How crooked is too crooked!?

[SupStk]

Since it's a mild build, I'm the guy that would consider a sharp whack with a FBH to stand the stud up straight...

I considered the same thing but didn't want to be the one to say it....

[DCal]

Since it's a mild build, I'm the guy that would consider a sharp whack with a FBH to stand the stud up straight...

I agree with Bill but I would try it in a vise not the head. I've also see the Poli-locks problem, it was very noticable with the old Jomar stud girdles.

[cgarb]

If it's tapped crooked enough to not allow the stud to sit flat on the guideplate, I would use a tap block and retap the hole straight and put locktite on the stud and retorque it. What's the worst thing that will happen the threads will fail? Then fix it with a helicoil or a timesert and move on. Probably tapping the hole straight and loctite will still be there 5 or 10 years from now most likely, threads are amazingly strong for what they are.

[af2]

Since it's a mild build, I'm the guy that would consider a sharp whack with a FBH to stand the stud up straight...

My thought also. Done many times with back yard stud installs.

[crazy_caseys_customs]

Thank you for all the many replies. I’d like to say I’m leaning towards the BFH idea, but unfortunately I already have more money in these heads than they’re worth, and I’m likely too dumb to turn back now...

I used some dykem and confirmed my fears that the very outer edge of the valve stem is taking all the load (I should have taken a picture). And while they’re not nearly as noticeable to the naked eye, I’ve got two more studs that are causing a similar pattern on another pair of valves, one of which has already had a repair attempted (heli-coil). The quote to fix all of this (from the only local machine shop without a questionable reputation) was in the $300-500 range. That’s a tough pill to swallow as now I will be in these stock 289 castings almost as much as an entry level pair of aluminum heads, but I can’t cry over money I’ve already spent, and at least now they will be right. Thanks again for steering me away from “just running it”.

[Geoff2]

There is a 'çheap' way of fixing this if the cam is hydraulic [ ie, you have some leeway with posi lock {PL} adjustment ].

Grind or file the bottom of the PL at at a slight angle, the angle you want to correct. Adjust PL grub screw so that PL is at the new 'correct' angle.
If lifter pre-load is a concern, then......if the r/studs are removable, you can use shims under them to get correct lifter pre-load. If studs are not removable, use shims between PL & trunnion.

[cjperformance]

Since it's a mild build, I'm the guy that would consider a sharp whack with a FBH to stand the stud up straight...

Bill, We're slight more cultured here in Australia, , id reach for my length of drilled bar stock , slide over the stud and give it a 'calculated' tweek till straight!! Job done.

[n2xlr8n]

Also check the poli-lock. Seen some where the threaded hole isn't straight with the body. Watch as threading it on the stud, any runout is very visible.

I have seen this as well. I thought my mind was playing tricks on me at first

x3.

Check the poly locks.

[Newold1]

I am glad you were able to look at and realize what this type of rocker misalignment can do to damage valve stems and valve guides.
When almost any rocker arm is crooked like this as it's tip sits misaligned on a valve tip, that kind of damage will take place. It side thrusts the valve!
That's why I would not just use simple methods like bending the crooked studs back straight. They are just going to bend back crooked under use and continue the damage to the valves and guides.
You don't really want to "bandage the patient" , you need to "stop the bleeding!" Fix the stud attachment in the head, with required machining and install all new studs.
JMO

[crazy_caseys_customs]

Remove the valve springs and check the straightness and alignments of valve stems, guides, tops of rocker stands, valve spring pockets. Check those two pushrods on a piece of glass for straightness.Check for valve stem wear and valve guide wear. You should try to relevel the stand tops to the deck and then install a good stud girdle to hold straighter alignments on the rocker studs as a group.

I also suspect as others here that the threading on those two stands was not straight from day one.

Fix the stud attachment in the head, with required machining and install all new studs.
JMO

Everything is brand new, with the exception of the drilled holes in the heads, which were there when I bought the cores. Next time I need to install studs and valves and check alignment before dumping money into a set of heads for porting, valve job, and springs, locks, retainers, etc.

The studs were brand new too, so I cannot imagine replacing them. They’re ARP’s, and they don’t appear to have bent by torquing them to 55 lb-ft in a crooked hole...

[crazy_caseys_customs]

If it's tapped crooked enough to not allow the stud to sit flat on the guideplate, I would use a tap block and retap the hole straight and put locktite on the stud and retorque it. What's the worst thing that will happen the threads will fail? Then fix it with a helicoil or a timesert and move on. Probably tapping the hole straight and loctite will still be there 5 or 10 years from now most likely, threads are amazingly strong for what they are.

Really not wanting to dump another $500 into these heads, I’m trying to wrap my head around how to remedy this myself. I don’t have access to any fancy equipment, and I’m not a seasoned machinist, but I do think I can figure this out. I have a Bridgeport clone, but it’s a nice sturdy one. And your tap block idea got me thinking...

A907A18E-C8E0-42D3-AAB7-F34C49F2B7E2.jpeg

Judging by the tip wear pattern, I have at least one straight stud on each cylinder. I can make a drill block with the correct spacing that bolts to the straight hole and allows me to drill the oversized hole for a timesert perfectly straight (without the bit flexing and trying to follow the crooked hole). I could then either make another block for tapping, or use the drill chuck to center my tap (my machine has a power tap feature, but I’m not ready to play with that yet). I think that if I took those steps it would be pretty hard to screw up. This is, of course, assuming that the stud angle is exactly perpendicular to the deck surface. If it’s not, I have no idea how I would level the head well enough to keep everything straight.

Anybody care to weigh in on this approach? I’d have to buy roughly $200 worth of timeserts and big-serts, so I’d only be saving $100-300...

Oh, and I know that’s too much dykem, and I know I need probably another 0.100” of pushrod length...

