Rocker / lash Questions

[FlyingDutchman]

Trying to chase down a tick / tap that sounds like it's coming from the valve train. Pulled a valve cover to look quick and noticed the rockers have a bit of play, mainly side-to-side as shown in this guys video:
http://youtu.be/hNcJjE9FDVk

Motor is a 355 LT1, CC503, stock intake/heads, LS7 lifters, CC hardened pushrods, GMPP guide plates, 1.6 ultra pro rr's, crane dbl springs, stock VC's.

Motor runs great, makes good oil pressure cold and around 30psi hot on the gauge. Gonna poke around more with a stethoscope after work with covers off.

Is there supposed to be any play? Or did these rockers come loose? Originally set them with motor out of car, didn't touch after that (~600mi on the build). I saw LTb1ow had a similar issue, less lash helped ?

Any insight is appreciated

[LTb1ow]

Those are not ultra pro mags FYI, those are GMPP looking aluminum rockers, which AFAIK are SA rockers. Confirm this before anything else.

[FlyingDutchman]

Originally Posted by LTb1ow

Those are not ultra pro mags FYI, those are GMPP looking aluminum rockers, which AFAIK are SA rockers. Confirm this before anything else.

Yeah those are GMPP SA rr's, but that's not my car lol just a video that show exactly what I'm trying to describe. I have ultra pro mag's.

[LTb1ow]

Ah, ok, easy enough then Every rocker setup I have done always has "loose" rockers like that, I would not worry about that. Steel bodied roller rockers will always be noisier, so you may be overthinking. But thats assuming the noise is consistent and not localized to one area.

How much preload did you go with and how did you go about doing it?

Rocker sweep look centered both laterally and axially on valve stem?

No binding on guideplates? Side to side, or depth

[FlyingDutchman]

Probably overthinking, I imagine the lifters bleed down a bit to allow movement. So far I haven't seen metal shards in my oil most people with "loose" rockers had pushrods bending / coming out of the seat, so I couldn't relate haha

Think I did 1/2 PZL by feel / watching lifter cup just before it started to wanna compress.

I'll have too look more closely after work, maybe pull one off and check sweep.

How would I know if the pushrods are binding ? The appeared to be touching the guide plate but isn't that normal to keep them from bouncing?

[LTb1ow]

Binding leads to this


Make sure the PR have space for full travel.

Can you get a sound recording of noise?

[FlyingDutchman]

Pulled cover, couldn't/didn't hear anything abnormal, phone didn't pick it up, maybe it's an exhaust leak? Ugh, I hate cars lol

[FlyingDutchman]

Update: After finally getting a base tune I took the car for some data logging. You could probably see where this is going apparently the car didn't like the high rpms as much as I did (motor sounded amazing!), so now the noise I was describing earlier is much more pronounced and accompanied by a slight knock/misfire/stumble at idle. I was able to get the car home without a significant loss in power and it still accelerated smooth. Oil pressure remained normal (30ish to 50ish on the gauge). Also, car had a tougher time starting since the new tune..

Here's a link to a quick video:

https://youtu.be/YeJ5I0XagaQ

Ideas?

[LTb1ow]

Either a header gasket leak, or rocker preload.

I would go over em all again, and just verify you have correct zero lash set, then whatever you wanted preload wise. I use 3/4 turn on mine.

[FlyingDutchman]

Originally Posted by LTb1ow

Either a header gasket leak, or rocker preload.

I would go over em all again, and just verify you have correct zero lash set, then whatever you wanted preload wise. I use 3/4 turn on mine.

Since noise was on driver side, pulled the cover again and all were good, except #1 intake was VERY loose. Since this was my first build and first time lashing valves prob didn't set poly lock on that one. Most likely loosened after yesterday's wot pulls. Will check passenger side and verify all are good. Thanks for the advice

[Pampered-Z]

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