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Head leak after rebuild

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Rozabikes Tim:

--- Quote from: McCabe-Thiele (Ted) on December 13, 2024, 08:53:02 PM ---The firm I used to skim my 500 cylinder head had a fancy newish  machine that could take off really small amounts.IIRC it ended up being just under 5 thou of an inch to remove all the marks near the main sealing rings. The surface was like a mirror, it wasn't daft money either about £40.

--- End quote ---

Who did you use Ted?

Murf:
I would agree Clamp marks and a lot of them, someone really didn’t want it to move did they! It’s another good candidate for the POs hall of horrors.  We really should start one.

K2-K6:

--- Quote from: McCabe-Thiele (Ted) on December 13, 2024, 08:53:02 PM ---The firm I used to skim my 500 cylinder head had a fancy newish  machine that could take off really small amounts.IIRC it ended up being just under 5 thou of an inch to remove all the marks near the main sealing rings. The surface was like a mirror, it wasn't daft money either about £40.

--- End quote ---

Getting the head set and clamped such that the surface is planar to the cutting blades is important.  Shows good method from them in that aspect. Any significant difference from original face would need a deeper cut to correct clamping and machine alignment error.

Ordinarily, first cut is as thin as possible, to then judge how low the low dips are in a competently assessing them. Then to consider just how much needs to come off in cleaning up the errors seen on this example in those dips.

McCabe-Thiele (Ted):

--- Quote from: Rozabikes Tim on December 14, 2024, 08:13:04 AM ---
--- Quote from: McCabe-Thiele (Ted) on December 13, 2024, 08:53:02 PM ---The firm I used to skim my 500 cylinder head had a fancy newish  machine that could take off really small amounts.IIRC it ended up being just under 5 thou of an inch to remove all the marks near the main sealing rings. The surface was like a mirror, it wasn't daft money either about £40.

--- End quote ---

Who did you use Ted?

--- End quote ---

Service Garage Ltd, they did all the specialist machining jobs for Mercedes Derby. I know my way there, it's sort of between villages probably Draycott.

Update they are on the outskirts of Borrowash

Rozabikes Tim:
Logged!

I've used SEP at Kegworth years ago. Had bearing surfaces on a crank metal sprayed and ground down. Think that was the Superdream 400 too!

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