Have you ever tightened one? I guarantee you they stretch. They're small/non-hardened bolts. Do it your way. I'll do it mine.

 

Yes.

Between you and Old Motorhead, can you tell me how my way will not get the results everyone's after? Just curious.

 

I never said they didn't stretch. But you're setting lash to the "stretched" (torqued) bolt. It ain't going to stretch anymore unless you torque it more. When you **** around with counting turns and ****, you no longer are setting a torque spec on the bolt. Riddle me this. Say you only need 1/2 turn, or maybe you need 1 and 3/4s turn (using y'alls turn counting method) to achieve your desired preload. What torque is that? 8 ft lbs? 12? 16? 60? The answer is...you don't know. You're not using lock nuts like in a stud mount setup. The torque on the bolt is WAY MORE IMPORTANT than how many turns it takes to get you in the sweet spot for preload. Why do you think OEM lifters have over 2 tenths of travel? Answer is when assembling on a line, the torque spec with the appropriate length PR puts the preload at optimal (give or take a few thou here and there) to work and make it through QC and live a long and happy life.

But you're right dude...do it your way. I could care less.

 

Ronin ... I can answer that.

Lets say you are using 1.7 ratio rocker arms. And lets say you would like around 0.79" lifter preload. You know that 1 full turn of the bolt from it's zero lash starting position will yield .079" lifter preload.

You don't stop turning the bolt down as it reaches 1 full turn (it may not even be tight at all yet at 1 turn) ... You continue counting the turns of the bolt until it's torqued down to the desired spec ...then you count the turns.

If it turns more than 1 turn, you need to use a shorter pushrod ... if it took less than 1 turn, you need a longer pushrod.
_____________________________________

We are looking for between 1 to 1 1/2 turns, which will insure the correct OEM lifter preload.

Note: The total plunger travel in the stock LS valve lifter is approx .200” (Two Hundred Thousands)

Note: If the bolt rotates less than 1 turn, you will need a pushrod that is .025” longer than stock (7.425”)

Note: If the bolt rotates more than 1 1/2 turn, you need a pushrod that is .025” shorter than stock (7.375”)
____________________________________

. . . . . . . . . . . . . .. . . . . . . . . . . . . . .1.8 Rocker Ratio . . .1.7 Rocker Ratio

1 . . . . . Turn of the rocker arm bolt = .076” lifter preload . . .079” lifter preload
1 1/4 . . Turn of the rocker arm bolt = .095” lifter preload . . .098” lifter preload
1 1/2 . . Turn of the rocker arm bolt = .114” lifter preload . . .117” lifter preload

.

 

You know .... The OP was initially asking how much preload on the lifter 1 full turn of the bolt would give .. he had heard a couple of very different answers.

My whole intention of responding to the OP's question was to tell him that when using a 1.7 ratio rocker arm, 1 full turn of the bolt equals .079" of lifter preload .. that's a fact

Then we start turning this whole thread into a pissing contest on the best way to set lifter preload ... shakes head

 

Not a pissing contest, it's just trying to make things easier. And FWIW everything you just said is exactly what my method is doing...yours just takes an unnecessarily long time to get there.

If you're at zero lash with the bolt torqued, you're at .000 preload right? So if you want a .050 preload, when you add that length to the PR (measured with the bolt at full torque) and what do you get? The correct length PR for the desired preload and the bolt fully torqued. And you don't have to fart around with counting turns and ****.

 

I think the difference is that they're measuring without using a length checker.

I suppose it could be argued that adjusting the length-checker is sort of a hassle, and if you're buying off-the-shelf pushrods then your resolution is a pretty coarse 0.025" so what's the difference.

I myself use a length checker and I extend it to zero lash after the rocker is installed. And I measure every valve. I wouldn't argue this is faster, but it's certainly better. Building an engine takes a long time anyway, why are we arguing about how to cut a few minutes out of a critical step?

 

Exactly ...

And it don't have to be perfect ... Again, the total plunger travel in the OEM LS hydraulic lifter is a very wide .200" (two hundred thousands of an inch)

In most cases, you would want your preload to be somewhere in the middle of the plunger travel ... that would be .100"

My guess .... anywhere between maybe .060" to .120" would be just fine .... with a total plunger travel .200", you have a pretty wide margin to set the preload.

One very respected engine builder I am aware of likes to see .060" preload, while another equally respected builder I am aware of likes .100"

 

I’ve had good results using the same method as ronin. Torque rocker arm bolt, set pushrod checker to zero lash, order pushrods that set desired preload.

 

Fair enough about the point mentioned of the dudes using it without a length checker. I wouldn't even bother setting up a valvetrain without one, nor would I do a head/cam/lifter swap without one. I'd just wait until I had the tools necessary to do the job right. But that's me.

