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Camshaft/Crankshaft timing


gr-made

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I put my 243431 0627-02 7605171 back together on my 64 Landlord. As I said in my post yesterday I thought it might be the valves that were causing only 15 pounds of compression. Tonight I took the head off and it was so obvious that I had the timing all wrong. On the compression stroke I had one of the valves wide open. Needless to say there goes all my compression. So I just tore the motor all the way back down again. I am getting very good at this by the way. My question is what is the specific sequence for timing while installing the crank and cam? For every two revolutions on the crank you have one revolution on the cam. So you can either have it timed correctly, or completely 180 degrees out of time. I guess my luck gave me the later. All of my Briggs Manuals just say to line up the two marks. Any help would be appreciated. GR-Made
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This is a cast-iron block motor isn't it? If it happens to be aluminum block you line up the timing mark on cam gear with the timing mark on the counter-weight on crank shaft, while the rod pin (on crank shaft) is at top-dead-center. Valves must be in first and crank and cam installed at same time. That's the best I know right now.. Good luck! Hope a full time mechanic might come on and help you out. Marion W. Kerr
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Yes it is a cast-iron block. I saw in the manual on the aluminum block engines to do exactly what you described putting the rod pin at TDC. However it mentions nothing about this on the cast iron blocks. The timing marks are impossible to line up exactly too on this design. The main bearing is in the way of the timing mark on the crank. Therefore a mark was put on the counterweight. As you spin the two you have to simulate about 15 degrees from where they meet. I can see someone being a tooth or two off very easily. And yes I hope a mechanic can come to the rescue for me on line. Thanks GR-Made Eric Thompson
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My Briggs manuals says the following: " All cast iron engines - Ball bearing except 300400 and 320400. Assemble the tappets, then insert can gear into the cylinder, pushing the cam gear forward into the recess in front of the cylinder. Insert crankshaft into cylinder. Turn camshaft and crankshaft until timing marks align, then push cam gear back until it engages the gear on the crankshaft with timing marks together. Insert camshaft. Place a small amount of sealer on the camshaft plug, then press or hammer it into the camshaft hole in the cylinder at the flywheel side. I hope this helps you. Good luck Al
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It's easy to get completely confused by timing but regarding crank/cam timing there is no such thing as 180 degrees off, IF the timing marks are correctly aligned. though the cam does turn 1/2 the speed of the crank, a full revolution is a full revolution. I swear everytime I rebuild a motor or replace a timing belt on a car, I have to remind myself of that basic rule.
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