Hello all. I'm installing a new head on my R53. Unfortunately, I had the threads pull out of the head in one of the mounting points where the bolts secure the rockets. I want to install a heli coil but was wondering how the locating pub for the rockers come out? I surely don't imagine I drill through that. Thanks in advance

 

Can you provide a picture or two? Trying to look up what you're talking about and everything I'm getting shows that the rockers seam to "float" on a pivot shaft that runs the length of the head, unlike a typical configuration where each rocker is individually bolted in place. Are you talking about the bolts that hold that in place, or am I missing something?

 

. The bolt runs through the shaft that hold the rockers in line. Here's a photo and I circled what I am referring to. Thanks for looking this up.

 

So, the threads are deeper inside the hole? I don't see threads on either one.

Unless someone knows a better way, likely that will have to be drilled out, sleeved and tapped, if that can even be done in that spot. I suspect those centering spacers press in. So, it would have to be extracted in order to do the work. Not sure how much that would cost. How much is a new head? It might be a drastic question, but depending on price and effort, it may just be better to get another head.

I've never seen one of these in person. So, I'm trying to guess based on other things I've seen.


Although, this thread may be of some help. http://forums.sohc4.net/index.php?topic=84855.0

 

Actually, a helicoil might work. You're correct about the centering spacer being the issue, though.

 

If look down the good hole (insert joke, here) are the threads sticking out farther than the center spacer? Should be, otherwise not sure how that would even work. If so, what about not drilling at all, utilize the bit of threads left to give the helicoil extra bite. ...or do they have to have a smooth surface?

 

Well, the way a helicoil works is you drill and then retap the hole to fit the helicoil since it is sightly bigger than the hole. The dowel (is this what you mean by spacer-what I have circled) does not have threads up to the top.

 

Thanks for the input. I saw this when I was researching and this is what made me feel like the helicoil will work. The head is a JCW head and may be a bit expensive; I still have the original head that is in good shape.

 

Fair point about how the helicoil works. I've never actually had to use one, and it makes sense that you have to retap the hole.

Based on the amount of material surrounding the hole, I'd imagine it should be fine. But then, I don't have he manufacturer's tolerance, either. Once thing to think about is that you will want to be very accurate and very straight with that, else the cap hole and the head hole won't line up right. Also, if you nick the edges, that dowel may not fit right. Should be pretty easy if you have access to a drill press.

Still, have to figure out how to get that dowel out.

BTW, "dowel" is a much better term for it. I couldn't really think of an accurate name.

 

Now, the question is... do you have the guts? lol

Side note: JFC, those things are expensive. I was expecting like $500, they're a friggin grand!

 

Repaired hole
Pin removed
Stripped hole
Just wanted to follow up with everyone and say thank you for the input and to show what I did. The dowel comes right out and is no sweat once you know it's made to be removed. I sprayed a bit of penetrating oil on to the dowel and waited a few minutes. I took a pair of pliers (not channel locks) and carefully worked the dowel out. Using pliers made it so I was grasping all around the dowel and evenly distributing pressure to wiggle it out and not distort it. Once I did this, I drilled, tapped the hole and inserted the heli coil. I have full confidence this will hold and by talking to machine shops, they all advised that it'll be stronger than the original.

A note of caution though, careful with metal shavings; prepare the surface and be ready with a shop vac. Also, when you are rethreading the hole, make sure you keep the tap as straight as possible so your screw goes in straight as it is mean to go in. I ended up grinding the end of the tap and not using the tool they give you in the package. This way, I was able to out a socket on it and have much more control. One other note-Be sure to work slowly when tapping the hole. Just out if sage practice, be sure to thread a few threads at a time and then back the tap out and clean in; no need to rush this.

 

I carefully grinded the end and used an old socket to insert this into.

 

Nice work! I hate those that handles for taps. They never stay tight, and arear a big pain.