Yup yup! An excellent explanation. In the beginning I wasn’t so sure, then when you went on to show the location of the ports and what they are and why the ports are there on the carb…it clicked! Thank you for taking the time to make this video. It’s still helping the community all these years later!!

I've turned a lot of wrenches and have never understood vacuum. You are an excellent teacher, thank you so much. You reminded me of a high school shop teacher~THANKS!!!!!

Tyler you nailed it. No one could have made it any clearer. Thank You. My life is complete.

I found this very informative. I'm a old school guy that is not a mechanic, but is trying to learn on 1962 Bonneville. You explain it clear enough for me to know how to understand the language so I have a better understanding of how to tune my car. Thank's!

Good video on this subject. Also good job on explaining purpose of vacuum. Yes, some people just want to hear what it is and move on, but they need to hear theories and discussion. I've been a engine buff since I was a kid but still didn't know about timed port very well until now. My grandma us to say " you can always learn regardless of how smart you think you are!"

Great video. I have been trying to find a good video on this subject. Finally found it. Really is going to be a big help on a project that I am working on. Thank you.

Loved the video. You gave me the answer I was looking for; how to figure out which is and is not a ported vacuum port by simply looking at my carb. A plus was that you did it with a carter 1bbl like I have on my ford 300, but that's not nearly as relevant as knowing how to figure it out myself on any carb anyway. Second thing, and a bonus, was the description of the temp controlled vacuum tree. Now I understand it's basic working parameters, and know exactly why it's placed where it's placed. The only question I could possibly have would be on that thermostatically controlled tree. Being screwed into the intake manifold raises the possibility for it to receive it's vacuum source from the manifold itself. That would be the question. If so, that means that even being unused, all ports on it would have to be blocked to not have a vacuum leak when the engine is at operating temp. If it's fed externally, meaning a larger feed port to the device that is fed from the carb or other port elsewhere on the intake, that would mean that it would be unnecessary to worry about blocking off anything at all on the temperature controlled vacuum tree if it's being unused at all. great video, though. It gave me the information to go figure out where ported vacuum is at any time, and on any carb.

Excellent video. I’ve been struggling with understanding the difference between manifold and ported and this really made me get it.

Tyler - Thanks for posting this very informative video. It does a great job at clarifying a confusing topic. I now understand the difference between ported and manifold vacuum. This will be helpful as I work through Carter BBD carburetor issues on a Jeep 258 CJ-7.

You did a great job explaining the concepts.... Thank you so much for taking time to make this easy to understand....

Thank you for this video, it cleared up some miss understandings.

Thanks - yours is the best video on vacuum systems I've ever seen. I'm installing a vacuum advance on the distributor on my 1951 Ford Flathead today. I appreciate this video more than you know!!

What a great explanation. Thanks for taking the time to make this video.

My 1977 F-150 (351M400) has a maze of rubber vacuum lines, and I was told that this was fitted on carbureted models for smog control before Ford switched to fuel injection, or something. One thing that was useful, when you talked about simplifying it reminded me, is take digital pictures before taking stuff off; I was able to put lines back on without having to know what they all do.

Dude, you just made this make perfect sense! Thanks! You're awesome!!

Thank you! This video helped me out with my old car. Now I know what that ported vacuum switch does!

Great Video. I wish my instructors and my bosses could cut through the crap and just explain like that. He'll I come from a long line of and that has my Uncle beat hands down. And that man taught me how to hunt. Well.

Thanks for the lesson Dr.Tyler!

At 15:55 of your video you talked about multiple ports being hooked up to a temp sensor to tell the vaccuum at what temp to come on at. I have a 1989 Chevrolet P30 chassis with a 7.4L 454 V8. Inside my water thermostat housing on top of the block there is a copper insert which takes a 'reading' of the water temp. This is where 4 of my vaccuum lines get hooked up to. I had always wondered what this was for. Now I know! Thank you, David 🐈

And that transition slot that you said don’t worry about. That’s the cause of most issues. People add to much curb idle. When they do not have enough timing. They open curb idle to raise rpm. In doing so. Your expose to much of the slot. That slot dumps fuel in. Rendering your idle air mixture screws useless. You can close them off and still idle because the open slot is allowing to much fuel into the carburetor. It’s a very important feature of the carburetor adjustment when properly set up.

