wheels" or Sled.

Of course I could be wrong and it is not even a Hudson part or idea, but a job shop part tacked on for the costumer. Can you "E" mail me better pics and I will confirm or deny this claim for us?.

Unknown

could also be a port for a magic marvel mystery oil upper cyl lubricater, what think yee??? bill albright

Unknown

I vote for an aftermarket upper cylinder lubricator. They were really popular in the 50's and 60's. I remember Texaco selling lubricant for that.

[Deleted User]

I must admit that I have never seen this on a twin H setup, but I don't believe it is for the purpose of injecting anything into the manifold. My reasoning is this, There is no mention of an opening for a fitting of any kind, only the spring loaded flapper valve. and since the flapper is on the outside of the block, I would assume it is for the release of pressure. The only time I would foresee a pressure buildup in the compensator tube would be during a backfire.

Bob

ArtS

One thing I forgot to mention about the device is that there is an eighth-inch set screw mounted on the side opposite the flapper valve. It's not visible in the pix that I posted in a prior message. The bore for the screw leads to the chamber inside the device. Maybe this screw is used to adjust the threshold for pressure release at the flapper. Sort of like the weight that sits on top of a pressure cooker release valve. Many thanks to all HET members for their opinions and creative thoughts on this issue. I am going to put a vacuum gauge on the compensator and fiddle with the set screw to see what happens during motor idle. ArtS.

[Deleted User]

A popular upper cylinder oiler looked like this http://www.ampcolubes.com/closer.html



I would think if this was for oiling the access would be on top not on the side. The upper cylinder oilers usually had a container that held the oil as shown in above link and if you follow the links you see the spec sheet with listing for Hudsons.

Unknown

Hey, I wonder if the machined injector plate for the upper cylinder oilers could be used to introduce nitrous on a hudson engine? just a thought....



I guess I got to get mine back together first....



not going anywhere with the tank out of it.

[Deleted User]

It looks like a Hot Idle Compensator that someone modified to work on this intake.

Basically they have a bi-metallic spring inside that would heat up when the engine

is turnned off, thus opening up and allowing the gas vapors that are trapped inside

the intake to escape.

Carter use these on the AFB's on the inside behind the secondaries.

Once the engines were turned off they would continue to heat up. This heat would

open the valve and allow the fuel vapors to escape from the intake. Once the

engine is started up when hot they should start faster, or so Carter's information says.

To me it looks like someone decided to add one here to help with the problem

the Twin H intake has with boiling fuel when hot and turned off. Kinda of a anti-hot flood

device.

One problem I know with them is that the springs get weak over time and it becomes

hard to get them to idle properly on the AFB's I have run in the past.

I do know that the AFB's on the stroked dual quad 308 (WA_HOO!) I have in my

50 Racemaker is running these on both carburators. So far I seams

to start real good but I havn't run it enough to find out for sure.

Hope this helps...

PaceRacer50

bobbydamit

Now that I ahve seen a closer picture, and one I could zoom in on, I admit, I AM WRONG.

IT IS CLEARLY A VALVE. PROBABLY DESIGNED TO BE A VACUUM COMPENSATOR. IT IS A ANCHORED PIECE OF SPRING STEEL THAT WOULD POP OPEN UNDER HIGH PRESSURE, LIKE A BACKFIRE IN THE INTAKE MANIFOLD AND OPEN INTO THE MANIFOLD THROUGH THE BRASS VALVE DISC DURING EXTREME VACUUM PRESSURE, LIKE BELOW 12-15 INCHES OF MERCURY OR HG OF VAC. I HAVE NO DOUBT IT IS A VALVE OF SOME SORT TO COMPENSATE PRESSURE CHANGES, BUT IT IS NOT THE INLET VALVE FOR THE WATER VAPOR KIT THAT I USED YEARS AGO.

INTERESTING, BOBBY

ArtS

One last comment on the compensator tube pressure relief valve. I put a vacuum gauge on the tube off the front end of the compensator (the one going to the top end of the dual action fuel pump). Got a rock-solid 21 in of Hg at idle with the pressure relief valve in place and secure. Open throttle caused quick loss of vacuum and then overshoot to 25 in and slow steady return to 21 in upon return to idle RPM. So all is well with this motor and the pressure release valve seems to have no adverse effect on intake air flow. Thanks to all who put their minds into solving this puzzle.