My high dollar 318 has a valve tick.
Been a while since I built a 318, how much turn on the rocker nut to adjust? I'm running roller rockers, does that make any difference?
Printable View
My high dollar 318 has a valve tick.
Been a while since I built a 318, how much turn on the rocker nut to adjust? I'm running roller rockers, does that make any difference?
over all you can get some valve train sound with roller rocker arms . back rocker off till you here noise draw the nut till just stops then a 1/2 or 3/4 max if that will not shut the valve train sound down you have other things goning on .for race stuff they will may make some noise we never went past 1/4 of a turn .you have the 318 magnum ?
Adding that a exhaust manifold leak can sound like a rocker adjustment.
No exhaust leaks.
Don't think its a magnum.
Thanks.
http://i304.photobucket.com/albums/n...e/IMAG0345.jpg
Nothing hitting. Does dodge have the same valve sequence as Chevy? Looks like there is no way to adjust these while it's running, I'll have to set them on the backside of the lobes
looks like rocker shafts are upside down-------- and with the adjuster nut/screw the way they look, you need longer pushrods
I want to sell this pos.
Why do you say that??????????just because you have a collection of minor very basic mistakes???????????
It's a big collection. And the biggest, most basic mistake, was buying this steaming turd.
Ok, finally got some feedback on my 318. I was told the valve sequence is the same for a sbc. Was also told the pushrods are symmetrical: can't be up side down. His opinion is that I probably bent a push rod.
Oh, he said ROCKER shafts look upside down. How do I check?
It's a sunny warm day in GA today (65) so I took a crack at it.
I put it TDC#1 compression stroke, and broke the rocker shafts loose, pulled the push rods.
Nearly all the rods on the right (pass side) were bent and all the rods on the left were straight. What would cause that?
How do I check correct rod length before I buy more?
The oil holes in the shaft are visible, they should be down against the rockers. That could cause enough friction to explain the bent pushrods.
Didn't I tel you the shafts were upside down in October?????
Yes, but I misread it and thought you said pushrods.
It's been on back burner since.
Ouch.
Gazinga
Ok, tomorrow I'll take a pushrod in to work and have the machinist modify it to make it adjustable. I'm still not entirely sure how to find the proper adjustment.
Setting Pushrods Length, Quick and Easy- Car Craft Magazine
Take a look at this
Great article.
Unfortunately, it didn't explain how to for my dodge. For me to change contact on valve tip, wouldn't I need to shim the rocker shaft?
Not sure that I understand, but don't you want your rocker contact point to be exactly centered on the valve stem when the valve is exactly 50% open? That will center the roller on the valve stem for the full travel of the rocker, equal (and opposite) distances from the exact center point when the valve is closed and 100% open. The only way to shift that contact point is by adjusting the pushrod length on a rocker shaft setup, as I understand it?
There is basic differance in geometry between shaft rocker system and stud mounted rocker systems----in a shaft system the valve heights and shaft heights should be worked out so the geometry is correct-----
In stud mounted systems everything is sorta self cancelling and somewhat forgiving---however every one puts in longer valves, changes rocker ratios from 1.5 to 1.6----etc
with the adjustment being done via the height on the stud, the pushrod length is how you correct for geometry---------
In this system on the mopar, the shafts are upside down with oil just squirting freely upwards and not lubing the under side of the rocker shaft ot the rocker----then the adjuster screws are screwed way down almost half way thru the lock nuts----they look like they are 7/16-20 thread which would equate .050 per revolution of the screw--so count the number of threads that you need to lengthen the pushrod---multiply by .050 and add that to the length of the current pushrods---they seem to be at very least 2 full turns down into the lock nuts plus are probably overextended 3 or 4 turns more underneath the rocker body---------
I don't believe you read the full article, probably only the studff about the stud mounted rockers-----------
It was lunchtime, and I was a bit rushed, so ill give the article another look.
BUT, It sounds like I just need to be in the mid adjustment of the rocker arm.
The machinist at work did a fine job modifying a pushrod to adjust. Now I just gotta remember to bring it home.
