Roller rocker hitting stud shoulder….

[Sport/Truck]

I got ready to mock up my engine and noticed when I adjust my rocker it hits the shoulder of the stud mount. (Stock heads w/screw in studs). I did the procedure where you set a 0 lash, then turn 3/4 turn more. From the pictures it appears I need shorter push rods….this will make my problem worse. These pictures are taken with 0 lash, they hit when I get close to 3/4 turn.

Ideas?
s/t

[70GMCer]

You most likely need +.100 push rods......Same thing happened to me. I went down to my local speed shop and bought an adjustable push rod from Moroso. For every 1 turn of the adjustable push rod, it is +.100 longer. It also tells how to use it. I used a magic marker on the valve stem tip, and then put on the rocker arm. Turned over the engine and that will show you how far forward and backward the roller moves on the valve stem tip. Adjust the pushrod until you have very little forward or backward movement. Then see how many turns of the adjustable pushrod there is. Hope this helps.

[Sport/Truck]

Originally Posted by 70GMCer

You most likely need +.100 push rods......Same thing happened to me. I went down to my local speed shop and bought an adjustable push rod from Moroso. For every 1 turn of the adjustable push rod, it is +.100 longer. It also tells how to use it. I used a magic marker on the valve stem tip, and then put on the rocker arm. Turned over the engine and that will show you how far forward and backward the roller moves on the valve stem tip. Adjust the pushrod until you have very little forward or backward movement. Then see how many turns of the adjustable pushrod there is. Hope this helps.

yes, in fact your post came up in my search. But look at the marks at 0 lash. I think I need shorter rods?
s/t

[sick69]

If you put shorter push rods in it will move the rocker closer to the head. Longer push rods will move the rockers up away from the head.


What about big block push rods? are they any longer? or to long?


Frank

[Sport/Truck]

longer push rods aren't hard to get, but it will push the roller tip out more. do you think it will be too much? It looks like it needs to have shorter rods?
s/t

[sick69]

As long as you don't go to much you should be fine. If you go with +.100 as stated above you should be ok. Obviously you don't need very much so try to keep it close to what you have already.

I would also call who ever made the rockers and see what they suggest or possibly the company you bought them from. Summit and Jegs have a tech line to call that could be of some help. I think the best bet would be calling the company that made them and see what they recommend for pushrod length.


Frank

[Sport/Truck]

Originally Posted by sick69

As long as you don't go to much you should be fine. If you go with +.100 as stated above you should be ok. Obviously you don't need very much so try to keep it close to what you have already.

I would also call who ever made the rockers and see what they suggest or possibly the company you bought them from. Summit and Jegs have a tech line to call that could be of some help. I think the best bet would be calling the company that made them and see what they recommend for pushrod length.


Frank

I'll use my dial indicator and see what .050 & .100 will get me. But I'm thinking it's going to put me near the middle of my valve stem at 0 lash. Not good, or is it?
s/t

[Ilike 72"s]

I had this problem on a 327 I built. Took a long time solving. My problem was I was using new lifters that I didn't pump up with oil first. When turning the pushrod on dry lifters with my fingers tips, It still rotated until I was way to deep into the lifter. I tried to start the car and it spun like an electric motor. No compression. I removed them and put into a pan of oil and worked the plunger with a pushrod, reinstalled with no problems. This will raise the heal of the rocker off the head. Hope this helps.

[Bob 68327]

I had this problem on mine also . I took the rockers off and put stamped steel long slots on it . Solved my problems !!! Don't look as pretty as the rollers!! Oh Well

[Sport/Truck]

I checked the rocker, taking care to measure at the precise point that the push rod pivots in the rocker. I checked the rocker’s position on the valve stem, and it’s in the middle.
Will this work? Are most of yours in the middle of the stud on the base circle?
s/t

[Sport/Truck]

Originally Posted by Ilike 72"s

I had this problem on a 327 I built. Took a long time solving. My problem was I was using new lifters that I didn't pump up with oil first. When turning the pushrod on dry lifters with my fingers tips, It still rotated until I was way to deep into the lifter. I tried to start the car and it spun like an electric motor. No compression. I removed them and put into a pan of oil and worked the plunger with a pushrod, reinstalled with no problems. This will raise the heal of the rocker off the head. Hope this helps.

I think I doing this correct. I stop at the first slight resistance if felt. But I agree with you they still spin in your fingers.
s/t

[BCOWANWHEELS]

ARE YOUR LIFTERS PUMPED UP WITH OIL FROM RUNNING ? DID YOU LET them soak in oil over night before installing them ? set at 0 lash and crank engine the adjust them.

