Head Gasket Replacement (Spitfire 1500)

[cliff.b]

Ok, cylinder head reinstalled with mini style flanged nuts. I discovered these need a 14mm socket and not 9/16 🙄

 

After I have refitted everything else and got it running, should I warm it up on the drive then re-torque or should I drive it around for a few miles before doing so? Or should I do both?

[chrishawley]

1 hour ago, cliff.b said:

After I have refitted everything else and got it running, should I warm it up on the drive then re-torque or should I drive it around for a few miles before doing so? Or should I do both?

Just happened ot be reading a 1959 edition of Practical Motorist in the bath (I really need to get up to date with my periodicals). Anyhow, standard recommendation was to torque head on assembly and then hot at 500 miles.

[cliff.b]

4 minutes ago, chrishawley said:

Just happened ot be reading a 1959 edition of Practical Motorist in the bath (I really need to get up to date with my periodicals). Anyhow, standard recommendation was to torque head on assembly and then hot at 500 miles.

Thanks for that. Sounds sensible.

[cliff.b]

Hmm, I have a nasty feeling I must have screwed things up in some way. Everything back together but decided to do a compression test before trying to start up and not only are the figures low, the pressure fades away slowly after I stop cranking. Just wondering if there is any possibility that this is because I am doing it when cold, but suspect I am grasping at straws 😒 Every cylinder is about the same.

Edited May 26, 2023 by cliff.b

[dannyb]

It should be done cold. The gauge should hold whatever reading the compression registers. Is the gauge faulty/Leaking.

Danny 

[cliff.b]

2 hours ago, dannyb said:

It should be done cold. The gauge should hold whatever reading the compression registers. Is the gauge faulty/Leaking.

Danny 

Yes, I have sat down and had a think and realise the gauge should hold whatever pressure is achieved, so my fears of compression leakage are probably a fault with the gauge. 

Regarding the lower reading, I first thought that if the gauge has developed a fault then that might explain the lower reading. Last time I did a test it was done warm and all 4 cylinders gave a reading of almost exactly 150. Now, after fitting the new gasket and tested cold they gave readings between about 135 and 145. 

My main concern though was the pressure falling away which I now presume I can ignore?

[cliff.b]

Thinking I probably wiped any oil that was on the bores off when I was cleaning stuff. Squirted  little through each plughole and now getting in the region of 175psi. Decided to try starting it although exhaust not connected yet.

 

 

[Pete Lewis]

if the gauge looses its best reading its the non return valve of the gauge thats leaking,  they are often just a tyre valve in the gauge head 

they are not that special  

Pete

[cliff.b]

9 minutes ago, Pete Lewis said:

if the gauge looses its best reading its the non return valve of the gauge thats leaking,  they are often just a tyre valve in the gauge head 

they are not that special  

Pete

It is only a cheap one. Will have a look at it some time and see if anything can be done. 

But need to get my exhaust fitted first and then might be able to make a car meet on Sunday morning 👍

[cliff.b]

Exhaust re-connected and run up to temperature ok. Then out for a gentle test drive. About 5 miles and no problems so far 🤞

[cliff.b]

About 40 mike's now & all seems well.

Here is a pic of the old gasket. One water gallery hole is misshapen towards the fire ring on the affected cylinder so presume that's where it failed.

 

Is the blackening around the fire rings usual or does that indicate some leakage?

[Pete Lewis]

it indicates the head was "loose"   lack of clamping lets compressions   escape all over the place past the fire rings  which should be clean and shiny 

all down to soft washers  

Pete

[cliff.b]

12 minutes ago, Pete Lewis said:

it indicates the head was "loose"   lack of clamping lets compressions   escape all over the place past the fire rings  which should be clean and shiny 

all down to soft washers  

Pete

Thanks Pete. I was wondering if that was the case but no experience to fall back on. Hopefully the new flanged nuts will stop it happening again 🤞

[Anglefire]

1 hour ago, cliff.b said:

Thanks Pete. I was wondering if that was the case but no experience to fall back on. Hopefully the new flanged nuts will stop it happening again 🤞

I used the flanged nuts when I rebuilt my engine - like them a lot - designed for the Metro MG Turbo I believe - or at least they used them! Got mine from Minispares from memory Classic Mini CAM4545 - Mini Spares Onlne Shop - I appreciate the link is of no use to you Cliff, but someone may be hunting for some later!

[cliff.b]

4 minutes ago, Anglefire said:

I used the flanged nuts when I rebuilt my engine - like them a lot - designed for the Metro MG Turbo I believe - or at least they used them! Got mine from Minispares from memory Classic Mini CAM4545 - Mini Spares Onlne Shop - I appreciate the link is of no use to you Cliff, but someone may be hunting for some later!

Yes, likewise. And also, for the benefit of anyone else fitting them, the heads are 14mm AF, not 9/16".

Don't ask me how I found that out lol.

[cliff.b]

As I have just said on another thread, I will shortly be doing my re-torque and as advised, was planning on doing this with the engine warm. But this seems to be yet another of those things where there is a difference in opinion.

 

So just wondered if anyone has anything definitive that clarifies this or if not, any compelling reasoning one way or the other?

 

I presume if warm the studs would expand, thereby lowering the clamping pressure, but wouldn't the specified torque take account of this? 

[johny]

With the mk1 six cylinder you have to take the manifolds off to get to some of the head bolts so surely it cant be done very hot!

[cliff.b]

10 minutes ago, johny said:

With the mk1 six cylinder you have to take the manifolds off to get to some of the head bolts so surely it cant be done very hot!

I will take that as a vote for cold then 🥶

[johny]

I should have done it like that but never got round to a retorque and now over 25 years later seems a bit pointless.... 

[cliff.b]

1 hour ago, johny said:

I should have done it like that but never got round to a retorque and now over 25 years later seems a bit pointless.... 

I did wonder if the engines got re-torqued after they were assembled in the factory.  

[Pete Lewis]

On 06/07/2023 at 07:48, cliff.b said:

I did wonder if the engines got re-torqued after they were assembled in the factory.

its not a operation ive seen mentioned in any triumph manual or service schedule   but it might be hiding somewhere in  a !st sevcice  in general its pretty pointless

Pete

 

[PeteH]

On 24/05/2023 at 16:29, AlanT said:

I use a wood chisel.

The rumbling I just heard. was probably Father, Capenter and Shipwright, spinning in his grave at the abuse of woodworking tools.😂😁🤞. The sort of behaviour I would have got a thick ear for as a youngster☹️.

Pete