1973 225 valve adjustment help!please!

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slantsixdan said:
It will roughen the idle, yes.



Usually not. But that reminds me, yet another reason to do it running is that you can take a look and see if the top end is oiling properly. You should get a good ooze/dribble of oil out the tip of each rocker arm. If some or all of them aren't oiling, it means you'll want to remove, disassemble, and clean the rocker assembly—also covered in the previously-linked post. If the rear is oiling but the front is not, it's usually because the rocker shaft has been installed wrong way round and/or upside down. There's a small flat ground on one edge of one end of the shaft; this is to be installed top-front. In the mid-1970s, the shaft and the rearmost bolt were altered to prevent misassembly, but earlier pieces require a careful eye.



Well, different goals will tend to produce different advice. Those who have the goal of helping you learn to do the best possible valve adjustment on a slant-6 will tend to give certain kinds of advice. Those who have a goal of slagging other board members may tend to give contrary advice, which may not even be based on much of any actual slant-6 experience, because they have higher priorities than helping you achieve the best result on your slant-6. Take a careful look at the tones of voice and the amounts of slant-6 experience reflected in each answer you receive and use what you see to decide how much faith to put in each poster's advice.
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i have two more questions for you... and that is ,does a slant usually have a slight lope at idle with a stock cam or is it all in the timing or could it be the timing chain has stretched and throwing the timing off? in other words should it be a straight smooth idle or do i need to advance the timing a few degrees? and i cant seem to find or reach the distributor hold down bolt . man it is really crampt on the right side of the engine for sure. and thanks again for your help and advice -
 
73AbodEE said:
does a slant usually have a slight lope at idle with a stock cam
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No. Go to the rear of the car and listen to the exhaust. It should be a very even sound with only very slight warble. If there's a pronounced rhythm to it, if you can hear one cylinder making different exhaust noise than the other five, then you've got confirmation that something's amiss. Look for a single-cylinder vacuum leak. Check at the rearmost intake runner's vacuum take-off tap; make sure all hoses connected to it are in good shape and are running where they're supposed to. Make sure there aren't any open vacuum nipples on it. Have you done the rest of a tune-up yet?

What's your ignition timing set at? Factory spec in '73 is 0° (TDC) but this is a very retarded setting meant to squeak the new '73s past Federal emissions type-approval tests. Try 5° BTDC. You will want to make sure the timing mark is accurate, because the outer ring member of the vibration damper can slip relative to the inner hub. To check this, stick a straightened-out coathanger wire or similar into the frontmost spark plug hole, and turn the engine by hand (easier with no spark plugs installed) until the wire stops moving upward out of the plug hole. Then check where the mark on the crank pulley is relative to the timing indicator.

could it be the timing chain has stretched
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Certainly could be! Remove the distributor cap and turn the engine manually with the fan and belt in one direction until you see the distributor rotor begin to move. Then turn it the other direction and watch the rotor; if there's any discernible lag between your moving the engine and the rotor turning, the timing chain is slack and will want replacement. It makes sense at that time to do a super-careful job of getting the camshaft timed precisely to optimise your engine's operation for economy. Details are in multiple threads and you can be pointed at one if your engines appear to need this sort of attention.


i cant seem to find or reach the distributor hold down bolt
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It's a 7/16" bolt just forward of the distributor body, holding the distributor hold-down plate to the block. Loosen it with an ordinary 7/16" socket on a long extension, then rotate the distributor counterclockwise to advance or clockwise to retard the timing. There is also a second bolt on the underside of the distributor, holding the hold-down plate to the distributor body. Once you've loosened the plate-to-block bolt, if you run out of adjustment room in the plate slot before you reach your desired timing setting, you can loosen the underside bolt and there's a much longer adjustment slot there. Doing so with the distributor installed requires a special wrench, either bought or cobbled (the official one, which also works well on the plate-to-block bolt, is here). If no special wrench, you'll have to remove the distributor to get access to the second bolt.

You'll want to ditch that cheesy air filter and find a correct air cleaner assembly to put back on. It's a thermostatic type that'll give you better driveability and economy (i.e., better performance), see here.

One other thing you'll want to do on this '73 if it hasn't yet been done: bypass the OSAC valve. It's on the passenger side of the firewall, and has one hose running to the carburetor and another hose running to the distributor. Run a hose directly from the carburetor to the distributor without stopping at the valve.
 
