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Discussion Starter #1
hey guys, tried searching on here for this problem, really didn't come up with much, except I did hear a few guys mention clearancing the rocker. My problem in a nutshell... I know my max lift with 1.6 rockers should be .525 without even dealing with the pushrod (another topic), the back of the roller rocker is hitting the poly lock on the stud. So pushing my valve down (checking springs) by hand I have a total of .595 clearance bf the retainer hits the valve guide. When I have my rocker on and push it by hand it only goes to .470. So I'm short by .55 thousands. (.525-.55=.470) Question is, should I clearance the rocker (don't wanna do) or would a longer valve help? I hate to have to buy new rockers cause I'm broke and trying to wrap this engine build up. Also as of right now the stock vortec pushrods of 7.125 are way short. I have a pushrod checker, but everything I read on this is "your pushrod is too long" so thats why I didn't even bring that in to play, no pushrod in the test and my rocker is hitting the poly lock. I can try and get some pics, but I don't have em on this cpu at the moment. Any thoughts on what I can do to get the clearance I need. Thanks
 

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So is the cam a roller lifter or a flat tappet? Stock roller pushrods are 7.200 and flat tappets are 7.800

If you're just letting the back of the rocker drop and screwing down the polynut all the way, then the rocker will be at such an angle that it will hit the polynut or the stud.

You really need to use a pushrod of some sort to at least be in the ballpark and knowing what type of lifter you're using will help even if it's not perfect.
 

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Discussion Starter #3
czar, thanks for the reply, I did have the checker pushrod in there. Yes full roller set up. hotcam with 1.6 rocker .525 at zero lash. Here is a pic of the geometry with the pushrod checker. Stock pushers I'm measuring 7.125. The pic here with the checker, I'll have to measure again, cant recall but they are like 7.5" I think, seemed like a huge jump. I'm running 1.800 tall 7/16" screw in studs. I really don't see any length pushrod solving the problem, that why I was pushing it by hand, but have checked it with different push rod lengths.
 

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czar, thanks for the reply, I did have the checker pushrod in there. Yes full roller set up. hotcam with 1.6 rocker .525 at zero lash. Here is a pic of the geometry with the pushrod checker. Stock pushers I'm measuring 7.125. The pic here with the checker, I'll have to measure again, cant recall but they are like 7.5" I think, seemed like a huge jump. I'm running 1.800 tall 7/16" screw in studs. I really don't see any length pushrod solving the problem, that why I was pushing it by hand, but have checked it with different push rod lengths.
First picture tells the story! The stud bosses need to be milled down by the thickness of the hex section of the stud.

Bogie
 

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Discussion Starter #5
ok, see I originally had screw in studs that were for guide plates, quickly found out they weren't gonna work, and found studs that were fully threaded under the hex. So really I need shoulderless studs? How would you torque those? I'd run a nut to till it bottoms out then torque it?
 

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Discussion Starter #6
ps. thanks bogie. def trying to avoid machine shop due to and money. Perhaps I could buy the tool and do them myself and or just get shoulderless studs?
 

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You intentions are good but do not try and machine the stud bosses with a hand drill or drill press. I know there are youtubers out there who have done this. This takes a mill or a valve guide machine to do this right.
 

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As mentioned above....Shoulder-less stud is what you need if you aren't going to mill down the stud boss for the hex stud.

Install the shoulderless by using two nuts tightened into each other on the fine thread rocker end of the stud, install stud into the head with threadlocker compound(loctite) or at least a sealer like rtv silicone, as some of the studs go into water passages under them. Remove the nuts and on to the next stud.

You may be able to use the polylock nut locked to the stud to do this, but the double nut method will prevent wear and tear on a polylock.
 

