I thought I would start a new thread for this latest concern of mine.
After I rebuilt my Holley Vaporizer carb for my 26 Tudor I have noticed a vibration in the motor that just won't go away! This thread is a follow up to the one titled "Truing up the inside of a roller timer".
I'll give you a little history on the issue.

I am now just getting the car going after working on it for many years and managed to get the rebuilt motor to start by cranking my A$$ off. There was some issues with the carb that I thought I would fix so as to make it start easier. Most importantly the brass nut that connects the carb to the intake manifold was broken and the float had a few holes and so the mixing bowl was over filling with gas. The motor ran great when I got it going. Note: I didn't have the starter fixed at the time to help start it so my son and I both cranked our A$$ets off to get it going again. I figured that if I would replace the float and connecting tube/nut then with the improved suction and float valve working properly the motor would start right up and all my woes would be dealt with. While I was at it I figured that I would replace the other brass in the carb including the needle valve, spray nozzle, etc. Well I did replace the parts that I had ordered and low and behold the T didn't start right up as anticipated (I had fixed the starter and purchased a new battery). It was a little hard starting and not something that I would like to try to get going with the hand crank!. I had a thread going titled "Popping in the Manifold" to ask for help and received many good responses to my query. I thought I had the popping question answered but still had the vibration issue with the motor. One suggestion was to try to run the motor with the fan blade detached. Another suggested to try run the motor with just 1 and 4 cylinder and then 2 and 3 to see if they were all firing. Today, I tried both potential remedies but neither proved effective. I then took the crank off and fashioned a tool that was able to mesh with the crank pin so that I would be able to turn the crankshaft back and forth to see if there was play in a connecting rod. Nothing came out of that except that there was a clunking sound that seemed to come from the transmission that I assumed was some play in the planetary gears or other gears and wouldn't come into play with the motor running. There is a slight knock that seems to come from the front of the engine when it is running. To turn the motor freely with the tool that I made, I took the spark plugs out and found that they were dark and carbon ed indicating a running too rich situation.
Question....Is this a common thing? Too much gas will cause a rich mixture but then what about the popping that results from turning the gas back?
Question....That vibration seemed to start after a backfire after I fixed the carburetor and I wonder if it could be the front main bearing? How would I check if there was play in that main bearing?
Question....Should I put some of the brass that I took out back in the carb.?

I think if you have vibration you should get inside the engine to find out why! Do a compression test,and check how far the crankshaft will move for and aft.As a member of the two part crankshaft club it will not heal itself! It will not wait until you are ready!! Bud in Wheeler,Mi.

Are all of the plugs sooty? Maybe you have an intake leak that is making one cylinder run leaner than the others. It would then be the first to pop back through the intake when you try to lean the mixture.

Does the vibration smooth out and go away when you rev the engine up, or does it get worse? Even if all of the plugs are firing, a big enough intake leak will kill the affected cylinder at Idle, but that cylinder will start firing again when the engine speeds up enough.

Do a Google search for "intake leak mtfca" and you will find plenty of old threads about the subject.

Is this vibration random or cyclic or just plain old running rough? What brass nut that connects the carburetor to manifold? I have found if the vibration is cyclic look for problems in motor or transmission. If random check for anything that can move from normal position(spark setting,loose coil or tired coilbox ,damaged wiring etc.) Rough running ,dirty or improperly gapped plugs,leaky intake manifold gaskets, carburetor issues etc are easy to check. I would try a KNOWN good carb first.

He has a vaporizer so he would have to change both the intake and exhaust manifolds to test with a known good carburetor.
To test for vacuum leaks I use a propane torch. With the engine running at idle, play the un-lit torch over and around the intake manifold and connections between the bowl and same. If the engine speed increases you have a vacuum leak.

If you want to find a vacuum /intake leak, find a modern garage with a "smoke" machine. It produces a low pressure smoke by heating baby oil, and uses shop air to blow it through whatever you are testing. Just wrap the hose with a rag and stick it in the intake of the carb, and watch for smoke to leak out! They use them to test evaporative emission systems on the new cars, but I used mine to find vacuum leaks, blown intake gaskets, leaks in vacuum operated 4x4 front hubs, and even water leaks around doors and windows!

