'99 Intrepid - Dealer Stripped Oil Pan Drain threads?

wrote:
> The weight penalty isn't very high or VW and Peugeot wouldn't have
> done it. Their blocks, cranks, and rods-in VW's case the whole
> assembled shortblock assembly-were the same. Isuzu, Mercedes Benz and
> Nissan had different blocks but made with the same patterns and
> tooling. Many people built good hot rod gas 350 Olds engines out of
> diesel blocks and cranks.
>
> Diesels are heavy usually because there is no penalty for weight in
> their application, not because they have to be.
>
> Automotive fuel injection and ignition systems are inexpensive (at OEM
> levels) commodity items, so almost all the work in building the spark
> ignition natural gas and propane Cummins and Series 50/60 Detroits was
> in designing a SI head and pistons. It's pretty trivial to hang a
> distributor somewhere off the cam or accessory drive.
>

Eh... a Diesel engine *does* need to be stronger than a similarly sized
and powered gasoline engine, as olds proved. their engine was plenty
strong for a gas motor but when used as a Diesel had all sorts of issues.

That said, intelligent design can go a long way towards offsetting the
"extra" weight. A VW engine isn't particularly beefy, although I don't
think I would want to use one in an airplane...

nate

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wrote:
> The weight penalty isn't very high or VW and Peugeot wouldn't have
> done it. Their blocks, cranks, and rods-in VW's case the whole
> assembled shortblock assembly-were the same. Isuzu, Mercedes Benz and
> Nissan had different blocks but made with the same patterns and
> tooling. Many people built good hot rod gas 350 Olds engines out of
> diesel blocks and cranks.

The Olds diesel was based on a gas engine to begin with. That is the
reason it was a piece of crap. Purpose-built diesel engines are much
heavier than purpose-built gas engines need to be. Sure, you can use a
diesel block and rotating components to make a gas engine, but it is now
a much heavier than necessary gas engine.


> Diesels are heavy usually because there is no penalty for weight in
> their application, not because they have to be.

Why would a manufacturer of an engine for any application put in more
metal than was necessary? Even if weight isn't an issue, cost is always
an issue and more metal costs more in general (highly machined parts
being an obvious exception). Most diesels have compression ratios and
thus cylinder pressures double or more that of gas engines. It takes
more metal in the cylinders, pistons, rods and crank to withstand these
pressures and still live a long life.


Matt

"Long life" in the case of the classic 855 Cummins might mean three or
four million miles or thirty thousand hours, and then finally being
scrapped because of obsolescence rather than structural failure. In
aircraft service an engine has a typical TBO of 2000 hours and a crank
or set of cases might go three major overhauls.

The 5.7 Olds was actually at the end of its design cycle a reliable
powerplant ....a fact few remember. Earlier ones had problems but
catastrophic crank or block failure happened, if at all, at well over
the 100,000 mile mark, when most gas counterparts had been replaced or
the car junked.

The bottom line is that VW and Peugeot determined that the per unit
weight and materials cost penalty was outweighed by cost savings in
commonality of parts. The weight penalty is simply not colossal and it
results in a gas engine that is more reliable and more rebuildable.

Art wrote:
> Actually, I was under the impression that there was a steel insert in
> aluminum pans to hold the plug so the stripping rate should be the same
> between aluminum and steel pans but aluminum pans are a lot more expensive
> to replace.

The LH car oil pans have no insert - 100% aluminum. I suspect there are
a lot of other aluminum-panned cars without inserts out there as well.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
adddress with the letter 'x')

Matt Whiting wrote:

> Bill Putney wrote:
>
>> Both the piggy-back and the OS plugs cleverly avoid the drill-and-tap
>> issue by having fluted self-tapping threads to form new threads into
>> the damaged hole (exactly like self-tapping screws, only bigger). All
>> that's needed is a wrench and about 10 minutes time.
>
>
> Where do the metal shavings from the newly self-tapped threads go?
>
>
> Matt

I used to be the one that raised that question every time this
discussion came up (you were part of the last discussion on this). At
that point, someone was always quick to point out that the shavings
would always stay in the bottom of the pan and not be sucked up by the
pickup tube. I'm guessing they're probably right. Another person
pointed out that the filter would catch them. I pointed out that the
filter is downstream of the pump, and I wouldn't want anything,
including soft aluminum chips, going thru my oil pump with 0.001"
clearances.

