Engine knock on a 1930

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lh

lh

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This Model A was restored by my brother in law. I don't think there is 100 miles on the restored engine. There is a knock for about 15 seconds when starting the engine then it goes away. It sounds like a loose bearing. Other wise the engine sounds fine.

So my next step is to remove the pan and plastigage the bearings. According to the literature I have read, babbit bearings can be adjusted because they are shimmed. If these bearings are inserts, the this is a bigger problem. The bearing clearances should be .002 inches. I am not looking forward to this.
 
Maybe just the oil getting up there if it sounds ok once running No worry! That's my take on it.
 
lh said:
This Model A was restored by my brother in law. I don't think there is 100 miles on the restored engine. There is a knock for about 15 seconds when starting the engine then it goes away. It sounds like a loose bearing. Other wise the engine sounds fine.

So my next step is to remove the pan and plastigage the bearings. According to the literature I have read, babbit bearings can be adjusted because they are shimmed. If these bearings are inserts, the this is a bigger problem. The bearing clearances should be .002 inches. I am not looking forward to this.
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How long was the car stored from the last time it was run till you started it up. There might be hardened oil or grease in the oil tubes which will destroy the bottom end in short order.
 
Back in the 70s my phaeton had a knock when first started. I removed the pan and found the oil tube to the rear main was missing about a half inch. Once running, the oil would bridge the gap and the knock would stop. I repaired it with a piece of rubber tubing and a couple of small hose clamps. It was a farmer fix but it worked great.
 
Does the knock go away when you step on the clutch? I had a similar knock that was caused by a bad thrust bearing.
 
lh said:
This Model A was restored by my brother in law. I don't think there is 100 miles on the restored engine. There is a knock for about 15 seconds when starting the engine then it goes away. It sounds like a loose bearing. Other wise the engine sounds fine.

So my next step is to remove the pan and plastigage the bearings. According to the literature I have read, babbit bearings can be adjusted because they are shimmed. If these bearings are inserts, the this is a bigger problem. The bearing clearances should be .002 inches. I am not looking forward to this.
Click to expand...

Was an aluminum cam gear installed? Mine is noisey upon startup till warmup...then quiet, even with 1000 miles on engine. Not a problem as I see it.
 
My 30 is doing the same thing. The noise goes away in about 15 seconds, Sounds like when the oil pressure comes up the noise stops.
 
We had the same on an engine and determined the cams center bearing had excessive play. Once the pump started to fill the void the knock disappeared.
Still running, but it gets a careful warm up session at every start.
 
Today I removed the pan. Took the rod that had the most "play" and plastiguaged the bearing and it was .0015". That is right on specifications. There are two shims on each side of the rod caps. The engine has new pistons and the rods look new also so the person who did the work appears to have done a good job. I am not going to check the main bearings because it is difficult to get to remove and install the bolts.
 
I checked all of my mains and rod bearings. Took one shim out of the front and rear main bearing. Everything looks great but still have the noise on startup. After it runs for about 15 to 20 seconds it sounds fine, Just going to leave it alone now.
 
I side with Jim Rogers. Pull the valve cover and probe each oil galley to the cam, and mains. Sometimes the galley was packed to keepchips out during machining operations and never removed. Also if the motor sat for a while debris can accumulate in the valve chamber reservoirs, also plugging up the oil galleys. Are the dipper caps on correctly? pickup facing the cam? Bob
 
The rod caps are facing toward the cam so that is OK. I am using 10-30 weight oil. I reinstalled the old oil pump, with crack, and pan today. The timing was severely retarded.

It runs much better. More pick up and go.

I could not fine a replacement oil pump, Snyders, Macs or Sacramento Vintage Ford. All of their oil pumps were out of stock. I will drive slow until I can replace it.
 
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