classic car forum header
Classic cars forum & vehicle restoration.
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 
How To Register     Posting Photographs     Privacy Policy     F/book facebook.com/oldclassiccar

Cylinder head gasket re annealing?
Goto page 1, 2  Next
Post new topic   Reply to topic    Classic cars forum & vehicle restoration. Forum Index -> Mechanical Restoration
Author Message
Reg Shaw



Joined: 28 Jan 2013
Posts: 37
Location: North Staffs

PostPosted: Sun Feb 10, 2013 9:14 am    Post subject: Cylinder head gasket re annealing? Reply with quote

When refitting the head to an Austin Eight's sidevalve engine, is it good practice to anneal the thick copper gasket before reassembly? The gasket is in good nick and has been off the car a week if that makes any difference.

Cheers in advance,

Ian.
Back to top
View user's profile Send private message
peter scott



Joined: 18 Dec 2007
Posts: 6543
Location: Edinburgh

PostPosted: Sun Feb 10, 2013 10:45 am    Post subject: Reply with quote

Hi Ian,

I've not tried it but for a thick copper gasket it certainly sounds like a good idea.

Peter
_________________
http://www.nostalgiatech.co.uk
1939 SS Jaguar 2 litre saloon
Back to top
View user's profile Send private message Visit poster's website
Kelsham



Joined: 18 Jan 2009
Posts: 349
Location: Llandrindod Wells Powys

PostPosted: Sun Feb 10, 2013 3:02 pm    Post subject: Reply with quote

It might be difficult to carry out as it is such a large item. It will need a good source of heat.
If it is copper asbestos I would not try. A solid copper gasket would benefit though.

Regards Kels.
Back to top
View user's profile Send private message
Reg Shaw



Joined: 28 Jan 2013
Posts: 37
Location: North Staffs

PostPosted: Sun Feb 10, 2013 8:32 pm    Post subject: Reply with quote

Cheers folks, when I got to re assembly today I noticed it was a sandwich job so didn't anneal. Bolted it all back up and all is well.

Thanks again, Ian.
Back to top
View user's profile Send private message
Jim.Walker



Joined: 27 Dec 2008
Posts: 1229
Location: Chesterfield

PostPosted: Sun Feb 10, 2013 9:33 pm    Post subject: Reply with quote

SOLID COPPER gaskets should ALWAYS be annealed if re-using by heating to cherry red and plunging immediately into cold water. A lot of heat is needed. Copper sealing washers should also be annealed if re-used AND any solid copper gasket or sealing washer if a long time on the shelf even if pristine. Copper does age-harden.
Jim.
_________________
Quote from my late Dad:- You only need a woman and a car and you have all the problems you
are ever likely to want". Computers had not been invented then!
Back to top
View user's profile Send private message
Kelsham



Joined: 18 Jan 2009
Posts: 349
Location: Llandrindod Wells Powys

PostPosted: Mon Feb 11, 2013 10:16 am    Post subject: Reply with quote

Jim, is it necesarry to plunge into cold water? I have always let washers and pipes cool naturally.

Rgards Kels.
Back to top
View user's profile Send private message
Roger-hatchy



Joined: 07 Dec 2007
Posts: 2137
Location: Tiptree, Essex

PostPosted: Mon Feb 11, 2013 10:30 am    Post subject: Reply with quote

Non ferrous metals can be done both ways

Air cooled or plunged

Aluminium needs a plunge

I have always air cooled
don't know if there is any benefit of one over the other.

Someone on here will know.

Roger
Back to top
View user's profile Send private message AIM Address
Jim.Walker



Joined: 27 Dec 2008
Posts: 1229
Location: Chesterfield

PostPosted: Mon Feb 11, 2013 10:37 am    Post subject: Reply with quote

Kelsham wrote:
Jim, is it necesarry to plunge into cold water? I have always let washers and pipes cool naturally.

Rgards Kels.


Got me there Kels!
As an apprentice I was taught to plunge Copper and cool ferrous metal as slowly as possible, covering with warm ash if possible. But I think treating ferrous metals that way is normalising rather than annealing.
It has never occured to me to try cooling copper slowly, At the same time I think it not a good idea to leave anything hot lying around un-necessarily?
Jim.
_________________
Quote from my late Dad:- You only need a woman and a car and you have all the problems you
are ever likely to want". Computers had not been invented then!
Back to top
View user's profile Send private message
Keith D



Joined: 16 Oct 2008
Posts: 1016
Location: Upper Swan, Western Australia

PostPosted: Mon Feb 11, 2013 12:51 pm    Post subject: Reply with quote

We always painted the used head gasket both sides with a thick coat of "Silver Frost" aluminium paint before reuse. Always seems to work fine.

Keith D
Back to top
View user's profile Send private message
Glenn Crawford



Joined: 06 Dec 2007
Posts: 73
Location: Dorset, SW England

PostPosted: Mon Aug 10, 2020 2:29 pm    Post subject: Cylinder head gasket re annealing? Reply with quote

I know this is re-opening an old discussion from 7 years ago but I have a reason. Being fed up with blowing modern head gaskets on a 1 litre Riley RM - with recently machined head and block faces - I commissioned a solid copper gasket. It has done perhaps 30 miles. Now guess what? Another leaking gasket, in a different place and with different symptoms (water in a spark plug - gas in the radiator) but blowing nonetheless.

