Chasing the knock.
 

I just purchased my 2nd Model A title says 1932 but it's a 1931 to me. Any way, it has a knock. It has been sitting in an 80 year old man's house for sometime. I had a previous problem of it not running well after a carb rebuild but it was solved with another carb. The car starts good, runs good, and drives out good but does have a knock. So I started investigating. I am a novice so if you see something in the pics by all means tell me. All the lifters are free. I do see a couple new valves. Pulled the cover to inspect the timing gear and is worn pretty badly. I have a new one on the way. I just tried to drain the oil and when I pulled the plug nothing came out. I had to stick a screwdriver in the hole to get the oil to come out. I then dropped the pan. Other than about a half inch of sludge I didn't find anything in the pan. Video is just for noise reference and was taken when I was trying to figure out the carb problem.

https://youtu.be/3R3eLKlvVmU

https://youtu.be/X1Jxiqp16Xwhttps://uploads.tapatalk-cdn.com/201...57dcd7782c.jpghttps://uploads.tapatalk-cdn.com/201...d4408d9fea.jpghttps://uploads.tapatalk-cdn.com/201...6e26a2050d.jpghttps://uploads.tapatalk-cdn.com/201...1b641658b9.jpghttps://uploads.tapatalk-cdn.com/201...d4c6a7be07.jpghttps://uploads.tapatalk-cdn.com/201...879484ef62.jpghttps://uploads.tapatalk-cdn.com/201...7e030af87e.jpghttps://uploads.tapatalk-cdn.com/201...f8c9f1354e.jpghttps://uploads.tapatalk-cdn.com/201...d6dd7bedd1.jpghttps://uploads.tapatalk-cdn.com/201...d1be6a0676.jpghttps://uploads.tapatalk-cdn.com/201...392fb1b55c.jpg

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Re: Chasing the knock.
 

you do have a dipper tray in your pan don't you?

Re: Chasing the knock.
 

The tray in the pan? Yes. I removed it to get to the sludge and get the pan cleaned.

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Re: Chasing the knock.
 

Backfiring could be a stuck valve. That's what mine was.
https://photos.app.goo.gl/iClD1SDIi2GlozyZ2

Fixed it:
https://photos.app.goo.gl/DfOHWJclaOtRwhMv2

Re: Chasing the knock.
 

Did you not check the oil level on the dipstick when you bought it?

Re: Chasing the knock.
 

From what I could see all the valves are moving freely. After the new carb and new plug contactor it no longer back fired.

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Re: Chasing the knock.
 

I did and it was spot on level with no sludge on the dipstick.

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Re: Chasing the knock.
 

Can you tell about where the knock seems to be coming from ?

Have you checked the lash of the timing gears ? Anything more than about .009" and they'll rattle. Yours don't look very good from the picture, but, checking the lash is whats needed.

Running the engine with the timing pin inserted and putting pressure on the gear is sometimes a good way to determine if the gear is bad/worn.

Re: Chasing the knock.
 

That thing needs a bath....before you clean valve chamber block crank and cam oil passages with wood dowels so you dont get debris in them

Re: Chasing the knock.
 

I ran with the side cover off and it sounded to me to be coming from the front of the engine. That's what led me to pull the timing gear cover. I will check the lash.

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Re: Chasing the knock.
 

That fiber gear can have a bad sounding knock when it is worn!!

Re: Chasing the knock.
 

I've had a couple of motors that looked like this. By the amount of dirt and sludge and the timing gear I'd say the oil wasn't changed often. Look at the scoring on # 2 and 3 cylinders. The Pistons are probley slapping.

Re: Chasing the knock.
 

Your car was likely built in 1932, but is of all 1931 parts. A friend of mine has a wide-bed pickup registered like that. Good luck with finding and fixing you noise.

Re: Chasing the knock.
 

It is really hard to tell by the picture, but it looks like your timing gear teeth are worn real bad.
To find the noise it is best to short out each cylinder one at a time. Do this before you tear it down. This way you can tell if it is a rod, main, or piston. It also tells you which cylinder or which main is knocking. It would not tell you if it is a timing gear.

Re: Chasing the knock.
 

I did this but not really any change in the knock.

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Re: Chasing the knock.
 

Since the pan is off, you should check the rod and main bearing clearances with plastigage, and check the babbitt condition of the caps. There are lots of threads on this in the search function. I also put 4x4 block of wood under the front wheels--the extra room makes things easier.

Re: Chasing the knock.
 

Just for comparison, here is a laminated fiber gear with about 1500 miles on it.

Re: Chasing the knock.
 

Good gosh mine is wore out!

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Re: Chasing the knock.
 

I did just notice both motor mount bolts are loose and I have not touched either. https://uploads.tapatalk-cdn.com/201...824c814373.jpghttps://uploads.tapatalk-cdn.com/201...89ded2b99b.jpg

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Re: Chasing the knock.
 

Might be a good time to yank that engine and go through it carefully. The dirt and sludge can't be doing anything but hurting. The car is nice enough to deserve a pretty, quiet engine, and give you a ton of piece of mind while you enjoy it.

Re: Chasing the knock.
 

If you don't replace the crankshaft gear it will eat the new camshaft gear again

Re: Chasing the knock.
 

Looks like a couple of engines that I have had.

