Technical Debris in reconditioned head?
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Technical Debris in reconditioned head?
Not just that which with expansion and contraction in use when dislodged will cause other problems, I am also looking at the longitudal machine marks, which some head gaskets will have a problem sealing if they are as deep as they look.
I suspect it was sand/grit blasted to disguise the poor machining.
It is strange markings as most cylinder heads are done using a milling machine, so how they got long machine marks in it I don't know, perhaps others on Forum can advise.
Not just that which with expansion and contraction in use when dislodged will cause other problems, I am also looking at the longitudal machine marks, which some head gaskets will have a problem sealing if they are as deep as they look.
I suspect it was sand/grit blasted to disguise the poor machining.
It is strange markings as most cylinder heads are done using a milling machine, so how they got long machine marks in it I don't know, perhaps others on Forum can advise.
This it what it looks like. Looks like circulair machining, right? Probably been sanded afterwards maybe?
They say they can't push those 4 inserts ( don't know the English term for it) out without destroying them, and they don't know if they can find new ones...
Really hesitant to use them as is, although they say it's fine...
Ah! I see that they are milling marks afer all, the close up in the other photo appeared straight across.
Still the marks are pretty deep, as I understand it when dealing with indirect injection chambers nthat are cast iron? in an alluminium cylinder head, the best option was a slow fine cut, where as I suspect they just blasted through quickly.
Then sand blasted to cover up poor machining, I would never ask them to sand blast, most machinest's would dip it in their cleaning tank to remove any loose swarf so no need to put grit in there.
If it wasn't for the grit, I would suggest a large sheet of plate glass with fine grinding paste and thin oil then work it back and forth to loose the machining marks.
I had a customers Triumph TR7 cylinder head that came back poorly machined and when I filled with coolant water ran out of the grooves, the machine shop tried to say it was a poor head gasket or that my torque wrench was faulty, I quickly proved him wrong on both counts!!!
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It looks like a very poor job. Ive never seen one look anything like that. As to the swarf tht reinforces teh view its a poor job unfortunately. I wouldnt put tht back without its being rectified, even if it means paying someone else to clean and reface the head. Its just not worth the risk of another major failure.
