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Combustion chamber repair?

3011 Views 22 Replies 10 Participants Last post by  1978alfa
I have a 1600 head I am starting to rebuild which appear good in all aspects bar a small dint in one of the chambers about 10mm up from the deck face. Impression in the surface is around 1mm in all dimensions.
It looks like someone dropped a sharp corner on the head when in storage.
Any view how to treat this... Do I need to get it welded up and the grind back or smooth the edges and ignore if chamber capacities are in balance.
Concerned about any welding breaking away or causing further damage.
I've no experience how robust the heads are!


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Please post an image. My, guess, do nothing.
Hmm, not the greatest detail but, from what I see, I would carefully remove the bits that are standing proud of the surface and then go ahead with the usual pre-rebuild checks including pressure testing, etc.
Dress the sharp edge away as it can promote detonation due to a hot spot. Thats it then try it out. Dont weld.
Head is full height and not looking to skim but raise the CR with new pistons.
Will dress as best I can before pressure/crack testing.
Welding not just inadvisable but a known no-no?
There is an ABB member in the US who has repaired many damaged aluminum heads but the cost is only justified if they are rare or have already had expensive modifications.
Send it to Jim Steck, BB member. 1600 heads are worthy of repair.
Unfortunately the wrong side of the atlantic to take advantage of his skillset. May see if a local specialist welder has any insight.
Good machine shops weld and reshape these all the time, if needed. That said, you don't want to do it if it isn't needed. Norman Racing in Berkeley, and I'm sure others, will repair valve, piston, foreign object damage, corrosion, cracks. The weld doesn't break off.
A friend in Coventry just had his ice-cracked Giulietta block welded up, great job and didn't leak. I can ask who he used, being on your side o' the pond.
I believe that a head that has been welded must be straightened post repair. No idea how difficult that is.
England has many amazing engineering shops that specialise in vintage cars. If you decide to fix it, they will be able to do it.

But, I think you are turning a mole hill into Everest. Clean up the high spots as andylarry said, CC the combustion chambers and move on
Would tend to agree Pete.
Sadly I have one of those personalities which knowing its there will fixate on it a a flaw!
May just enquire about cost a such a small job and bundle as part of the rest of the head work.
This thread may make you more comfortable about just cleaning it up
Indeed... Puts my 'issue' in perspective.

Depending on the state of material ageing and hardness welding make things go soft. If this is adjacent to the fire ring then it can sink into the head. The infamous k series head suffered because 105c plus was enough to soften these heads and blocks come to that which were hardened. Result liner sinkage and fire ring sinkage . I doubt the 105 engine was that sophisticated, well it wasnt.

If you really want to do more then once its deburred peen the material with a cut off nail which will put the material into compression and prevent crack propagation then leave it alone.
The good thing about a thinned wall to the jacket is the thermal stress in the material goes down not up so provided it can still take the pressure stress its better to be thin. There you go your justification for leaving it alone.

Any ex aircraft engineers on here like me will be familiar with the concept.
If you still insist on going further then I have heard good things about the head shop in warrington
Here is an example of Jim Steck's work on a Lotus cylinder head. Pic 3 should be first !
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Ouch! I hate when that happens!
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