lester Posted April 28, 2011 Share Posted April 28, 2011 I have a 78 datsun 280z. Last year the head got a bolt sucked thru it and ultimately ruined it.(How a bolt got in there, we still have no idea). Decided to go ahead and purchase a rebuilt head off of ebay...what a terrible mistake. This head has been nothing but trouble. The problem is the threads on the top of the head that the rocker arm holder threads in to are gone. The dumbass that rebuilt it obviouslt did a terrible job. So what happens is the rocker arm holder comes lose and starts to make a very annoying tapping. We have tried JB weld twice now. It actually worked for a good 700 miles, then vibrated loose again. What are your guys suggestion to get this fixed? We were thinking take it to a machine shop and have them insert a helicoil, but are afraid we'll have to take apart the entire top end again which we now know is a pain. Another thought was to have a machine shop just weld the holder in place, but don't know how perminate this fix is. Any help is greatly appreciated! Quote Link to comment Share on other sites More sharing options...
sweetleaf Posted April 28, 2011 Share Posted April 28, 2011 Drill it and install a Timesert. In case you don't know what that is, here you go. http://www.timesert.com/ Quote Link to comment Share on other sites More sharing options...
lester Posted April 28, 2011 Author Share Posted April 28, 2011 Looks like a good idea, but don't want to mess it up. How hard would it be to drill this and make it perfectly straight? Quote Link to comment Share on other sites More sharing options...
Tony D Posted May 1, 2011 Share Posted May 1, 2011 The pivot is spherical, it's more important to get it in the right spot to make the rocker arm ratio consistent with the others, than to have it straight up and down.... Quote Link to comment Share on other sites More sharing options...
Pharaohabq Posted May 2, 2011 Share Posted May 2, 2011 a good machine shop should be able to either weld and retap that, or install the timesert straight and in the right spot. Though you might consider finding another head somewhere since the cost of a new head is pretty cheap in comparison to machine work. Not that a used head shouldn't be cleaned planed and setup with a valvejob and new Viton seals(for unleaded gas use) before installation. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.