Lucky me I got a blown head gasket for my birthday. Yay! So last week I pulled her apart, machines the heads, ported and polished, new gaskets all around from block up, as well as new ARP bolts all the way around block up. Today I was installing first head and middle bottom bolt wouldn't tighten. When I pulled it out the threads from the block came with it. So now I have a block with striped threads. What do you guys recommend I should do? I have seen inserts but are they good? Do I have to pull block out? Should I do all of them the same?
Is there away to tap the hole bigger and use a larger bolt; if its a stud can you get a stud with two different thread types. Im trying to say ive had these types of things happen on my race bike, 10mm bolt strips in the head that holds cams down, I just tap it to 1/4 20 and a bigger bolt and was good to go..Inserts suck ive never had good luck with them..
Good question. I'd take a closer look at that area if it were and if there's nothing wrong other than the stripped threads, drill it out and tap it for a 1/2" bolt rather than toss a good block for one stripped hole.
It does seem to stop a little short when I chase the threads with a tap, maybe like a bolt broke off at some point. I do have a shorter head bolt and I'm thinking it must have come from that hole. As far as surface and block, they look fine, and I wasn't able to locate where the head gasket blew. The gasket came apart when pulling.
Take a phillips screw driver and stick it down one of the good holes, then mark the depth. Then drop it in the bad hole and compare readings. The 1980-up blocks have open holes, clear thru the decks into the coolant jackets on the bottom side holes. The top holes are blind holes on all blocks, as are the bottom holes on pre 1980 blocks. (not 100% on the year of the change to the open bottom holes, but it was sometime in the 1980's) Just me, but I wouln't trust a heli coil in a head bolt location. Id drill and tap to 1/2NC before doing that, this will be done anyway to install the helicoil.
I ordered a heli coil kit. I will look close at it and choose whether to heli coil or just use 1/2" bolt tomorrow. I do not want to but a new block, since within the next 5 years I plan on getting a coyote 302 and super charge it. Right now I want mine to run good, but now waste money buying a block that is getting replaced.
Hmmm hang on im kind of one of those,would that do... Hey thats usually my suggestion, but I must admit it is an awesome suggestion. And short of getting a new block one of the best fixes available. You can get them or some similar products at Motion industries or one of the other industrial supply places in salt lake, I also know I can get them from Herricks industrial in Ogden if need be for you.
if you oversize the one hole to a 1/2 bolt you need to compensate for the bigger bolt in the one hole having a different stretch than the smaller bolts. a buddy of mine had to do this. he used arp bolts and talked to arp tech. arp was able to give him the correct torque values for the different bolts.
Well I just called emhart, the manufacturer of heli coil, and they had some good info for me. I will forward the torque charts and studies when I get them in my email. Basically he told me that helicoil helps distribute force between more threads than even factory cut threads. Normally force is shared between the first 3-4 threads, where the springy aspects of the heli coil is proven to hold with significantly more. He said that several auto manufacturers are actually using them as oem equipment. He also assured my that a helicoil will out perform a plug style insert like time sert or keen sert. He is sending me an independent study that shows helicoil on top in every aspect.
