Burt wrote:
> "jim beam" <nospam@example.net> wrote
>
>
>>original surface on these things is near mirror. that way, there's no
>>small grooves for gas to leak along. if the head was machined on a
>>traditional milling machine, particularly this alloy head, it's /very/
>>hard to do without leaving scoring marks in it. last time i had to lap
>>a head was to cut out the grooves from a bad machining job where the
>>cutting die was picking up excess material on each pass of an exterior
>>edge, then dragging that chunk across the rest of the head leaving gouge
>>marks.
>
>
> Try using a single-blade cutter, instead of the two-bladed cutter. This
> is slower but yields a cleaner cut.
>
> If they're caused by deposits, try removing the hard calcium deposits around
> the water jacket openings. The deposits can be picked up by the tooling
> and drug across the surface leaving a groove.

it shouldn't be machined at all [or at least, not with "traditional"
gear] for the reasons stated. it just needs to be lapped on a properly
flat rigid bed.

 

Radiators are relatively soft. I once saw the neck of the radiator had
become "out-of-round", causing several new radiator caps to blow air bubbles
into the puke can because an effective seal was not formed. A new radiator
fixed the problem. You might check for gunk build-up in the neck which
could cause an incomplete seal.

Later, Ralph

 

Radiators are relatively soft. I once saw the neck of the radiator had
become "out-of-round", causing several new radiator caps to blow air bubbles
into the puke can because an effective seal was not formed. A new radiator
fixed the problem. You might check for gunk build-up in the neck which
could cause an incomplete seal.

Later, Ralph

 

Radiators are relatively soft. I once saw the neck of the radiator had
become "out-of-round", causing several new radiator caps to blow air bubbles
into the puke can because an effective seal was not formed. A new radiator
fixed the problem. You might check for gunk build-up in the neck which
could cause an incomplete seal.

Later, Ralph