Should have read the post more carefully!!

Thanks all for your responses!
I will have to look up how to test the crankshaft for movement fore and aft. When I was turning the crank back and forth with the pin I could hold a fiberglass rod in each cylinder to see if there was any play there and there wasn't. I'm suspecting the front main bearing but not sure. I will have to have a look to make sure.
I also checked for intake leaks but will try with the propane torch. That is a good idea and one that I have not tried. I like the smoke machine idea also. I have been wanting to build one to check for a possible leak in my GM 5.3 v8, so to use it on the T intake will have it serve another purpose.
The plugs are all new and I had set the gap at .020" as per something that I read on the forum and yes they were all "sooty"!
The vibration starts with the engine start up and stops when the engine stops. It doesn't go away when you speed up the motor. I am going to do a little more experimenting with the intake leak and compression test and maybe try to pinpoint the area of the knock with a stethoscope.
Thanks again. I will report back tomorrow with what I find.

Look at your pan and mounts over very close.Anything broken or bent? Open the little cover on top of the trans anything lose,missing? I think i read in your first post it was rebuilt? Do you know what was done at rebuild? I once shopped for a tractor the salesman said was all rebuilt,and when i saw the engine pan had not been removed i asked the service mgr?? Rebuilt no,all we did was a valve job!! Bud.

Hmmm! I have to think back 25 years when my dad did the motor. I was away during the day working. I know he did the head and rings, gauged the bearings. etc. He was a competent mechanic having overhauled many motors in his lifetime and here on the farm. The motor ran for about 10-15 mins and then it got busy and that was it until I started it up a few months ago. Of course I did a lot of work to the restoration in the meantime but didn't start it in those 25 years.
I will drain the oil today and take the pan off and have a look. I did have the cover off the transmission to adjust the bands after the first run outside 2 months ago. I could barely move fore and back because bands were too loose. It was at the same time that I overhauled the carb, starter. It was on the next test drive a few weeks ago that I noticed the vibration, popping in motor.
I'll have a look and also will investigate the intake leak question. Thanks.

Had to take the starter button off to clean before I could start the motor. Before I started it I took the belt off the fan and then when it was running I used the propane torch (unlit) to test for vacuum leaks. Non were detected after a few passes back and forth to the two intake locations. I put the belt back on and started it again and the motor ran fine with no popping. In looking at the motor I did notice one thing that wasn't right and I wonder how I didn't notice it before seeing that I took the spark plugs out to set the gap. They are not the right spark plugs for the motor. What made me second look it was that I noticed some bubbling around the threads of two of the spark plugs. I couldn't find the old plugs to try so will have to get some new ones. The plugs that are in the motor now are Champion 25 and they don't have a seal ring and don't thread all the way into the port. That can't be right? I guess it was all dad could find back then when he shopped for new plugs locally. If anybody knows these plugs maybe you can offer some advice. Should they thread in deeper? Maybe I have to re-thread the port? These plugs are quite long. Don't know if they really have to be that long. I will look around the forum and see what I can find about spark plugs.
I have to order some other parts at the same time so will get some proper plugs and for now will concentrate on other work on the T. No use fooling with the motor until then. Thanks again.

Model T plugs use 1/2 inch pipe thread, no gasket. A little bubbling around the threads isn't ideal, but probably not a huge issue. Some folks use a small piece of aluminum foil wrapped around the spark plug thread to help seal - kind of like industrial strength teflon tape!

Do a Google search for "spark plugs mtfca" and you'll see all sorts of discussions on folks' favorite plugs. Me, I like Edison 14s:

Thanks Mark for that tip! I will try that foil idea on my Champion 25 plugs. I see some guys use them so I guess they are ok for the motor!

