How to tell intake and exhaust valve with the intake manifold on?

I had a heck of a noise going on in my 350 V8 chevy engine. I checked it out and one of the rocker arms was quite loose.
I am reading up on how to set the clearance on the lifters. I snag #1
cyl and get it at TDC using the marks on the flywheel. I can tell the cyl # by the stamp on the engine block. Then I can set certain exhaust and intakes to proper clearance. No problem since all the cylinder numbers are marked on the head.
1. BUT how do I tell which is exhaust and which is the intake valve with the intake manifold on? Been looking in the book and I see no info on that.
Then I move and set it for #6 cyl and then do the rest of the rocker settings.
2. Been wondering how come that rocker was so loose. As I understand it, the hydraulic lifter is just an oil filled damper chamber to take up erratic slackness within fine limits. If it was stuck it would make a clicking noise, but would not be THAT loose? Or do I misunderstand?
thx BSA
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wrote:

You normally don't have to adjust hydraulic lifter valve lash after the initial adjustment. Try some Sea Foam or something else made to free stuck lifters before you horse around with this. You could have a bad lifter(s) or flattened cam lobe(s). I put cams and new lifters in a Ford 352 and a Chevy 350. Used the method below, and never adjusted rockers with the engine running. No problems. Start at TDC #1 and work around the valves in firing order per the instructions below. Zero lash means when the pushrod stops turning freely in your fingers as you tighten down the rocker. You should be able to find a picture to sort out intake from exhaust. I think the exhaust is on the left as you face the head, but find a picture. Think hard about what you're doing, and what the actual problem is. I've got the feeling you're wasting your time.
http://www.hotrodders.com/forum/valve-lash-adjustment-52345.html "Hold the phone!! Everyone cover their toes cause I am about to start stomping...... We have covered this many times. Chiltons is a piss poor way to set lash as is the method with the engine running. The only proper way to set lash is one cylinder at a time when the engine is on the stand before it is fired. You set the exhaust valve when the intake valve opens and has about half closed and the intake valve as the exhaust starts to open. What this does is insure that the valve is on the back side of the lobe opposite the ramp. Using chiltons method you have some valves that are actually starting to open. This is especially true for engines with agressive cam profiles. Using the running method you either beat the piss out of the BRAND NEW cam while it is breaking or you let it idle while you set the valves....either is bad.
If you set the valves properly one cylinder at a time you can go 1/4-1/4 turn past zero lash and you are set from now on. I never take the valve covers off of an engine once I have cranked it unless something is wrong and have never had an issue with not having the valves set properly. Chris"
--Vic
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BSAKing wrote:

With the valve cover off this is VERY easy. Take a look at the exhaust manifold. Notice how there are three sections that bolt to the head? They are almost exactly in line with the exhaust valves. One on each end and two in the middle.

A bad lifter can collapse and cause the rocker to become very loose. It also will NOT repair itself. You need to actually open the engine up and replace/repair the bad lifter. It could also mean that the cam lobe has ground down. The way to check that is with a dial indicator. You place it on a good rocker for the same valve (intake for intake and exhaust for exhaust) and see how far it travels then put it on the ? one and see how far that one moves, it should move almost exactly the same amount (almost because you will have some differences depending on the lifter/lobe wear) Another item on SBCs is that on the older engines with press in rocker studs they can pull out of the head over time, causing a loose rocker and then you need to reinstall it and pin it OR use a screw in stud conversion kit.

--
Steve W.

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On 4/7/2011 9:22 PM, BSAKing wrote:

What generation is this engine? Or, what year was it made?
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BSAKing wrote:

You may have a bad camshaft. What year is the engine?
-jim

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Hi - all this great info has given me food for thought.
When I tightened the other rockers - it was only a smidgen - like maybe 1/8 turn at most just take a bit of slop out - some I actually loosened a tad. Just to get them sounding quite similar with just a 'little' noise on each thru a garden hose. (I know - I can hear the purists and experts cringing... lol, but I did not know any better)
That one noisy one though I had to turn a bit and now you have me worried. lol.
I think I'll get some Sea Foam and run it through - it may loosen that one and then I can re-adjust. All I can say is that from the limited bit that I drove it - it was a lot smoother for sure....
It is a 1976 corvette l-48 350 smogger - with about 125K miles on it. Never been opened up. FWIW, I usually do my own oil changes and I have never seen any metal grounds or debris in it.....
I'll try the loosening route first with Sea Foam (it sounds like a highly recommended product from what I read on the web) - if no go, then I guess I will have to gird my loins and pull the intake manifold. I am just a weekend mechanic and have never done any heavy duty engine work, so let's try the obvious first - that seems to make the most sense.
Thanks for all the great info - REALLY helpful!
BSA
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BSAKing wrote:

