Thread: valve set on a 318

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Originally Posted by jerry clayton

Didn't I tel you the shafts were upside down in October?????

yes and they`re still upside down in janurary >>

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?

Originally Posted by firebird77clone

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

Originally Posted by firebird77clone

.....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.

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.