Jump to content

Cylinder head nuts question


Recommended Posts

Hi,I'm putting my son's 1600 motor back together that someone else took apart.I got a box of nuts and washers but are missing some thick head stud washers and nuts also do they require lockwashers? I don't see any.I guess it wouldn't hurt to add them.

Link to comment
Share on other sites

On 5/12/2023 at 9:18 PM, Buick35 said:

missing some thick head stud washers and nuts also do they require lockwashers?

Ex-Dealer VW aircooled mechanic:   Do not use lockwashers.  Find the original high quality machined, thicker flat washers that are way better than a cheap thin stamped hardware store flat washer.    


there were differences in 1600 engines because as VW increased HP, AND torque went up, then some people did not downshift enough on long hills because it had more torque.  That lugging up hills and the higher heat from more smog rules would cause the cylinder head stud threads to "pull" or "strip" out of the engine case.  


The older 1600s had thick head studs (10mm) that could not "stretch and then contract" when engine was cold or then hot, so VW came out with thin diameter studs (8mm in center but still 10mm threads), called "stretchy studs" and these also used steel threaded inserts in the case at every stud.  These two things fixed the stripped head stud issues.  (when the studs stripped with age and miles, the heads got loose, and when engine is cold, the engine sounded like bad exhaust leaks with popping sounds.


When a shop gets a bug motor for rebuild, they first will try to torque the heads to specs to see if the threads are holding, before they take it apart to rebuild.  It sucks to rebuild the engine only to feel the studs stripping as you assemble the heads onto engine.

Link to comment
Share on other sites

Thanks,I guess I'll remove the lock washers I installed.I put on the thin internal locking ones.It has the 8 mm studs and I torqued them to 18 ft.lbs. I'll try to locate some thick washers but now I doubled up on the missing four with thinner ones. It has a set of Kadrone carburetor but I wish he had a single Holley instead.He's going to order a distributor next.Someone said a 009 one doesn't work well with Kadrones.Greg

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Create New...