This morning I had a little time so I tried the foil tip. I also used a little anti-seize to help get the job done. I checked the motor mounts under the car and all was nice and tight. Started the motor and it runs good, no popping. It's bad weather here so will have to wait to take it for a spin around the yard. I had checked the knocking noise with the stethoscope yesterday and could not hear anything in regards to knocking. I will see if that continues when I get it outside! The vibration still persists. Not a fender shaking vibration but a constant make your skin itchy kind if you have your hand on the front fender. Vibrates the tools off the running boards. Vibration speeds up as you speed up the motor. I had adjusted the transmission bands before I noticed the vibration. Is there anything in there that can go out of balance? I also rebuilt the starter and have been using it to start the motor. For the flywheel to go out of balance a piece of the ring gear would have had to been broke off. I guess some magnets could come off? The mag is working. I will have to take the pan off tomorrow to see if something wrong in there!

Good luck, hope it's something easily fixed.

Was back at it today and drained the oil. The first thing that came out was the piece of bolt or set screw that is in the following picture. I was wondering all day what it could be from because it looked like a set screw with a flat screwdriver slot. I continued to take the pan off (what a mess!) to see what was up inside the motor. I didn't find anything loose but I did find that I could move the crankshaft toward the fan. If I took pressure off the bar the crank would go back toward the transmission. I found that if I pry it to the fan side and then take pressure off that there would be a knocking sound as the crank would come to a stop. Probably the knock I was hearing. The amount of play appeared to be about 3/64". I checked for up and down movement in the crank at the main bearings that would indicate a loose fit but did not find that. Neither in the rod bearings.

Now that I see the picture it looks more like a piece of pinned bolt that has sheared off or broke off at the pin. I will have to take the transmission cover off tomorrow. Can anybody possibly identify this?

Looks like a clutch finger adjustment set screw, should be 3 of them. The slot is for a cotter pin to lock it in place.

Or a rod bolt. Wat diameter is that piece of broken bolt? That's a cotter pin hole, not a set screw.

IMO, that looks like a piece of a high gear clutch adjusting screw. Can you post a picture of the inside of your transmission, through the top access cover? Rotate the engine by hand to move each of the three screws into view and make sure they are there and are cotter pinned to keep them from losing their adjustment.

Thanks guys. Royce. Too bad I wasn't smart enough to just put the ruler horizontal in the picture. That is a 3/8" fine thread and the piece is about 1/4" long to the center of the hole. Not to jump the gun but it looks like a broken bolt to me now. It took a little punishment at the break because it is scratched up there pretty good. That could also have been the source of the knock that I heard! Yikes!!
Thanks for those pics Mark and Dan. I will surely have a look at the clutch adjustment screws tomorrow to be sure. Those pics show screws that appear to be much longer than the one that I have but I will have to have a good look at everything in the morning. Thanks again.

In for lunch so thought I would post what I found. Basically nothing. All the rod bolts are there and have their pins. Nothing in the motor that would have a bolt like that other than the rear main which is castled and pinned. The adjustments on the pedals are that size but again everything in place and finally the set screws for the clutch adjustment are in place and secure. All bolts are accounted for and secure. All magnets and their bolts are there and secure. Can't find anything that the piece could be from! Unless you guys have any further ideas I will have to assume that the piece came to be there by accident.

Did you check if all of the wrist pin bolts are all in place in the pistons ? I know that doesn't fit so well with what you found.

I did check that, Kevin, but thanks for your input! I thought I might find something that could cause that vibration in my search this morning. Getting kind of frustrating! I am going to try and do a compression test tomorrow. That might show more than I want to know!

Working on the T is fun and I can tweak it all day! This morning I had to get help from the better half to step on the starter button while I did a compression test. She was good to come and help me seeing that it was around 0 F. I don't think that I can see anything wrong in the compression that would cause any vibration! Number 1 and 2 were 50, 3 was 48 and 4 was 46. That was with one compression stroke. If nothing else I am getting to know my way around the old girl! I did notice that #1 plug was very wet and a little dark but not really sooted and the rest were nice and clean and light brown/tan color. Could be a number of things that might cause the wet plug. When I shut it off last time I shut the main gas going into the carb inlet and let it run dry. You would think that all the plugs would be dry when I took them out to do the compression test. What do you guys think?