[Newold1]

My suggestion before you even start redrilling the rocker stud holes is to take a known straight metal bar or such cut to a lenght that will allow you to lay it over all the removed 8 stud locations. Take a look at the clearance if obvious from one stand to the next and if necessary use some thin feeler guages to measure any gaps side to side and fore and aft that would indicate the stud bases are not straight and level.

Reason being is even if you redrill and thread insert new straight threads, the studs have a shoulder that stops on the base and if that surface is not straight and level when you tighten the stud to lets say 50lb/ft. the stud will tend to seat crooked at the angle on the base irregardless of the straight threads because there is a certain amount of slop in those coarse threads.

If the bases check straight and level, then you have to rethread them and your method sounds doable. I think that if the stands on the head are not straight level on the top and you use your mill to slightly cut all the tops a small amount on the correct level to the deck you might be able (believe it or not)to reuse the existing tapped threads even if the threads are slightly cocked because of the slop in coarse threads. The rocker stud shoulders themselves will tighten down usually straight when pulled to torque and locktiting them into place will keep them put. Also don't be afraid to cut a small amount off the tops of the stands as with studs they can be shimmed accordingly or it looks like you might need a new set of proper length pushrods anyway and the individual rockers are not like shaft rockers where setting height is more critical. I would also still recommend getting a set of stud girdles and stiffening and aligning things up.

Hope my suggestions and ideas help and are useful. Don't get frustrated or discouraged, you'll get er done!

[crazy_caseys_customs]

My suggestion before you even start redrilling the rocker stud holes is to take a known straight metal bar or such cut to a lenght that will allow you to lay it over all the removed 8 stud locations. Take a look at the clearance if obvious from one stand to the next and if necessary use some thin feeler guages to measure any gaps side to side and fore and aft that would indicate the stud bases are not straight and level.

Reason being is even if you redrill and thread insert new straight threads, the studs have a shoulder that stops on the base and if that surface is not straight and level when you tighten the stud to lets say 50lb/ft. the stud will tend to seat crooked at the angle on the base irregardless of the straight threads because there is a certain amount of slop in those coarse threads.

If the bases check straight and level, then you have to rethread them and your method sounds doable. I think that if the stands on the head are not straight level on the top and you use your mill to slightly cut all the tops a small amount on the correct level to the deck you might be able (believe it or not)to reuse the existing tapped threads even if the threads are slightly cocked because of the slop in coarse threads. The rocker stud shoulders themselves will tighten down usually straight when pulled to torque and locktiting them into place will keep them put. Also don't be afraid to cut a small amount off the tops of the stands as with studs they can be shimmed accordingly or it looks like you might need a new set of proper length pushrods anyway and the individual rockers are not like shaft rockers where setting height is more critical. I would also still recommend getting a set of stud girdles and stiffening and aligning things up.

Hope my suggestions and ideas help and are useful. Don't get frustrated or discouraged, you'll get er done!

Thanks for that. That is a check I can definitely handle. These ARP studs have rolled threads instead of cut threads. I don’t know all of the correct terminology, but in my experience they are a little tighter fit in any given threaded hole than, say, a grade 8 bolt of the same size, which may account for why they’re not pulling the studs straight (you can see in that photo that the hex on the stud isn’t fully seated against the guide plate on the inside edge of the crooked stud). Anyway, given that, and given that my bases are flat, or that I can at least get them flat, what would you say to just running the tap straight into the crooked hole to enlarge the thread, and then letting the flat pull the stud straight, rather than going the insert route. Also, these all go into water. Does red loctite still work going into a water jacket? I was using ARP’s thread sealer before...

Thanks again for the advice...

[Newold1]

I see what you are saying and obviously these heads were fitted with new ARP rocker studs and possibly had to be retapped then to accommodate a larger thread. This could be when they were tapped crooked and if that's the case and you verify the stud bases in the head are level and even then the only solution would be to rethread those bases straight most likely with a thread sert as running a tap of the same size back into those crooked threads would most likely overcut the threads and create a possible stripout or tear of some of the threads. That tap is going to follow those crooked threads in iron and it might break the tap under pressure trying to force it in a straight vertical position while it cuts threads.
I think in your case if you retap the threads and get them straight without thread serts I would use DEVCON epoxy and not worry to much about getting them back out in the future. If you end up having to use thread serts I would stay with Loctite Black Max thread lock/sealer to make sure the water issue is handled and I think that should be on the treads of the serts and the studs.

[crazy_caseys_customs]

I see what you are saying and obviously these heads were fitted with new ARP rocker studs and possibly had to be retapped then to accommodate a larger thread. This could be when they were tapped crooked and if that's the case and you verify the stud bases in the head are level and even then the only solution would be to rethread those bases straight most likely with a thread sert as running a tap of the same size back into those crooked threads would most likely overcut the threads and create a possible stripout or tear of some of the threads. That tap is going to follow those crooked threads in iron and it might break the tap under pressure trying to force it in a straight vertical position while it cuts threads.
I think in your case if you retap the threads and get them straight without thread serts I would use DEVCON epoxy and not worry to much about getting them back out in the future. If you end up having to use thread serts I would stay with Loctite Black Max thread lock/sealer to make sure the water issue is handled and I think that should be on the treads of the serts and the studs.

I’m not going to mess with trying to tap the crooked holes straight, I’m sure they’re too far off. I’m going to go straight to threaded inserts. I am completely unfamiliar with the Black Max, but a quick google search says it’s “instant”. Is there adequate work time for a threaded connection? I’m sure if I get my insert set permanently, the ARP thread sealer will be sufficient for the studs themselves. I’ve never had it leak, in anything. And it would be beneficial to be able to remove those studs later if I have to.

Thanks again for all the advice...