How much preload does 1/2 turn calculate to if using 1.6 ProMags 7/16 polylocks? Called comp and the guy was a complete A$$ after holding for almost 20 minutes.

 

The lifters dictate the required preload, not the rockers. I use 1/2 turn with stock lifters without issue.

 

x2 on that....some even say use a 1/8-1/4 turn but then they at times the rockers/lifters are noisy and you can go up to 1/2 turn and quiet them down a bit.

 

lifters dictate how much preload you need but tha actual preload is accomplished by the rocker nut but if you are looking for a measured value the thread pitch on the rocker stud should tell you. I would measure the distance between the peaks of two adjacent threads and theoretically that is going to be your preload for one full turn.

 

After making sure you have the right PR length, Id also say 1/8 to 1/4 turn past 0 lash is good.

 

7/16 studs are 20 threads per inch on the top. That makes 1 turn = 1/20th or .05 of an inch. So an 1/2 turn would be .025".

3/8 studs are 24 threads per inch on the top. That makes 1 turn = 1/24th or .04166 of an inch. A half turn would be .02083".

Seems kinda funny when you stand back and look at the numbers and how much difference that small amount can make.

 

Exactly what I needed to know. Thanks

 

That would be true if the rockers were 1:1 ratio but they aren't.

 

So do you know how to calculate in for the ratio or just going to make a statement without any critical feedback?

 

Yep, but since stopping miss-information here is apparently frowned upon go ahead and use shoebox's calculations.

 

Do you really need to be a dick about it, the guys asking for help not for **** responses.

 

Well I set up my dial indicator tonight to check whether or not the thread count was acurate. It turns out that it was right on the money give or take a few thousandths for operator error. I wasn't trying to be rude, its just that your comment didn't have any corrections and that is what I was looking for.

 

I think I know what you might be trying to say, but the preload calculations are exactly correct, since it only affects the travel at the lifter when you are doing it. In actual operation, differing ratio rockers will have whatever their multiplying effect is on valve travel that is consistent with their ratio. I have never really heard of anyone changing their lifter preload based on rocker ratio, though. I guess it could be something to consider.

 

 

Correct.. He knows his poop!

 

He can't help it, he's just a KID who thinks he knows it all...