Exhaust stud lock washers

[5thhorsemann]

Crushing your nuts in a vice is a bad idea!!!

But seriously, they are deformed and hardened to a specification, too much "crush" and you can damage the stud or head casting, or both. Not enough and the nut could loosen when it heats up. Spend the couple of bucks and get the good parts made to go into an aluminum head.

Edited July 11, 2012 by 5thhorsemann

[siteunseen]

Part number for the M8 deformed nuts. I bought a great header from MSA but the stud kit was wrong.

[grantf]

I bought the same stud kit and installed both mnifolds. Hmm time to rethink this now. I may go with lock washers.

[8DC]

I too just recently installed the MSA manifold bolt kit on my car thinking they were Nissan original parts (a few of the bolts even came sealed in Nissan parts bags). I didn't think much of it until I saw this thread, but the nuts are definitely "normal" nuts as I was able to thread them on by hand. I just had to retorque them this weekend because the manifold was leaking and I suppose I now know the reason. >.<

I was also disappointed that the MSA manifold bolt kit did not include the thick washers that are used to join the manifolds.

Another question I have is what is supposed to be used on the far ends of the stock manifold where it has enlarged holes. Just large flat washers?

Also, I assumed that flat washers went under the small bolts on the exhaust manifold (i.e. the three found in the center) even though none were included with the MSA kit and none were on the car when I removed the manifold. Is this correct?

Edited July 17, 2012 by 8DC

[zKars]

While I hate the argument that goes "well I've been doing it that way for years and its worked just fine" due to the obvious "one off" bad statistical implication, but I gotta say, I've never used these fancy self locking nuts on any manifold I've ever had the pleasure to fondle, just regular nuts and split locks, and never ever had one come loose, maybe just need re-torquing after the first run/heat cycle. While it is a good idea to use self locking nuts, and may in fact be the Nissan intended "right" way, I'de hardly suggest that going with regular hardware as being any significant risk. Maybe my engines run with less vibration than some of you-all's ...

Maybe my opinions are clouded by the fact that taking these self locking nuts on and off requires a wrench the entire way for every single one, and since some of them are hard to get to for an old man, ones that spin on and off easy are my preference. Maybe also the frequency with which I do this to my and other cars also has a bearing on my opinion and the statistical chance that they have enough time in place in vibrate loose....

[John Coffey]

While I hate the argument that goes "well I've been doing it that way for years and its worked just fine" due to the obvious "one off" bad statistical implication, but I gotta say, I've never used these fancy self locking nuts on any manifold I've ever had the pleasure to fondle, just regular nuts and split locks, and never ever had one come loose, maybe just need re-torquing after the first run/heat cycle....

Maybe my opinions are clouded by the fact that taking these self locking nuts on and off requires a wrench the entire way for every single one, and since some of them are hard to get to for an old man, ones that spin on and off easy are my preference. Maybe also the frequency with which I do this to my and other cars also has a bearing on my opinion and the statistical chance that they have enough time in place in vibrate loose....

Exactly! I have never used metal lock nuts on the intake or exhaust of any of my street or racing Datsuns. And I don't install them on customer cars unless the customer specifically asks for them. A regular M8 class 10.9 nut with a new split ring lock washer (every time) and I've never had an exhaust leak caused by the nuts working loose.

[grantf]

Exactly! I have never used metal lock nuts on the intake or exhaust of any of my street or racing Datsuns. And I don't install them on customer cars unless the customer specifically asks for them. A regular M8 class 10.9 nut with a new split ring lock washer (every time) and I've never had an exhaust leak caused by the nuts working loose.

I think you have answered my question and perhaps saved me another gasket blow out.