basics on pushrods
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From: Honah Lee
i use to preoil them. Have a small circle tin. Fill it up to the top of lifter, Use a pushrod, to push down the piston and hold it. Usually takes a minute or so for the bubbles to start popping out of the inlet hole in the undercut. Once it stops bubbling, a couple of strokes and the piston is pumped up. The problem here is most of my rebuilds do not have adjustable pushrods. So I need it to bled down to turn freely.
Once down .100 and on base circle, that s a high as the piston ever get. In fact, up and down the curve, it probably looses a little Of course, oil pressure fills it back up as it turns on the base circle.
If the lifter is worn out or full of trash, it bleeds off too much and taps when it starts rasing valve.
The steel liner in the aluminum cylinder surely grows. Valves get a little longer. However, only a few thousands difference in intake and exhaust. (.003 or so) But also keep in mind, so does the steel pushrod.. The valve and pushrod cancel out a lot of cylinder growth I think. Aluminum moves a lot with heat. I personally think you can see a difference in primary chain play in a cold and hot engine.
Once down .100 and on base circle, that s a high as the piston ever get. In fact, up and down the curve, it probably looses a little Of course, oil pressure fills it back up as it turns on the base circle.
If the lifter is worn out or full of trash, it bleeds off too much and taps when it starts rasing valve.
The steel liner in the aluminum cylinder surely grows. Valves get a little longer. However, only a few thousands difference in intake and exhaust. (.003 or so) But also keep in mind, so does the steel pushrod.. The valve and pushrod cancel out a lot of cylinder growth I think. Aluminum moves a lot with heat. I personally think you can see a difference in primary chain play in a cold and hot engine.
Last edited by Jackie Paper; Sep 10, 2019 at 05:59 PM.
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