Larry, you mentioned a backfire before the vibration developed. What kind of timer are you running? My car backfired when I forgot to set the lever to retard before cranking. The Anderson timer flapper caught on the contacts and bent one of them, making for hard starting and erratic running. Just something else to check.

Allan from down under.

It is a roller timer. I have had it off and trued up the inside. I am thinking maybe a bad coil? I changed 2 and 3 around thinking it might be one of them but haven't moved #1. I will try that next time I start it up. Really weird! Like something out of balance yet everything is in place.

I started her up today and it ran rough so I opened the coil box and found #1 coil not firing. I fiddled with the adjusting nut and got it to fire. Meanwhile I had to hold a few of the coils down to keep them in contact. I did a quick test to see if it was firing on all four and it was. Still vibrating a few of the coils loose but running smooth. I guess I will have to do some coil tests to see what is up there. Never did that so any recommendations will help. I went for a ride around the yard a few times and then on the gravel road and had no issues. I have never driven a T before so I don't know how it is running in terms of power. No backfire or popping or hesitation. I have to get it going in low pretty good to be able to get it to go in high without powering out. Don't know if that is common? Quite a jump from low to high for a small motor. Just a touch of soot on #1 plug when I took it out after letting the carb run dry.

I took the coils out today and did the resistance test between A and B secondary winding. 1 was 2800, 2 was 2940, 3 was 3250 and 4 was about 3300 ohms. First question would be...are coils 1 and 2 strong enough?
I spent some time working on 4 cleaning the contacts and setting it up according to the info that I found here in the forum. My next question would be...these may not be Ford coils because they don't have the same tension spring as the Ford diagram that I found. Does that make any difference in the nominal 3200 ohm resistance that Ron (The Coil Man) states in his post here in the forum some years back when asked if a lower resistance would make a coil refurbish-able or not?

I could only find barely visible letters on one of the coils. RK. They were all the same so they are probably all RK's. I got them all cleaned out and adjusted and put them in. The T was hard starting so I knew a few of them weren't firing. I got it running and it was only firing on two cylinders so I played with the point spring a little on one and it started to fire. The other needed to be backed off about a 1/2 turn on the adjusting nut to get it to work. All four were firing nicely and the motor ran purrfect. Still the annoying vibration! Maybe it is supposed to be that way and I never noticed it before?

If it's that bad and you can't find it not to worry,in time it will find you! Bud.

Yes, that's what I'm afraid of! I have to find someone that has one that I can see run. Maybe I'll check youtube there might be something there.

Larry, does it vibrate badly in neutral while just sitting still, or when driving? Maybe you can take a vid of the car running and we could get a better idea. All T's rattle a bit but i would worry about serious vibration. Here's mine running in high gear at a pretty low speed.

https://www.youtube.com/watch?v=lSDHjgIbYqI

Wow,John! You guys have such beautiful cars! I'm kind of reluctant to show mine but if it will help to diagnose this I will try get a video to post. I see you have it on youtube! Is that the only way to show a video here or probably the easiest?
It vibrates all the time! In gear or not. Positive it is in the motor/transmission area. Thank you for your response. Larry

Yes, a link is the only way to post a video here. Youtube is pretty easy.

https://www.youtube.com/watch?v=6ZzX1Wwrkq8

Hi Larry,

In your post on Feb. 04 @ 7:42 PM you state that the plug gap is .020" and I feel that gap is way too small. Champion recommended .025" and many of us have found that a gap wider than that often runs much better. You may want to try .030" or even as much as .035".

Another point: are you absolutely, positively sure that the firing order is correct? They can start and run with an incorrect firing order, but they won't run well as they lack power and have a "vibration". It should be (from the front) 1, 2, 4, 3. Good luck with your project. Bill

(Message edited by bharper on February 15, 2017)

(Message edited by bharper on February 15, 2017)

How to wire the coil box and timer:

Mark, thank you for posting the picture, I couldn't find mine in my computer. Bill

Was called away by the better half so didn't have a chance to work on the T. Thanks for your responses Bill, Mark, John and Steve. I had read in the forum about plug gaps so adjusted mine back to around .030. I don't know where I got that .020 gap setting but I'll try anything! Well almost anything! I will check that firing order also. It can be anything and I'll admit to having the wrong firing order if it will fix this. If my next post is a youtube link then my T didn't run as nice as John's in the post above. Thanks guys.

