I'm replacing the head gasket on a older v8 car and when I went to install the head bolts, I noticed that I wasn't able to thread the bolts all the way down by hand. They went down easy with the wrech, however?

I'm worried that I won't be able to get an accurate tq setting if there's drag on the threads. Do you think it's worth it for me to remove the heads and tap the threads or do you think I'll be alright?


thanks

 

they'll be alright, dont worry about it

 

It's definitely going to affect the tension on the bolts but how much depends on how tight the threads are. If it's just a stock rebuild it may not matter but if it's a performance rebuild for peace of mind I would pull the heads back off and chase the threads.

If the threads are going into a water jacket are you using RTV on the threads and if they are not are you using oil on the threads? They should not be dry.

 

just a stock crapper.....

the head bolts don't go into the water jacket. I followed arp intstrutions and used 30wt oil.

I'm not sure why there tight. I pulled the bolts back out and relubed them only to find them tight again.

On one of the bolts, there were two tiny marks on the threads so I'm guessing the bolt hole threads aren't perfect.

thanks for the replies

 

dont re-tap. your more likely to f it up. just torque em to spec and dont over think it.

 

Did you compare the length of the new bolts to the old bolts? It sounds like they aren't too long, though, the threads are just tight. Are the old bolts tight? You can actually buy a thread chasing tap that won't cut new threads it will just clean up the old ones. It think ARP actually even sells them.

 

There the same bolts.

I think what happen was when I went to remove he head, water and oil fell into the bolt holes. I blew out the holes but I think rust may have developed inside them.

I went back to the car and rethreaded the bolts on the exhaust side and they went in like butter. So I'm gonna let it sit overnight and hopefully it'll sort itself out

 

everytime you chase threads with a tap, you remove material - car craft magazine
http://www.carcraft.com/techarticles...ing/index.html

I'm gonna just tq them down tomorrow. I really need to get this done.....

 

Exactly, that's why you use a thread chasing tap.

 

even a thread chase removes some material....if he had said it was still tough with the wrench then I might consider it, but he didnt....dont over think this one, In all honesty your torque wrench probaly isnt that accurate anyway....(what are you using).....just go a little past the spec if your still worried, The old v8s are not as nearly as finicky to torque as newer engines are. hell you could probaly get away without even torqueing it

 

I honestly didn't know that. I just posted that to brieftly summarize the article, which i thought was pretty good.


I'm shamefully using a cheap china tq wrench. However, I have confidence in it because I did my integra with no problems.

 

I think you are right, in the end it's not really going to matter. Blowing out any water or oil from the female threads is probably more important than tapping them in this case.

 

I blew out all bolt holes before the heads went on