440-3 Vacuum Pressure

LJ-TJ · November 12, 2016, 02:30 PM

Anybody no what the standard Vacuum pressure is suppose to be at idle. Thanks. I believe standard idle speed should be 600 RPM. Thanks Hm?

DaveVA78Chieftain · November 12, 2016, 04:15 PM

http://www.gregsengine.com/using-a-vacuum-gauge.html

Thats manifold vacuum, not distributor advance vacuum

LJ-TJ · November 13, 2016, 10:18 AM

Once again Dave you came through for me. Great article. One last question? What would be a good gauge to buy? Harbour Freight, O'Rillys, N.A.P.A. Heading State side in the next few days and want to pick one up. Thanks again mate.

Rickf1985 · November 13, 2016, 11:49 AM

Vacuum gauges are pretty basic instruments and just about any of the above will do what you need.

DaveVA78Chieftain · November 14, 2016, 07:27 PM

Like Rick said, there is no best. My only suggestion is one that has a 3" to 4" face for ease of readability

https://www.summitracing.com/parts/anm-cp7803?seid=srese1&cm_mmc=pla-google-_-shopping-_-srese1-_-actron&gclid=COD6296_qdACFRBWDQod-I0E9g

LJ-TJ · November 14, 2016, 08:31 PM

All right

That's what I was looking for. Appreciate it. I'll pick one up when I go State side in a few weeks. I just didn't want to buy junk. Us neophytes look up to you guys for a little guidance. Thanks again.

M & J · November 14, 2016, 08:41 PM

Yeah, old guys need a big gauge per Dave.

LJ-TJ · November 14, 2016, 09:07 PM

Ok! Smart A%#. How ever. No one seems to know what the standard Vacuum pressure should be,be at idle. Is it 13? 15? There has to be a starting point. D:oH!

DaveVA78Chieftain · November 14, 2016, 10:37 PM

Engine Speed	Reading	Indication of Engine Condition
Smooth and steady idle (800 to 1200 RPM)	Between 17 to 21 inches	Engine is in Good Condition, but perform next test to be sure.
Open and close throttle quickly	Jumps from 2 to about 25 inches	Engine is in Good Condition.

Hmm, I think the first row of the table on that page I pointed (reprinted here for your viewing pleasure) to says a steady vacuum between 17 and 21 in Hg at idle. Range is used to account for engine age, wear and compression ratio. The 2nd row test is used to determine if you have a good seal. When you open the throttle quickly, ~ 2 in Hg, you loose vacuum do to the sudden opening of the throttle plate. When then close the throttle quickly ~ 25 in Hg, the air flow through the carb is cut off so the engine acts like a vacuum pump resulting in a large vacuum. Checks seals (carb gasket, intake gasket, valve seals, etc.) and rings. The "steady" part relates to burnt valves, missing cylinder, etc.

LJ-TJ · November 21, 2016, 06:42 AM

Ok! So went out and bought a Vacuum gauge from N.A.P.A. My question now is where do I tap into in order to get the proper vacuum measurement. Oh! It's a 440-3 with a Carter Thermoquad Carb. Thanks guys. Sorry Dave/Rick

https://actron.com/content/vacuum-and-pressure-tester-kit

87Itasca · November 21, 2016, 11:45 AM

You need to find a vacuum line that is going to a connector on the top of the intake manifold, not at the base of the carb.

LJ-TJ · November 21, 2016, 11:46 AM

This is suppose to be a picture but not sure if it will work.

legomybago · November 21, 2016, 02:09 PM

Look for a small port directly on the intake manifold, if no port use the (blue) egr port on you pic.
that port is full manifold vacuum.

LJ-TJ · November 21, 2016, 04:42 PM

Awwwww your in trouble now

I gots a NEW CAMERA. I don't know how to work it but I got one. Soooos
I tried out my new Vacuum gauge today (MAYBE) I fire up the old girl and let her idle up for a bit. RPMs ran at between 500 and 600 RPM once she warmed up. The Oil pressure was at 32 psi, the Oil Temp was 140, The water Temp was at 170, the Trans Temp sat at 100 Vac Gauge on the dash read 13 and the volts at idle when on dual ran 13.5 and when on single 14.0.
So I found a hose that ran from the valve cover to the bottom on the Carb that was Teed off and ran the Vacuum gauge on the dash. So I poped it off and hooked up my new supper dupper N.A.P.A. Vacuum gauge and at idle it wandered back and forth between 17 and 18. When I burped the throttle it back fired up through the carb the vacuum gauge needle went to 0 and then jumped up to 24/25 and then settled back at 17 to 18.

My question is did I take the vacuum from the right place and what does any of this mean.....GOOD/Bad/ or Oh god you are so screwed. D:oH! The back fire through the carb got my attention real quick.

legomybago · November 21, 2016, 05:12 PM

Are you on the PCV valve hose?

LJ-TJ · November 21, 2016, 05:26 PM

I believe so. Hm?

DaveVA78Chieftain · November 21, 2016, 09:32 PM

PCV Valve hose is not a good spot. The PCV valve opens resulting in false readings (to low). Do you still have the cruise control hose available?

LJ-TJ · November 21, 2016, 09:44 PM

Naw this is all I got. Hm?

legomybago · November 21, 2016, 11:02 PM

Use the port closest to your coil, just below the idle mixture screw on the carb.

LJ-TJ · November 22, 2016, 07:03 AM

They keep talking about attaching the vacuum gauge to the intake manifold. There's a larger hose at the bottom of the picture that goes I believe to the intake manifold. Should I maybe trying to tap into that hose to hook up my vacuum gauge. Also I have only two vacuum hoses at the front of the carb. should I be taping into the large one or the smaller one? Hm? Hey is said I wasn't the brightest bulb in the chandler. D:oH!

legomybago · November 22, 2016, 10:00 AM

Looking at your pic, the distributor is plugged into the "ported" vacuum, this should be unplugged and capped at the carb when you do a vacuum test. The next larger port over is for your PCV valve, the next small port over would be your full manifold vacuum port. Do you not have this other small port on your carb? (Sounds like you don't). My 440 has a small port tied into the large rear vacuum line fitting that supplies vacuum to your brakes. This small port supplies vacuum to my cruise control. You could probably find it on the web searching "440 cruise control vacuum fitting"?? I don't have a pic of mine at the moment. When you do "make" a full vacuum port on that engine, you should connect your dash vacuum gauge to it for full time use. This is what I would do TJ i??

legomybago · November 22, 2016, 10:03 AM

You may need something like this for it to be correct
Image result for 440 cruise control intake manifold port options

legomybago · November 22, 2016, 10:10 AM

This would be better....
Image result for 440 intake manifold vacuum two port

LJ-TJ · November 22, 2016, 10:40 AM

I'll have to keep my eyes peeled for some thing like that. Thanks. I'm heading over to the wreckers in the next few days and I know were there's a 440-3 with a thermoquad. I'll see what it's got. Ooooop I ment to say "Auto Recycler's" D:oH!

Rickf1985 · November 22, 2016, 11:09 AM

There is a pipe plug in your intake manifold in the front right by where the PCV line bends around and comes back to the valve cover. I can't quite see if that is in a a manifold runner or water passage but it should be in the front cylinder manifold runner and if so you can use either of Lego's pictured fittings. Keep in mind that you can use a fitting from any American engine, does not have to be Dodge. If it appears to be the same size it will be, it is 1/4" pipe thread.