"jim beam" <spamvortex@bad.example.net> wrote in message
news:Z4mdnYYlAsIxAYnYnZ2dnUVZ_oKdnZ2d@speakeasy.ne t...
> Hendersauce wrote:
>> Hey Mike, Thanks for the response. Turns out pops knows a bit more
>> about head gaskets than I thought. He has all the tools, and we have a
>> mechanic who's gonna come over and remove the head, and take it to an
>> auto shop to get it milled.
>
> do NOT get the head milled unless it is warped. i've seen many an alloy
> head screwed up this way. and they get slapped back on the block
> regardless so the owner has to go back again in 6 months and gets soaked
> for a new motor.
>

I defer to the group experience on this. I've had the luxury of stumbling
across a first-rate cylinder head shop (Arizona Cylinder Head for those in
the Phoenix area) and never had to worry about unnecessary work or bad work.
I agree, if a shop falls short in either of those areas it could make a
slightly bad situation much worse. A slightly gouged mating surface is the
path to perdition.

Mike

 

"jim beam" <spamvortex@bad.example.net> wrote in message news:Z4mdnYYlAsIxAYnYnZ2dnUVZ_oKdnZ2d@speakeasy.ne t...

> do NOT get the head milled unless it is warped. i've seen many an alloy
> head screwed up this way. and they get slapped back on the block
> regardless so the owner has to go back again in 6 months and gets soaked
> for a new motor.
>
> 1. remove head.
> 2. do a rough check for flatness.
> 3. if ok, clean it up /carefully/.
> 4. check for flatness again.
> 5. finish cleaning.
> 6. re-use.
>
> google this group for recent talk-through of this procedure on an accord.
> oh, and the reason milling is such a gamble is because if the cutting
> piece picks up a piece of crud, it drags it all the way across the head
> gouging a deeper and deeper furrow in the surface as it goes.

People have been resurfacing head or aluminum alloys for years
and only the inexperience would drag the crud all the way across the head.

> in old cast iron heads, this doesn't happen, so in the old days, it was ok to
> do this as a routine service procedure. old habits die hard, and in
> this case, can be very destructive. the head needs to be finished to
> near mirror finish to give a long term seal. if you really /must/ skim
> the head, make sure you inspect the work of the shop on other heads
> before you let them touch yours. if they produce near mirror, go ahead
> and use them. if they produce stuff with milling marks and ridges on
> it, move right along. and don't believe any story about the head
> needing milling marks to "grip" the gasket - that's bunk.

A near mirror finishes are too expensive for the average car owner
could afford. Unless the car manufacturer requires a near mirror
finish, don't bother with it.

 

"jim beam" <spamvortex@bad.example.net> wrote in message news:Z4mdnYYlAsIxAYnYnZ2dnUVZ_oKdnZ2d@speakeasy.ne t...

> do NOT get the head milled unless it is warped. i've seen many an alloy
> head screwed up this way. and they get slapped back on the block
> regardless so the owner has to go back again in 6 months and gets soaked
> for a new motor.
>
> 1. remove head.
> 2. do a rough check for flatness.
> 3. if ok, clean it up /carefully/.
> 4. check for flatness again.
> 5. finish cleaning.
> 6. re-use.
>
> google this group for recent talk-through of this procedure on an accord.
> oh, and the reason milling is such a gamble is because if the cutting
> piece picks up a piece of crud, it drags it all the way across the head
> gouging a deeper and deeper furrow in the surface as it goes.

People have been resurfacing head or aluminum alloys for years
and only the inexperience would drag the crud all the way across the head.

> in old cast iron heads, this doesn't happen, so in the old days, it was ok to
> do this as a routine service procedure. old habits die hard, and in
> this case, can be very destructive. the head needs to be finished to
> near mirror finish to give a long term seal. if you really /must/ skim
> the head, make sure you inspect the work of the shop on other heads
> before you let them touch yours. if they produce near mirror, go ahead
> and use them. if they produce stuff with milling marks and ridges on
> it, move right along. and don't believe any story about the head
> needing milling marks to "grip" the gasket - that's bunk.

A near mirror finishes are too expensive for the average car owner
could afford. Unless the car manufacturer requires a near mirror
finish, don't bother with it.

 

"jim beam" <spamvortex@bad.example.net> wrote in message news:Z4mdnYYlAsIxAYnYnZ2dnUVZ_oKdnZ2d@speakeasy.ne t...

