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Post by ramblinman on May 18, 2015 12:24:38 GMT -5
... on 157QMJ engine? does it come up the cylinder to the valves and then splash the chain?  my chain isn't getting any oil, the rocker arms and bearings are getting very little. |
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Sophomore Rider
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Post by phssthpok on May 18, 2015 12:48:03 GMT -5
IIRC there is a pressurized oil passage in the block that feeds oil to the rocker shafts and from there it is distributed to the rest of the valve train with a flow back passage where the chain returns to the crank. In theory the oil flowing down said passage 'splash-lubes' the chain...
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Post by JerryScript on May 18, 2015 14:32:00 GMT -5
The oil pathway runs up the head bolts to the rocker arm assembly. That is why you have dowels to keep it positioned properly.
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Post by geh3333 on May 18, 2015 17:18:52 GMT -5
The oil pathway runs up the head bolts to the rocker arm assembly. That is why you have dowels to keep it positioned properly. There is also a passage that feeds the cylinder right ? |
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Post by JerryScript on May 18, 2015 18:40:44 GMT -5
Same passage IIRC.
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Post by geh3333 on May 18, 2015 18:46:13 GMT -5
Same passage the oil just shoots out a different port " lower" its probably a smaller port so the oil makes its way up higher. |
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Post by ramblinman on May 18, 2015 20:12:34 GMT -5
The oil pathway runs up the head bolts to the rocker arm assembly. That is why you have dowels to keep it positioned properly. There is also a passage that feeds the cylinder right ? the cylinder gets splashed from the crank |
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Post by JerryScript on May 18, 2015 21:20:13 GMT -5
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Post by rcq92130 on May 18, 2015 22:25:35 GMT -5
Same passage the oil just shoots out a different port " lower" its probably a smaller port so the oil makes its way up higher. No pressurized oil to the gudgeon pin or rings, George. It's a "splash" system - each time the crank reaches the bottom it splashes down into the oil reservoir. Some of that (in theory) splashes up to the wrist pin & cylinder wall. The only pressurized oil passage brings oil from the block up thru a passage in the jug, then continuing up thru a continuation of the passage to where the valve train is. I think it then spurts out on the rocker shaft, then eventually falls back into the block thru the slot where the valve chain is spinning. Kind of a Chinese system of lubricating the wrist pin, IMHO. But i guess it sort of works OK. |
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Post by JerryScript on May 18, 2015 22:39:47 GMT -5
There is no dedicated passage in the jug, it flows up through one if the head bolt holes directly to the rocker arm assembly.
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Post by rcq92130 on May 18, 2015 22:50:11 GMT -5
There is no dedicated passage in the jug, it flows up through one if the head bolt holes directly to the rocker arm assembly. Yeah. That IS the pressurized oil passage. |
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