Thank you so much for your time and advice
please check your Direct massage

 

I don’t know why you would question the factory process, especially when they’ve specifically stated how important it is in the manual. I understand that ‘cracking’ bolts makes you nervous, but don’t put any oil on the threads!

 

yes!

Lubricate the under the head so it turns easily. Pretty much required on "Torque to Yield" Bolts. ARP provides grease with their bolts just for this purpose.

 

thank you so much Larry

 

If you stripped the threads in the block you will need to use an insert. They work well but make sure you get one that is suitable for a headbolt. Sadly this is a common problem with Aluminum blocks/heads. The extreme expansion of the metal during use causes strain on the threads.

FWIW, I used ARP bolts which cost more but aren't "Torque to Yield", can be re-used and are set to a specific torque and not degreed.

 

Trying to think of something constructive to say here. I almost don't want to but I'm sure there are a lot of us watching this thread feeling the same way. I think the correct way to repair the damaged threads would be with a threaded insert in the damaged hole and a replacement OEM bolt or alternately high quality replacements like AM4884 mentioned earlier in the thread. I'm not sure I personally would just ream out the bolt hole to a larger size and use a non-factory spec larger bolt. How would you know the correct torque for the new bolt? Will it even fit through the hole in the cylinder head without reaming it out as well? Is there enough material around the bolt hole to do that without compromising the cooling or oiling passages? I also would not want to be the next owner of a vehicle of any type that was repaired that way.

I give you a lot of credit for getting as far as you have, don't misunderstand. I definitely didn't think it possible to get the heads out with the engine in place, for example. Great job. I personally would gone down a different path to repair the damage.

 

Somewhere I have a table of pull-out force for a given size bolt & thread. There are specs for the # of threads, so as you go up in diameter, make sure you have enough threads to ensure engagement.

You can do what you want (go up size, custom bolt diameter), but you will absolutely want to go to a stronger bolt and not grab one off the shelf. Aluminum blocks stretch quite a bit and unlike an iron block will easily generate the force needed to snap a bolt. In general a 12.9 bolt is recommended / suggested but at least a 10.9 (which is what the torque-to-yield use once bolts are).

The problem arises when the bolt isn't tight enough and works lose over time which stresses the threads and eventually causes a head gasket failure. I would be looking at the ARP catalog and trying to decide what bolt is long enough, and large enough in diameter to serve as my replacement. And then torque it to whatever ARP specs that bolt for. It will have been from a head bolt use and thus be a reasonable choice.

 

Congratulations. That was some serious wrenching on a budget. Hope you enjoy driving it now!

Did you use the Jaguar thread inserts or helicoil?

 

Glad to see and hear it running, you definitely took on some issues and managed to get it going in a short amount of time. Great job.

 

Thank you very much

 

Most impressive repairs! And likely better than new.

My only advice is to take your time when warming it up - took 10 minutes this AM to get my oil to 140 degrees F. That's when the fun begins!

 

A huge congratulations for tackling the job and getting the issue resolved. I appreciate all of these threads on repairs, and the willingness to take them on. I like doing my own repairs in the older cars and bookmark threads like yours for possible future needs.

Thank you for sharing your journey.

 

Well done, sir. Very happy to see you're back in business. I can't imagine performing that kind of work myself, let alone in the conditions you were faced with.

 

remarkable!! even in the prime of my life i wouldn't have attempted it. *sigh*

 

You are one brave man and good for you that all your very hard work came through.