Ok so last night I got my BTR valve springs done...now I am about to measure for my pushrod length so maybe I can pick them up before the store closes.

I saw videos of people doing a marker method, but I have read that cant be dont on LS motors.

On my LS6 I need to measure. I understand getting a cylinder at TDC etc, what I dont get is how do I know what preload I want? I see other threads where people find their length and then add a preload. How do you find your preload? I am using stock LS6 rockers that are in my 243 heads.

 

needing advice on LS6 lifter preload as soon as possible...store will close before too long.

 

Do you have an adjustable pushrod?

If not - look here: https://ls1tech.com/forums/15457558-post1.html

AND

"If you are not familiar with the EO/IC method for determining valve events in a 4 stroke engine, its very simple:
For a given cylinder as the Exhaust valve is Opening, the intake lifter will be on the base circle of the cam and lash/preload should be checked for that intake valve.
For a given cylinder as the Intake valve is Closing, the exhaust lifter will be on the base circle of the cam and lash/preload should be checked for that exhaust valve."


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Yes I have the comp 7702. I am turning it out 10 turns so 7.3. Have cylinder one at tdc. Put the pushrod in adjusted to 7.3. Snug my rocker and just barely over hand right with socket. Then lift the rocker tip up and down. At 7.3 there is no play whatsoever. Even at 9 turns there is no up and down play. So now I am kind of confused. This is new cam. Comp 238/242 615/610 113+2 and btr springs.

 

Double check your work - make sure the TDC that your at is on the compression stroke, or use the EO/IC method above. Also make sure that during the measurement step the rocker is actually snug. It sounds like the rocker is less than snug when you are taking the measurement, but snug when you do the check.

 

Looks like 8 and 3/4 turn is where I get zero play. So 7.275 length is where I get no up and down tick.

 

Should be compression stroke. Timing dot on cam and crank gear are lined up so 1 and 5 at TDC compression

 

What lifters?

 

Just checked exhaust valve also. 8 1/2 turns is too short. 8 3/4 is no play.

 

Stock 01 ls6 lifter in a z06

 

Oh and I meant cylinder 1 and 6

 

There can be some differences between valves, but that is okay with hydraulic lifters.

The lengths you are coming up with seem short, but that could be attributable to the base circle change with the cam.

 

Now I'm really confused. Tdc is still one 1 and 6. Went to do 6 intake and 8 3/4 is too short. :/

 

You want pushrods that are 0.050 inch longer than the shortest measured length. That will give you at least 0.50 inch preload everywhere with a little more on some valves. You need not measure every valve.

 

I'm still stumped though cause both valves on cylinder 6 tdc are way different than cyl 1 at tdc

 

From Service Manual

Rotate the crankshaft until the number one piston is at top dead center (TDC) of the compression stroke. In this position, cylinder number one rocker arms will be off lobe lift, and the crankshaft sprocket key will be at the 1:30 position. The engine firing order is 1,8,7,2,6,5,4,3. Cylinders 1,3,5, and 7 are left bank. Cylinders 2,4,6, and 8 are right bank.


With the engine in the number one firing position, tighten the following valve rocker arm bolts:
•Tighten the exhaust valve rocker arm bolts 1,2,7, and 8 to 30 Nm (22 ft. lbs.).
•Tighten the intake valve rocker arm bolts 1,3,4, and 5 to 30 Nm (22 ft. lbs.).

Rotate the crankshaft 360 degrees .
Tighten the following valve rocker arm bolts:
•Tighten the exhaust valve rocker arm bolts 3,4,5, and 6 to 30 Nm (22 ft. lbs.).
•Tighten the intake valve rocker arm bolts 2,6,7, and 8 to 30 Nm (22 ft. lbs.).

Install the valve rocker arm covers.

 

Now I checked 3 and 8 3/4 turn is too short. What is up with my cylinder one lifters

 

Try checking the Cylinder 1 valves individually using the EO/IC method (Post#3) and see if you get a different result.

 

Just got 10 1/4 turn for cylinder 3 tdc for both intake exhaust.

 

Ok I will after I check cyl 2 real quick.