Bad cams were common in that era - although you would think the bad ones would have been weeded out by now. If it is the cam lobe worn down you should be able to see that valve not moving as much as the others. And if it is a bad cam the clacking will be back fairly soon - they wear pretty fast once they start.
Changing the cam is not that hard and they should still be some available in junk yards.
-jim
    

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LMAO. You are kidding, right?!?! You do not get a cam from a junk yard! Get a new one. Plenty around. If it comes to that, get an RV cam or one above the stock cam. 125K, you should change the timing chain anyway.
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willy wrote:

Those cams tended to fail because of manufacturing defects. The ones that didn't have the defective hard facing would outlast the rest of the engine.
Any cam you find in the junk yard for this engine will be either like new or junk. It's pretty easy to spot the difference.
-jim
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Your telling me it makes sense to take the time to pull cams in yards in hopes of finding a good one? Your telling me a yard is gona let you take apart a good engine? Your telling me you would buy a good engine from a yard, take it home and rip the cam out of it to put in another engine? All that work and what do you have? You still have a used cam and lifters when your done. And speaking of lifters, you gotta keep them matched up with each lope. Guess your gona tell him to use the timing chain that came out of the yard also?!?! Cam and lifters for small blocks are not expensive. For christ sakes use your head!
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willy wrote:

You are guessing it would be difficult. I've stuck several bone yard cams in small block chevys.
He can buy a new cam and lifters if he wants to spend the money, but the engine isn't likely to last any longer.
-jim
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wrote:

New cams and lifters were pretty cheap when I did mine. I wouldn't buy any worn mechanical part from a boneyard unless I could mike it to new specs. Besides, this stuff has a tendency to snowball. On an old engine if you replace a cam, you start thinking about the cam bearings. Then the mains and crank seals. On my 352 I decided to do it all at the beginning, because I had the desire and energy, Big job if you DIY unless you're half machinist and have a good shop. I had my garage floor and rented an engine hoist. I took the crankcase, crank, rods and pistons to what they used to call a "speed shop" around here. They tanked the crankcase, polished the crank, miked everything, installed the cam bearings, and sold me the cam and bearings that fit their miking. Think the cam had a bit more lift. About 30 bucks IR. But that's 1975 dollars. Mains were different than original because of crank wear and polishing. Rings were different than original due to bore wear. I did the ridge reaming and bore polishing myself. Heads were reworked at another shop. It all came together fine except the head shop screwed up the guides or seals so I was sucking some oil. Not too bad and I lived with that. Just pissed me off. Probably had $12-1500 hundred in parts and shop work. And a whole lot of labor by me. It's a serious endeavor unless you really enjoy doing it. I don't regret it, but once was enough. My 350 had the about the same miles as the OP, maybe less. Hard to say since it was a rebuilt. Found the sticker on the crankcase. A major rebuilder but I can't remember the name. This was about 1990. A valve went bad so I pulled the heads, took them to a shop. The shop told me one of the heads was a 305 and recommended they get a boneyard 350 head and work that. Anyway that all went okay. I put new lifters in. Cost maybe $500 total and a lot of labor from me. Three months later a rod started knocking and I junked it. Rust was overcoming it anyway. My bottom line now for valve train or lower end issues is either junk it or buy a crate engine if you want to keep the car. But I don't really trust rebuilts either, since I had a bad one. I had my mech put a Targetmaster 307 crate engine in my son's car about then years ago, but that's a new engine with a good warranty. As soon as you start pulling heads for anything but a gasket you've got a good chance of going backwards moneywise. That's just my view. Usually rust has almost destroyed a car here before an engine becomes an issue. A fiberglass Vette is a different issue. Should be answers on a Vette forum. I hope that Sea Foam works for the OP. I've freed up sticky lifters on old V-8's before. Think I used "Engine Flush" products. Those were beaters, and I'm not recommending that. Not even sure about the Sea Foam. Think I used it for injectors once, Didn't work. I needed new injectors. You can find all kind of stories on the internet.
--Vic.
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Well - I have been reading the updates here.
Where I am now is that I took the most logical route and that was to stuff some Sea Foam in it. I also cleaned up the ignition to see if it would cure some of the roughness.
I have only done a few miles in it. There is a still valve noise, but it "seems" a little less severe. I will drive it for a bit and then pop off that valve cover again and check to see how far down the nut is WRT to the others and touch up the adjustments as best I can based on the info here and see where we are then. I think the nut travel was much the same from recollection, so it may be at the end of the day that It will only need adjusting after the Sea Foam does it's work. Time will tell I guess. That's the best, at the worst new cam, etc. Moderate would be new lifters... but one step at a time.
I note the dissertation about cam shafts. Always an unpleasant possibility, but it actually runs a little better now, so I have my fingers crossed.
If I do have to go to the trouble, I certainly would not put in a used cam, lifters, or timing chain - I mean what's the point of that? The differential in the cost of those parts (used vs new) is far offset by the time and effort involved. AFAIK those parts are readily available new.
Keep you posted.
BSA
PS. "someone that can't dsitinguish an intake from an exhaust valve sure as hell shouldn't attempt changing a camshaft. " - You could very well be right, and I probably would not tackle it because of time and equipment. But please don't mistake unfamiliarity with stupidity. (at least I am not afraid to ask, and I do know how to spell "distinguish"). lol.
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wrote:

Don't recall how you located the noise and whether this applies. But one time I was *sure* I heard a bad or stuck lifter. When I examined the sound up close I found it was a leaking exhaust donut gasket.
--Vic
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There wasn't the slightest implication of stupidity, although after reading your latest complaint (quite apparently you're also wholly unable to recognize the incorrectly sequenced letters in an obvious typo), in addition to your original plea for help (and advising a novice not to tackle a camshaft replacement on an SBC without available, onsite, experienced assistance, IS in fact help of the first order), I can readily understand how and why you might very justifiably and understandably be senstive. about an issue of competence.
But if in fact your otherwise empty, miserable existence is so conspicuously impoverished, wanting and devoid of actual meaning that for it to afford you any value whatsoever you desperately resort to cruising newsgroups (while solciting assistance, no less) for perceived errors in spelling, grammar, diction or punctuation (therewith providing your sole raison d'etre), in a pathetically feeble attempt at mocking those that would strongly discourage you from making a likely critical error, far be it from me to deny you that crucial perquisite ;^)
Best of luck to you, given your approach and personality, you're going to sorely require all you can possibly muster.
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OMG! Touchy are we....? And totally unable to understand an ironic comment it seems. That's ok - we all have our days. You may also want to look up the definition of "lol" in internet shorthand...
In any event, to everyone else, thank you for taking the time to answer my request for information and advice. It is most helpful and appreciated.
If it is a major rebuild, it is certainly beyond my capability and desire - I would be the first to admit it. If it does fall into that camp, on a 35 year old engine I note the comments from another poster and I could see it being a bottomless pit with a very hard to justify cost-benefit. Not sure what the heck I would do then...
The most I would have any desire or capability to address is some easy component replacement and/or adjustment. I am going to remove the valve covers again and re-examine and try to adjust everything armed from info from here and the service manual. I'll see where that gets me. I would hate to relegate old Betsy to the bone yard after having had her for 35+ years, so wish me luck.
I will LYK how I make out.
BSA
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OMG! Touchy are we....? And totally unable to understand an ironic comment it seems. That's ok - we all have our days. You may also want to look up the definition of "lol" in internet shorthand.
******** You may rest assured in the most certain knowledge that I've forgotten, yet still retain, more about Computer Systems and Sciences than you're ever going to have the slightest inkling about.
In any event, to everyone else, thank you for taking the time to answer my request for information and advice. It is most helpful and appreciated.
If it is a major rebuild, it is certainly beyond my capability and desire - I would be the first to admit it. If it does fall into that camp, on a 35 year old engine I note the comments from another poster and I could see it being a bottomless pit with a very hard to justify cost-benefit. Not sure what the heck I would do then...
The most I would have any desire or capability to address is some easy component replacement and/or adjustment. I am going to remove the valve covers again and re-examine and try to adjust everything armed from info from here and the service manual. I'll see where that gets me. I would hate to relegate old Betsy to the bone yard after having had her for 35+ years, so wish me luck.
I will LYK how I make out.
BSA
**** Here's a little more assistance that you can desperately use: Just leave the damned thing alone before you cause substantial bodily injury (or worse) to yourself or other unfortunate innocent victims in the vicinity.
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"You may rest assured in the most certain knowledge that I've forgotten, yet still retain, more about Computer Systems and Sciences than you're ever going to have the slightest inkling about. "
A possibility most certainly, but highly unlikely. thanks for your comments.
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BSAKing wrote:

In case your statement is genuine.
    The mostly likely component that has failed on your engine is the vacuum advance on the distributor. If after 35 years the diaphragm is still intact it would be a minor miracle. The difference a working vacuum advance is rather subtle because it only functions when the engine is under light loads. But a defective vacuum advance will over time cause all sorts of engine damage including the type of problems you are having.
Get one at a parts store or on ebay: http://tinyurl.com/5rtxtea
-jim

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e is the

A very astute observation Jim! Thanks - and it is the original as I really have had the car since day #1. It certainly should be replaced as a preventative measure. I'll look into sourcing a repladcement as part of all of this.
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