> do NOT get the head milled unless it is warped. i've seen many an alloy
> head screwed up this way. and they get slapped back on the block
> regardless so the owner has to go back again in 6 months and gets soaked
> for a new motor.
>
> 1. remove head.
> 2. do a rough check for flatness.
> 3. if ok, clean it up /carefully/.
> 4. check for flatness again.
> 5. finish cleaning.
> 6. re-use.
>
> google this group for recent talk-through of this procedure on an accord.
> oh, and the reason milling is such a gamble is because if the cutting
> piece picks up a piece of crud, it drags it all the way across the head
> gouging a deeper and deeper furrow in the surface as it goes.

People have been resurfacing head or aluminum alloys for years
and only the inexperience would drag the crud all the way across the head.

> in old cast iron heads, this doesn't happen, so in the old days, it was ok to
> do this as a routine service procedure. old habits die hard, and in
> this case, can be very destructive. the head needs to be finished to
> near mirror finish to give a long term seal. if you really /must/ skim
> the head, make sure you inspect the work of the shop on other heads
> before you let them touch yours. if they produce near mirror, go ahead
> and use them. if they produce stuff with milling marks and ridges on
> it, move right along. and don't believe any story about the head
> needing milling marks to "grip" the gasket - that's bunk.

A near mirror finishes are too expensive for the average car owner
could afford. Unless the car manufacturer requires a near mirror
finish, don't bother with it.

 

"Ricky ****" <RickyWang@has.none> wrote in message
news:jJqSg.5123$TV3.3285@newssvr21.news.prodigy.co m...
>
> A near mirror finishes are too expensive for the average car owner
> could afford. Unless the car manufacturer requires a near mirror
> finish, don't bother with it.
>
My retired ex-partner has done some milling for me in his garage, and the
output of the milling machine can be described as "near mirror finish." If a
milling machine isn't producing that sort of output, it's because the head
hasn't been dressed lately. That's the sort of neglect that can weaken the
head gasket seal as combustion gasses insinuate their way through the gaps.

Actually, I don't think debris produces the milling marks. The cutter head
is an abrasive disk spun at high speed that is scanned across the surface in
the plane of the disk The edge of the disk cuts a flat groove at a preset
thickness, then is moved laterally to cut an identical groove beside that,
and so on. Milling marks appear if the wheel edge is not true.

Mike

 

"Ricky ****" <RickyWang@has.none> wrote in message
news:jJqSg.5123$TV3.3285@newssvr21.news.prodigy.co m...
>
> A near mirror finishes are too expensive for the average car owner
> could afford. Unless the car manufacturer requires a near mirror
> finish, don't bother with it.
>
My retired ex-partner has done some milling for me in his garage, and the
output of the milling machine can be described as "near mirror finish." If a
milling machine isn't producing that sort of output, it's because the head
hasn't been dressed lately. That's the sort of neglect that can weaken the
head gasket seal as combustion gasses insinuate their way through the gaps.

Actually, I don't think debris produces the milling marks. The cutter head
is an abrasive disk spun at high speed that is scanned across the surface in
the plane of the disk The edge of the disk cuts a flat groove at a preset
thickness, then is moved laterally to cut an identical groove beside that,
and so on. Milling marks appear if the wheel edge is not true.

Mike

 

"Ricky ****" <RickyWang@has.none> wrote in message
news:jJqSg.5123$TV3.3285@newssvr21.news.prodigy.co m...
>
> A near mirror finishes are too expensive for the average car owner
> could afford. Unless the car manufacturer requires a near mirror
> finish, don't bother with it.
>
My retired ex-partner has done some milling for me in his garage, and the
output of the milling machine can be described as "near mirror finish." If a
milling machine isn't producing that sort of output, it's because the head
hasn't been dressed lately. That's the sort of neglect that can weaken the
head gasket seal as combustion gasses insinuate their way through the gaps.

Actually, I don't think debris produces the milling marks. The cutter head
is an abrasive disk spun at high speed that is scanned across the surface in
the plane of the disk The edge of the disk cuts a flat groove at a preset
thickness, then is moved laterally to cut an identical groove beside that,
and so on. Milling marks appear if the wheel edge is not true.

Mike

 

Michael Pardee wrote:
> "Ricky ****" <RickyWang@has.none> wrote in message
> news:jJqSg.5123$TV3.3285@newssvr21.news.prodigy.co m...
>> A near mirror finishes are too expensive for the average car owner
>> could afford. Unless the car manufacturer requires a near mirror
>> finish, don't bother with it.
>>
> My retired ex-partner has done some milling for me in his garage, and the
> output of the milling machine can be described as "near mirror finish." If a
> milling machine isn't producing that sort of output, it's because the head
> hasn't been dressed lately. That's the sort of neglect that can weaken the
> head gasket seal as combustion gasses insinuate their way through the gaps.
>
> Actually, I don't think debris produces the milling marks. The cutter head
> is an abrasive disk spun at high speed that is scanned across the surface in
> the plane of the disk The edge of the disk cuts a flat groove at a preset
> thickness, then is moved laterally to cut an identical groove beside that,
> and so on. Milling marks appear if the wheel edge is not true.
>
> Mike
>
>
the point for both of you is that a /lot/ of head shops out there simply
use the same cutter on an alloy head that they use for cast iron. the
best case result is a grooved head that is a /long/ way from smooth.
and worst case is the gouging i'm warning you about - i've seen it many
times guys, so beware.

