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i have a 302 and want to know how to adjust the valves. I tried to set them to zero lash at TDC and then turn it in 3/4 turn but they bottom at at that setting. what should they be set at?

Thank you
 

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I assume that this is a hydraulic lifter engine and an adjustable valve train. You need to turn the engine by hand so that the lifter is on the base circle of the cam for that valve. Make the adjustment, then repeat the process for each of the 16. Normally you loosen the adjusting nut, then slowly tighten as you wiggle the pushrod with your other hand. Once it makes contact (can't wiggle) you tighten 3/4 turn more then tighten your locknut.

Most Ford small blocks did not have adjustable valve trains.
 

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i have a 302 and want to know how to adjust the valves. I tried to set them to zero lash at TDC and then turn it in 3/4 turn but they bottom at at that setting. what should they be set at?

Thank you
I'm fairly sure that year of 302 has what Ford called "positive stop" rocker arms....

...meaning you tighten the rocker nut down to the "stop" and then torque to spec.

They are not adjustable with the nuts.

Adjustment is done with longer or shorter pushrods.
 

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Adjustment is done with longer or shorter pushrods.
This is the factory recommended method, however most of us don't have an assortment of pushrods to substitute, or even the tools to measure them.

Back when I was in high school and inherited a small block with worn heads, had them rebuilt for $225, then reinstalled them and faced with this adjustment issue, I came up with a solution. I used stacks of washers and the factory nuts to pull the rocker studs out, cut 1/4" off each stud bottom to make room at the bottom of each press hole (probably not required), then reinforced the studs by stacking nuts over the entire threaded length, and hammered them back in at 1/4" lower height. I then reinstalled the rockers and adjusted each valve assembly in turn, using a second lock nut to keep the correct height.

That trick served me quite well, since I drove the car another 85k miles or so before I sold it.
 

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I do it with the engine warmed up & running- pretty foolproof. It REALLY helps if you have an old set of valve covers with the tops cut off, so the oil being pumped up through the pushrods doesn't run down the side of the engine onto the exhaust manifolds. Here's a couple of YouTube links:


 

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This is the factory recommended method, however most of us don't have an assortment of pushrods to substitute, or even the tools to measure them.

Back when I was in high school and inherited a small block with worn heads, had them rebuilt for $225, then reinstalled them and faced with this adjustment issue, I came up with a solution. I used stacks of washers and the factory nuts to pull the rocker studs out, cut 1/4" off each stud bottom to make room at the bottom of each press hole (probably not required), then reinforced the studs by stacking nuts over the entire threaded length, and hammered them back in at 1/4" lower height. I then reinstalled the rockers and adjusted each valve assembly in turn, using a second lock nut to keep the correct height.

That trick served me quite well, since I drove the car another 85k miles or so before I sold it.
Very clever.:bow:

These days the pushrod length checking tool and
different length pushrods are easily available.

https://www.summitracing.com/int/search/part-type/pushrod-length-checkers

Comp Cams and many other cam companies will have in stock,
or build you the pushrods you need for very reasonable prices.

When I built my 428CJ and converted to roller lifters and rockers,
I got a pushrod checker tool from Crane Cams and after determining the length needed,
I ordered the pushrods from Crane. I am using their roller rocker setup.

I don't remember now exactly what I paid... but the price of the custom pushrods was reasonable.
 

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If they are out of adjustment by just tightening them down, I would start troubleshooting. Really the question then would be, why do you think it needs a valve adjustment?

The positive stop works pretty well in most applications unless something is mismatched. If that is the case, the best way to do it is to buy an adjustable pushrod, measure zero lash/zero preload length, then add .060 and buy pushrods, (before you buy, check that the length works for all, if your valve job is bad, valve tips are worn, or some other issue, correct first) or if you intend to make future changes or any real spring pressure, swap to screw in studs.
 

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Very clever.:bow:

These days the pushrod length checking tool and
different length pushrods are easily available.

https://www.summitracing.com/int/search/part-type/pushrod-length-checkers

Comp Cams and many other cam companies will have in stock,
or build you the pushrods you need for very reasonable prices.

When I built my 428CJ and converted to roller lifters and rockers,
I got a pushrod checker tool from Crane Cams and after determining the length needed,
I ordered the pushrods from Crane. I am using their roller rocker setup.

I don't remember now exactly what I paid... but the price of the custom pushrods was reasonable.
I have the same "checker" tool, rebuilt my 390 with rollers the same way that you did, ordered custom pushrods as well (Smith Brothers, $200 including shipping). However the tool I was referring to was the caliper long enough to measure the "checker". I used a tape measure to determine the length within 1/16", probably not precise enough to do the job unless you have an adjustable valve train. That's why my rebuild has adjustable roller rockers.
 
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