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Cylinder head gasket


Martin White

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Seems the problem is a bit more serious the cylinder nearer the rear of the car is pitted/corroded. And this is where the gasket blew. I suspect previous owner has left it with coolant from a previous gasket blow before putting new gasket on and selling to me :-). 
my question is where do I go from here rebore/ new liners/ new engine???

Any advice welcome and does anyone know a good engine specialist in the midlands? 
Despite the bad news I am actually quite enjoying getting my hands dirty although I think getting my hand in my wallet might not be quite so enjoyable, hopefully not too bad??

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so its had a life of burning coolant      so  would the pitting clean up ????    its not at its best but providing you dont get pinking or very lean burning the crown will last quite well 

i take it youre just driving not racing ???  

do you want utopia or just fun driving no point going  deep pocket syndrome if you only go for a picnic

Pete

 

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16 hours ago, Martin White said:

Please see attached. Was speaking to an engine specialist who told me to gently wire brush away and he sees all the time. 

I wouldn't wire brush, try plastic scouring pads, metal pot scouring pads (not Brillo pads!) or very very fine tooth-brush-sized brass wire brushes - you don't want to make scratches so use plenty of lubrication until you're sure that it's only surface marking and not actual pitting or damage. What's the lip like on that lower cylinder? 

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remove  the studs and use very oily fine wet and dry on a hard block clean it till all the black residue has disappeared 

you cant damage the head face , , add oil to the bores and paper towel to collect any debris 

wind engine over a few times cleaning the bores as you turn 

Pete

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Martin,

to what do you refer?   In your picture, there's mottling on the bore wall, or the marks on the block face?   Either way, IMHO, unless you can feel the marks with your fingertip, you can ignore them.   The 'fingertip test' will detect less than half a thou on an otherwise smooth surface, and that is no problem.

 

Pete,   Would you like to revise your last post?    Yes, use fine W&D in oil to polish a face, if you need to, but the residues will contain carborudum (silicon carbide) dust.    Carborundum has a Mohs Scale hardness of 9, it's the example material for that hardness, only diamond is harder!     After using such a scouring material, the block should be washed, first with a degreaser, then with lots of hot soapy (detergenty) water.  Lots and lots and lots!     Rebuilding a engine requires almost surgical cleanliness!   

Otherwise some carborundum will be left in the engine.  1200 grade W&D paper has grit particles about 3micrometers wide, when the smallest that an oil filter can remove is ten times bigger.      The grit will continue to circulate, accelerating wear.

John

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I think it is more than surface pitting. Have been chatting to a mechanic today and he asked me if the car had power before the gasket blow which it did. Seemed to run fine. Will dress the surface of the cylinder as suggested and put back together. Will compression test all four cylinders and see what I have got. Can I do this without put everything back together??? Does the engine have to be running? Never used a compression tester before. If still no good then will have to bite the bullet and get the engine out I guess. Thoughts ladies and gents?

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Can you feel the mottling, Martin?  If not leave it severely alone, unless you plan to fit new piston rngs, in which case hone the walls, with the right tool.  And then as above WASH out the bores to remove carborundum dust.

If you can feel the "mottling" then you have no hope of piston rings that seal, unless a hone will remove the mottling, and the uneven 'feel' to the bore wall.  If not then a rebore is required.

Sorry, but you asked and messing about with Wet & Dry will not cure the problem.      Which was a blown head gasket, which this mottling has nothing to do with, except possibly as a result of the failure.

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mottling is not a problem 

John yes aware of the particles , just most have to use what ever they have 

ive never worn an engine out whatever agent ive used to scour scrape or abrade over the years 

bearing in mind the amount of casting junk left in our engines a bit of W & D is better than reassemble something covered in previous  grott 

Pete

 

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14 minutes ago, Martin White said:

Sorry guys getting out of sync with replies. Mottling on the bore wall

Hi Martin, you can do a compression  test by simply bolting the head back on with the head gasket.. Nothing else is needed, it does not need to run it just needs to turn over on the starter.  

Tony.

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Thanks for all your advice. Have just used a plastic scourer and amazingly now smooth as silk 👍👍👍

Shocked at how quickly corrosion appeared. Seemed really quite bad
 

Looks like a lucky escape!! One relieved Spitfire owner! Fingers crossed no more blown gaskets

thanks again guys you have all really helped

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Can't be definitive, as I'm into six cylinders, but their manifolds have similar access problems.   I can only reach one of the nuts with an open ended, and a conventional length spanner cannot be swung enough to engage the next flat.

Although you can buy sets of "Stubby" spanners, my solution was to take a cheap spanner, shorten it  by cutting off the least useful end (probably the ring) so that you have a better swing on it, and grind the open end thinner, if that is needed.

Here's mine.     I put a length of old central heating copper tube around it and wired it on, protecting the wires from my fingers with electric tape, so that it was more comfortable to apply maximum torque by hand.   Obviously, I can't get a torque wrench to this nut.   I can't rember why there's a tommy bar in the pic!

John

 

Cut down spanner.png

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Dan Ten is normally in a  ....Mess

mask on  mask off ,    

just as well you didnt make duxford your rig would have been on permanent  siberian  choke 

one good thing about the forum is most help is based on varied experience  from the many ,  not myths from the few  

keep smiling 

pete

 

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yes theres debris or old fire ring in the 1 oclock  to 2.30 zone 

need to find out just what it is   metal or carbon debris 

certainly needs cleaning out or the new fire ring wont seat correctly , 

and if its been there from a previous failure it explains why this one had gone 

Pete

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