I shorted every cylinder and it seemed to go away on every cylinder...
I'm not an expert on knocks so I don't know what type of sound is for what type of issue
Going to make a better video tomorrow and short it so you guys can hear and let me know what you think it could be...
For now take a listen... I am sure someone has heard this type of knock before...
Sounds tinny, like something hitting a part of the pan, do you have those internal supplementary oil tubes that attach to the inside of the pan rails?
I would recommend pulling the pan inspection cover and having a look see with a strong flashlight.
Mark had a good suggestion. Can you locate the area the sound is coming from? I had something like this and thought it was coming from the fan area. The next think I knew the engine stopped cold. It turned out to be a loose magnet and the sound was the clip. The magnet let loose and lodged between the pan and the mag. This happened after I stopped for the second time and attempted to start with the starter. It gave one grunt and that was it. At first I thought I had a broken crankshaft. I was lucky!!! No damage to the pan but needed a new mag.
Use a mechanics stethoscope to isolate the sound location. 5 dollar tool at harbor freight. Touch it around different spots on the engine while running.
Yes I am trying to figure out where it is coming from so I am going to try the stethoscope idea...
When I first got my truck I pulled the pan cover off and saw scratches in the pan. Found the cause was from the cotter pins of the connecting rods
Sounds like loose rods.
My T sounded a bit like that once. It turned out to be carbon on top of the pistons hitting the high compression (Z) head. It's pretty easy to pop the head off and take a look.
The stethoscope is a great way to locate noises. If you don't have one around a screwdriver pressed up to the engine with your ear to the handle end works pretty well too. The longer the screwdriver the better... keeps your head away from ignition voltage and spinning fans!
Check the timing gears. Sounds like a lot of backlash in them. Also, remove the generator and have a look at the gear on it, and check out its bearings.
I'll add, more than "looking" at the generator gear, make sure it's tight on the shaft and the pin is in place. Also, look for obvious wear on it.
As I suggest above, I really think this sounds like very noisy timing and/or generator gears.
My 2c... I don't think its Carbon. The sound is too irregular.
Mine was making a knock like that also before I rebuilt it.
Please take a video where you retard and then advance the spark lever. I'm no expert but I think Herm is probably closest to correct.
If the knock goes away on full retarded setting, its the rods, in my inexperienced opinion.
The other thing to know if is you are using a reground cam... If the cam is reground enough, and you don't have the thrust washer kit to keep it from "walking" forward, it could be that the front cam lobe (exhaust cyl 1) is knocking on the front cam bearing. That would also explain the irregular knocks being heard. It could be taking a few revs to walk forward and contact the bearing,
Anyway, I hope this helps,
I don't think it's the rods. Too random a sound and more clanky than knocky.
Alright, going to do a video where I retard and then advance the spark lever.
Okay, here is the new video. I drove her around the block a bit just to get her warm.
Video starts off with the spark all the way down (advanced) and ends where I tell my son to place the spark half way from advance.
If it has that sound and it is not present at higher revolutions what do you think is the problem ? Not rods I adjusted those and it has similar sound at idle and goes away when revolutions are stepped up. Thanks for input.
As Jerry suggested, check the easy things first. Be sure to check the crankshaft pulley and the pin that goes thru' it. I once had that tapered pin slightly protruding on one side to the point where it began to hit the nose of the pan which sounded much like a rod knock. Loosen fan belt and check pulley and pin carefully,.....not hard to do,.......harold
Sure sounds like rods to me.
My guess rods not aligned, and took a thrust, and you can also hear a hollow piston slap sound also.
Crankshaft pulley wiggled a bit (with the belt on) going to pull the belt off tomorrow and see what's up with it.
If its loose then a new crankshaft pulley is in store... thinking about getting the aluminum that has the split for tightening.
Like you said Harold... check the easy things first.
Do I have to remove the radiator to replace the crankshaft pulley?
Crankshaft pulley?? I've had a lesson on them, see thread on "small crankshaft pulley". Be careful in getting the aluminum pulley. I know you don't have to crank your car (starter) but when it is necessary you want to be able to do it. Some of the aluminum pulleys will not fully engage the ratchet and the crank will slip off the pin holding the pulley on. The pulley is not deep enough. It may only be the small pulley on early cars but I would ask around about the large pulley before I went to the trouble of buying and installing. Just my .02.
A section of heater hose works well for helping locate point of noise. One end held to ear and other end searching.
Is there any end play on the crank?
Did someone install bolt-on crankshaft counterweights? These were popular among restorers 30 years ago. 'Dunno if their use still is, though.
