454 chevy stripped head bolt hole
 

any you guys have any ideas about fixing one stripped hole in the block of a head bolt? heli coil? size i need? ive got just one that is stripped out right in the middle and its a long one not the short one in the bottom after i get it fix ed im going to studd this one thanks mike in new mexico

They make tools to drill and tap your block straight but if you cant find one you can make one if you have access to a mill. take a piece of steel at least one inch thick and drill a hole in it thats the tap drill size,then drill another one next to it and tap that one.on the other end cut a slot that is wider than the 7/16 bolt.position the slot so it will reach any other head bolt. simply center the fixture up on the bad hole and bolt it down.using the tap drill size hole to square your hand drill,drill the bad hole to tap drill size. loosen the fixture and position the hole you tapped over the bad hole and clamp it down. screw the tap through the fixture and into the block.thats all there is to it.Bill

i have had better luck useing a key insert over heli coils. just my .02 worth

What is a Key Insert?

Ed

I have used Hendrens method and found it to be easy. It's pretty much imperative that the hole be perpendicular to the deck and w/o the block your hand drill will wobble enough to make the hole oversize. Ditto when you tap and then you have threads that are far from perfect. Makes it possible to strip or pull the heli-coil if not done right.

key insert is a thead insert with 4 locking pins that you drive in to lock in place. they don't come out or pull like a heli coil.

Ed,
I think this is what he is talking about. You can get them in carbon or ss. I have used them in my machine shop and they do work very well. They make a tool to set the pins once they are screwed in. I make a threaded installer that screws into the ID and has an OD that stays inside the pins, then use the tool to set the pins.

http://www.jlindustrial.com/JRI-6592...T/product.html


Curtis

that is what i'm talking about. i buy then from macmaster car. that is what they call them is key sert. best fix i have found. can't beet them on rocker bosses, etc..

I too have used these,for many years,they are a great fix for cast iron and aluminum

i guess it depends on where you live..we call them nut serts...works well

brian

inserts
 

hey guys thanks a million for the advice i knew i could count on you guys for some "correct" and helpfull help. im trying to see whats available to me in my area of the us before i order something thanks again mike

Re: inserts
 

Hey Mike,

Good to see you back on the site (RJ), you been missing a while, i thought maybe you were harvesting the tumble weeds.
You can go to (MSC direct.com) that's where we buy all our shop supplies, they are called lots of thing but the name i reconagise is KEEN SERTS, they have been around for 40/50 yrs.

Zip.

inserts
 

Mike I had an old 427 tall deck block that I ran blown alky for a few seasons, ya need to stud that thing NOW, just FYI, I probably had 7 or 8 helicoils in that thing by the time I chunked it. It was filled and the heads were solid castings so water was not an issue. Stud it, you'll be fine. Stud the mains while yer in there too. 8) JB

inserts
 

I forgot - use some antisieze on those stud threads - both ends. :shock: JB

head bolt
 

hey guys!! thanks for all the info it is very helpfull you guys are great i just finished the "nut insert" thanks bj and yes i did "stud" the block man what was i thinking? anyway torqued all the nuts down to specs and for the moment every thing looks great. now if i can only figure out how to keep the intake bolts[some i cannot get to unless the blower is off the engine] fro getting loose on me and leaking oil. thanks guys mike [tubleweed rusler]

:D :D ....This is the preferred way....I did mine with a friend an electric hand drill....a metal square.....and alot of luck....you have to make sure the drill is square up and down and side to side....go slow and be patient....drill out the threads and we helicoiled it i think it is 7/16th treads and repair kit is available at local parts stores for bbc...then insert thread repair and locktite it in....then do not over tighten the head right away go in stages and slowly torque this bolt to specs....good luck :D :D

Permatex #2 is a non-hardening sealant perfect for intake bolts.Also works good on the preload bolts on girdle-type rearend covers

head bolt strip
 

I had the same problem I went to a big truck parts store they have herical kits for that type of stuff

454 Stripped Head Bolt Hole.
 

There are numerous thread repair methods, Heli-Coil, KeySerts, thread inserts. Heli-Coils will work for the majority of times and is synonymous with thread repair and although not fool proof is the most common method. If the threads pulled out and you get the proper thread depth for the Heli-Coil it will hold. The common problem I see with Heli-Coils is that the Heli-Coil is not put in deep enough to where the the first coil pulls out. The coil is to long,the insert extends beyond the thread. The tang can not be removed cleanly, it gets pushed aside or distorts the coils. This will either chew up the bolt or the coil will screw out of the bottom of the deck surface. Manley has the fixture to drill the hole square to the deck surface, when drilling by hand. The fixture accomates drill bushings and supplies the proper drill bushings for 7/16" or 1/2" threads. The fixture could also be used to drill for Keyserts or thread inserts with the purchase of the proper drill bushings available from any machine shop tool supplier (ie McMaster or MSC). In most cases threads will pull during the final torque of the final assy and the repair has to be done by hand on the motor. I have had after repairing one thread and after reinstalling the head another thread will pull out. This generally happens with old blocks and there is no way to tell if a thread will pull out. If you have run a tap through the threads (common practice) you unknowingly created the problem. In essence you have made the thread to loose or taken away from the root diameter of thread and do not have proper thread engagement. ARP makes "clean out taps" that do not remove material or thread restoring taps are available from tool suppliers. If,as was suggested, the milling machine can accomodate the block, it might not be cost effective to repair one thread.

Manley Performance makes a jig for drilling and taping square to the deck surface as we have one as it has come in handy over the years.

could have preheated the block,and welded it up- then center punch,redrill,and new tap
no bull about it, no crappy helicoils,glues,crossthreads ect....
cast iron is fixable- i think theres ni55,and ni99 rod to use- one is machinable more than the other