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Discussion Starter #1
Hi,

I have hydraulic lifter that shoudnt need any tunes, but i never checked the valves load since i got the car 2 years ago.

Cruising around 2900 RPM without any load, the engine makes a small vibration noise, which desapear at other engine rotations and other loads. It comes clearly when decelarating slowly under light load from 3100 RPM to 2600 RPM.
I have no idea what this might be.
It doesn't seem to make any noise at still stand at the same 2900 RPM, but i will check that again to be sure, with a body's ears in the engine bay.

Now anyway i think about checking the load on the valves, i know how to do it theorically on the V8 and understood the working of it.

The thing is i did it once on a 4 cylinder 1.5 l engine, whose crankshaft could simply be rotated by hand. Now a V8 is something else and i wonder HOW damn i will rotate the crankshaft accuratly?
I don't like the idea of the starter without ignition because i feel like it won't be accurate.

Thank for your inputs.
 

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is this a standard or automatic transmission?could be an out of balance clutch or driveshaft,wheel bearings?
anyway the tried and true way of adjusting lifter preload on a chevy v8 here in the usa is to warm the engine to running temprature,remove a valve cover and,one at a time back the adjustingnut out until you hear the rocker arm clatter then turn it back in until the clatter just stops,then slowly add 1/4 to 1/2 turn more(make sure they are all the same)to preload the lifter.repeat for the other 15 and you're done!
a few tips if you do it this way...try to find some oil deflectors that clip on the rockers to keep oil from shooting all over your engine bay,keep idle as low as possible,have an extra quart of oil on hand.also clean the rocker cover rails and gasket surfaces of the valve covers thoroughly and apply a thin film of silicone sealer to the valve cover and cover side of the gasket only.on the head side use a thin layer of heavy(clean)grease like wheel bearing grease. this will allow you to remove the valve cover and gasket(carefully)as a unit next time and save you $ on gaskets.also the "spreaders"that fit between the valve cover hold down bolts and the covers are a good idea to help prevent leaks.
they help to evenly distribute the bolt's load.
good luck!
Eric
 

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just remembered...a worn pilot bushing can cause what you describe as well.
 

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Discussion Starter #4
hey, thank you !
This isn't the way i would have think to set valves ! I would have done it 'theorically' with searching the balance point of valves, etc ...

I'll set the valves the way you told me then. But i wonder how i will avoid to splash oil every where..

For the noise : I listened at still and it seems it doesn't come from the engine. It seems my exhaust vibrate at that RPM's . Strange hum? but i sratched the headers to exhaust attach point on a bump, maybe therefore...

Marc
 

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Discussion Starter #5
oh, i forgot to tell you about the transimssion i have a restored (by myself) muncie 21.
 

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yeah marc,exhaust leaks can sound a lot like lifter noise.as for the oil splash most automotive stores will sell little clips that fit over your rocker arms to deflect oil.get the all metal ones,the teflon and spring wire types don't work well.also keep the idle as low as possible.
Eric
 

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What about adjusting the valves with Harland Sharp roller rockers? Dont you have to use a feeler guage on these rockers? This is a stupid question but: My new car runs vacuum advance and my old car didn't when it says to set the timing, disconnect the vacuum advance and plug it. Which end are you plugging the port from the carb or vacuum canister?

Later, Erik
 
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