Just to add what i use when adjusting when it's running is a bit of cardboard that fits between the guard and top edge of the head and that catches any oil that spatters around,less messy that way.
 
i have new plugs/cap/rotor/wires and it does have somewhat of a rythym to the idle. i bypassed the vacuum lines going to the firewall. i can tune a four barrel 318 or big block all day but these sixes seem to be a little more tempermental but it could be me. i noticed a change with the idle rythym after i messed with valves . could that be related? i can hear kind of a puff with a couple cylinders but not a solid miss . from my v8 experience its almost like a timing issue but i did not notice it before the valve adjustment. the previous owner kind of mickey moused a few things but it has a brand new holley one barrel and has worked great so i ruled that out as a possible mixture issue. i will get it exactly on top dead center and see exactly where the rotor is and go from there. i like to advance the timing on my v8s so i wanted to do that anyways as i pretty sure it is still at the factory setting. thanks again you have given me much insight!
 
You might have stumbled over what many of us stumbled over on our first \6 valve adjustments: it's easy to get so wrapped up in paying attention to the clearances that you miss the changeover in the middle of the engine, where two intake valves are next to each other. So you're going along, adjusting alternate valves to 0.020" and 0.010", and you get half the adjustments backwards. Result is rhythmic idle and puff/chuff out the exhaust. Front to back or back to front it's E - I - E - I - E - I - I - E - I - E - I - E.
 
slantsixdan said:
You might have stumbled over what many of us stumbled over on our first \6 valve adjustments: it's easy to get so wrapped up in paying attention to the clearances that you miss the changeover in the middle of the engine, where two intake valves are next to each other. So you're going along, adjusting alternate valves to 0.020" and 0.010", and you get half the adjustments backwards. Result is rhythmic idle and puff/chuff out the exhaust. Front to back or back to front it's E - I - E - I - E - I - I - E - I - E - I - E.
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funny you mention that ! i caught myself doing that the first time around and i when back over it again. im going out and trying it with the engine running this time. do i just plug the pcv to keep it running? and how do you keep the gauge from flopping around between the valve and rocker. sorry so many questions lol
 
Review the suggestions at the linked valve adjustment, which addresses your latest questions of how to slow down the engine idle speed, how to deal with the PCV, and how to hold the gauge and wrench so your hand doesn't get jerked around.
 
slantsixdan said:
Review the suggestions at the linked valve adjustment, which addresses your latest questions of how to slow down the engine idle speed, how to deal with the PCV, and how to hold the gauge and wrench so your hand doesn't get jerked around.
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OK the verdict is IN. with all due respect to all of you who have different methods of adjusting valves (specifically the 225) the best way I found was with the engine RUNNING. not only was i able to HEAR what i was doing but i could tell when a specific cylinder was out of wack and after trying it WITHOUT the engine running i found i had not adjusted a few valves correctly. thats not to say i was even doing it correctly BUT i know i was damn close. but NOW i have extinguished ALL the ticking and the engine is PURRING like a kitten ! THANKS DAN for your help and advice and also to all of you that gave your input. I am so stoked to have this thing running the way it should !
 
slantsixdan said:
Errrrr…fer serious? I have never, ever seen or heard of this actually happening. That doesn't mean it's impossible, of course, it just means I haven't seen or heard of it actually happening. Have you? Much more common is for the adjustors to be too loose to hold an adjustment. Methods of dealing with that are covered in the link.
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Yeah, I've had it happen to me a couple of times on a slant, once on a 273, and many times on a poly 318. All engines were super crusty inside and hadn't had an adjustment in decades by the look of it. After my second one wrung off, I decided I would just pull the rocker assy's off and clean them thoroughly if I found them that nasty again. Loose ones are much more common... especially if someone has removed all the adjusters and cleaned them on a wire wheel or ran a tap through the adjuster.
 
73AbodEE said:
well im new at it so im probably wrong about it being accurate ,maybe im just a little chicken of firing it up with the valve cover off and sticking my fingers where they dont belong lol, anyways it sure sounds tons better and i hope i havent created more problems by messin with it .....
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Trust me it's not that hard. I did it for the first time not too long ago and as long as the idle is low it's pretty simple. I also just bought my first slant two months ago so I know how daunting it sounds....the hardest part was getting use to trying to get the socket on while the rocker while it was moving. I still have all my fingers!
 
