One of these studs is not like the other!

[Joshua]

On my 76' V1000 motor i have had a small but annoying head gasket leak.

So, in my effort to stop said persistent head gasket leak I have re-torqued the head. This lessened the leak some, probably to a tolerable amount, but me being me I could not be satisfied with that.

So off comes the head, gasket seized to cylinder mating face around the 10 o'clock cylinder stud. All the four o rings on the studs were hard and brittle when taking them off. Then off comes the cylinder which has the base gasket glued to the face of it with what looks like blue Permatex / liquid gasket.

All cleaned up and ready to install, base gasket down, o rings on studs at 12 and 6, cylinder down over piston, head gasket down, then comes the head.

All looks good to this point.

When I go to install the 4 remaining o rings on the cylinder studs I start with the 2, then the 4, then the 8. When I get to the 10 o'clock position where the previous head gasket was stuck on and there is no smooth stud showing? All I see are threads!!! 

Off come the o rings and head and too my surprise, one of the head studs has a longer threaded portion, almost 1/4 of an inch? Also to my eye it may be a narrower stud overall?

This is my first guzzi motor, and first time breaking it down to any level outside of a valve adjustment.

Is this normal?? To have a different head stud?

I can't believe it would be good to have threads located where an o ring is supposed to seal oil from getting past??

Picture included, opinions on what to do are appreciated.

Is it very hard to set in a new head stud, are they available?





Many thanks,

Joshua

[RinkRat II]

 I'm in the same boat as you Joshua , having never pulled one down, but is that stud in upside down maybe??

      Paul B

[Joshua]

I'm in the same boat as you Joshua , having never pulled one down, but is that stud in upside down maybe??

      Paul B

Thanks Paul!

 I was just thinking about that after looking on Harpers Moto Guzzi for the replacement part! I noticed in their picture one end had longer threads!

[rodekyll]

The stud is in upside-down.  It will probably come out if you double-nut it.  No need to replace it.  Just reinsert it other-end first.

Good eye btw.   

[Joshua]

The stud is in upside-down.  It will probably come out if you double-nut it.  No need to replace it.  Just reinsert it other-end first.

Good eye btw.   

Thanks rodekyll! I was thinking that!

Is thread locker required or suggested on threads going into in the case?

Joshua

[Joshua]

P.S. What is the required torque value for head stud installation?

[Chuck in Indiana]

FWIW, there is a special tool for studs. It will take them out or install. (How do it know?  ) Not very expensive, and much more elegant than double nutting. I'll be back shortly with an example.

for instance, I have this set.
http://www.cornwelltools.com/webcat/products/CBS4MSRIS-%252d-4-Piece-Metric-Stud-R%252d-I-Set.html
If you build one engine, it is worth the money. 

[Joshua]

Great news and so so news.

The stud came out without much resistance.     

The threads are the same length on both ends, so I guess I can assume it's the wrong stud.   


I assume Harpers is the only source for this type of part?

Joshua

[RinkRat II]

P.S. What is the required torque value for head stud installation?

Book shows 40-42Nm head bolt torque
   
     Paul B

[Joshua]

Book shows 40-42Nm head bolt torque
   
     Paul B

Would that be the same for the stud insert to block / case?

That seems high for the aluminum case?

[guzzisteve]

We had to make sure the loose studs were tight in block for the 1st flat tappet ordeal. The torque was 16-18ftlbs, that is in to the block, double nutted.

[Scud]

you do have to slide some O-rings down over the threaded parts of (I think two) studs. A little oil is a good idea.

[RinkRat II]

Would that be the same for the stud insert to block / case?   

    No. I would install the studs to case with a minimal torque like 8 to 10 Nm . sealant is not required as the gasket should do the sealing to the case, but that's a personal preference.

       Paul B
 

[rodekyll]

I've probably got that stud.  I'll take a look.

[Joshua]

I've probably got that stud.  I'll take a look.

Again thanks rodekyll!

I placed one on order from Harpers, they showed having it in stock. $20 bucks plus shipping isn't to bad.

[Joshua]

We had to make sure the loose studs were tight in block for the 1st flat tappet ordeal. The torque was 16-18ftlbs, that is in to the block, double nutted.

Thanks guzzisteve!

[rodekyll]

$20 for one?  I've been giving them away.  I've got a coffee can full if you need more. 

[Joshua]

$20 for one?  I've been giving them away.  I've got a coffee can full if you need more.

I can always cancel the order. It is Sunday. That is very kind of you. My knowledge of appropriate costs is out of wack a little, it seems.

P.M. sent your way.

[Joshua]

Just an update for all, head stud installed new gaskets and o-rings, done a few re-torques, now on to riding a bit. She is dry and tidy!

Thanks to all who helped and offered advice!

Much appreciated!

Joshua

[Lannis]

Just an update for all, head stud installed new gaskets and o-rings, done a few re-torques, now on to riding a bit. She is dry and tidy!

Thanks to all who helped and offered advice!

Much appreciated!

Joshua

And the follow-up is much appreciated too.   The group doesn't always get those.

May the highway unroll in front of your wheel for many happy miles.

Lannis

[Chuck in Indiana]

Just an update for all, head stud installed new gaskets and o-rings, done a few re-torques, now on to riding a bit. She is dry and tidy!

Thanks to all who helped and offered advice!

Much appreciated!

Joshua

Yes, thanks for the update.  Just a thought.. you could use that $20 you saved  as a donation to the board.  I was looking at the donation status for this year, and it's a little low. The Guzzi people on this list with hundreds of years of combined experience? Priceless. 
Don't get me wrong, I'm not singling you out. It just seemed to be a good place to offer a gentle nudge to everyone.

[rodekyll]

He did.

[fotoguzzi]

FWIW, there is a special tool for studs. It will take them out or install. (How do it know?  ) Not very expensive, and much more elegant than double nutting. I'll be back shortly with an example.

for instance, I have this set.
http://www.cornwelltools.com/webcat/products/CBS4MSRIS-%252d-4-Piece-Metric-Stud-R%252d-I-Set.html
If you build one engine, it is worth the money.

how does that tool work?

[Chuck in Indiana]

how does that tool work?

Uses cam action to grab the stud below the threads, both tightening and loosening. No stretched threads from double nutting.

[rodekyll]

I have an extractor that works like a keyless drill chuck.  It opates with a air impact wrench.  With the air in reverse the chuck Jaws tighten behind the threads and keep getting tighter until the impact force turns it out.  I can strip all of the studs from a Guzzi case in about three minutes.

This tool works to extract only. Here's an example v@$15.  Your local AutoZone probably stocks them.


https://m.ebay.com/itm/Broken-Thread-Stud-Extractor-Tool-Damaged-Nut-Threading-Bolt-Head-Socket-Remover/112687633084?hash=item1a3cb4d2bc%3Ag%3AGJUAAOSwZqZaMFlL%3Asc%3AUSPSFirstClass%2198260%21US%21-1&_nkw=stud+extractor&_from=R40&rt=nc&_trksid=p2380057.m4084.l1313.TR8.TRC2.A0.H0.Xstud+extractor.TRS0