I have heard a sound similar to yours in an engine with such add-ons. The rear counterweight worked itself loose and flailed around as the crank revolved. The sound changed depending upon speed and load on the engine. Turned out that the bolts on the counterweight had loosened. There's not much clearance between the weight and the crankcase with these weights installed, so even a little movement can cause metal-to-metal noise. Of course, the longer the condition was left unchecked, the worse the sound became. Removing the bottom inspection tray allowed the bolts to be loctited into position and the noise went away without seemingly damaging anything. No harm, no foul.
If your engine does not have bolt-on counterweights, ignore what I just wrote.
Robert, chasing down a knock from a video may just be an exercise in futility, since everyone hears different things, in different ways from their own experiences. I agree with everyone that says you need to try to isolate the area where in fact the noise is coming from, then that may rule out some of the speculation, and you won't be chasing your tail in diagnosing it. If it was my engine, i would bring it to the point of knocking and then ground out each cylinder, to see if i could audibly hear any difference, therefore tracing it down to one cylinder, or not...just my 2 cents...Good luck.
John, going to start simple... Looks like the crankshaft pulley is loose. Since I need to re-core/replace the radiator I am going to tackle these issues at that time:
1st remove the generator, attach block plate run engine
(Usually its the generator that makes all that noise) If noise is still present:
(don't know which to do first but I think removing the pulley should be done first)
2nd crankshaft pulley, since it is loose I know it needs one. By now the radiator will be getting re-cored so I remove and replace the pulley.
3rd Since I have the pulley out I am going to remove the timing gear cover and inspect. If it needs replacement then we remove and replace timing gear. I should have the radiator back so I put it all back together again and run engine, if I did things right things will be a lot quieter.
Next the Knocking.
If the above didn't solve knocking issues then its time to go farther in.
4th remove head and de-carbon pistons/valves (if needed) seal and run engine. If knock is still there:
5th Rods check to see what's going on. Unfortunately I have never done this so I need a way to visualize the work Thus why I had asked in another post about videos or books with step by step instructions with pictures.
But like I always say... I'll cross that bridge when I get to it.
At least if I do get as far as the rods my engine will be have been gone through and fix/repaired/replace with new parts so I know any new issues will come from somewhere else.
Okay, gonna take a quick video showing the crankshaft pulley wobble and post it...
You don't have to do all that work to check if it's the pulley that makes the sounds - just loosen/remove the fan belt and feel on the pulley if it's loose. If it is, wedge a little piece of thin steel from a can in between the pulley and the crank and try starting - if it takes away the sound, then you know what it is, no need to do all the other stuff at once.
Yes, the radiator may have to come off for access to do a proper fix, but just for testing if it's the source of the sound you can probably do it with the radiator in place. For a short test of just a minute or two, you don't need to reattach the fan belt. Don't stand in line of the pulley if the temporary wedge get loose.
With regard to testing the pulley. You can do as Roger suggests, or just remove the pulley entirely and run the engine without it. No big deal for just a few minutes worth of testing and it's loose enough to rattle it will come off easily.
If your timing gears are really worn, removing the generator and running without it can be even noisier than before since the load of the generator on the gear train has been removed and the excessive backlash is then allowed to "play".
Looks loose to me!
Any suggestions on which pulley is the best one?
I have read small pulley and large pulley, the engine is a 23. So which pulley is correct for this year?
I have heard some say that running the large pulley with the small fanhub (brass or cast iron) is not a good idea because the fan will spin too fast, increasing the chance of stress cracks and launched blades. Also, finding a belt to work with that combination can be challenging. Good luck with your project. Bill
The pan won't allow you to use a large pulley on a small hub, no room to put it on.
This is a great reference thread
Just had a chance to view your pulley wobble video. Yes, that's VERY loose. Start by replacing it with the large aluminum split type pulley that the vendors sell. That may the source of all your noise right there. Even if it isn't, it needs to be replaced, (or repaired if you have the know-how & facilities to do so).
Thanks for the answer Jerry...
So I'm going to go ahead and order the Adjustable 3 3/4" crankshaft pulley.
Big question: Do I have to remove the pan? I know radiator has to come off if I want to make the job easier...
And if I have to remove the pan any special procedures you all can recommend to make the job as painless as possible?
Thanks in advance...
Robert--Not to belabor the issue, but ask the supplier of the pulley to test to see if the crank pawl will hook onto the pin in the crankshaft. If it will not, you will not be able to hand crank to start the engine without the pawl tending to slip off. I know you probably use the starter but there may be a time when that fails and you have to do it the "old fashioned way".
No, you don't have to remove the pan. There should be room enough to slide the old pulley off and slide the new one on. The split pin that comes with the new pulley can sometimes be tricky to drive in. You can grind a small chamfer on the end you insert to make it a little easier.
(I've never had the trouble that R.S. refers to above. However, in another thread on this forum, he certainly demonstrated that he did.)
I would check the condition of the existing pulley (and the crank) before ordering anything. There are cheap ways to fix it if it isn't too badly worn..
(Message edited by cahartley on March 03, 2016)