Pushrod lengh
Thread Starter
Teching In
Joined: Feb 2019
Posts: 14
Likes: 1
Pushrod lengh Hi guys, just want your thoughts on this,
I have milled the heads on my LQ4 by 0.040''. Standard LS pushrods are 7.400'' so you would think i need 7.360'' pushrods to compensate, but I have just checked with a pushrod length checker and I am only getting to 7.225 with no lash. So even with a preload of 0.050'' that is only 7.275 which seems to short?
Anyone have any ideas how this works?
Thanks
Sam
I have milled the heads on my LQ4 by 0.040''. Standard LS pushrods are 7.400'' so you would think i need 7.360'' pushrods to compensate, but I have just checked with a pushrod length checker and I am only getting to 7.225 with no lash. So even with a preload of 0.050'' that is only 7.275 which seems to short?
Anyone have any ideas how this works?
Thanks
Sam
I just had a set of heads milled .025 . I installed them with OEM GM gaskets and with some 7.350 pushrods I already have, I have too much preload.
FWIW the OEM pushrods are not 7.400 they are actually in the 7.38 range.
FWIW the OEM pushrods are not 7.400 they are actually in the 7.38 range.
Thread Starter
Teching In
Joined: Feb 2019
Posts: 14
Likes: 1
Thanks for your response
Sam
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Verdad Gallardo Thread Starter
Teching In
Joined: Feb 2019
Posts: 14
Likes: 1
What length pushrods do you think you are going to need?
I suspect 7.325 to achieve proper pre load. I already had 2 spare sets of pushrods from other projects laying around.
With 7.375 I achieved 1 3/4 full turns past 0 preload Torqued to 22 FT LBS
With 7.350 I achieved 1 1/2 full turns past 0 preload Torqued to 22 FT LBS
I did not have my adjustable pushrod length checker with me. I need to pick it up and Verify
1 Full turn is .079 Pre load.
So 1 1/2 full turn Should be roughly .0118 Pre load.
I dont want to post a non sponser site since they sell parts But I found a really good tech article on lifter preload
Here is the video they made showing actual lifter preload as you turn the factory bolt 1 full revolution.
With 7.375 I achieved 1 3/4 full turns past 0 preload Torqued to 22 FT LBS
With 7.350 I achieved 1 1/2 full turns past 0 preload Torqued to 22 FT LBS
I did not have my adjustable pushrod length checker with me. I need to pick it up and Verify
1 Full turn is .079 Pre load.
So 1 1/2 full turn Should be roughly .0118 Pre load.
I dont want to post a non sponser site since they sell parts But I found a really good tech article on lifter preload
Here is the video they made showing actual lifter preload as you turn the factory bolt 1 full revolution.
Thread Starter
Teching In
Joined: Feb 2019
Posts: 14
Likes: 1
I suspect 7.325 to achieve proper pre load. I already had 2 spare sets of pushrods from other projects laying around.
With 7.375 I achieved 1 3/4 full turns past 0 preload Torqued to 22 FT LBS
With 7.350 I achieved 1 1/2 full turns past 0 preload Torqued to 22 FT LBS
I did not have my adjustable pushrod length checker with me. I need to pick it up and Verify
1 Full turn is .079 Pre load.
So 1 1/2 full turn Should be roughly .0118 Pre load.
I dont want to post a non sponser site since they sell parts But I found a really good tech article on lifter preload
Here is the video they made showing actual lifter preload as you turn the factory bolt 1 full revolution.
https://www.youtube.com/watch?v=pB40wxeR-NM
With 7.375 I achieved 1 3/4 full turns past 0 preload Torqued to 22 FT LBS
With 7.350 I achieved 1 1/2 full turns past 0 preload Torqued to 22 FT LBS
I did not have my adjustable pushrod length checker with me. I need to pick it up and Verify
1 Full turn is .079 Pre load.
So 1 1/2 full turn Should be roughly .0118 Pre load.
I dont want to post a non sponser site since they sell parts But I found a really good tech article on lifter preload
Here is the video they made showing actual lifter preload as you turn the factory bolt 1 full revolution.
https://www.youtube.com/watch?v=pB40wxeR-NM
Thanks again.
Sam