Solid vs Hydraulic Lifters
Thread Starter
Racer
Joined: Sep 2008
Posts: 344
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From: Marietta GA
Solid vs Hydraulic Lifters
OK, here's a question. The 350 replacement engine in my '63 Roadster has a valve train tick on the passenger side cylinder bank. I took off the valve cover to discover free play in most of the rockers. Here's the question: can I determine if I am dealing with solid or hydraulic lifters without pulling the intake? I'd like to just reset the valve lash and see if my problem is solved but I have no idea if I am dealing with solid lifters (needing some lash) or hydraulic lifters (needing 1 turn of preload). I was obviously not involved with the buildup of the engine. The engine runs very strong (quicker than my survivor '72 LT-1) and all valves appear to lift to the same degree when running with the valve cover off (whew, no wiped cam lobe).
Thanks
Thanks
Race Director
Joined: Jan 2003
Posts: 17,693
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From: Central Arkansas
You might have to pull the intake and a lifter to examine to be relatively sure. You could also run the valves just checking what clearances you have now. If they turn out to all be in the .024 to .032 range then it would appear you have a solid cam. Have you ever experienced an exhaust manifold leak before? It could sound like a very loud, solitary lifter - except normally it will go away or markedly decrease as the engine warms up.
Dan
Dan
Team Owner
Joined: Mar 2003
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From: Greenville, Indiana
You can start down one bank of cylinders and adjust the valves as hydraulics. You won't get too far before the engine will die or start to miss badly if you have solid lifters. After one or two cylinders, the answer to your question should be obvious.
Your replacement engine could have anti-pump up lifters in it. If it does, they'll usually make noise at idle.
Your replacement engine could have anti-pump up lifters in it. If it does, they'll usually make noise at idle.
Last edited by MikeM; Jul 26, 2009 at 07:37 AM.
Thread Starter
Racer
Joined: Sep 2008
Posts: 344
Likes: 50
From: Marietta GA
Good info. The engine is actually quiet at idle when cold then develops the tick under throttle. As the engine warms, the tick gets louder. Interestingly, the tick is louder when the engine is under load, almost gone as the engine slows from upper rpm to idle with the clutch disengaged. My '63 service manual states that these intermittent valvetrain sounds may be from improperly adjusted valves. I suppose I could adjust the lifters to zero lash or 1/4 turn preload but I hate to risk getting valve to piston clearance issues. The exhaust manifold is a possibility but I am still baffled with the rockers being loose. They appear to have just a little less than zero lash where the rockers (stamped steel, original style) feel loose and rock side to side when on the cam base circle.
Team Owner
Joined: Mar 2003
Posts: 26,118
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From: Greenville, Indiana
Now that you've given a better explanation of your symptoms, my money is on an exhaust manifold leak at the head. Probably just one port.
Have a helper load the engine up a little by dragging the clutch, in gear, and you stick a pvc pipe or similar down around the exhaust ports. If you have a leak you can try tightening the manifold, installing a gasket or removing the manifold and have it resurfaced.
Team Owner
Joined: Oct 2000
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From: Washington Michigan
Pick a rocker arm where the rocker is loose (lifter on the base circle of the cam), and push down on the pushrod end of the rocker arm; if you note movement, you have hydraulic lifters - if there's no movement, you've got solid lifters. 
Team Owner
Joined: Mar 2003
Posts: 26,118
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From: Greenville, Indiana
I don't know if you can do this with the engine not running but you can do it while the engine is running. If you push down hard enough, the rocker will start making a very loud clacking sound and the noise will disappear when you relieve pressure and the lifter pumps back up.
The problem here is some people can't push hard enough.
Race Director
Joined: Feb 2004
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From: CT
This is the only way you should check without removing one of them
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Le Mans Master
Joined: Nov 2008
Posts: 5,691
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From: columbus oh
also on the same rocker.....use a nylon or leather hammer and a few slight dead blows on the top of the rocker....this will bleed the lifter so you can push down on the top of the rocker with the heel of your hand...engine not running of course...good luck
Team Owner
Joined: Oct 2004
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From: altered state
St. Jude Donor '05
Let the car sit overnight. Next morning check the rocker arms, if you can wiggle them a bunch you more than likely have hydraulics (lifters will bleed down and giove you a little slop).
Or on checking preload... Once the up and down slack in the pushrod is gone you shouldnt be able to tighten it much more; a hydraulic you will.
JohnZs method works well btw
Or on checking preload... Once the up and down slack in the pushrod is gone you shouldnt be able to tighten it much more; a hydraulic you will.
JohnZs method works well btw
Last edited by cv67; Jul 26, 2009 at 09:51 PM.
Thread Starter
Racer
Joined: Sep 2008
Posts: 344
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From: Marietta GA
Just an update. I did find two mildly loose exhaust manifold bolts but no change. The noise does appear to be coming from one valve: cylinder 6, exhaust...just a bit more metallic sounding from the rest. I am not able to detect any compression when pushing on the pushrod end of the rocker running or off (even while pressing HARD). I suppose this means I may indeed have mechanical lifters. In any event, I believe I will pull the intake prior to any significant valve adjustment. Now one more question...any problem just changing one lifter in what I imagine is a flat tappet cam? Any need to run a 20 min high rev cycle to break it in if replaced?
Le Mans Master
Joined: Jan 2002
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Just an update. I did find two mildly loose exhaust manifold bolts but no change. The noise does appear to be coming from one valve: cylinder 6, exhaust...just a bit more metallic sounding from the rest. I am not able to detect any compression when pushing on the pushrod end of the rocker running or off (even while pressing HARD). I suppose this means I may indeed have mechanical lifters. In any event, I believe I will pull the intake prior to any significant valve adjustment. Now one more question...any problem just changing one lifter in what I imagine is a flat tappet cam? Any need to run a 20 min high rev cycle to break it in if replaced?
There were no gaskets installed on the exhaust manifold/head interface from the factory, but people do use them. If there was a gasket, and it is blown, simply tightening the bolts won't fix it.
You will either have to pull the manifold, and have it trued up and clean the head surface of the old gasket remnants, or clean the remnant gasket material from the surfaces and use a new gasket.
In older vehicles I have been able to just back all the bolts back far enough to scrape the old gasket off, and slide some new ones in.
Mark
Team Owner
Joined: Mar 2003
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From: Greenville, Indiana
Mechanical lifters will not make an intermittent click just because of temperature, rpm or load changes. Exhaust leaks will.
Thread Starter
Racer
Joined: Sep 2008
Posts: 344
Likes: 50
From: Marietta GA
Interesting comments on the exhaust issue. The car does have exhaust gaskets and they appear clean (metallic). It doesn't look difficult to remove the manifold for inspection however I did not hear any sound at the exhaust flange with my mechanic's stethescope (basically a 12 " piece of brake line pressed against my ear...).
Le Mans Master
Joined: Nov 2008
Posts: 5,691
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From: columbus oh
Interesting comments on the exhaust issue. The car does have exhaust gaskets and they appear clean (metallic). It doesn't look difficult to remove the manifold for inspection however I did not hear any sound at the exhaust flange with my mechanic's stethescope (basically a 12 " piece of brake line pressed against my ear...).
