Different length pushrods same head.
#1
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Different length pushrods same head.
So I installed a cam and 799 heads on my lq9 and I'm seeing that I need different length pushrods on different cylinders. I tried to calculate what I needed by using calipers on the cam before I installed it andcouldnt get consistant base circle readings. Thought it was me, now I think it actually has different size base circles.
I bought the cam second hand on the forums, it was a custom grind. Can I simply use different length pushrods and be done or did I get screwed by the seller?
Thanks.
I bought the cam second hand on the forums, it was a custom grind. Can I simply use different length pushrods and be done or did I get screwed by the seller?
Thanks.
#3
I am going through this myself, mine are 7.40 on the drivers side and 7.325 on the pass. First, yes you can run it with different sizes, I did. Usually you see different from exhaust to intake but I've never seen one side to the other. I am thinking it is in the block casting as I am not running the stock lifter trays.
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Ordering a push rod tool in the AM so we'll see when it comes in.
What I did notice is as I rotated the engine a few times with the stock pushrods a few that seemed off fell into place. (by into place I mean similar to the rest) with stock rods it seems I'm at exactly 0 preload on 6 cylinders. One has a hair of play more than the others, and another seems to have a little more than needed preload. I'm going to run a compression test on that cylinder to check if it just slightly opening the valve or not.
What I did notice is as I rotated the engine a few times with the stock pushrods a few that seemed off fell into place. (by into place I mean similar to the rest) with stock rods it seems I'm at exactly 0 preload on 6 cylinders. One has a hair of play more than the others, and another seems to have a little more than needed preload. I'm going to run a compression test on that cylinder to check if it just slightly opening the valve or not.