I want to sort this out - driving a 70 year old car is not supposed to be an experiment. I am confident that the new gasket has all the right shapes and dimensions, and that there's no underlying problem with the engine, but I can't tell whether or not it is properly annealed. (The maker claims it was).

So, does anyone have a rule of thumb for testing whether a head gasket is adequately annealed?
Back to top
View user's profile Send private message
Miken



Joined: 24 Dec 2012
Posts: 379

PostPosted: Mon Aug 10, 2020 6:51 pm    Post subject: Re: Cylinder head gasket re annealing? Reply with quote

Glenn Crawford wrote:


So, does anyone have a rule of thumb for testing whether a head gasket is adequately annealed?


As long as copper is heated all over to dull red it will be annealed.
It makes no difference to the hardness if you quench it or not.
Although the thermal shock from quenching will remove a lot of the black scale which forms and makes it more pleasant to handle afterwards.
I find the black stuff gets in the pores of your hands and is hard to clean off afterwards. Also less work to clean the gasket ( try using a scotchbrite type scourer).
Back to top
View user's profile Send private message
petelang



Joined: 21 May 2009
Posts: 310
Location: Nottingham

PostPosted: Mon Aug 10, 2020 8:43 pm    Post subject: Reply with quote

Glen, have you had the head separately pressure tested? Maybe there's a small crack somewhere letting the coolant in?
I also had repetitive problems with gasket failures ultimately with cracks appeared in the block face where the studs on the thinnest part had burst it open. A costly job, complete strip and block stitching needed but then they took rather a little too much off to plane the block flat so the pistons protruded slightly and I had to have a shimm laser cut to make up the loss.
I coated both sides of the shim with copper paint from the states and then both the head and block face with "Indian Head" shellac also from USA as many forums reckon this stuff is mustard for such problems.
I've had no problems since.
One other problem I had before was core plugs on the top of the head weeping and after cleaning all the block face threads and studs I had coolant creeping up the threads and stud holes and weeping into the engine. This was a very tiny leak, only occurred after engine turned off hot and was just a trickle but removing studs one at a time and refitting with stud lock stopped it.
All these problems meant I had to change the oil about six times in one year! Ruined by emulsion in oil. I'm really glad that saga is over.
Peter
Back to top
View user's profile Send private message Send e-mail Visit poster's website
Glenn Crawford



Joined: 06 Dec 2007
Posts: 73
Location: Dorset, SW England

PostPosted: Tue Aug 11, 2020 8:31 am    Post subject: Reply with quote

Thanks both for the reply (and for frightening me by reminding me of the myriad things that can go wrong).

This engine has been completely reliable apart from eating head gaskets and there have been good reasons for each event: one faulty gasket, one faulty set of head studs with not enough thread, one holed inlet manifold causing pre-ignition. It could be a crack, but I am thinking not, as the car has covered virtually no mileage since the holed-inlet-manifold incident and the new leak is in a completely different place. I will know more when I pull the head off, later today. Perhaps the problem is something else entirely.

Since posting, I have spoken to the gasket manufacturer (Dobsons) who assures me that I don't need to re-anneal his gasket which is annealed at their works before despatch, so I won't; but I have the information now, for future use.
Back to top
View user's profile Send private message
peter scott



Joined: 18 Dec 2007
Posts: 6543
Location: Edinburgh

PostPosted: Tue Aug 11, 2020 9:08 am    Post subject: Reply with quote

Hi Glenn, Do you have any stud inserts?

Peter


_________________
http://www.nostalgiatech.co.uk
1939 SS Jaguar 2 litre saloon
Back to top
View user's profile Send private message Visit poster's website
Glenn Crawford



Joined: 06 Dec 2007
Posts: 73
Location: Dorset, SW England

PostPosted: Thu Aug 13, 2020 4:08 pm    Post subject: Reply with quote

No, thank the Lord; though almost all of the 12 studs have had thread inserts (helicoil type) fitted. All the studs were secure.

On removing the leaking gasket it was undamaged, and once I had cleaned it off it looked as if it had never been used. In fact, too much so, because there were no raised areas showing where the waterways etc go. It was as if I had not tightened the head nuts enough, but in truth I had over-torqued them by around 10% compared with recommended value. There are twelve 3/8" studs with 3" of unthreaded shank, normally torqued to 45 lb.ft (60 N.m).

So I had a further conversation with the makers and asked their main man what he would expect. He said that "unused" appearance was wrong, and asked me whether I had greased the cylinder head studs before fitting the nuts - which I hadn't, because I understood that this was not recommended practice. The feller says it makes a huge difference, adding 50% to the clamping force, which I am happy to believe, but what do other forum users think about this practice? I thought that cylinder head nuts are fitted and torqued-down dry.
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    Classic cars forum & vehicle restoration. Forum Index -> Mechanical Restoration All times are GMT + 1 Hour
Goto page 1, 2  Next
Page 1 of 2

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
Forum T&C


php BB powered © php BB Grp.