Again, I'm not trying to get in a pissing match...I just want to ensure nobody throws in a towel over something this simple. Spend the 20 bucks and buy a PR length checker.

 

Alright guys, thought I should follow up since I'm still messing with this engine trying to get it to quiet down.

I ended up calling Manton Pushrods and talking to their guy there, after telling him everything that was going on, giving him my measurements (and more importantly how I got those measurements) and what I was trying to accomplish he recommended a 7.445-7.450 length pushrod to get me on the tighter end of spec based on the aluminum block and what Johnson recommends. At this pushrod length the Johnson lifters would be around .040-.045 of preload which is pretty much on the money. I also ended up going with slighter larger 11/32 pushrods for higher stiffness, when I received these pushrods in the mail I also noted that the oil holes were noticeably smaller on the Mantons vs. the BTRs that were previously installed. I don't think this makes a difference, just something I noticed.

After installing the pushrods the engine starts and sounds much better, having more noticeable thump at idle and a more "normal" mechanical lifter/rocker sound as well as giving much better part throttle response in lower RPMs. However, this did nothing to remedy the issue I've been experiencing which is a clacking noise on startup that I thought was happening due to almost no lifter preload/short pushrods. With the pushrods at the now correct length and proper preload having been attained the engine still makes the same noise which sounds similar to when a cam phaser goes out on an engine with VVTI. The same noise will appear after I've driven the car for a while and then let it sit for 15 minutes or so, only this time in addition to the clacking on startup it will also make the noise at low RPM with load on the engine until I go through the RPMs a few times.

Anybody else have any advice on what may be causing this issue? Are Johnson lifters just inherently very noisy?

 

What's wrong with using a brand new set of GM lifters in the engine.

My engine is very quiet and all I have for lifters is the stock GM ... Even when I replaced the stock 1.7 ratio rocker arms with aftermarket 1.8 ratio roller rocker arms, the valvetrain is still very quiet (and that's with the stock GM lifters too).

 

I've personally never had a problem with the GM lifters themselves. What I have a problem with is a 10 cent piece of plastic "holding" a metal valvetrain component moving at 3500 rpm. Most of the time that cam lobes get wiped in these motors is because a lifter tray fails and allows the lifter to spin in their bore. I'd rather have a steel link bar holding them together...or at least a dog bone connector like in the old pushrod 5.0s. Anything other than the plastic BS.

 

I've already answered this question previously in this thread.

Anybody have any idea?

 

I agree. I've said this many times. Here goes, again;
I've got close to $15,000.00 in my LS7. I think I can come up with a few bucks for a pushrod length checker. For me, it's a no brainer, and dead nuts. But hey, whatever flips your trigger. As my old grinding dept. boss used to say, "there's more than one way to skin a cat's ***"!

 

Hm, I suppose nobody here really has any idea.

Thanks anyways.

 

Dude...what? Several methods have been described on what to do in this thread.

 

now that's some epic trolling...

 

What I did on mine is I stuck with the same manufacture Manton on this to keep consistencies. I order a pushrod that was I know was to short by say .020-.040. I put that pushrod in and tightened the rocker arm to 22 ft pounds. I then did the old flat tappet cam feeler gauge test. Say in this case it was say .035 on gauge - now with a 1.8 rocker arm that is about .020 on the other side for zero lash (1.8 x .020 = .036). I then say I need .040 preload so I order from Manton a pushrod of that length + .040 to account for the preload. I also test some other cylinder to make sure they are all in the same area. By sticking with Manton through entire process it keeps it consistent and factor in all the ball measurements and how they measure pushrods versus other guy etc. This also accounts for that last tweak (say 1/8 of a turn) in tq wrench where I am not sure it moves it just kind of situates itself (the rocker arm). For these lifters like guys mentioned above I think you come in around 1/2 turn +/- when I did this method.

 

The more mathematics involved, the greater the chance of a mistake. I'm happy for you that your way works, for YOU. My way works for most, including me. I'm always listening and game for doing things differently, IF it's truly better. For me, and most pro's, a checker has less margin for error, is dead nuts, is much quicker, and needs one math equation, adding .080"-.100" to the zero lash figure. Quick, simple, accurate, and costs less than 3 Iridium spark plugs. Engineers will tell you that a design that has the least motion and/or movement to accomplish the task at hand will be the most feasible, the most reliable, and most economical in the long run, than one which requires more parts and more monkey motion. Another phrase often used is "let's not reinvent the wheel, here". IMHO, guys who count bolt turns are reinventing the wheel. I digress......