Ducati Monster Forum

Moto Board => Tech => Topic started by: MonsterMadMarty on December 04, 2014, 05:03:26 PM

Title: Fitting New Head Studs
Post by: MonsterMadMarty on December 04, 2014, 05:03:26 PM
As in the title I'm fitting new head studs! I've removed the heads but not the cylinders so running a tap to clean the old thread once the stud is removed is kinda difficult! So I've been blowing the hole with air, then cleaning the old stud thread, winding it back in and out, blowing with air again then fitting the new stud (just the one so far).

The new and old studs are excatly the same lenght.  The old studs sit 73.4mm proud of the cylinder. The one new stud I've fitted so far I can only get in to sit 74.3mm proud.  I don't want to force too hard and snap or weaken the new stud so does the extra 0.9mm matter?

Cheers  [thumbsup]
Title: Re: Fitting New Head Studs
Post by: SpikeC on December 04, 2014, 06:59:53 PM
 Shortcuts generally do not end well.
Title: Re: Fitting New Head Studs
Post by: Speeddog on December 04, 2014, 08:04:50 PM
Remove cylinders and pistons.

Clean threads with a tap.

Confirm studs will screw in to the proper depth/height.

Install studs to the proper height, with blue loctite.

Without delay, install the cylinders, heads, and head nuts, and torque to a 'installed' level.

Next day, remove cylinders and heads, and reassemble from there.

Don't re-use piston pin clips.

Title: Re: Fitting New Head Studs
Post by: MonsterMadMarty on December 04, 2014, 09:05:26 PM
Quote from: Speeddog on December 04, 2014, 08:04:50 PM

Remove cylinders and pistons.


Why remove the pistons? Is it possible to just replace the rings?
Title: Re: Fitting New Head Studs
Post by: oldndumb on December 05, 2014, 09:08:23 AM
Most DIYers use taps with a taper at the start end. If that is the what you are using, and you still cannot get the correct height, a plug or bottom tap might be called for. A taper end tap will not clean the bottom threads in a blind hole.

Ditto the shortcut opinion with an addition is that it usually only applies when the operation is critical.
Title: Re: Fitting New Head Studs
Post by: Speeddog on December 05, 2014, 09:36:04 AM
Quote from: MonsterMadMarty on December 04, 2014, 09:05:26 PM
Why remove the pistons? Is it possible to just replace the rings?

Removing the pistons saves you one episode of 'Fun With The Ring Compressor'.

You could remove the rings instead, but be very careful with the oil rings, they're cast iron and quite fragile.

And I've edited the above, torque to 'installed' value while the loctite cures.
Title: Re: Fitting New Head Studs
Post by: MonsterMadMarty on December 05, 2014, 02:14:37 PM
Cheers SD,

I get what you are saying now! (I'm a bit slow) if I remove the pistons keeping them in the cylinders I don't need to wrestle with the rings!  Ordered some pistons pin clips.

[thumbsup]