I tried a valve lash adjustment on my 351W as per the instructions in the Chilton manual, who's information I am beginning to trust less and less. Here's a direct quote from the book:
"...rotate crank 270 degrees to point 3... adjust exhaust nos 6 and 6..."
Hmm.. last time I checked my engine didn't have two #6 exhaust valves. Worked it all out and found it to be a lousy misprint, should read exhaust 2 and 6.
But thats neither here or there, the main point of this being that after following the Chilton instructions exactly (except for the blatantly incorrect information) my engine runs worse than it did before.
I am less than pleased with the accuracy of their manual.
Can anyone point me to instructions on valve adjustment that are a bit more detailed, and... uh, accurate?
The easiest way I've found to adjust valves is after disabling the ignition (doh! you've already got the plug wires off) start on one side and work your way down. Turn the engine over 'til the exhaust valve on the cylinder you're working on just starts to move, then set the intake on that cylinder. Then turn the engine over until the intake valve completely opens and is just closed and set the exhaust on the same cylinder. You don't have to be too worried about exactly where the crank is. This method puts the lifter on the base circle of the cam and you have quite a bit of tolerance. Then go to the next cylinder and do the same thing.
For me this does two things:
1) I'm not worrying about which valves to set at a particular crank setting. and
2) I'm sure I adjusted all the valves.
This works best for solid lifters IMHO. Hydraulics I find adjust better with the engine running, unless you have the positive stop rocker studs or pedestals, in which case all bets are off 'cuz they're not adjustable.
Hope this helps.
To adjust them with the engine running, after installing your modified valve covers, loosen the adjustment until the rocker clatters and then tighten just enough to just eliminate the clatter. Go down the line and set them all like that. Then with the engine off adjust them slowly about 3/8 to 1/2 turn tighter. Works great for me.
I agree about the chiltons and the haynes to some extent. I think they gave all the info to a secretary and she got it all mixed up when it was typed.
Tighten them all down to the specified torque (I hope we can trust that figure) regardless of where the engine is. There are ways to get some adjustment. Ford's official way is to buy longer or shorter pushrods. Some people also use shims under the sled fulcrum type rocker arms.
It's not the lifters;
I just had the same thing on one rocker after a cam and lifter swap. (It's a pain on EFI to have to keep taking the upper intake off to get the pass. side rocker cover off!)
I just tightened it back down and almost got it all buttoned up when it got dark. I'll let you know what happens in the morning.
I'll second Franklin's emotion. I have no idea where all these adjustment proceedures came from because a stock 351W NEVER had adjustable rockers. What year engine do you have and what modifications have been made? If it is an early engine with stud-mount rockers and it is still clattering after you start it up with all of the rocker nuts torqued to spec, I can see three possibilities.
1. At some point one or more of the rockers have been overtightened and the nut is pulling back over the threads and loosening up.
2. There is a parts incompatibility issues regarding pushrod length or severely worn valve tips.
3. The lifters simply haven't had enough time to pump up yet. I've worked on several that for some reason took quite awhile to quiet down.
Can you tell us a bit more about exactly what it is that you're working on and what changes/modifications have been made?
This is an ugly thought, but one that has merit - if they all suddenly got noisy and you're trying to correct the problem, the possibility exists that there is another issue causing the lifters to collapse. I find it hard to believe that they'd all give up the ghost at the same time. How is your oil pressure? Have you verified it with a mechanical guage? If the pressure is OK, there make be a blockage in the oil galley feeding the lifters. This would be easy to check by running the engine with the covers off. If you're not getting any oil up through the pushrods to the rockers, then you've got oiling system troubles.
I've made a few new discoveries since last night, main ones being a) my 351W (although stock) is not the original motor, and b) I also have a positive-stop valve train.
I think here is where my confusion began, because the Chilton manual only refers to the positive stop valve train as being installed on early 302 motors, so I was completely missing the information.
Finally identified that I have fulcrum style rockers and positive stop studs. I wonder if this is an unusual configuration for a 351W? The Chilton manual says nothing about 351W's ever having this valve train.
So anyway, I am heading out to try setting up the valves as per the 302 method mentioned in the book; torque down the rocker nut, bleed down the lifter, measure the clearance with a feeler guage, and adjust clearance with the rocker nut as nessecary.
Does this all sound correct?
Oh.. and how this all began... I had a few cylnders that were clattering pretty bad, so following the instruction as per Chilton for mid 70's lash adjustment I tried to tighten it down to eliminate it. At that point saw all the "rocker slop" on all the valves and started trying to adjust all vales as per the manual, thus my current situation.
Never mind, I just got this all figured out refering back to some older manual pages that were sent to me. Positive stop - torque em' down and be done with it.
Sory for all the hassle, I blame Chilton. All the info was there, but organized in a rather unusual manner that didn't become clear untill I compared the two different sets of instructions and sorted it out.
So in closing... to avoid future headaches could anyone reccomend a shop manual that might be a bit better than a Chilton or Hayes?
Yeah, I never did like the Chilton's. They're OK if you already know what your looking for and just need torque specs, etc. You could always get the CD-ROM version available here.
As to the pedestals: (see my first post) If you still have clatter with them bolted tight, check the pivot area for wear.
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