'99 Intrepid - Dealer Stripped Oil Pan Drain threads?

Thanks for posting. Yes - it's a well known problem. Another simple
under-$10 solution is to buy what's called an oversize thread
(designated by the manufacturers as an "OS" thread) plug. Available at
any chain auto parts store on the oil plug racks along with the standard
thread replacement plugs and (generally awful quality) plug gaskets.

The helicoil would have been a good solution - the downside being that,
on the LH cars, there is not room enough to drill or tap straight into
the existing hole due to a frame member being in the way - thus there
would be the labor expense of removing and replacing the pan just to
install the helicoil.

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.

You have to ask yourself who had been doing your previous oil changes
and stripped it out. But it is a very common problem (due to very
stupid people being hired for doing oil changes in certain dealerships
and quick change shops).

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

 

Well said. I posted a while back about having my drain plug
(repeatedly) rounded off by various oil change shops. Funny, it's
lasted 18 months and looks like new ever since I decided to change my
own oil. What worries me far more is what else has been, or might have
been, neglected or damaged during this most simple of maintenance tasks.
I also wonder how much damage might have been done by the screwdriver
a minute lube shop left in the engine compartment in my wife's Jeep, had
I not found it the next day.

 

Where do the metal shavings from the newly self-tapped threads go?


Matt

 

The new plug is magnetic and holds on to them.

 

What if the pan threads are aluminum?

Matt

 

The Porsche PFM was technically very successful. It failed because of
Porsche's refusal to accomodate the trends and their pricing, which was
higher than a Lycoming or Continental because they thought their
product was more turbine-like.

Most of LyCon's market is now either Experimental or STC retrofit to
certified aircraft-i.e.,O-320's in 150s to replace 0-200s or 0-235's,
0-360's to replace O-300 or GO-300 Skyhawks, etc. Porsche refused to
sell to homebuilders and would only allow STC conversions if they did
the work themselves to ridiculous standards.

Porsche also chose to carry full product liability insurance, having
decided that their US auto distribution operations could be vulnerable
to judgment. Product liability insurance has taken another upswing with
the low interest rates prevalent today.

When the certificated PFM engine's parts went out of line production
as the new Porsches transitioned engines, and it became apparent the
OEM market would never pay a premium over LyCon gross overpricing in
the first place, Porsche chose to pull the plug in grand fashion. They
paid Mooney a bundle to offer the PFM owners a choice-trade their
aircraft for a brand new one or get a new Continental FWF on theirs.

I think they actually got the FAA to rescind the type certificate,
meaning the aircraft were no longer eligible for standard category
operation if the owners had proven truculent.

 

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 main complaint about the Lyconentals is that they are too expensive
and have old technology. Everyone says look how cheap modern high-tech
car engines are. The implication is that it is a piece of cake to make
a high-tech AND inexpensive airplane engine using similar technology.
Porsche found that this isn't the case and it is well rumored that Honda
and maybe Toyota have also investigated this market and chose to pass.
The reality is that airplane engines run at much higher continuous power
outputs than almost any other engine, except maybe some marine
applications. It simply isn't easy to design a lightweight and cheap
engine that can last in this application.

That was my point. Porsche couldn't do anything that Lycoming or
Continental wasn't already doing. That is my definition of success and
Porsche wasn't successful.


Matt

 

Marine and light aircraft duty cycles are very similar and given a
proper redrive an engine that does OK in continuous duty marine service
will do OK in a light aircraft. Getting the power to weight down can be
a challenge but there are enough experimental operators flying Subarus,
V6 Fords, and other engines to prove the concept is essentially sound.
Any of the US car makers' V8 engine lines will, in properly built
configuration, put out 300 hp for ten minutes and 250 hp continuously,
and at a all-up weight with radiators, coolant, and redrive around 650
lbs. that's heavier than the equivalent Lyc or Continental-but not
radically so. It is the same weight as a R-985 Pratt which will run at
450 hp forever. But factor in total weight of fuel and the aerodynamic
drag penalties of each and you will see that for a long enough range
the total weight is less for the automotive V-8 which can operate at a
BSFC , at these cruise power settings, air-cooled engines can't.

The Orenda V-8 and the Thielert TAE 125 are, when one cuts through the
sales verbiage, auto conversions as well. They seem to be doing OK.

 

Really? How many Orenda V-8's have been sold? How many Thilerts?


