Valve noise problem.

[liquidrush]

I've got a 1600 AH engine that I rebuilt the top end on, new pistons, rings, cylinders, cylinder heads, rocker shafts, modified rocker arms and new thick aluminum push rods, nothing high performance at all. It always had some valve noise no matter what adjusters I used and currently I have the porsche style on there. I asked about this before and it was recommended that I set lash to loose zero which I did. The engine is quiet on start up and for the first few minutes of operation and then I'm getting valve clatter from the left side only. I've checked adjustment cold and it's right where I set it, nothing is loose at all. I've pulled all of the sheet metal and re-torqued the cylinder heads and I still get the same thing. It doesn't seem excessive but it's definitely audible while driving and at idle. So the bottom line is I have a nice quiet engine on start up and for the first few minutes of operation and then I get valve noise from one side. It would seem that as things get hotter they get bigger. Maybe I should just live with it.

[volksworld]

so check it hot and see if its excessive....many times valve train noise isnt from the lash at all, its from the rocker arm sliding back and forth on the shaft ....with stock rockers this is controlled by the spring washers on the shafts....as they wear thinner they lose their tension and allow the rockers to slap back and forth....with "solid shaft" setups you have to juggle the shims or add more to get the right clearance to keep everything quiet....and with aluminum pushrods go back to stock lash settings....and double check your exhaust...an exhaust leak can sound a lot like a valve tap

[mark tucker]

I woulkdent go more than .002" less than what the cam calls for on lash. and set the rocker side play about .002~.004" and it should be quiet. if you dont have "solid" rocker shafts that are adjustable... get them.DO NOT use serated valve spring shims to set side play!!!!

[mikedjames]

It does not take a lot of side play on a solid rocker shaft to clatter.
By setting the lash quite low ypu are probably encouraging the rockers to push harder sideways against the shims on the shaft as they warm up.

If you havent properly sideways shimmed the rockers with the Porsche style adjusters, they can go over centre on the valve stems and try to go down the sides of the valve stem.
I lost one that way.

Which is not good. So I would shim the rockers so the adjusters are pretty central on the valve stems, and side play is small.
. And set lash loose zero when it is warmed up, that after all is what the stock cold .006 is aiming at - about zero warmed up with aluminium push rods. It does not matter how thick they are, its the rate of expansion of the metal.
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[FreeBug]

Actually, there isn't that much margin you can move the rocker along the shaft, if you're using the ones with oil grooves.

[mark tucker]

[Axitech]

Stupid questions that fit here:
Oil flow to the head is lifter bore to lifter, lifter to pushrod, pushrod to rocker, rocker shaft and on through to adjuster threads. Does the oil travel around the threads to get to top of valve? I’m about to install elephant foot adjusters and want to make sure oiling is sufficient.
I’m running aluminum pushrods at ‘loose zero’. Notation with elephants foot adjusters says ‘needs valve lash or won’t get sufficient oil and will gall quickly’.
Can I run these AND ‘loose zero’ adjustment?
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He said to them, “But now if you have a purse, take it, and also a bag; and if you don’t have a sword, sell your cloak and buy one. Luke 22:36


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[oldschool5er]

[Axitech]

Gaaaa, long day! I am running the steel adjustable pushrods! Too many hours in a hot shop today.
_________________
He said to them, “But now if you have a purse, take it, and also a bag; and if you don’t have a sword, sell your cloak and buy one. Luke 22:36


The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.-Thomas Jefferson

[Zed999]

I once rebuilt a 1600 top end with 1mm (0.004") deck that was fine cold but when it warmed up the piston just kissed the head. It sounded pretty much like valve noise. No damage but the piston crown was super clean where it hit.

[jeffrey8164]

@ Liquid.
Set your lash to .006 with the aluminum push rods.
BTW, elephant feet do clatter as do swivel ball.
And. What do you mean by “modified rocker arms”?
Are they ratio’d or just oil mods?
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“Let he that is without oil throw the first rod”
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[Axitech]

Jeffrey, I screwed up. Steel pushrods installed at loose zero. Got answer from John@ ACN and there is enough lash hot to not worry about it. Thanks.
Not sure where I said modified rockers?
_________________
He said to them, “But now if you have a purse, take it, and also a bag; and if you don’t have a sword, sell your cloak and buy one. Luke 22:36


The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.-Thomas Jefferson

[liquidrush]

When I overhauled the engine I machined the rocker arms at the valve end so that the larger adjusters would fit in and I think I have one shim under each of the pedestals. I also cut the oil groove as others had suggested. It's nice and quiet cold. I bought some .010 shims and will double check the rockershafts for rocker arm side lash this weekend.

[mcmscott]

I bet you have a rod bearing talking to you.
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[Brian_e]

I agree with Scott.

Brian
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[Q-Dog]

Top end only rebuild? Why? How many miles on the bottom?
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Brian

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