Ok, I think I managed to get a video on youtube. I did check the firing order and that was right. This might give you an idea of how it runs. It starts right up and seems to run good just vibrates. Have a look and a listen here. Sorry it isn't a little clearer!
https://youtu.be/5pW6TSJLgtM

Long shot, but take your belt off and check the bottom pulley. They wear and get loose and cause a pretty good shake/vibration

Larry, I can certainly understand how all that vibrating metal would be quite annoying. One thing i did notice is that you have it up on blocks on a concrete floor which would definitely amplify the vibration. Have you run it sitting on all 4 tires since you got it running? The baffling part is that you said this all seemed to start after it backfired, because it doesn't seem to run all that bad.

Brian,
If you take your belt off, your pants fall down! How does that help???
(Sorry I don't have anything really significant to add to this thread)

Haha! That's funny David! I tried it anyway just in case!
I had taken the belt off and ran it for a while with no change but thanks for the idea, Brian.
John. Yes, I have had it outside for a few short spins with no change to that vibration that I noticed. I will probably have it down and for another spin tomorrow so will take better notice of how much being off the blocks changes the vibration. What makes it even more baffling is that it started that vibration on the very first start up after my first attempt to drive it outside a few months back. The clutches were slipping so when I got it back inside while I waited for carb parts to arrive I adjusted the transmission bands and did some other work. Then when the parts came I overhauled the carb and starter. When I started it the next time is when I noticed the vibration. Is it because of backfire or the adjustment in the transmission? I don't know? I'm going to take the cover plate off the trans. and see if I missed something. It's a vibration that seems to be motor imbalance from the vibration in the bumper irons. What do you think? To me it is a rapid vibration like every rev of the motor rather than a misfire or coil/spark related! I might have to do like Kenneth said and wait for it to find me!

Maybe take the bendix and starter back out and have a helper turn over the engine by hand to confirm all of the magneto magnets are in place and secure?

Are all the fasteners tight for the accessory front bumper?
From the video, the engine doesn't sound all that bad, they weren't any Rolls Royces from the factory - some were worse than others. That's why it's important to balance all the internal engine parts when rebuilding a Model T engine.
Maybe one of the rods lost its babbitt and was replaced with a pre 1920 heavy rod? That would explain the vibrations.

Thanks Mark and Roger. I wish my dad was here so I could ask what he did when he overhauled the engine 25 years ago. I'm sure he could offer some help along that front. Yes an engine balance my be the answer and thanks for that input about the heavy rod!. I will do the starter removal for a better look at the magnets. Like the Martian said on the Bugs Bunny cartoon. "There's something awful screwy going on around here!"

Have you done a compression test?

Just a thought but, on one of my T's there will be a vibration sometimes and not others. I assume it has to do with the way the drums line up. If they line up in balance it runs smooth but if they line up at the point where they are in the most unbalanced position the vibration is noticeable. To my knowledge the drums and flywheel were not balanced when the motor was rebuilt so that is the only explanation I can think of. The vibration definitely is not as a result of a miss or carburetor as the car idles smoothly and pulls well.

Thanks Ken and Val for your input. I did do a compression test and all four were around 50psi. I had it off the blocks today and went for a ride and it seems to be getting worse! It runs good and seems to have power. The reason why I feel it is getting worse is that I could see out of the rear view mirror before. Today it was vibrating so badly that it shook the mirror beyond being able to see anything even if I put my hand on it. I will have to look inside the starter hole to see if there is a missing magnet and if not then I may have to pull the motor. Val mentions drums out of balance and that could be the problem seeing that the problem started when I tightened the bands and now today with getting worse. I will start it again tomorrow and see how it goes. If it isn't any better then I will have no choice! Thanks all.

Larry,

I looked at your video. I'm not sure that I'm seeing anything abnormal. Model T's do vibrate. Granted, some more than others.