I looked again, only one sentence pertains to rocker shaft set ups. It says pushrod length is critical for valve lash, but doesn't elaborate.
In your particular case---turn over the shafts----set adjusting screws in the middle of the range from full up with cup against the bottom of the rocker to a down adjustment that leaves a full nut on the lock nut-----measure with your adjustable rod---see if that will work on all 16 or whether you'll need 8 and 8 for intake and exhaust, etc------at this point you can look to see where the wear marks are on your valve tips--should be fairly small and centered in the middle------
I'd come down and help you but I once wrote a song about happiness was Ft Benning in my rear view mirror!
Would have gotten on it today, but I bought a PILE of tools at co$t instead.
Got back on it today, sixty degrees and sunny.
Rocker shafts are good, not upside down. What you see in the picture is weep holes in the rocker arms.
I looked at the adjusters on the rocker arms, they have two and a half turns available from their pictured position ( flush )
So I ran it all the way out, and back in a full turn. I opened up the adjustable push rod, and it looks about 3/16" longer. I'll get an accurate measurement tomorrow at work, as I don't have a long enough caliper at the house.
Also, I blacked out the top of a valve stem, and rolled the rocker tip against it. The mark is slightly off center, to the inside, exactly where It's supposed to be.
It measures out to be 2.2 mm longer than the originals
So as you rotate the engine through a cycle, that mark should go from slightly off center to the inside to slightly off center to the outside, precisely equidistant from the centerline of the valve tip if everything is set perfectly, right? Just wanting to be sure I understand what you're saying, and my understanding of what's right.
went across I20 from Anniston Al toward Atlanta Friday afternoon------------
You were almost in my neighborhood.
Got my set of pushrods. Apparently, a set is eight, and one should order two sets for a motor.
The adventure continues
Spring is here in the south.
I have the gauges cluster installed, new sending unit, and steering column with new blinker switch and coupler. ( not the rag joint ). Fuel guage might be working, if not calibrated.
Installed the newer longer pushrods on the intakes, the old ( undamaged) on the exhaust. That saves me a bill. Also the longer rods adjust above center, as the old ones adjust below center. Runs good, but a light tick tack on driver side.
Also installed a new heater valve and actuator cable.
Going to try again adjusting the (roller) rockers. There is a backfire on the passenger side which worries me.
I am using the Chilton manual valve adjustment procedure for a sbc, as the firing order is apparently identical. Sure wish I could use the 'tick' method, but it's not possible to make adjustment with motor running.
If anyone has a better way, I'd love to hear it.
Valve adjustment attempt #2 no better. Still an exhaust backfire on passenger side, still a nasty tick on driver's side.
I'm thinking there is maybe a problem with using the stock sbc sequence?
The procedure for adjusting has been posted a bunch on here but it may take some searching to find it. With #1 at TDC compression, loosen both rockers until you have a slight up & down play in the pushrod, then tighten until the play is gone (just lifting the pushrod and allowing it to fall back, no pushing down on the push rod), then turn 1/4 turn tighter and lock it down. Turn the crank pulley 90 degrees and do the next one in your firing order, and repeat for all eight, turning 90 degrees for each cylinder. Piece of cake.
Ok, I was thinking of giving that one a try next.
My Chiltons says put it on tdc#1, then gives 8 rockers to adjust, then rotate 360, and do the remaining 8. Firing order is the same, but maybe something is different somewhere.
How long do the lifters need to rest after crank rotation?
Lifters don't nee any rest. Your not compressing the lifters.
Ok, I tried again, adjusting each cylinder at tdc, in firing sequence.
No more backfire on passenger side, but still a tick on #3 exhaust.
Could it be a collapsed lifter?
Turn it down another full turn to see if it goes away-------------if it does, then back it out 1/2 turn see what happens---If quiet---put valve cover on---if it needs more adjusting--trial and error til its quiet and smooth running----------
HAve you measured the tappet lift with a dial indicator??????????(will indicate the possiblity of a flattened lobe-)