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ps. thanks bogie. def trying to avoid machine shop due to and money. Perhaps I could buy the tool and do them myself and or just get shoulderless studs?
As mentioned by ericnova72 this is what you need; see picture. Install with doubled nuts to lock them to the stud so you can torque it use red Locktite on clean threads. Another way is to buy a 3/8ths fine 24 thread/inch coupling nut; screw it about half way on the stud then run a matching threaded bolt down till the bolt and nut lock with each other then pull it to torque then holding the coupling nut with a wrench to prevent it turning, unscrew the bolt then remove the nut <<<
>>>. Or use a poly-lock. This does away with having to buy a tool, remove heads, mill chips everywhere or send to shop, clean and reinstall. Most every parts outlet lists these things they are not expensive like 10 bucks see here <<< Screw-In Rocker Studs, 3/8 Inch - Speedway Motors, America's Oldest Speed Shop >>>

You will either need heads that have the guide slots in them or you will have to use self guiding rockers as these shoulderless studs cannot position sheet metal guide plates. If you need sheetmetal guide plates for the push rods which need to be the hardened type then you're back to milling the stud bosses. At the machine shop that should be less thana 100 dollars so by the time you buy the cutting tool you've spent about the same and didn't risk leaning how to use it by messing up a boss or two.

Bogie
 

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Discussion Starter #10
cool thanks fellas, wish I woulda caught this before. But hey atleast I didn't buy my pushrods yet. I always thought you needed to mill that down for the thickness of the guideplates, thats why I found these studs that are fully threaded so they thread flush to the stud boss. But its all clear now, I'll order them up so I can proceed. This is my first time using studs and roller rockers. I'm pretty sure on most of it, except the darn studs which isn't hard to understand.
 

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Yep, stud boss has to be milled down the thickness of the guideplate and the stud's hex portion, so it doesn't interfere with the underside of the rocker .
 

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cool thanks fellas, wish I woulda caught this before. But hey atleast I didn't buy my pushrods yet. I always thought you needed to mill that down for the thickness of the guideplates, thats why I found these studs that are fully threaded so they thread flush to the stud boss. But its all clear now, I'll order them up so I can proceed. This is my first time using studs and roller rockers. I'm pretty sure on most of it, except the darn studs which isn't hard to understand.
Your not the first one of us to have been down this road.

When you use guide plates that thickness has to be added to the amount taken off for the hex of the stud. Double whammy!

Bogie
 

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Discussion Starter #14
this is my go to site on engine questions, however dunno why I just always read or misread that you need to mill down the whole hex thickness. Now I know and atleast it isn't a big expense. Thanks for the replies guys. I'll post more when I finish up the engine and or if I got any questions before I do. All I got to do now is pushrod length and button it all up. Its a full roller carbed vortec sbc 9.5:1 static compression, running the hotcam with 1.6 rockers. Should be fun.
 

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Those look like the same $100 ebay rockers I tried to put on a guys engine a few months ago. I had the same problem with the polylock relief in the rocker hitting on the polylock before full lift.
Confused me at first as I was checking piston to valve clearance and really didnt expect an interference issue. I sold the guy some Comp steel rockers and let him have his ebay rockers back.
 

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ok, see I originally had screw in studs that were for guide plates, quickly found out they weren't gonna work, and found studs that were fully threaded under the hex. So really I need shoulderless studs? How would you torque those? I'run a nut to till it bottoms out then torque it?
If you plan on using a stud like this DO NOT torque it down to the normal 55ft lbs! You will split the stud boss......I guarantee it! I would rather have my pressed in studs pinned then usethisgarbage. If you are going to use these studs I would seriously suggest just to snug then up and then pin them with a 5/32 roll pin. Seal them up with a good thread sealer (not loctite, the **** don't work, I guess maybe in a lab where every single thing is perfect)

Again if you torque them studs I guarantee you won't like the results. And leave the loctite at the store.
 

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I'm referring to the ones you are calling shoulder less. I look at these studs as a quick way to repair a pressed in stud that has been pulled from the engine. What you are wanting to use them for is a crutch and a cheap way out. Do it right or just don't do it. Comp cams sells a stud boss cutter for doing this. With careful setup and execution they can be milled at home preferably in a drill press.
 
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