Just for conversation. Engine looks really dirty and we know timing gear is shoot. Without knowing what the knock sounds like. If it were mine. I would put in a new timing gear. Clean everything, including screen on oil pump. Than put it back together. Put in 4 1/2 quarts of 20-50 HD motor oil and one 16 oz blue bottle of STP. Five quarts needed because you removed oil pan. Fresh gas with MMO. Oil the distributor. Grease the throw out bearing. Grease everything. Check steering box, transmission, and rear end. Don’t forget u joint (I use John Deere Cornhead grease) also in steering box.

If your lucky, after running for awhile, it will be fine. If not, than we all have to talk again.

Change oil again after a couple hundred miles. Good luck. Enjoy.

As I said before. Car looks good. 80 year old owner, might have not seen maintenance it needed for a few years. Doesn’t mean the old owner did not love car.

Re: Chasing the knock.
 

Yes. This pretty much sums up my thoughts as well.

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Re: Chasing the knock.
 

engine was run with non-detergent oil to have that kind of sludge all over

Re: Chasing the knock.
 

Agree with Farrell in Vancover. The engine is old, dirty and the knock is substantial. You can dick around with various things piecemeal for a long time trying one thing at a time. My personal opinion is that the noise is not coming from a fibre camshaft gear, although it may well need to be replaced, or not, depending on measurements. The photos are inconclusive. The fibre gears rarely make noise like that. Tear it down and do it right. The car is really good looking and deserves a good engine.

Re: Chasing the knock.
 

I agree.

Re: Chasing the knock.
 

A couple of years ago my A was making a faint knocking type of noise that no one could isolate....using stethoscope or wood dowels. It ran fine, but got slightly worse over time. Then, one day, I decided to take it to our local Model A mechanic, but on the way, it suddenly quite running. Had it towed via AAA to his garage.....a couple of hours later we determined the fiber timing gear had stripped out, and replaced it with a new laminated one. Noise was gone; in this case it was a fiber timing gear going bad....yours sounds much worse, so may well be something else, but those gears need replacing in any event.

Re: Chasing the knock.
 

Everyone, including me, has our own idea of what could be going on with your engine.

As I mentioned to you earlier. I have had a couple of cars that looked the same way, and sounded very much like yours.

Many years ago we pulled a Model A out of a barn that it had been sitting in for over 35 years. When we got it running it was making all kinds of different sounds. We pulled pan and it looked like yours, timings gear was also shoot.

We rebuilt oil pump, replaced timing gear, cleaned oil pan, put back together. Started engine using oil I mentioned in earlier post. It ran great, but still had a couple of light knock type sounds. Added rebuilt distributor and leakless water pump. Engine now ran right. The little valve noise it had went away after some driving with the MMO in gas and the high detergent motor oil doing its job.

It’s 40 years later, and that same engine is still running strong. No noise, great compression, no knocks or smoke.

If you rebuild you still are going to need a good distributor and water pump. Plus other things.

If it isn’t broken, don’t fix it. What will it cost you? Gaskets and a timing gear that you need anyway.

Your car looks like it was well cared for. I would take a chance. Good luck. Enjoy.

Re: Chasing the knock.
 

Did you run it with the fan belt off to make sure the noise is not coming from the fan, water pump or generator and their pulleys? Cracked fan blades will make a lot of noise when engine is running.

Glen

Re: Chasing the knock.
 

Re: my above post regarding cracked fan blade. Inspect it carefully before you run the engine to look for cracks near the hub. You don't want to be anywhere near a blade when it lets loose.

Glen

Re: Chasing the knock.
 

Yes I did. Knock still there.

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Re: Chasing the knock.
 

I agree with WHN. Clean out the pan and oil pump screen. Replace the timing gear. Start it up and see what happens. I had 2 fiber timing gears wear out and create a knock. I replaced the second fiber timing gear with an aluminum timing gear. No more problems..

Re: Chasing the knock.
 

Service your main and rod bearings..looks like there are shims on the rods but couldn't tell if the mains have any shims from the picture.No main bearing shims? she's on her last go round,time to start looking for a good babbit man..

Re: Chasing the knock.
 

How did you run it with the valve cover off?? If your oil pump was pumping properly ( dirty screen) then all your oil would be on the floor.

Re: Chasing the knock.
 

Reckon you are going deeper than a timing gear and a clean up..there are some suspicious looking items on your lower end..2,3 and 4 rods look newer than 1..the cylinder walls are badly glazed...center main bearing left bolt is turned,wonder if it has a cotter pin or if its loose The front main bearing appears to have no shims at all. Got any history on this engine?

Re: Chasing the knock.
 

Back when I was in college my A developed a knock. After pulling it down my timing gear was badly worn--replaced it knock went away. Good chance that yours is the problem

Re: Chasing the knock.
 

To add, I too would check/adjust the crank bearings [ and check/adjust oil pump clearances] as long as the base is off for the cleaning.

I like to set bearings at .0015" [ the rear even a bit tighten if I can]

Re: Chasing the knock.
 

Honestly my opinion would to pull the motor and go for a rebuild once and for all. Even if you fix the knock, looks like that motor doesn't have much life left. and be careful if you do drop the mains/rods caps. ive had a few were the Babbitt basically fell apart soon as i dropped it.
Patsrestoration.com

Re: Chasing the knock.
 

A worn out Cam Button (spring) will make one knock.

Re: Chasing the knock.
 

Well I got this far today. I hope this is evidence this is my knock. Also that's my son at the end. He had to get in there and help.

https://youtu.be/lDI6grnm-Z0https://uploads.tapatalk-cdn.com/201...08bb337b75.jpg

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