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I have installed a BTR stage 2 V2 cam, delphi ls7 lifters, stock head gaskets, stock ported heads, che trunnion upgrade on a 2010 LS3. Using old 7.4 pushrods to figure out the preload and using the turn method. From zero lash to 22 inch pounds I am getting 1-3/8 of a turn. Is this acceptable or do I need to go shorter?
I think you have a little bit too much preload. Based on your information, you have about 0.108 preload. Ideal preload is supposed to be about 0.080. But 0.108 is actually not bad and may work just fine.
I don't know what BTR recommends for the preload on their cams so it is a good idea to give them a call and ask them.
I always try to shoot for 0.080 preload on a stock LS7 lifter. But the LS7 lifters are very forgiving when it comes to the preload. Other lifters such as Johnsons are more specific and narrow on the preload range.
So, if it was me, I would get a set of 7.375 length pushrods. But I would also check what preload I end up at with the shorter pushrods.
I think you have a little bit too much preload. Based on your information, you have about 0.108 preload. Ideal preload is supposed to be about 0.080. But 0.108 is actually not bad and may work just fine.
I don't know what BTR recommends for the preload on their cams so it is a good idea to give them a call and ask them.
I always try to shoot for 0.080 preload on a stock LS7 lifter. But the LS7 lifters are very forgiving when it comes to the preload. Other lifters such as Johnsons are more specific and narrow on the preload range.
So, if it was me, I would get a set of 7.375 length pushrods. But I would also check what preload I end up at with the shorter pushrods.
I have attached a very useful guide to preload.
Thank you for the advice! I did call BTR and asked for their thoughts about it and told me they want it between 1-1/4 and 1-1/2 turns so I am good with a 7.4 pushrod.
I would order an adjustable pushrod and double check, I prefer this over the counting the turns to 22ft lbs method. You should be fine with the 7.4’s but if it were me I’d like to know exactly where I’m at on preload. I think BTR recommends like .100 preload on the LS7 lifters but I could be wrong. I personally would feel better around .080
Help with pushrod length
