Best fix for 18deg. head ?

Help guy's, I pulled the threads out of my 18 deg. big dukes this weekend and need to know the best way to make sure it dosen't happen again. I'm thinking of having the rocker stands welded together since too my knowledge, no one makes a one piece rocker stand for 18 deg. heads. Will this help and is their anything else I can do, tuneup, steel incerts, etc.. Thanks Jody.

 

I have a brand new set of tit. intake valves for them heads will sell cheap..dave

 

You can buy longer bolts from Jesel are T&D. Drill and tap the exhaust threads deeper and use the longer bolts. Do not over torque. This will pull the heli coil up and break the threads.

 

inserts

I use Keylock inserts that I get from MSC, also use the long bolts from Jesel or TD like previously posted....that seems to cure the problem, the Keylocks won't back out.....they are more expensive though.

 

Hi Jody, did an exhaust or intake or multiple threads pullout? If it was exhaust threads, do the bosses on the 18 deg dukes have a cut away portion for head stud clearance? How much thread engagement is there on the affected bosses? I only ask so many questions after having a similar problem myself and finding the answers the hard (read expensive & time consuming) way myself.
PM if you like.
Jimmy

 

Jimmy, you are correct, it is the exhaust rocker stands. They have this damn cutout on one side for head bolt cleareance. My plan, after hearing what these guy's have said, is to use keylock inserts as long as possible,weld the stands together, maybe try to drill and tap a second smaller bolt in the stand, and back down the overdrive to around 25% on my high helix retro.

 

If it were mine I would leave the blower overdrive alone, do all the things you are saying and I would also use as long of a bolt as possible.
We first made sure that our bolt hole was tapped all the way to the bottom, then took too long of bolts and cut them to the maximum length. We have had no problems.

 

Jody,
I just went through this. There are a couple of things that can be done. First you can drill the threads out of the right side exhaust stand hole that holds the cross shaft for the rocker (I assume you are using shaft rockers). Then either drill and thread the head or better yet put a thread insert under the stand and 0install a stud and nut. This will help stabilize the exhaust. The next step would be to tie the stands together, which I did. Call me if you want to know how I did it. 541-389-9881 Scott

 

Another hint Jody, after you have repaired and strengthened the exhaust bosses and stands, I`d recommend checking the intake valvetrain on the affected cylinders very closely. When I had this problem on one cylinder, the intake lifter on the same cylinder smashed the axle out of the body and caused even bigger problems. This was explained to me as caused by the intake valve having to open against the retained cylinder pressure that the smaller area exhaust valve would normally let out. The large area intake valve has a hard time opening and tranmits all that load back down to the cam. In my opinion putting a new lifter in that/those holes would be cheap insurance.
An open question-- why the hell do these rockers have such short bolts in the kit?

 

Keep the suggestions coming, my Father taught me that to be truly smart you don't need to know everything, just the people that do!! Thanks for all the help. Jody Stroud

 

Ah yes you sparked my memory. Usually when I break something exhaust, like a rocker arm, my intake pushrod bends/breaks. Same deal just different weak link.

Why the bolts aren't longer I don't know

 

Weak liNK

hI Jody,dad is good 100%. I wish all advice was so easy. We have just had FOUR rain affected dates followed by a trans failure out of TEN dates for the whole F@@ck@@en rain affected @@@@@ season @@@
Trying real hard to smile
Jimmy

 

I would love to here more about tie-ing the rocker stands together on the older Pontiac 427 Heads...I know...I know...thats old school stuff...Well, I still live there.
I have seen that Jesel makes a new 1 piece stand for the Dart Big Chiefs.
I wonder how close the Big Duke system is to the Pontiac 427 stuff. I know the are similar in a lot of other ways.

Mudwrench

 

In general we've seen guys add on to rocker systems. The whole idea is to tie the intake and exhuast systems together, so take your pick, bolting or welding.
Personally I would weld on ears then bolt the two together. This would leave room for adjustment later.