and the biggest point in all this is that for most repair shops that use
these kinds of milling services, they never get to see the consequences
so they never learn any different. most cars are high mileage when the
head goes the first time. if it goes a second, the car gets sold or
junked. for my personal vehicle, i want the repair to last at least as
long as the original - that's 140,141 miles. that's never going to
happen on a grooved head because gas channels along the groove base.
it's slow at first due to gasket sealant, but that sealant erodes, and
then you get leakage again.

unless you have access to a shop that can produce a bona-fide high
quality near-mirror finish, milling a head that is not warped is simply
"monkey see, monkey do".

 

Michael Pardee wrote:
> "Ricky ****" <RickyWang@has.none> wrote in message
> news:jJqSg.5123$TV3.3285@newssvr21.news.prodigy.co m...
>> A near mirror finishes are too expensive for the average car owner
>> could afford. Unless the car manufacturer requires a near mirror
>> finish, don't bother with it.
>>
> My retired ex-partner has done some milling for me in his garage, and the
> output of the milling machine can be described as "near mirror finish." If a
> milling machine isn't producing that sort of output, it's because the head
> hasn't been dressed lately. That's the sort of neglect that can weaken the
> head gasket seal as combustion gasses insinuate their way through the gaps.
>
> Actually, I don't think debris produces the milling marks. The cutter head
> is an abrasive disk spun at high speed that is scanned across the surface in
> the plane of the disk The edge of the disk cuts a flat groove at a preset
> thickness, then is moved laterally to cut an identical groove beside that,
> and so on. Milling marks appear if the wheel edge is not true.
>
> Mike
>
>
the point for both of you is that a /lot/ of head shops out there simply
use the same cutter on an alloy head that they use for cast iron. the
best case result is a grooved head that is a /long/ way from smooth.
and worst case is the gouging i'm warning you about - i've seen it many
times guys, so beware.

and the biggest point in all this is that for most repair shops that use
these kinds of milling services, they never get to see the consequences
so they never learn any different. most cars are high mileage when the
head goes the first time. if it goes a second, the car gets sold or
junked. for my personal vehicle, i want the repair to last at least as
long as the original - that's 140,141 miles. that's never going to
happen on a grooved head because gas channels along the groove base.
it's slow at first due to gasket sealant, but that sealant erodes, and
then you get leakage again.

unless you have access to a shop that can produce a bona-fide high
quality near-mirror finish, milling a head that is not warped is simply
"monkey see, monkey do".

 

Michael Pardee wrote:
> "Ricky ****" <RickyWang@has.none> wrote in message
> news:jJqSg.5123$TV3.3285@newssvr21.news.prodigy.co m...
>> A near mirror finishes are too expensive for the average car owner
>> could afford. Unless the car manufacturer requires a near mirror
>> finish, don't bother with it.
>>
> My retired ex-partner has done some milling for me in his garage, and the
> output of the milling machine can be described as "near mirror finish." If a
> milling machine isn't producing that sort of output, it's because the head
> hasn't been dressed lately. That's the sort of neglect that can weaken the
> head gasket seal as combustion gasses insinuate their way through the gaps.
>
> Actually, I don't think debris produces the milling marks. The cutter head
> is an abrasive disk spun at high speed that is scanned across the surface in
> the plane of the disk The edge of the disk cuts a flat groove at a preset
> thickness, then is moved laterally to cut an identical groove beside that,
> and so on. Milling marks appear if the wheel edge is not true.
>
> Mike
>
>
the point for both of you is that a /lot/ of head shops out there simply
use the same cutter on an alloy head that they use for cast iron. the
best case result is a grooved head that is a /long/ way from smooth.
and worst case is the gouging i'm warning you about - i've seen it many
times guys, so beware.

and the biggest point in all this is that for most repair shops that use
these kinds of milling services, they never get to see the consequences
so they never learn any different. most cars are high mileage when the
head goes the first time. if it goes a second, the car gets sold or
junked. for my personal vehicle, i want the repair to last at least as
long as the original - that's 140,141 miles. that's never going to
happen on a grooved head because gas channels along the groove base.
it's slow at first due to gasket sealant, but that sealant erodes, and
then you get leakage again.

unless you have access to a shop that can produce a bona-fide high
quality near-mirror finish, milling a head that is not warped is simply
"monkey see, monkey do".