Tyler thanks for your time. Very well done.

You are just the man! Thanks for you time and explanation... this was all gobblydegoop before I watched. Well done and I know what you mean when you say "Ogaadebugalr valve" I am sure I have several on my Land Cruiser :) - Good stuff keep em comin'

i love these vids i watch em when im bored cause im a carb geek lol

great tutorial i really learned alot keep up the good work..............

Thank you explaining the TVS

Outstanding. Great job and thank you

Thanks,learnt something,put it to test tomorrow

So that's what that vac. line dingus on the thermostat is! I've always wondered what it was for,and I don't think I've ever seen one that was still connected. IIRC,I think I've also seen them in the top of the intake manifold. Learned something new today. :)

Thank you this was a good lesson for me i have a dodge flathead six with dual carbs and now i understand what ported vacuum is!

the best explanation I've seen!

More carb videos, very informative.

Good stuff man!

Good vid. Had a guy ask me what a MAP sensor was hooked up to, port or manifold? Thought it was a dumb question (m= manifold) but after I thought about it, I could see where it could be confusing. The MAP is hooked to a manifold VACUUM but is measuring the PRESSURE. Actually thanked the guy for asking. Anyway......... thanks for taking the time to share your knowledge

Thanks, that makes it easy to Understand.

Good explanation!

My EGR system in my "78 Camaro with a 350 used a "ported vacuum switch" that was basically a vacuum switch in series with the EGR valve. It sensed my coolant temperature, and opened up when the engine was warm. It, presumably, was not needed when the engine was still cold.

Thanks for the video!

thanks for the reply--like you mentioned--i also thought of changing out the metering block but seeing how this carb was just rebuilt / along with the possibility of non matching passages, i just left the vacuum line off the dizzy for the time being. its also seems to run great with out the line being hooked up, however the car is not on the road and driving at normal conditions either. i will be watchin your vids-take care

Great vid 👍

Great video

Wow thank you for explaining that well. I also have a 74 valiant and I been trying to figure out how to get better idle I'm sure its a vacuum issue. Im gonna take waht you just tought me and try and apply it. Thank you very much!!!!

Not to be confused with a vacuum amplifier. Which I believe applies the vacuum source from the manifold to things based on a separate vacuum signal from the carb. As in a lean burn system. The vacuum amplifier steps up the level of vacuum to operate the egr valve and something else I don't recall but you get the point. There is also a solenoid that blocks egr functions until after a set time period or engine temperature. 😊

Haha..that's a good one. It's said that you can swap the metering block with one that has the ported vacuum port, but the gotcha may be that your carb does not have the passages drilled that need to be there to conduct the vacuum signal. You can also lock-out the vacuum advance and simply use initial and mechanical advance to get your total advance number. I'm going to be doing a video on that subject soon.

Good explanation

5 years later and I'm the only one looking at the glasses on the table? Lol. Were you getting ready for a tea party or did we miss the tea party? Lol. There is a video on KZfaq of a guy honing Cylinders in an engine block. Oil, lubricant, flying everywhere. Then you look in the background... And there is a dresser and carpet on the floor. He was doing it in a bedroom. Lol

Hi Tyler I was having trouble with surging while driving my 70 duster it has a 360 2 barrel it’s bone stock and after watching your video I went and looked and I had the vacuum advance hooked to the manifold vacuum and I switched it to portal vacuum and it runs better with that

Correct. Also, since the EGR is in effect a vacuum leak, letting it open at idle speed would cause the engine to idle poorly or not at all.

Thanks man. Carbs are black magic to me. Where do I plug in my laptop to tune it?

u the man, thx!!!

Excellent

Witch vacuum should I use for a vacuum gauge to check my idle mixture screws? Thanks for all your explaining on how vacuum works Tyler😉

It's basically an "access channel" that is exposed to manifold vacuum at the ends. It has a couple ports coming into it from above.

Did anyone else go "Ahhhhhhhhhh i see" at about 10:10? lol

Awesome!

Thank you!

Thanks, that makes it easy to understand. What is that large C-shaped manifold port that surrounds both throttle throats, the one that is snaking around about 4 inches long?

Thank you

Thanks!