[PanelDeland]

If the fixes above did not fix them there was a story in one of the mags(Probably Car craft or Chevy HP0 where they had this problem and had the rockers ground or milled in the area that is hitting.It was very minor but gave them the clearance needed.I believe the rocker manufacturer gave them the solution.Sorry I can't say which mag I read about 10-12

[Sport/Truck]

Originally Posted by PanelDeland

If the fixes above did not fix them there was a story in one of the mags(Probably Car craft or Chevy HP0 where they had this problem and had the rockers ground or milled in the area that is hitting.It was very minor but gave them the clearance needed.I believe the rocker manufacturer gave them the solution.Sorry I can't say which mag I read about 10-12

I'm going to call scorpion about that option too. I figure I only need .060 to clear.
or the other option is to mill the head where the stud screws in.
s/t

[glock35ipsc]

Your original post said screw in studs, but the pic looks like OEM press in studs? Am I missing something there? All the SBC I have done with screw in studs had to have the boss milled way down.

[Sport/Truck]

I went the cheap way, no mill work just taped & threaded.
Most people have them milled to use guide plates, and they require
the special stud with the hex head which reduces flex. I may end up havening to have that done after all, if I didn't screw myself. since they
are already drilled and tapped they may not be deep enough for the other style studs.
My original intention was to use stock or roller tipped stamped rockers.
s/t

[brianthelion02]

Im wonderin if that type of rocker arm stud is compatible with that style of rocker??

[Ilike 72"s]

More info. 350--StocK head--stock spring--stock lifter. Pumped up, or not?? What rocker was ordered and what push rod and length? Studs a stud. Wouldn't think thats an issue.

[glock35ipsc]

Originally Posted by Ilike 72"s

Studs a stud. Wouldn't think thats an issue.

Not necessarily so.

If you mill the pads and use a quality screw in stud with the hex head you will have plenty of clearance. If the rockers are self-aligning you won't need to use guide plates. But even if they were self-aligning, I would use guide plates myself. They are cheap insurance.

[Sport/Truck]

Originally Posted by Ilike 72"s

More info. 350--StocK head--stock spring--stock lifter. Pumped up, or not?? What rocker was ordered and what push rod and length? Studs a stud. Wouldn't think thats an issue.

yes, 350, stock heads, Lunati springs & lifters not pumped up-but this is debatable, as I'm very careful to set 0 lash, using only a light touch.
These are scorpion rockers (house brand) and using the old stock push rod to mock up and check length.
which looks like I need shorter rods...making my problem worse.

the studs are screw in.
s/t

[Richard H.]

You only need to do it to one lifter to check it by pumping it up in some oil and putting it back in.
You want zero lash then set it at .002 with a feeler gauge. Please forget spinning the push rod.... it's up and down motion only. The.002 will will probably get you feeling better at what you are seeing. Look at it this way ,you are using Lunati springs , roller rockers , and new lifters, soooo... a non stock valve train does not have a manual to adjust with. If you do this and still have the rocker issue then longer push rods will help.
You need to pump up those lifters,, you got nothing to lose by doing it.

[Sport/Truck]

Originally Posted by glock35ipsc

Not necessarily so.

If you mill the pads and use a quality screw in stud with the hex head you will have plenty of clearance. If the rockers are self-aligning you won't need to use guide plates. But even if they were self-aligning, I would use guide plates myself. They are cheap insurance.

I don't think these are self-aligning rockers. And for me to be able to use guide plates I will need to machine the slots for the push rods.
While I was taking this picture, I got to looking at the slot....and it didn't look like it was big enough for the rod to pivot the full .486 that it needs....
looks like may need to have this machined.
I hope it won't be a problem since my heads were already drilled & taped.
s/t

[PICKMUP]

You need to go to a "good" machine shop that does performance engine work on a regular basis. They will have the right answers and the right equipment to do the job.
It helps if you do the clearance checking using either a light testing valve spring or a solid lifter that sits the push rod in the same position as the hydrolic. The heavy springs may be pushing the lifter down at full lift/pressure.

[glock35ipsc]

If they are not self-aligning rockers, and you don't you guide plates, that is a recipe for disaster. Something needs to hold the rocker in line with the valve stem and the push rod.

I'm not so sure the non-slotted push rod holes will matter too much if you aren't using a high lift cam. I've ran some big ones without having a clearance issue there. Of the SBC heads that I have built, the slotted push rod holes are narrower to keep the push rod straight. The newer crate motors, with the bigger hole, use a rocker arm that is slightly recessed at the valve stem to keep them from sliding off one side or the other.

The thread size should probably be the same. The machine shop will mill the boss down enough to make room for the guide plate and the hex head, and will drill a little deeper if they need to and tap the fresh hole.

If you want to run rollers on that head, you will NEED either self aligning rockers OR guide plates.

[Sport/Truck]

Originally Posted by glock35ipsc

The thread size should probably be the same. The machine shop will mill the boss down enough to make room for the guide plate and the hex head, and will drill a little deeper if they need to and tap the fresh hole.

If you want to run rollers on that head, you will NEED either self aligning rockers OR guide plates.

I'm going to call the machine shop this AM and get the price to mill the bosses.
My concern is that these were already drilled & taped. If they need to re-drill to go deeper- then it will take away some of thread in what was already done.
I'll get back tonight with the word from the shop.
Thanks to everyone for the help.
s/t