I have a lot of noise coming from the front of the engine. I pulled the alternator and ran it, noise still there. Then removed the fan belt, noise still there. I tore the engine down for other work and looked at the timing gears. What do you think? PK
The camshaft gear looks quite worn, but that does not mean it is the only source of noise. You really need to use a stethoscope and different engine speeds and throttle openings to locate get a better idea where the source of the noise "might" be located....
Yes Tony I did the stethoscope check. I checked down the lower block and the head. The noise is loud from idle to full throttle and definitely coming from the front. PK
A loose crank pulley can make enough noise to sound like your engine is going to self destruct.
Pat, the question is has the noise always been there or has it just started? The lower gear is not factory but the top looks original. This means the engine has been apart and reline bored. Could be a worn cam bearing causing the top gear to start riding high on the lower one?
Remove cam gear [look at rear]
and see if its' drive peg holes are not elongated
This problem cannot be seen from the front as the drive pegs only go through to about half way.
The noise from this will come and go with engine revs.
How much backlash is between the gears? Might be time to replace both gears.
It's usually best to replace both gears at the same time. Putting a new gear w/a used gear doesn't make sense.
This engine has always had this noise but it is getting louder. The front pulley was loose when I first got the car, I repaired that. I'll get a dial indicator on it tomorrow but there is some backlash. This engine was rebuilt in 1966. PK
Did you check the rods?
It looks from your picture that there is quite a bit of backlash between the gears.
Could you describe the noise? Is it a rapping when you are just going along about 25-30 mph but disappears when you accelerate or deccelerate? Is it worse when pulling a hill? These symptoms describe a bearing knock.
A constant howling noise would indicate a gear. The noise from a gear with too much backlash would be bad because of the spring tension on the camshaft would tend to move it back and forth as the valves open and close. With metal gears, you could probably go for a long time before it would stop your car from running.
I would suggest that you replace both timing gears and the alternator gear if you decide to replace the gears. Also check for looseness of the front cam bearing which could cause the camshaft and gear to move away from the crankshaft. A worn bearing there could cause premature wear of the gears.
I do have a light rod knock which is why I pulled the engine down. I figured I would go after everything while I was at it. The noise is constant. I'll get some time on this project tonight and tomorrow with the information gained from this thread and post back. PK
I checked the backlash crank to cam gear at each spoke. I got 0.005, 0.006, 0.005. The cam to alternator gear is 0.005. Also I checked the cam front bearing movement up and down and get 0.010. When I rotate the crank I can hear the gears click when the front lobes come off the tappet. PK
That is a lot of play in the camshaft bearing. You have problems that need to be investigated. Time to pull the motor.....
You can easily replace the camshaft and / or the camshaft bearings without pulling the motor. I would start by pulling the camshaft and then think about replacing the cam bearings and the crank / cam gear set for sure. This will be a good time to lap the valves, since those will need to be removed.
If the cam bearing fits the cam properly it is an easy task to shim the bearing in the hole with shim material.
While I'm at, what is the max cylinder taper? How about piston clearance? I'm going to post same pictures of my #3 rod bearing tonight on here. It looks like it wiped in the center but feels smooth running my finger over it. Thanks for any comments, PK.
I once had a cam shaft making noise. Sort of bouncing in and out due to excess end play. I believe it was from Snyder's I got a Camshaft Throughst Washer Kit. I see Mac's has this kit also ($31.95 Mac's). I used two of the shims and the noise was gone.
#3 rod bearing. PK