I have two quadrajets. One on a running 403 one on a 307 that did run a few weeks ago. Tried timing the 403. Hooked up a vac gauge to the dizzy port. Mostly because it was an easy way to plug it. No vacuum in any rpm. Pulled of the carb tried compressed air. Completely blocked off. Went to the 307 carb. Same thing. What is going on? Please help.

Good explanation thank you I have a project I'm trying to finish ultra low budget it's a Japanese 4banger with a carter BBD carb from an early 80s dodge pickup fit on manifold like they were made for it Starts great idles cold smooth as mole hair It's running pig rich any help ?

Great Video! I learned a lot. My 83 CJ7 has a this BBD carb and it is running real rough. As it warms up it runs better but still rough. When I rev the engine I get BLACK smoke. Real Black. What would you suggest. I have been told it is too rich. Thanks again for this great video. :)

Sir I have watched all the videos that you have posted about the Quadrajets. I am a Novice Mechanic. I am working on a 86 Chevy Monte Carlo. On the Quadrajet that I have I am referring to the Vacuum breaker. Even after the engine reachs operating temp. The Vacuum breaker is not releasing Vacuum to allow the Secondaries to open at all. Do you have some helpful advice for me so I may fix this problem?

I have an ‘86 Toyota pickup with an R22. I replaced all the vacuum lines a couple of years ago and it took 10 feet of vacuum line to get the job done. Don’t know who designed the system but it’s just nuts.

How do I know if my temperature control vaccuum switch is working? Even when my motorhome is warmed up I can't feel an inward flow of vaccuum trying to engage my EGR valve. I have a 4 line sensor coming out of my thermostat casting. Please help. David 🐈

I have a 1983 GMC Suburban, the cruise control diagrams don't show exactly where the engine vacuum line connect to or gets it vacuum from. Do you know? i have 1 going to the accumulator 1 going to the throttle and cant find out where it gets the vacuum from.

You seem to be the guy I Need to talk to. I seen you do a Lean Burn Convert on your Diplomat and is what I want to do. I have the 6280 carb. I believe this one doesn't have port vacuum to run the Advanced vac on the distributor. Everywhere I've read says I need a Card with port vac....except one place which said I could "run off the the vacuum solenoid, this coupled with a throttle switch controls vacuum, giving a ported vacuum source." Does that sound right to you? Thanks. any help to save $$$ would be great

Could you do a video on the lock up converter. I have a th350c in my 84 c10 square body. I have heard it needs to have manifold and then someone say that it needs ported vacuum. I've heard it needs to be ran through a tcv switch. It's sort of a mess and a headache. Could you explain this if possible? I thank you for your videos on the quadrajet. I am running one on my truck. Best carb ever built IMO. Thanks.

Good video but you had said that an EGR valve runs off of a ported vacuum and then you said that the EGR on that carburetor go to a manifold vacuum that's the only contradiction I saw in the video

great vid--i have a question. on my 69 chevelle i have a holley carb that has no ported vacuum on it. question is--where do i hook up my vac advance line to??

Can you help me? I have a 1980 Chevy Camper Special 454 Silverado. I have just a few questions.

hi, on edelbrock 750 has vacuumport named "timed" i guess thats a ported vacuum place, right?

I have a 1987 D150 with a carter carb BBD that us junk I would like to replace it with a far simpler version for 1/3 the cost. Can I do that with a power brake booster and just use a manual choke ?

Ported vacuum did not come along until the late 60’s and 70’s. Why would manufacture matter? Think about it. An engine is an air pump. Regardless of make. Ported vacuum was used because lower base timing creates higher exhaust temps. The theory was to burn off exhaust better. It was a band aid if you will. Manifold vacuum adds timing when the air fuel mixture is lean. Allowing the leaner mixture to burn better. No different then when you are cruising along and you have vacuum adding timing. When the mixture is lean and the timing helps burn the lean mixture. When the RPMs go up. The mixture richness and the vacuum drops off. Guess what. All that extra timing goes away wether you are on ported or manifold. Curve your distributor to allow a base timing of around 12 degrees. Adjust your vacuum pot to allow in about 10 degrees. And run it on manifold. And never look back.

The accent. Is the Arkansas?

Haw can You talk soooooo much about so simple thing. Blah blah blah al around. I just wanted to know what it is.