Matt

 

Well, you could ask them, but it has to be more than PFM's... I saw
the refitted King Air demonstrator do a max perf TO out of Jabara in
Wichita on a really cold day . I don't think he rolled more than a
thousand feet and climbed out like a lightly loaded 23/24 Lear
(remember those?)

http://www.centurion-engines.com/sales/sales_start.htm

 

Read the section marked with an asterisk (it is near the bottom:
http://www.mrrpm.com/

I was thinking this was the case, but wanted some backup before posting
such here. It will be curious to see if Thielert has long-term
commercial success. They may in Europe, but I doubt we'll see
widespread adoption state-side. The reality is that all engines evolve
over time to well suit their application. Car engines are really good
for cars, but not for bull dozers or airplanes. Likewise, airplane
engines are good for airplanes, but not for cars or dozers. Likewise,
the dozer engines.


Matt

 

I was thinking this was the case, but wanted some backup before posting

The Euro's have more money and the fuel delta is far higher over
there. In fact there is no more avgas in much of Europe. If you have a
A-65 Continental or any 80/87 engine you burn auto gas. A TIGO-541 Lyc?
So Solly!



The reality is that all engines evolve

This was more true decades ago. All gasoline marine inboards are auto
engines and the outboards are headed that way as well. Modern
construction and ag equipment is all diesel and they are using the same
engines as trucks, gensets, and marine-the days of purpose built
engines like the early Cat dozer engines with two stages of
purpose-built gas starting engines and the German Lanz Bulldog are
over. The fact is, car engines have developed a great deal for auto,
and marine, stationary, genset and pumping purposes whereas LyCon have
atrophied.

If you did develop a clean sheet of paper recip for aircraft use,
today, it would be a V-type,liquid cooled, en bloc construction engine,
it would probably be a diesel (you can always turn a four stroke diesel
into a gas engine but not the other way around) and it would also be
excellent for marine and other uses. And you'd sell it for those as
well. If you were smart you would build it in some country not on the
best terms with the U.S. and certify and import it through a small
company with no assets to speak of, incorporate it so that no court
anywhere could deem it a personal holding corporation-which is what
idiots like Richard Collins mean when the whine how evil lawyers can
"pierce the corporate veil"-and put in the charter that the company
_cannot purchase_ product liability insurance. And you would sell core
engines and all parts on the same basis whether they were going in
certificated aircraft or not-thus spreading certification costs across
a wide base. (Not certifying and selling only to experimental operators
would be a poor option IMO, because 1) when times get tough car
conversions will become MUCH more appealing, and 2) I expect the FAA to
be forced to put the kibosh on cookie-cutter production "homebuilts"
like RV's in the near future.)

 

I'm not familiar intimately with marine engines so I'm not sure what
they are doing today. They have used auto engines for years, but they
used to use the truck versions that had different cams, more cooling
system capacity, etc. They weren't stock engines from an automobile.
Maybe that has changed, but I doubt it. It is overkill to design an
auto engine that will run all day long at 75% power output as that just
isn't required in an automobile. It just wouldn't make economic sense.

Ag, genset and marine are very similar in their requirements so using
the same engines for these applications isn't a big deal. However, they
are all quite different from aircraft applications where weight is a big
deal.

Isn't this what Orenda tried? They didn't fare too well... How do you
turn a four stroke diesel into a gas engine? Gas won't work well at
18:1 and higher compression ratios and you need a spark to ignite it.
Neither are easy modifications to a diesel.


Matt

 

Actually some of the smaller automotive engines seem to be, especially
European ones. The VW 4-cyl. comes to mind.

Sure they are. Different cylinder heads take care of both easily.

nate

 

It is overkill to design an

Small block, big block Chevy. You had 2 and 4 bolt blocks and forged
and cast cranks. Same dimensions. Mercury Marine proved you could get
2000 hours at 250 hp out of a 327 Chevy in the 60s. When gas was cheap
a lot of saltwater fishing boats ran them commercially and they would
run them at 75% power all day every day.

VW and Peugeot had gas and diesel engines that shared blocks, cranks
and rods, and in the case of VW the entire lower end. You could convert
one over without pulling the engine if so inclined. It was also
possible to convert the 5.7 Olds diesel to gas in-frame if you found a
set of '60s heads that would give 10:1 compression with diesel
pistons-but you had to pull the rad and AC condenser to swap camshafts.
Pulling the engine and changing pistons worked better.

There are spark ignition natural gas and propane versions of most
Cummins diesels. There is also a methanol burning 6V92 two cycle
Detroit Diesel.

 

That is a good point. Smaller engines will be running at a higher
percentage power output than larger engines generally. I was thinking
more of the US, where I live, as we relatively few vehicles that need
even 20% of their rated power most of the time.

Making the combustion chamber that much larger to lower the compression
ratio to gasoline land will likely result in pretty poor combustion
performance. And after this modification, you have a very heavy for its
power gasoline engine. And you need a fair bit more than just a
cylinder head. You need the rest of the ignition system, a different
fuel delivery system, etc. All in all, not a trivial modification.
Possible, yes, practical, probably not.


Matt

 

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

 

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.

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