73AbodEE said:
well im new at it so im probably wrong about it being accurate ,maybe im just a little chicken of firing it up with the valve cover off and sticking my fingers where they dont belong lol, anyways it sure sounds tons better and i hope i havent created more problems by messin with it .....
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Trust me it's not that hard. I did it for the first time not too long ago and as long as the idle is low it's pretty simple. I also just bought my first slant two months ago so I know how daunting it sounds....the hardest part was getting use to trying to get the socket on while the rocker while it was moving. I still have all my fingers!
 
mrhollywood said:
Trust me it's not that hard. I did it for the first time not too long ago and as long as the idle is low it's pretty simple. I also just bought my first slant two months ago so I know how daunting it sounds....the hardest part was getting use to trying to get the socket on while the rocker while it was moving. I still have all my fingers!
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i tried it with a socket on the first one then switched to a 3/8 box end wrench which worked much better and a little less intimidating ! now that ive done it one with the engine running i will always do it that way , it really was easy !
 
Bill Dedman said:
I am a novice at this, but here's what I do:

Remove the valve cover.

Attach a push-button switch to the starter relay so you can "bump" the engine with the starter. You can turn it by hand, with a wrench on the crank bolt (assuming it has one; some apparently don't), but it's tiresome.... even with the spark plugs removed. The pusbutton starter switch is easier.

Pull the wire out of the coil and ground it, so the engine won't try to fire.

With the valve cover removed, you can see the rocker arms and the valve springs. The cylinders are numbered 1 through 6, front-to-rear.

Starting with the forward-most (very first) valve spring/rocker arm, use the pushbutton to turn the engine to the position where the valve NEXT to the first one, (the second one back) is open a good bit(at least, halfway)... you can tell, by the action of the valve-end of the rocker arm.

With that (second) valve somewhat open, you can be assurred that the one you are working on (adjusting) is in the correct position (the lifter on the heel of the cam, not the lobe) to be adjusted.

Take a feeler gauge and select the .018" thickness and slip the blade in the space between the valve stem and the rocker arm "pad" where it touches the valve.

If it goes into that space without any resistance at all, the clearance is set too loose. On the other end of the rocker arm, there is a threaded screw that contacts the pushrod on the bottom side. Turn it clockwise, until you feel a slight resistance to pulling out the feeler gauge blade.
If you get it too tight, just back the screw off a little, 'til you're satisfied. Take your time.

When it feels "right," with a slight resistance to pulling out the gauge, you are done with that valve.

Now, go to the next valve toward the firewall, and repeat the procedure, being careful to make sure the other valve FOR THAT CYLINDER is open, preferably, all the way, but at least halfway open. That's the one you just adjusted.

Remember; the valves are all in a row, and in pairs (Intake/Exhaust) so just because a valve is NEXT TO the one you are adjusting, that doesn't necessarily mean that you can use it as a reference point in its travel, to position the crank so you can adjust the valve next to it. The first two valves are for cylinder #1; the next two, for cylinder #2, and so on... you get the idea. As I said, they're in pairs. One group of two han NOTHING to do with the next two, for the activity we are talking about.

I use .018" for a "cold" setting. Ideally, these valves should be set on an engine that is up to operating temperature, and running, but this will probably get rid of your "ticking."

I hope I didn't insult your intelligence; I don't know how much you know...

Good luck with this.

Any more questions, just ask away...
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You explained that very well for a "novice". Very helpful. Thanks.
 
slantsixdan said:
That's how most of us slant-6 freaks do it, because most of us find that's the way that gives the best results. It's not the only possible method of getting a satisfactory adjustment, though. You're wise to raise an eyebrow at methods that are high-handedly professed to be uniformly best for any/all solid-lifter engines; optimal procedures vary widely across different engines with different adjustable valvetrains. It's your decision, of course.

BTW, those Chinese-made chrome valve covers are problematic and it looks like yours may not be set up correctly with respect to the PCV—which will louse up your idle quality and create other problems. See Thread 1 Thread 2 Thread 3. If you are bound and determined to keep this valve cover on your engine, and if you can make the bolt holes line up, then set up the breather and PCV this way.
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I have a chrome oil cap breather with grommet on my stock valve cover, and I hate it, the grommet is way too small to hold it steady. Will these parts work on the stock cover?
 
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