my 66 327 makes a lot of upper engine noise like its low on oil. dip stick is showing full or very close to it. oil presure is great. any ideas? thanks for your input.
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Re: 66 sounds low on oil
kelly----
First thing to check: remove a valve cover and see if oil is squirting out of the holes on the push-rod end of the rocker arm with the engine running, of course. If it is, there shouldn't be any problem with top end oiling and your noise problem must be emanating from somewhere else. Do this test quickly and have someone turn off the engine quickly after you've determined if the oil is flowing. Otherwise, you'll have oil all over the place.In Appreciation of John Hinckley -
A quick check...
pull a valve cover and run engine. Are you actually getting oil? Mine did this once 400 miles from home. Timing chain wear had allowed the cam to shift, reducing oil flow. A new chain set and a gear button cured it.Comment
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Re: A quick check...
You got solid lifters?Comment
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Re: 66 sounds low on oil
How about changing your oil? How much do you have? Are you sure have the right dip stick? In addition, solid lifters make a lot of noise compared to hydraulic lifters.
GaryComment
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Re: 66 sounds low on oil
Actually, if properly adjusted using the Williams/Hinckley rocker ratio adjusted lash specs, mechanical lifters should not be that noisy.
DukeComment
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Re: 66 sounds low on oil
Duke,
You'll have to elaborate on this one, or just point me in the right direction. I've never heard of the "Williams/Hinckley rocker ratio adjusted lash specs". I have a 70 LT-1 that could use some quieting down, but I don't want to burn valves.
KevinComment
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Re: 66 sounds low on oil
Kevin -
E-mail either me or Duke and we'll send it to you (the direct e-mail feature from this board doesn't accommodate attachments).Comment
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Re: 66 sounds low on oil
"mechanical lifters should not be that noisy"
Quite correct, but "should not be THAT noisy" is a matter of individual perspective. How noisy is noisy? It all depends on "what the definition of is is."
GaryComment
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Re: 66 sounds low on oil
Loud is a "clacking" sound. Correct is like a bunch of sewing machines hidden under the hood. Does that help?Comment
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Re: 66 sounds low on oil
Please define "a batch"Comment
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Re: 66 sounds low on oil
I'd say muted sewing machine. Fact of the matter is that is you adjust your valves to the OE spec they will be too loose. The valves won't open until after the opening ramp ends and set down on the seat before the closing ramps begins. This will increase noise and since the valve is set down on the seat at higher than ramp velocity, the rate of vavle seat recession will increase.
By using the "rocker ratio adjusted" lash specs, you can be assured that valve will be opened and closed "on the ramp", and at idle, an average buy might not be able to detect that the engine has mechanical lifters.
DukeComment
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Re: 66 sounds low on oil
I just bought the car on sunday. I drove it home about 45 min. then I noticed the"sewing machine". I think it does have solid lifters. lets say I check under the valve cover and no oil is pumping. what next? thanks for all your help. kelly39831Comment
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Re: 66 sounds low on oil
Buy a set of vavle cover gaskets and pull the covers. Set the engine at TDC #! on the firing stroke (dist. rotor pointing at #1, not #6) and use feeler gages to see if there is lash (clearance) between the valve stem and rocker arm. If there is you probably have a mechanical lifter cam, but who knows what it is or what the proper clearance is. You'll have to try to find out the history from previous owners. Measure and record the lash for all valves. If you-mail me I will send you the procedure for checking lash. The actual lash might help ID the cam.
If there is no clearaance it probably has hydraulic lifters.
I say "probably" above because there have been reported cases of hydraulic lifters set with lash and mechanical lifters zero-lashed. Bubba is everywhere!
Start the engine and see if oil squirts out the top of the rocker arm pushrod seats. It probably will. If not, the lifters are probably clogged.
Sounds like you've got a project ahead to try and determine at least what you have.
DukeComment
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Re: 66 sounds low on oil
kelly-----
Then, you get to start "tearing into" the engine to find out where the problem is. My guess is that you're going to find that oiling is ok. Likely, the cause of the sound you hear is a worn camshaft timing sprocket and/or stretched chain. This is a very common problem with Chevrolet engines, especially if the engine still has the original cam timing sprocket in it. Most of these OEM sprockets were cast aluminum with nylon teeth.The nylon teeth eventually wear or break off in chunks.In Appreciation of John HinckleyComment
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