However, when I did mine, after running the self-tapping O.S. plug in
without washer, I removed it, inserted the straw of a full can of brake
parts cleaner all the way into the hole (so the tip was past where any
chips would be), and flooded the bottom of the pan for several seconds
with a cup or two of cleaner, and let it run out rapidly. I then poured
a quart of oil into the regular filler, let it drain out, and then
repeated the parts cleaner flush. This was followed by visual
inspection to make sure there were no chips trapped in the threads of
the hole.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
adddress with the letter 'x')

Bill Putney wrote:
> Matt Whiting wrote:
>
>> Bill Putney wrote:
>>
>>> Both the piggy-back and the OS plugs cleverly avoid the drill-and-tap
>>> issue by having fluted self-tapping threads to form new threads into
>>> the damaged hole (exactly like self-tapping screws, only bigger).
>>> All that's needed is a wrench and about 10 minutes time.
>>
>>
>>
>> Where do the metal shavings from the newly self-tapped threads go?
>>
>>
>> Matt
>
>
> I used to be the one that raised that question every time this
> discussion came up (you were part of the last discussion on this). At
> that point, someone was always quick to point out that the shavings
> would always stay in the bottom of the pan and not be sucked up by the
> pickup tube. I'm guessing they're probably right. Another person
> pointed out that the filter would catch them. I pointed out that the
> filter is downstream of the pump, and I wouldn't want anything,
> including soft aluminum chips, going thru my oil pump with 0.001"
> clearances.

I'm not convinced having seen some high speed photographs many years ago
of the inside of a crankcase of an operating engine. The oil is pretty
"active" in the oil pan.


> However, when I did mine, after running the self-tapping O.S. plug in
> without washer, I removed it, inserted the straw of a full can of brake
> parts cleaner all the way into the hole (so the tip was past where any
> chips would be), and flooded the bottom of the pan for several seconds
> with a cup or two of cleaner, and let it run out rapidly. I then poured
> a quart of oil into the regular filler, let it drain out, and then
> repeated the parts cleaner flush. This was followed by visual
> inspection to make sure there were no chips trapped in the threads of
> the hole.

That is probably about as good as you can do. Personally, I'd still be
inclined to remove the pan and replace it with a good used pan from a
salvage yard or have a machine shop insert a steel sleeve or weld shut
the existing hole and drill and tap a new one.


Matt

Matt Whiting wrote:
> Bill Putney wrote:
>
>> Matt Whiting wrote:
>>
>>> Bill Putney wrote:
>>>
>>>> Both the piggy-back and the OS plugs cleverly avoid the
>>>> drill-and-tap issue by having fluted self-tapping threads to form
>>>> new threads into the damaged hole (exactly like self-tapping screws,
>>>> only bigger). All that's needed is a wrench and about 10 minutes time.
>>>
>>>
>>>
>>>
>>> Where do the metal shavings from the newly self-tapped threads go?
>>>
>>>
>>> Matt
>>
>>
>>
>> I used to be the one that raised that question every time this
>> discussion came up (you were part of the last discussion on this). At
>> that point, someone was always quick to point out that the shavings
>> would always stay in the bottom of the pan and not be sucked up by the
>> pickup tube. I'm guessing they're probably right. Another person
>> pointed out that the filter would catch them. I pointed out that the
>> filter is downstream of the pump, and I wouldn't want anything,
>> including soft aluminum chips, going thru my oil pump with 0.001"
>> clearances.
>
>
> I'm not convinced having seen some high speed photographs many years ago
> of the inside of a crankcase of an operating engine. The oil is pretty
> "active" in the oil pan.
>
>
>> However, when I did mine, after running the self-tapping O.S. plug in
>> without washer, I removed it, inserted the straw of a full can of
>> brake parts cleaner all the way into the hole (so the tip was past
>> where any chips would be), and flooded the bottom of the pan for
>> several seconds with a cup or two of cleaner, and let it run out
>> rapidly. I then poured a quart of oil into the regular filler, let it
>> drain out, and then repeated the parts cleaner flush. This was
>> followed by visual inspection to make sure there were no chips trapped
>> in the threads of the hole.
>
>
> That is probably about as good as you can do. Personally, I'd still be
> inclined to remove the pan and replace it with a good used pan from a
> salvage yard or have a machine shop insert a steel sleeve or weld shut
> the existing hole and drill and tap a new one.
>
>
> Matt

You run the very real risk with one from a salvage yard of the threads
having been weakened (on the verge of stripping), but the idea of
helicoiling one from a salvage yard is a good idea - which is what I
tried, but the helicoil was put in crooked so that the gasket would not
fit flush to the land area and so would not seal - fortunately I
realized that before going to the trouble of swapping the pans. At that
point, I decided to cut my losses and replaced the original stripped out
pan with a new pan (with the same potential for stripping, except I do
my own oil changes - the original one had been stripped when I bought it
at 58k miles - it had been a fleet vehicle).

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
adddress with the letter 'x')