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Glenn Crawford
Joined: 06 Dec 2007 Posts: 69 Location: Dorset, SW England
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Posted: Mon Sep 22, 2008 8:56 pm Post subject: Head nut torque with solid copper gasket |
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I've a pre-war car in my workshop (it's a Riley Nine) which has come in to have its head torqued down. Trouble is, it's been fitted with a solid copper, rather than a copper-asbestos, head gasket, and I feel that I need to take this into account when tightening the head. It has twelve 3/8" BSF studs holding the head down.
First part of question: who would like to offer a correct torque figure for this setup? And is that less than, same as, or greater than the torque for the copper-asbestos case?
Second part of question: with engine hot, or cold, and why?
All informed opinion welcome and appreciated!
Glenn Crawford |
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peter scott
Joined: 18 Dec 2007 Posts: 7118 Location: Edinburgh
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Posted: Mon Sep 22, 2008 9:15 pm Post subject: |
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Hi Glenn,
Is the gasket entirely flat or are there corrugated rings around the various aperatures?
Peter _________________ http://www.nostalgiatech.co.uk
1939 SS Jaguar 2 1/2 litre saloon |
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Glenn Crawford
Joined: 06 Dec 2007 Posts: 69 Location: Dorset, SW England
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Posted: Mon Sep 22, 2008 10:20 pm Post subject: |
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I didn't fit the gasket myself, but my understanding is that it's just a plain sheet of copper, and fairly thick - the bit which I can see along the side of the engine looks as if it's around 0.5mm / 0.020". |
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Rick Site Admin
Joined: 27 Apr 2005 Posts: 22446 Location: UK
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Phil - Nottingham
Joined: 01 Jan 2008 Posts: 1252 Location: Nottingham
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Posted: Mon Sep 22, 2008 10:45 pm Post subject: |
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Cast Iron engines with cast iron heads are always torqued down hot.
Those with any alloy head/block or both must be stone cold at least 24 hours.
Cannot help with torque settings though - eveness is more crucial I would say but quite tight using a normal length spanner (92?) hand held and use this to set the torque wrench.
This assumes unstretched and not too oily bolts _________________ Rover P2
Rover P4
Rover P5 & P5B
Land Rover S2 & S3
Morris Mini Traveller Mk2 |
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peter scott
Joined: 18 Dec 2007 Posts: 7118 Location: Edinburgh
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Posted: Mon Sep 22, 2008 11:13 pm Post subject: |
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For what it's worth the Riley RMs (i.e. post war) are as follows:
for the 1.5's torque figure is 540in.-lb [6.21 m.-kg.]
for the 2.5's torque figure is 900in.-lbs. [10.35 m.-kgs.]
The friend who supplied this info will tell me whether they used plain copper
sheet tomorrow.
Peter _________________ http://www.nostalgiatech.co.uk
1939 SS Jaguar 2 1/2 litre saloon
Last edited by peter scott on Tue Sep 23, 2008 11:23 am; edited 1 time in total |
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Uncle Joe Guest
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Posted: Tue Sep 23, 2008 7:35 am Post subject: |
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Sorry to disagree here, but there are quite a few cast iron block/head engines that must be torqued cold. My Chrysler and Ford V8's are two examples... |
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Ray the rocker
Joined: 01 Aug 2008 Posts: 187 Location: south wales
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Posted: Tue Sep 23, 2008 9:59 am Post subject: torque head settings |
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I agree with uj,on most engine rebuilds especially cast head /blocks,torque settings are made at room temperature making sure you sytematically start in the centre and work outwards.
After an initial road test,the head is retightened and tappets adjusted to suit when engine is at running temperature.This applies to O.H.V. engines with side valve considerably easier---as there are no tappets to adjust.
