ryan23

iTrader: (5)

Did a "wipe test" but admittedly I'm clueless as to whether what I'm seeing is normal. I'm an OHC guy, what can I say?

Could some of you guys chime in and let me know how it looks. I torqued cylinder 1 I+E rockers to 22 LBS on the base circle and rotated the crank 720 deg. I used a sharpie on the valve stem. Thanks in advance!



Ryan

GMPerf

Are you using stock rockers? Then you would need to zero lash them on the base circle and see how many turns you get for pushrod length

ryan23

iTrader: (5)

Stock rockers. I was under the impression (according to the FSM) to be on the base circle and torque to 22 Ft/LBS.

Ryan

GMPerf

But from the base circle to 22ft lbs is how many turns? You should look for 1 turn or so

HavATampa

iTrader: (49)

Here we go again. You guys with the zero lash and x amount of turns just confuses everybody. You have to tighten the stock rocker bolt to 22 ft. lbs and that's it. The pushrod length isn't going to change that fact. When the rocker stands bottoms out on the heads that's when the torque settings kick in. Also, wiper swipe isn't affected by pushrod length, but by the height of the rocker arm stands.The pics you posted look strange, the swipe marks are very crooked to the right but does show some leaning toward the intake, which means a slight shim adjustment should be added. But it's so close, I wouldn't worry about it.

GMPerf

If you don't have dial indicator to measure pre-load, then counting turns is next easiest... You could hang a valve open or have a noisy valvetrain if not checked. Many factors involved. I have done 400 LS1 buildups btw.

PREDATOR-Z

No disrespect to your 400 buildups, but stock rockers are NON ADJUSTABLE.
Meaning you cannot adjust lifter preload with those.
Only 2 ways to do it are:
1- Custom pushrod length
2- Shimming rocker stands.

So stock rockers are torqued 22ftlbs and all that does is hold the rocker.
Over torking will put stress on bolt and threads (could strip them)
Under torquing will just make your rocker walk.

There is no lash adjustment either on NON adjustable stockers. Just finger tighten and trq to spec.
That is all

ryan23

iTrader: (5)

Wow, you guys can sure get confusing fast.

1st off, I am using OEM rockers with OEM (comp replacement) lifters. I do not see ANY reason why I should deviate from the FSM in regards finger tight/torquing to 22 ft/Lbs.

My question had to do with the "swipe test" picture above. I do not see how pushrod length doesn't play into this. Quite the contrary, everything I have read (here and elsewhere) has said that the manner in which the rocker walks across the valve tip is indicative of correct geometry. Correct geometry being influenced by pushrod length. What I wanted was a pair of "trained" eyes from someone who has a bit more LS1 building experience than me. This person would probably be familiar with this test and could look at the pic and say, "it's fine" or "it's fucked" and here's why...

Brent @ TEA sold me the heads, H/Gs, cam and pushrods. The pushrod length is "probably" OK, however I don't like to leave anything to someone else. I have built a number of motors outside of the LSx world and every time I've left a measurement to someone else it was inevitably wrong. Nothing against Brent, he was extremely helpful.

Havatampa:
Thanks for the feedback. As far as the crooked mark goes, that's why I initally posted the pic. It looked a bit off center. The rocker stand is new, along with the heads. The rockers themselves are used. Do you think I should swap through a couple different rockers to see if it's isolated? When you say it looks like it's "leaning toward the intake", what specifically are we looking at?

Thanks for the help guys,

Ryan

PREDATOR-Z

Calm down.
How did you do the "wipe test"?

ryan23

iTrader: (5)

I'm calm...never was upset :shrug:

I used a sharpie and marked over the valve stem. Then I set the rocker stand in, cylinder 1 intake and exhaust rockers, and tightened them finger tight. Then I torqued both rockers to 22 ft/lbs (after verifying they were on the base circle, cyl 1 @ TDC). Then rotated the engine over twice. Stopped at the same spot I started. Loosened the rockers and observed the pattern above. Thought the intake looked a little strange, so I snapped a pic and posted it up here to try and get some feedback.

Thanks!

Ryan

HavATampa

iTrader: (49)

Sounds to me like you did the wipe test correct. I'm no expert by any means and never claim to be. And you don't need to be one to do this test correctly. If you notice you have less marker left on the intake port (or intake manifold) side of the valve stem than the exhaust port (or header) side which means the rocker pedastal needs to be shimmed up just a little, probably only .010" - .015". But don't trust those numbers, I'm going by a picture. I really wouldn't worry about it unless you just want to experiment. That's the best way to learn this stuff. What you are looking for is to have the marker wiped off from the center most part of the stem and have the marker left evenly on both I and E sides of the stem. That puts less side strain on the valve and the guide. Everytime I've done this test it's been with HS roller rockers and the pattern is a lot cleaner and sharper looking than with stock rockers. Some stock rockers do have a tendancy to rock a little crooked. Try the test on a few more rockers and on another bank, if it's consistent marks, it should be ok. Do a search for "wipe" and "swipe", a lot of good info here on this subject. The wipe test is the easy part, finding the right size shims can be tough. I lucked up and found some stainless steel washers from Lowe's that were perfect for my setup. Some online sites sell shims for this purpose though. And since you are using the stock rocker pedastal rail, I would imagine you would want to use the same size shim across the whole bank.

GMPerf

Guys i know the OEM rockers are non-adjustable. I change pushrod length to get the pre-load. 1 turn is roughly .035-.040" in pre-load. Same thing as using a dial indicator. Just trying to simplify things, because not many people have the correct tools. It is always recommend to check pre-load.

Ryan23, the swipe test does not get affected because the rockers are 'hard' seated on the rocker stand. They are not a 'full floating' setup like a LT1 for example. The OEM LS1 rockers will always have proper swipe whether you use 7.200 or 7.400 pushrods. It will be the lifter that sees the difference in pushrod length.

I still like counting the turns from zero lash, it gives you a very good estimate.

Byter

iTrader: (1)

Also, the swipe test needs to be performed with SOLID lifters not HYDRAULIC lifters if you are trying to determine the correct pushrod length. Let's say you inserted a longer pushrod right now. Your swipe wouldn't change, but the preload on the lifter would because the extra length of the pushrod would just push the lifter plunger more.

With the non-adjustable stock rockers, current valve height(s), and springs, your valvetrain geometry is set. All you can do now is adjust the preload on the lifters by using different length pushrods.

HavATampa

iTrader: (49)

But, you need to adjust the swipe before you check the preload. If you don't fix the swipe first, you will throw your preload measurements off after you add shims.

GMPerf

But if its a stock rocker, stock pedestal height, stock rocker stands, (the valve is most likely the same height) the wear pattern should be perfect. I know the swipe looks funny, maybe the stand wasn't sitting flat on the other end? I would double check the wear pattern... Maybe use of a thin layer white grease instead