Calling Garibaldi (DILAVAR)
 

Hi I would like to hear your thoughts about Dilavar head studs. Is it OK to use them (on mag) or must they be avoided? Should it be a full set, or just a half set? Full threaded shank or not? etc

tahnks

After a lot of investigation I did my 2.7 with steel upper and dilivar lowers. There will be a lot of contrary opinions on this.

On a 3.0 rebuild I'm doing, I've 3 out of 12 Dilavar studs that are boken. It's odd (to me) that Dilavar was used on the hot side only and steel for the rest. I guess I'll never know why as the history of this engine was lost.

I would only use dilivar on a mag 2.7. On anything else I would use steel.

Don't forget Mahle replacements, even for 2.2 and 2.4, are now Nikasil just like the 2.7 -- no longer Biral...

After seeing what kind of thunder my post on Loctite created, I am going to be careful from now on. I think a lot of people took it out of context, and reading the last few threads, I am convinced that there will still be a lot of people using the Loctite on their rod bolts- hey! More power to them.

To get off topic for a moment in terms of web forums, you have to understand that anyone and everyone is entitled to and using their ability to voice their opinions and experiences. Point being that you really have got to be careful as you have no real way to test the validity of the info on the internet unless you do it yourself. So just understand that.

Back to the Dilavar. I am not going to say its good or bad, or what to use or not to use. I will share my experiences.

While I never truly delved into the subject on the evolution and trends of the head studs that have been holding the heads on 911 for the past 40 years, I can share with you the few odds and ends I can remember. If you want a history lesson, well go and look it up for yourself. I know that a number of people have used dilavar with success, but I have also heard of people having failures with them. If I remeber correctly, there were a number of variations of the theme along the way. SOme guys love them, ohters have had some problems with them. I suppose it has a lot to do with the application, preparation, and who is putting it all together in terms of their skill level.

So be clear- I really have no comment on dilavar. When I build a motor, I use ARP head studs. I have had no problems with those. That I can tell you.

In closing- especially on the magnesium cases- the culprit is not the hardware as many people think- its the case material. Face it- magnesium cases are now old, and probably very tired, and mag is constantly trying to return to its raw state- so its dying even if its sitting on a shelf. So the material the stud is going into is questionable. After all the issues with the studs were that they would yank the threads out of the case, or snap in half. So there is a high quality head stud on the market that I use, that way it allows me to eliminate that as a potential failure point, and focus on the next weak link in the line which in your case- is the case.