Possible Crank/Cam gear Timing Issue C-113

   #1  

arlen4720

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Well, I'm mildly panicking...hopefully for nothing.
I'm rebuilding a Farmall B, and have had my share of struggles.
It seemed fairly obvious to line my cam gear up with the punch on the crankshaft gear. I noticed at the time that #1 was not at TDC, but a few deg past TDC on the intake stroke. I thought it strange, but I haven't worked on one of these before.
There was a clear single punch on the crank gear, and a clear single punch on the cam gear, and a double punch on the cam gear 180 deg from the single punch. I checked, double checked and went on my merry way and installed the front cover and pulley.
Then I was watching a Youtube video from the Canadian Redneck and he casually mentioned that when you time the governor to the cam by lining up the double punches that #1 will be at TDC at that point. He didn't specify if it was compression of exhaust stroke.
Mine is not that way. I was hoping if someone can confirm if it truly is at TDC when the marks are all in line. And could you confirm if compression or exhaust.


Here is a picture of the governor gear lined up with the double punch on the cam gear. Here #1 is a few deg past TDC on the intake stroke.
C9288A66-8461-4991-9F9F-2AA282129BEE.jpeg



Here is a pic of the mark that I lined up with the crank punch mark. Here #1 is a few deg past TDC on power stroke. The marks are a little puzzling here, but that big mark is 180 from the very clear double mark of the 1st picture. There are actually 4 marks here on the cam gear if you look close!
I hope I am just confused.
I should note that the crank was not the original, but the Cam and governor are the originals.

EE9F3FB0-AB94-4390-8E3F-15D125D7CA9E.jpeg
 
   #2  

denchen

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With the crank not being the original, I think I would turn it over by hand and check the tappets are both on the rock when the piston is at top dead center. If not, I think it would be a good time to worry. If the piston is past the top as you say, then I guess it would be slow to start and run rough with no power, plus run hot, but it shouldn't do any damage.
 
  
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arlen4720

arlen4720

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With the crank not being the original, I think I would turn it over by hand and check the tappets are both on the rock when the piston is at top dead center. If not, I think it would be a good time to worry. If the piston is past the top as you say, then I guess it would be slow to start and run rough with no power, plus run hot, but it shouldn't do any damage.
Not sure I follow you, but my real question is if the piston on #1 should be at TDC when timing marks on gears are all aligned, and if so, would it be on compression or exhaust stroke.
 
   #4  

denchen

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Years ago when I used to dismantle some old engines, they never had timing marks, so before dismantling, we would put our own dot marks for timing. That being said, if your crank is different to the original, then it could easily be a tooth out. Sometimes someone would bring an engine in they had taken too bits and couldn`t get it together or they had assembled but it run rough, probably because they hadn`t dotted the teeth. Anyway the way I was taught was to turn the engine and get the piston at TDC. If its firing on number one, then both valves will be shut, but on number four, at the same TDC the exhaust should just finished shutting, and the inlet just starting to open. We called this `just on the rock`. So on your 4 cylinder, turn the engine until on number 4 cylinder the exhaust has just closed, and the inlet `just` starts to open. Numbers 1 and 4 pistons now must be exactly at TDC, if not something is not right. You can `rock` the engine back and forward and see both valves move. I hope you can understand this.
 
  
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arlen4720

arlen4720

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Years ago when I used to dismantle some old engines, they never had timing marks, so before dismantling, we would put our own dot marks for timing. That being said, if your crank is different to the original, then it could easily be a tooth out. Sometimes someone would bring an engine in they had taken too bits and couldn`t get it together or they had assembled but it run rough, probably because they hadn`t dotted the teeth. Anyway the way I was taught was to turn the engine and get the piston at TDC. If its firing on number one, then both valves will be shut, but on number four, at the same TDC the exhaust should just finished shutting, and the inlet just starting to open. We called this `just on the rock`. So on your 4 cylinder, turn the engine until on number 4 cylinder the exhaust has just closed, and the inlet `just` starts to open. Numbers 1 and 4 pistons now must be exactly at TDC, if not something is not right. You can `rock` the engine back and forward and see both valves move. I hope you can understand this.
Yes that makes sense. I was hoping to resolve it before I put the head on though. I’m not sure I can gauge it precisely enough by just sticking the push rods in and watching those.
 
 
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