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Discussion Starter · #1 ·
Hi,
I need a lesson in "How Stuff Works"
I know that with hydraulic lifters oil goes up the inside of the pushrod to oil the rocker
arm and topend. Question 1 is how do the rockers/topend get oiled in a solid lifter
setup?? Now question 2: Is oil coming up from the pushrods a strictly hydraulic lifter
thing?? Third and final question is of course how to tell the diff. between solid and
hydraulic on an assembled engine.

Now to the engine that brought up all this. Its a 66 289 block w\66 289 heads.
We only have the NAPA receipts and don't know much about what they did to it but it
makes all the right sounds for solids. Sounds like a misadjusted valve or 2 burbling
through the carb though so we want to adjust them all and cant tell if they're solids or
way outta whack hyds. They're adjusted to .0014 cold (good for solids, outta whack for
hyds) We tried to test for the 'give' that a hyd. lifter has but couldn't tell. We took out a
pushrod but couldn't see anything.

This engine was built by NAPA for the PO 5 years ago and driven 70 miles to a
house where it sat until we bought it last August. Has 80psi oil pressure at cold idle,
seems to run alittle rough but everything else generally seems OK. You people ROCK,
Thanks in advance.

Kyle
 

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Great questions!

Question 1 is how do the rockers/topend get oiled in a solid lifter
setup??

The exact same way...the oil flows into the lifter and up the inside of the pushrod to the rocker arms.

Question 2: Is oil coming up from the pushrods a strictly hydraulic lifter
thing??

No, it' the same see above.

Third and final question is of course how to tell the diff. between solid and
hydraulic on an assembled engine.

I have no idea! (But I anxiously await the answer!) C'mon Johnpro, or Art!

P.S. Are the rockerarm studs screwed inor pressed ? This "Might" indicate that the motor was converted over to solids at some time during it's life. I doubt though that a solid lifter motor would be built by NAPA.
 

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If you pull a pushrod and look into the top of the lifter bore and you see a lifter with 2 wire type retaining pins on either side that look like they're holding more internal parts down, then you have hydraulic lifters. If not they're solids.

IIRC, all pushrods are hollow and allow oil to move to the rocker.

lash for hydraulics is 0 lash + 1/4 to 1/2 turn down of the adjusting nut so they can be pre-loaded.
 

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On a running assembled system you can hear the solid lifters...the klickety-klak is a hallmark of K-code..HiPo engines. On a properly assembled but not running engine hydraulic lifters rocker arms should be 'cranked down' with no play to pre-load the lifter. Solid lifters have to have a gap between the rocker arm and valve stem to prevent burning the valve. Its been a while since I was a mechanic but I think this is right.
 

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That's not exactly true...On my solid tappit lifters (I've got two old sets, plus the ones currently in the car), the top of the lifter looks exactly like the hydraulic: there the internal c-clip that holds the inner portion of the lifter. But once you take the lifter apart, there's the difference. In the hydraulic lifter (IIRC, its been awhile since I took one apart) there's a spring and some other mechanism, where the solid lifter just had a plug that comes out.

When I get home from work...I will take apart each type of lifter and post a pic.
 

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Drain the oil from the engine and fire it up , if after a minute or 2 the lifter collapse and it starts clacking real loud from the valve train then you have hydraulic .... of course you'll need to rebuild the engine but atleast you'll know what the parts are when you rebuild it !
On a serious side , Im thinking most flat -tappet (Solid Lifter) engines have screw in studs .... I could be wrong and just because your heads have screw-ins does not mean you have solid . The only way I could tell for sure to tell if your engine has hydraulic lifters would be to compress the lifter in it's bore .
Either remove the rocker arm , and place something to prevent damage to the lifter end and then push it in . It should "slosh" in and out if it's hydraulic . If solid it won't move . It takes a bit of a shove , you might want to pratice on a new/spare/used lifter so you know what Im talking about .
 

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I set the lash in my k code at 20. This is with a cold motor. Runs like a r#%@d ape.
 

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I set the lash in my k code at 20. This is with a cold motor.

I'll assume iron heads. This sounds about nominal. Hot usually is in the .022-.027" range. I set the lash on the race car at .015" cold but it has Edelbrocks and they grow a bit.
 

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C'mon guys! Answer the question!

"Third and final question is of course how to tell the diff. between solid and
hydraulic on an assembled engine"

The key is "on an assembled engine"!!!!

I can't tell him how to tell on an assembled engine! :: ::
 

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Since others have answered your questions I thought I would add that, to a practiced ear, mis-adjusted hydraulics tick and solids clatter. There is a difference in the sound, mainly due to the difference in the ramp profile of the solid lifter camshaft. This is why you can run hydraulic lifters on a solid cam profile but not vice-versa.

If you have a friend with a solid lifter cam, go listen to their engine and you'll see what I mean. I've never run any other type of camshaft in my racing engines and there's a big difference in sound between it and a stocker with loose lifters. The current cam in the engine is so quiet when warmed up (composite valve covers help dampen noise further) that most people couldn't even tell the car was running solids.

If your engine came from NAPA and has pressed-in rocker studs, likely it has a hydraulic camshaft and one which is OEM in profile or close. Only way I could tell for sure is to compare the ramp profile to a known-solid profile. The existence of the clearance ramp would be telling. Obviously, if the cam has a part number stamped on it, that could be traced.

Let us know if you need more assistance...
 

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I can't tell him how to tell on an assembled engine!

See my answer elsewhere the thread. He might not be able to run the test I formulated but clearance ramp profiling should suggest the lifter type. Also, he should be able to visually inspect the lifters with the intake off as he tightens the rocker stud. Any longitudinal movement of the pushrod seat would indicate hydraulic lifter (not necessarily camshaft); that's OK; he can run hydraulic lifters on either a solid or hydraulic profile (at least one near to OEM specs).

Hope the CenCal heat hasn't go to me...let me know *G*
 
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