Cheers----Ray the Rocker. |
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peter scott
Joined: 18 Dec 2007 Posts: 7118 Location: Edinburgh
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Posted: Tue Sep 23, 2008 11:20 am Post subject: |
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The post war cars use a thin copper asbestos gasket but in the absence or any other info I would use the same torque setting as the RM 1.5 litre namely 45 lb-ft. The absolute value, assuming you are not stretching or pulling the studs out of the block, is probably less important than having them all tightened evenly.
If you use a jointing compound I can highly recommend Hylomar. Until I discovered Hylomar I had always used Hermetite.
As others have said, re-check after the car has been run.
Peter _________________ http://www.nostalgiatech.co.uk
1939 SS Jaguar 2 1/2 litre saloon |
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Glenn Crawford
Joined: 06 Dec 2007 Posts: 69 Location: Dorset, SW England
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Posted: Tue Sep 23, 2008 12:35 pm Post subject: |
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Thanks one and all. I don't see a definitive answer in there! Someone has told me (regarding the hot/cold question) that because cast-iron expands at a faster rate than the H.T. steel studs, torquing should be done cold - so that the head clamps more tightly as the cast iron warms up. But I haven't been able to check the science behind this idea.
Just to conclude: my investigations this morning have proved that the head gasket is still leaking despite the higher torque (I dare not go more, the studs may rip out from the block - it happens on Riley RMs, which are essentially a pre-war engine developed from the Riley Nine). So it's head off time.
Your comments on jointing compounds are noted, but I hate the idea of using it on a head joint! - Glenn |
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peter scott
Joined: 18 Dec 2007 Posts: 7118 Location: Edinburgh
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Posted: Tue Sep 23, 2008 12:43 pm Post subject: |
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Hi Glenn,
You won't regret using Hylomar and it will certainly solve any water or oil leakage issues. It is much more effective at high pressures than other compounds I've tried. I have no connection with the company. I just love their product. I have have used it on three different cylinder heads now without any problems.
Peter
p.s. All three of the above were with a single thin copper sheet gasket although admittedly of the Corrujoint variety. _________________ http://www.nostalgiatech.co.uk
1939 SS Jaguar 2 1/2 litre saloon |
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PAUL BEAUMONT
Joined: 27 Nov 2007 Posts: 1281 Location: Barnsley S. Yorks
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Posted: Tue Sep 23, 2008 1:26 pm Post subject: |
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I have to agree with Peter about Hylomar - with one exception. It does not like modern petrol, so do not use it on fuel systems. It generates little blue balls that are sure to block something!
I do tend to agree with Glenn though on the head gasket. I would prefer it without sealant ( a little grease maybe) I suggest that if it is not sealing under reasonable torque then a skim is needed.
Someone once told me that if you use a solid copper gasket it needs to be annealed first to make it soft as copper work hardens when you butcher it like making a gasket from sheet. Thoughts anyone?
PAUL |
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Uncle Joe Guest
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Posted: Tue Sep 23, 2008 4:29 pm Post subject: |
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Yes, copper gaskets should be annealed before being reused.
I've always found Hylomar to be good with aluminium, but I do know that it shouldnt be used with some modern fuels/lubricants. The one that I have used for a while now though is Permatex 300. Copes with anything that it comes into contact with.... |
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pigtin
Joined: 23 Nov 2007 Posts: 1879 Location: Herne Bay
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Posted: Tue Sep 23, 2008 5:45 pm Post subject: |
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I seem to recall having to anneal copper head gaskets and I can confirm that Hylomar is brilliant. _________________ Due to the onset of my mid eighties I'm no longer sprightly and rarely seen in my Austin special. I have written a book though. https://amzn.eu/d/7rwRRqL |
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wrinx
Joined: 22 Jun 2008 Posts: 142 Location: Derbyshire
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Posted: Tue Sep 23, 2008 11:36 pm Post subject: |
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Is Hylomar just for use with copper head gaskets, as opposed to other materials?
Not sure if anyone recalls my thread about HG problems...but I think it may reoccurring!
wrinx _________________ www.alfaromeo155.co.uk | www.alfamatta.co.uk
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